360 research outputs found
РАСЧЕТ МАГНИТНОГО ПОЛЯ ТРЕХФАЗНЫХ КАБЕЛЬНЫХ ЛИНИЙ ПРИ ДВУСТОРОННЕМ ЗАМЫКАНИИ СОБСТВЕННЫХ ЭКРАНОВ КАБЕЛЕЙ, ОХВАЧЕННЫХ ФЕРРОМАГНИТНЫМИ СЕРДЕЧНИКАМИ
In this paper we obtain compact expressions for the magnetic field shielding factor of a high-voltage three-phase cable line consisting of single-core cables with two-point bonded cable shields and ferromagnetic cores installed. To obtain these expressions we develop the analytical model of the cable line. Following assumptions are made to develop the model: the current distribution in each cable shield is uniform, cylindrical ferromagnetic cores covering the cables are not magnetized to saturation and their magnetic permeability is constant, each of the ferromagnetic cores is magnetized only by the core current and the shield current of the cable that it covers, the magnetic field inside ferromagnetic cores is axisymmetric, the magnetic field is plane-parallel over the entire cable line. We consider common cases of flat and trefoil cable lines. The proposed expressions for the magnetic field shielding factor are verified experimentally. The physical model is made of three cables of the type NA2XSF(L)2Y-110 1´240/70. It is shown that the difference between numerical simulation results and experimental data lays within 15 %.Получены компактные соотношения для расчета эффективности экранирования магнитного поля высоковольтной трехфазной кабельной линии, состоящей из одножильных кабелей, которые охвачены ферромагнитными сердечниками, при двустороннем замыкании собственных экранов. Рассмотрены кабельные линии с укладкой кабелей треугольником и в плоскости. Предложенные соотношения для расчета эффективности экранирования магнитного поля верифицированы экспериментально
Tianeptine induces expression of dual specificity phosphatases and evokes rebound emergence of cortical slow wave electrophysiological activity
Funding Information: This work was supported by the Academy of Finland (grant numbers 276333 , 305195 , 312664 , 322906 ) and the Finnish Pharmaceutical Society . Funding Information: This work was supported by the Academy of Finland (grant numbers 276333, 305195, 312664, 322906) and the Finnish Pharmaceutical Society. T.R. is listed as a co-inventor on a patent application wherein new EEG monitoring tools potentially enabling the development of rapid-acting antidepressants and the efficacy monitors thereof are disclosed. T.R. has assigned his patent rights to the University of Helsinki but will share a percentage of any royalties that may be received by the University of Helsinki. Publisher Copyright: © 2021 The AuthorsBackground: The precise mechanism governing the antidepressant effects of tianeptine is unknown. Modulation of brain glutamatergic neurotransmission has been however implicated, suggesting potential shared features with rapid-acting antidepressants targeting N-methyl-D-aspartate receptors (NMDAR). Our recent studies suggest that a single subanesthetic dose of NMDAR antagonists ketamine or nitrous oxide (N2O) gradually evoke 1–4 Hz electrophysiological activity (delta-rhythm) of cerebral cortex that is accompanied by molecular signaling associated with synaptic plasticity (e.g. activation of tropomyosin receptor kinase B (TrkB) and inhibition of glycogen synthase kinase 3β (GSK3β)). Methods: We have here investigated the time-dependent effects of tianeptine (30 mg/kg, i.p.) on electrocorticogram, focusing on potential biphasic regulation of the delta-rhythm. Selected molecular markers associated with ketamine's antidepressant effects were analyzed in the medial prefrontal cortex after the treatment using quantitative polymerase chain reaction and western blotting. Results: An acute tianeptine treatment induced changes of electrocorticogram typical for active wakefulness that lasted for 2–2.5 h, which was followed by high amplitude delta-activity rebound. The levels of Arc and Homer1a, but not c-Fos, BdnfIV and Zif268, were increased by tianeptine. Phosphorylation of mitogen-activated protein kinase (MAPK), TrkB and GSK3β remained unaltered at 2-hours and at 3-hours post-treatment. Notably, tianeptine also increased the level of mRNA of several dual specificity phosphatases (Duspss) – negative regulators of MAPK. Conclusion: Tianeptine produces acute changes of electrocorticogram resembling rapid-acting antidepressants ketamine and N2O. Concomitant regulation of Dusps may hamper the effects of tianeptine on MAPK pathway and influence the magnitude of homeostatic emergence of delta-activity and TrkB-GSK3β signaling.Peer reviewe
CAD systems as a method of research of mechanical properties metal roof support
В работе представлена методика анализа металлических арочных
крепей, позволяющая исследовать компьютерную трехмерную модель крепи при различных видах и величинах нагрузок.The paper presents a methodology for the analysis of metal roof support
that allows with use of computer explore the three-dimensional model to be fixed for different types and magnitudes of loads
College of Arts and Sciences at Governors State University Announces Winter 2008 Dean’s List
The College of Arts and Sciences at Governors State University recently recognized undergraduate students who earned a 3.7 grade point average or higher during the Winter 2008 trimester
Structure and function of an RNase H domain at the heart of the spliceosome.
