Negative Object; Apophatic Gesture

Representing absence without naming or referencing the objects in question brings to mind the example of apophaticism – a tradition in theology that names what the divine is not, exploring the limits of human knowledge through negation. Considering the absent object in an apophatic way can foster attentiveness to the things that populate our lives, revealing that when objects go missing or lose their usefulness there is an indefinite loss - not only of the object itself, but also of worlds and relationships that once existed. It might seem a lofty term for lowly objects – a fur coat, a postcard, a bulldog clip - but it is a vernacular sense of the apophatic I wish to access

Turbine engines bladed disks’ with circular damping links forced vibration

Викладено методику досліджень вимушених коливань вінців робочих лопаток турбомашин з коловими демпферними зв’язками. З використанням методу кінцевих елементів розроблено удосконалену математичну модель секції «сектор диску - лопатка з демпферними зв’язками», що враховує конструктивну неоднорідність пера лопатки та диску. Наведено результати розрахунку амплітуд та частот вимушених коливань, викликаних дією змінної газодинамічної сили, для двох основних типів вінців робочих лопаток турбіни. Представлено залежність амплітуд вимушених коливань від змінної складової газодинамічної сили.The problem of turbine engines bladed disks with circular damping links forced vibration has been studied. All calculations have been provided for the two main disk’s types, used in the turbo machinery manufacturing. Purpose. The new adaptive mathematical model of turbine engine bladed disks with circular damping links forced vibration should be developed by means of finite elements method. Design/methodology/approach. Borrowed from the literature on finite elements method main mathematical models and some types of the finite elements can’t be used for the correct description of the foregoing problem. The matter is that turbine blades and disks have constructional non-homogeneity, which hardly ever could be correctly explained, using well-known finite elements and their mathematical dependences. On the other hand the variable aerodynamic force influence has also been taken into consideration. That is why the new model, which consists of sections, including disk’s sector, the whole blade and parts of damping links, has been developed. The finite elements methodology has been used for the forced vibration frequencies and amplitudes of this section calculation. Such approach gives an opportunity to describe the forced vibration of the whole bladed disk as the superposition of the developed sections. Findings. It is found that even non-homogeneous turbine engine’s bladed disks’ forced vibration problem could be correctly solved by means of finite elements model, using the newly developed mathematical model, which consists of bladed disk’s sections. Originality/ value. The developed mathematical model and main dependences could be used for the turbine’s and compressor’s bladed disks under non-stationary aerodynamic force vibration problem solution.Изложена методика исследования вынужденных колебаний венцов рабочих лопаток турбомашин с замкнутыми на круг демпферными связями. С использованием метода конечных элементов разработана уточненная математическая модель секции «сектор диска - лопатка с демпферными связями», учитывающая конструктивную неоднородность пера лопатки и диска. Приведены результаты расчета амплитуд и частот вынужденных колебаний, вызванных воздействием переменной газодинамической силы, для двух основных типов венцов рабочих лопаток турбины. Представлена зависимость амплитуд вынужденных колебаний от величины переменной составляющей газодинамической силы

Библиометрический анализ научного сотрудничества в исследованиях по проблемам моральных дилемм и морального выбора

The authors attempt the bibliometric and scientometric approach toward analysis of scientific cooperation in research of moral dilemmas and moral choice using Scopus bibliometric tools. The sector-specific dimension of the studies of moral dilemmas and moral choice is considered. The authors conclude that the share of psychological journals on the subject has significantly increased with dominating psychological research problems (in contrast to the traditional philosophical dimension). The involvement of the world's leading scientific publications in the information support of research on moral dilemmas and moral choice is emphasized. The conceptual integrity of periodicals is revealed, the conclusion is made on the promising vectors of studies on the subject of moral dilemmas and moral choice. The main author research collaborations, as well as their main thematic focuses are specified. It is noted that modeling of the process of solving moral dilemmas, identification of factors for solving moral dilemmas, neurophysiological correlations of the process of solving moral dilemmas, moral modification due to various clinical aspects are the problems most relevant and demanded by the world leading scientific journals.В статье предпринят библиометрический и наукометрический подход к анализу научного сотрудничества по проблемам моральных дилемм и морального выбора – на материале библиометрической системы Scopus. Рассматривается отраслевой аспект исследований по указанной тематике, делается вывод о существенном наращивании доли психологических журналов и, соответственно, преобладании психологической проблематики (в отличие от традиционной философской). Анализируется вовлечённость ведущих мировых научных изданий в информационную поддержку изучения моральных дилемм и морального выбора. Выявляются концептуальные единства периодических изданий, на основании чего делается вывод о перспективных научных направлениях. Определяются основные авторские коллаборации в исследованиях по изучаемым проблемам, а также главные темы их работ. Отмечается, что наиболее актуальными и востребованными в информационном пространстве ведущих мировых журналов являются такие темы, как моделирование процесса решения моральных дилемм; выявление факторов решения моральных дилемм; нейрофизиологические корреляты процесса решения моральных дилемм; моральная модификация в связи с различными клиническими аспектами

Observation of subkelvin superconductivity in Cd₃As₂ thin films

We report an experimental observation of superconductivity in Cd3As2 thin films without application of external pressure. The films under study were synthesized by magnetron sputtering. Surface studies suggest that the observed transport characteristics are related to the polycrystalline continuous part of the investigated films with a homogeneous distribution of elements and the Cd-to-As ratio close to stoichiometric Cd3As

Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts

We consider the electrical current through a magnetic point contact in the limit of a strong inelastic scattering of electrons. In this limit local Joule heating of the contact region plays a decisive role in determining the transport properties of the point contact. We show that if an applied constant bias voltage exceeds a critical value, the stationary state of the system is unstable, and that periodic, non-harmonic oscillations in time of both the electrical current through the contact and the local temperature in the contact region develop spontaneously. Our estimations show that the necessary experimental conditions for observing such oscillations with characteristic frequencies in the range $10^8 \div 10^9$ Hz can easily be met. We also show a possibility to manipulate upon the magnetization direction of a magnetic grain coupled through a point contact to a bulk ferromagnetic by exciting the above-mentioned thermal-electric oscillations.Comment: 9 pages, 6 figures, submitted to Physical Review

Targeting dsRNA-specific single-chain Fv antibody fragments to different cellular locations in Nicotiana tabacum L.

Expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. We investigated the effect of cellular expression site on the stability and yield of double-stranded RNA (dsRNA)-specific single-chain Fv-fragments (scFv) in transgenic tobacco. Two antibodies (J2 and P6) belonging to the V23(J558) heavy chain variable gene family but differing in the light chain variable domain were used. scFvs were targeted to the cytoplasm – with or without anchoring them in the plasma membrane –, into the endoplasmic reticulum (ER) and to the apoplast. Although high mRNA concentrations were detected in all cases, scFv proteins accumulated only when scFvs were made ER-resident by appropriate signal sequences. When the ER retention signal was removed to allow scFv-secretion to the apoplast, no scFv-proteins were detected. Despite the strong homology of the VH-sequences of J2 and P6 antibodies, only P6 provided a stable scFv scaffold for intracytoplasmic expression. J2-scFv could not be stabilised neither by adding a C-terminal stabilisation signal nor by anchoring the protein at the cytoplasmic side of the plasma membrane (PM). It was found that dsRNA-specific J2-scFvs are active in vivo and enhance Potato Virus Y induced symptoms in infected tobacco. This is the first report describing the expression and biological effect of RNA-specific antibodies in plants