An inverse source problem for the heat equation and the enclosure method

An inverse source problem for the heat equation is considered. Extraction formulae for information about the time and location when and where the unknown source of the equation firstly appeared are given from a single lateral boundary measurement. New roles of the plane progressive wave solutions or their complex versions for the backward heat equation are given.Comment: 23page

A global Carleman estimate in a transmission wave equation and application to a one-measurement inverse problem

We consider a transmission wave equation in two embedded domains in $R^2$, where the speed is $a1 > 0$ in the inner domain and $a2 > 0$ in the outer domain. We prove a global Carleman inequality for this problem under the hypothesis that the inner domain is strictly convex and $a1 > a2$ . As a consequence of this inequality, uniqueness and Lip- schitz stability are obtained for the inverse problem of retrieving a stationary potential for the wave equation with Dirichlet data and discontinuous principal coefficient from a single time-dependent Neumann boundary measurement

Exclusonic Quasiparticles and Thermodynamics of Fractional Quantum Hall Liquids

Quasielectrons and quasiholes in the fractional quantum Hall liquids obey fractional (including nontrivial mutual) exclusion statistics. Their statistics matrix can be determined from several possible state-counting scheme, involving different assumptions on statistical correlations. Thermal activation of quasiparticle pairs and thermodynamic properties of the fractional quantum Hall liquids near fillings $1/m$ ($m$ odd) at low temperature are studied in the approximation of generalized ideal gas. The existence of hierarchical states in the fractional quantum Hall effect is shown to be a manifestation of the exclusonic nature of the relevant quasiparticles. For magnetic properties, a paramagnetism-diamagnetism transition appears to be possible at finite temperature.Comment: latex209, REVTE

Энергетическая эффективность малого биореактора в различных климатических зонах

The authors proposed a model for estimating the heat balance and energy efficiency of a bioreactor that makes possible for a small-sized reactor operating on a relatively low-energy substrate to determine the critical volume, under which the existing climatic conditions allow year-round fully autonomous operation of the digester, as well as for evaluation the potential energy efficiency of such a bioreactor (output commodity heat). For the numerical characteristics of the climatic zone, it is proposed to use the average annual temperature and/or the “degree-day of the heating period” (DDHP) indicator common in construction heat engineering; the DDHP value more adequately characterizing the unevenness of the average monthly temperature distribution, i.e. degree of climate continentality. At the same time, the value of the critical volume of the bioreactor, at which year-round autonomous operation of the digester operating on the municipal sewage sludge, is possible, varies from 7.5 (Vladikavkaz, DDHP = 3410) to 17.0 m3 (Tomsk, DDHP = 6938), i. e. increases almost in proportion to the degree-day of the heating period. It should be noted that when using a substrate with a high biogas yield, e. g., pig manure (a biogas yield of 40 g/kg is adopted), the critical volume in all cases is less than 1 m3. Such results are relevant only for relatively low-energy raw materials. The nature of changes in the output of commodity heat, depending on the volume of the bioreactor and climatic conditions, is quite expectable, viz. the amount of heat that is useful for business interests is higher, the higher is the reactor volume and the milder is the climate. However, when the reactor volume is less than 5 m3, the non-linearity of the graphs is much higher, i. e. for a designer of especially small bioreactors, it seems mandatory to carry out such calculations. The obtained numerical values can be useful both for the designer of bioreactors and for the customer of the project when evaluating the economic efficiency of the planned new innovations.Предложенная модель оценки теплового баланса и энергоэффективности биореактора позволяет определить для реактора малого размера, работающего на относительно низкоэнергетическом субстрате, величину критического объема, при котором в данных климатических условиях возможна круглогодичная, полностью автономная работа метантенка, и оценить вероятную энергетическую эффективность подобного биореактора (выход товарной теплоты). Для численной характеристики климатической зоны предлагается использовать среднегодовую температуру и/или распространенный в строительной теплотехнике показатель градусо-суток отопительного периода (ГСОП), более полно характеризующего неравномерность среднемесячного распределения температур (степень континентальности климата). Величина критического объема биореактора, при котором возможна круглогодичная автономная работа метантенка на осадке городских сточных вод, изменяется от 7,5 (Владикавказ, ГСОП = 3410) до 17,0 м3 (Томск, ГСОП = 6938), т. е. увеличивается практически пропорционально значению градусо-суток отопительного периода. Следует отметить, что при использовании субстрата с большим выходом биогаза, например свиного навоза (выход 40 г/кг), величина критического объема во всех случаях менее 1 м3. Такие результаты актуальны только для относительно низкоэнергетического сырья. Характер изменения выхода товарной теплоты в зависимости от объема биореактора и климатических условий вполне ожидаем – количество полезно используемой в интересах бизнеса теплоты тем выше, чем больше объем реактора и мягче климат. Однако при объеме реактора менее 5 м3 нелинейность графиков намного выше. Поэтому для проектировщиков особо малых биореакторов проведение подобных расчетов обязательно. Полученные численные значения могут быть полезны как для проектировщика биореакторов, так и для заказчика проекта при оценке экономической эффективности планируемых нововведений