Precursor-messenger RNA (pre-mRNA) splicing encompasses two sequential transesterification reactions in distinct active sites of the spliceosome that are transiently established by the interplay of small nuclear (sn) RNAs and spliceosomal proteins. Protein Prp8 is an active site component but the molecular mechanisms, by which it might facilitate splicing catalysis, are unknown. We have determined crystal structures of corresponding portions of yeast and human Prp8 that interact with functional regions of the pre-mRNA, revealing a phylogenetically conserved RNase H fold, augmented by Prp8-specific elements. Comparisons to RNase H–substrate complexes suggested how an RNA encompassing a 5′-splice site (SS) could bind relative to Prp8 residues, which on mutation, suppress splice defects in pre-mRNAs and snRNAs. A truncated RNase H-like active centre lies next to a known contact region of the 5′SS and directed mutagenesis confirmed that this centre is a functional hotspot. These data suggest that Prp8 employs an RNase H domain to help assemble and stabilize the spliceosomal catalytic core, coordinate the activities of other splicing factors and possibly participate in chemical catalysis of splicing
Electromagnetic wave refraction at an interface of a double wire medium
Plane-wave reflection and refraction at an interface with a double wire
medium is considered. The problem of additional boundary conditions (ABC) in
application to wire media is discussed and an ABC-free approach, known in the
solid state physics, is used. Expressions for the fields and Poynting vectors
of the refracted waves are derived. Directions and values of the power density
flow of the refracted waves are found and the conservation of the power flow
through the interface is checked. The difference between the results, given by
the conventional model of wire media and the model, properly taking into
account spatial dispersion, is discussed.Comment: 17 pages, 11 figure
Choosing of optimal start approximation for laplace equation numerically solving
In the last few years, repeatedly increased the role of simulation systems for solution of physical problems, particularly in the microwave and electronics. This article focuses on the promising methods for setting an initial approximation for the numerical solution of the Laplace equation. We investigate Dirichlet problem for a case of two-dimensional area with lime border, numerical scheme for solving this equation is widely knowns it finite difference method. One of the major stages in the algorithm for that numerical solution is choosing of start approximation, usually as the initial values of the unknown function are assumed to be zero, which may serve as a lead to a large number of iterations in finding the numerical solution. It is shown that there is a way to set a start approximation, which can significantly reduce the number of iterations in the solution of the Laplace equation.Keywords: Laplace equation; approximation; net; Dirichlet problem; finite differencemethod
СОПОСТАВИТЕЛЬНЫЙ АНАЛИЗ ДОИСЛАМСКИХ ПРЕДСТАВЛЕНИЙ О ВЗАИМОДЕЙСТВИИ СО СВЕРХЪЕСТЕСТВЕННЫМ МИРОМ НА МАТЕРИАЛЕ ХАДИСОВ
The article describes a number of the Prophet Muhammad’s notions about the circumstances of interaction with supernatural beings reconstructed on the basis of the Hadith material. These notions are refl ected in such actions of the Prophet as wrapping up during the sending down of revelations, wearing clothes inside out during the performance of the ritual, refusal of certain types of food, etc. Such practices largely refl ect the ancient Arabian ideas about the behavior of a person being in contact with the transcendent. They can also be compared with similar rituals related to other cultures.В статье описывается ряд реконструированных на основе хадисов представлений пророка Мухаммада об обстоятельствах взаимодействия со сверхъестественными существами. Эти представления обнаруживают себя в таких действиях Пророка, как закутывание во время ниспослания откровений, ношение одежды наизнанку во время исполнения ритуала, отказ от определенных видов пищи и др. Такого рода практики в значительной степени отражают древнеаравийские воззрения на поведение человека, контактирующего с потусторонними силами. Они также могут быть сопоставлены с аналогичными ритуалами, относящимися к другим культурам.