Formulas and equations for finding scattering data from the Dirichlet-to-Neumann map with nonzero background potential

For the Schrodinger equation at fixed energy with a potential supported in a bounded domain we give formulas and equations for finding scattering data from the Dirichlet-to-Neumann map with nonzero background potential. For the case of zero background potential these results were obtained in [R.G.Novikov, Multidimensional inverse spectral problem for the equation -\Delta\psi+(v(x)-Eu(x))\psi=0, Funkt. Anal. i Ego Prilozhen 22(4), pp.11-22, (1988)]

Synthesis of Si-Y Coatings on Nb in Fluoride-Chloride Molten Salts

The preparation of multicomponent coatings based on silicon and yttrium on the niobium substrate was investigated. Y-Si/NbSi2 coatings on the Nb substrate by currentless deposition in molten salts were produced. The preparation of NbSi2 layers is carried out in NaF-NaCl-Na2SiF6 melts with the addition of Si powder. The preparation of Y-Si layers is carried out in NaCl-KCl-YF3 melts containing Y powder. Coating samples are studied using SEM. It is established that sequentially synthesized coatings are characterized by a two-layer structure. Using the EDS method, the chemical composition of the obtained layers is established: Y - 26.68; Nb - 62.55; Si - 10.76 wt. %. The oxidation test of the obtained coatings Y-Si/NbSi2 on Nb samples is performed. It is found that testing at 1200 oC for 2 hours leads to a mass loss of 62 mg/cm2•h. © Published under licence by IOP Publishing Ltd.Ministry of Education and Science of the Russian Federation, Minobrnauka: 14.578.21.0238, RFMEFI57817X0238The study was carried out with financial support of the Ministry of Education and Science of the Russian Federation within the frames of the Federal target program, the agreement number 14.578.21.0238, identification number RFMEFI57817X0238

Фазозарождение кремния на стеклоуглероде в расплаве KF-KCl-K2SiF6

Silicon nucleation process was invesigated in melt KF-KCl-K2SiF6 on glassy carbon substrates at 675 ºС by chronoamperometric method. Using data of the chronoamperograms the linear dependence I – τ3/2 was constructed. That fact testified the progressive nucleation mode of silicon. As seem from SEM micrographs silicon crystals obtained by a single pulse had different sizes, that also confirmed the progressive nucletion mode.Методом хроноамперометрии изучено зарождение кремния на стеклоуглеродной подложке в расплаве KF-KCl-K2SiF6 при температуре 675 ºС. Выявлено прогрессивное фазозарождение кремния. Из SEM-микрофотографий зародышей кремния, выращенных на стеклоуглеродной подложке в потенциостатическом режиме в интервале потенциалов от –0.005 до –0.03 В в расплаве KF-KCl-K2SiF6 при Т = 675 ºС, видно, что в условиях одного эксперимента они имеют размеры, различающиеся в несколько раз, что подтверждает прогрессирующий характер возникновения зародышей кремния. Показано, что когда к рабочему электроду при прочих равных условиях прикладывается более отрицательное значение потенциала относительно кремниевого электрода сравнения, то количество сформировавшихся зародышей на поверхности электрода растет

ОТОЗВАНО: Фазозарождение кремния на стеклоуглероде в расплаве KF-KCl-K2SiF6

Following the joint decision of the Editor-in-Chief and the journal's Ethics Committee, this article has been retracted. The article (its original Russian version) is an erroneously published duplicate of a paper that has already been published in Chimica Techno Acta 2014;1(2):67-72, doi:10.15826/chimtech.2014.1.2.1047. One of the conditions of submission of a paper for publication is that a paper has not been published previously. As such this article represents a severe abuse of the scientific publishing system. Our Editorial Board takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.Данная статья была отозвана по решению главного редактора и комитета по этике редколлегии журнала. Причиной этому является тот факт, что русскоязычная (непереведенная) версия данной статьи уже была опубликована в Chimica Techno Acta 2014;1(2):67-72, doi:10.15826/chimtech.2014.1.2.1047. Таким образом, данная статья нарушает этические нормы научных публикаций. Статьи, отправляемые на рассмотрение в журнал, не должны быть где-либо опубликованы ранее. Редколлегия журнала Chimica Techno Acta серьезно относится к данному требованию и приносит извинения читателям в связи с тем, что данный факт не был замечен ранее на этапе рассмотрения манускрипта

Influence of the high-power ion-beam irradiation of a hydroxyapatite target on the properties of formed calcium phosphate coatings

The physical-mechanical of properties of biocompatible calcium phosphate coatings deposited onto titanium and silicon substrates from erosion materials, which are generated by irradiating hydroxyapatite (synthetic and natural) targets by means of the high-power pulsed ion beam of a Temp-4 accelerator, are investigated. A calculation technique for predicting the rate and energy efficiency of deposition using pulsed ion beams is proposed. Their characteristics are analyzed as applied to the formation of calcium phosphate coatings