ТОРГОВАЯ ТЕРМИНОЛОГИЯ В СИСТЕМЕ КОНЦЕПТУАЛЬНЫХ МЕТАФОР КОРАНА
Quranic metaphors describing theological ideas in commercial terms are an important source of knowledge about social and economic conditions and values existing in the Arabian society at the time of the Quran’s revelation to the prophet Muhammad. A comparison of the frequency of the metaphors’ appearance in the Mec-can and the Medinan suras shows equal importance of commerce for the populations of both Mecca and Medina (Yathrib). The concrete use of certain metaphors and images in the Meccan and the Medinan suras depends on the content of the verses, their audiences and the specifi c circumstances of the Revelation.Метафоры в Коране, описывающие богословские идеи с помощью торговых терминов, являются важным источником сведений о социально-экономических отношениях и ценностях общества, в котором произошло ниспослание Корана. Сравнение частотности их употребления в мекканских и мединских сурах свидетельствует о равной важности торговли для жителей как Мекки, так и Медины. При этом преимущественное употребление конкретных метафор и образов в мединских и мекканских сурах зависит в первую очередь от содержания соответствующих айатов, их адресатов и конкретных обстоятельств их ниспослания
Звуковой символизм в Коране как отражение древнеаравийской картины мира (на примере четырехсогласных корней)
Sound symbolism plays an important role for artistic devices and rhetorical techniques of the Qur’an. On the lexical material from four-consonant roots that could be described as an extremely archaic layer of the Arabic vocabulary, the article discusses ideophones (words that express an idea or convey a certain impression through their sound) in the Qur’anic Arabic. The article also describes their morphological structure and etymology of ideophones in the Qur’an. Semantic analysis and classification of these lexical units show that words of the language of the Qur’an, derived from four-consonant roots, dominantly describe the characteristics of movement, sound and visual sensations. The abundant set of sound-symbolic vocabulary in the language of the Qur’an reflects a cohesive, holistic worldview. Within that worldview a human being did not contrast himself with the environment and other living beings, but felt that he was a whole entity with them. He perceived sounds and other phenomena of the surrounding world as manifestations of otherworldly forces and supernatural beings, and this vision determined the sacred nature of the vocabulary that described these phenomena and its special rhetorical persuasiveness, as well as the emotional impact on listeners of the Qur’anic text. Moreover, a comparison with similar phenomena in other cultures allow us to suggest that sound-symbolic vocabulary was of the great importance for creating the performative function of the Qur’anic text, which was perceived as having special power to influence the world.Звуковой символизм является одним из важнейших средств художественной изобразительности и риторических приемов в Коране. На материале слов, образованных от четырехбуквенных корней и относящихся к чрезвычайно архаическому слою лексики арабского языка, в статье рассматриваются идеофоны (слова, выражающие какую-либо идею или передающие определенное впечатление посредством своего звучания) в языке Корана. Также в статье приводится описание их морфологического строения и этимологии. Семантический анализ и классификация идеофонов показывают, что большинство используемых в Коране лексем, образованных от четырехсогласных корней, описывает характеристики движения, звуковые и зрительные ощущения. Состав и богатство звукосимволической лексики в языке Корана отражает нерасчлененную, целостную картину мира, в рамках которой человек не противопоставлял себя окружающей среде и другим живым существам, а ощущал себя единым целым с ними. Звуки и явления окружающего мира воспринимались им как олицетворение потусторонних сил и сверхъестественных существ, что определяло сакральный характер описывающей эти явления лексики, ее особую риторическую убедительность и эмоциональное воздействие на слушателей коранического текста. Более того, сопоставление с аналогичными представлениями в рамках других культур позволяет предположить большое значение звукосимволической лексики для формирования перформативной функции коранического текста, который воспринимался как обладающий особой силой воздействия на окружающий мир
- …