38,719 research outputs found
Magnetic and dielectric properties of cobalt ferrite/titania composites
No full textIn order to develop materials with both magnetic and dielectric properties, recently a lot of researchers concentrate their work to process and study composite ceramics with both magnetic and dielectric phases. Cobalt ferrite Co Fe2O4 and TiO2 are good candidates for this type of composites as they have good magnetic and dielectric properties respectively.
New cobalt ferrite/titania (CFO/TO) ceramics composites were prepared by conventional solid state reaction with a CFO/TO ratio ranging from 2 to 8. Composition, crystalline structure and microstructure of the sintered ceramic composite bodies were investigated and the phases content volume percentage were determined. Dielectric permittivity ( real part of permittivity and dielectric losses) and magnetic permeability (real part of permeability and magnetic losses) were measured at room temperature in a range of frequency from 100 Mhz-1 GHz. Dielectric and magnetic properties were analyzed as function of the microscopic structure (SEM analysis) and phase compositions (XRD analysis). The formation of the ternary compound (FCTO) was found in composites with the TO/CFO bigger than 3
Synthesis and characterization of novel ferrite–piezoelectric multiferroic core–shell-type structure
No full textElectrophoretic deposition of bilayer composite films based on CoFe2O4/TiO2 and PZT
No full textIn the recent years the interest of the research community towards multiferroic composite materials was growing fast. A number of papers relates to bulk materials while less attention is focused on films. Electrophoretic deposition (EPD) was applied to prepare magnetoelectric (ME) composite bilayer thick films based on perovskite phase and spinel cobalt ferrite as some of the best piezoelectric and magnetostrictive oxides belong these crystal groups. The co-deposition of titanium oxide (TO) and cobalt ferrite (CFO) nanoparticles and the deposition of niobium-doped lead titanate zirconate (PZTN) were made from colloidal suspensions in ethanol keeping constant voltage and recording the current. Good adhesion and compaction of the green film were achieved by optimization of deposition voltage and time while high density of the film and minimized interphase reactions occurred after sintering. The deposited volume, the mixing of dielectric and magnetic phases and the density and ordering of the films have been verified by electron scanning microscopy after heat treatment. No reactions between the different phases was found. The piezoelectric properties were measured on the sintered films
Composite BNT-BT 0.08 /CoFe 2 O 4 with core-shell nanostructure for piezoelectric and ferromagnetic applications
No full textIn this work, we report on the synthesis and characterization of BNT-BT 0.08 /CoFe 2 O 4 biphasic composite with core-shell structure. This artificial core (BNT-BT 0.08 )/shell (CoFe 2 O 4 ) heterostructure was prepared by sol-gel method and the resulting composite was characterized in term of microstructure, dielectric, piezoelectric and magnetic properties. BNT-BT 0.08 /CoFe 2 O 4 sintered ceramic shows high permittivity (ε′ ≥ 30) and high dielectric losses (tan δ ≥ 10) in the low frequency range (ν ≤ 10 4 Hz), remnant polarization (Pr) of ∼7.7 μC/cm 2 and, remanent magnetization (Mr) of 24 emu/g at 5 K and of 14 emu/g, at room temperature. The present study reveals that the ferroelectric, piezoelectric and magnetic properties of this new architectured composite depend on the amount of each component and, can be tailored by adjusting their synthesis conditions. BNT-BT 0.08 /CoFe 2 O 4 core-shell material investigated in this work provides a novel way to exploit new applications for the multifunctional composite, such as piezoelectric sensor, magnetoelectronic sensors and data storage devices
S. I. Gessen in Memoirs and Assessments of V. V. Zenkovsky: Page from Intellectual History of Russian Emigration
No full textThe relationship between S. I. Gessen and V. V. Zenkovsky, representatives of Russian philosophical, psychological, pedagogical and social thought, is considered as an episode of the intellectual history of the Russian diaspora. It is argued that the image of S. I. Gessen, formed in the scientific works and memoirs of a famous teacher, complements the idea of his personality, of the position S. I. Gessen held in the scientific, pedagogical and social life of the emigration. An analysis of the relationship between two thinkers over a quarter of a century is presented. The conclusion is drawn about the “internal dialogue” between them, which developed on the pages of emigre periodicals, was recorded in correspondence with like-minded people and became the subject of reflection and self-reflection in scientific works. The author pays special attention to assessments of the theoretical contribution of S. I. Gessen to Russian and European philosophical and pedagogical thought, which are given in reviews and surveys, the essay “Russian Pedagogy in the XX century” and “History of Russian Philosophy”. It is shown that in this context, the responses to the death of S. I. Gessen and memories of him, which make it possible to determine the attitude of V. V. Zenkovsky not only to S. I. Gessen the thinker, but also to man, acquire great importance
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
TeX v jednoduchém unixovém prostředí
No full textsummary:Při ladění TeXového dokumentu potřebujeme mnohokrát opakovaně pouštět TeX, podívat se, jak dopadl výsledek v prohlížeči DVI nebo PDF souboru, mrknout na výpis TeXu na terminálu, podívat se případně do logu a celou činnost opakovat. V tomto článku je ukázáno, jak tuto práci dělá autor článku. Proces "editor-TeX-kuk" je zde podporován jednoduchými unixovými nástroji: bashovým skriptem texloop, který si autor pro tyto účely vytvořil, dále terminálem Xterm a jednoduchým editorem, který umí navázat na klávesovou zkratku spuštění příkazu v systému. Čtenář se zde může inspirovat a přizpůsobit tyto nástroje svým vlastním potřebám. V článku je popsána funkce skriptu texloop, dále je neformálně rozveden dlouholetý vývoj autorova vztahu k textovým editorům a konečně je zde uvedena konfigurace terminálu Xterm, aby vyhovoval českému prostředí jak v kódování ISO-8859-2, tak v kódování UTF-8. Pro kódování UTF-8 si v závěru článku vygenerujeme TeXový formát csplain.summary:By debugging a TeX document it is necessary many times repeatedly to run TeX, to look for the result in DVI or PDF file, to gander the TeX output on the terminal, or eventually to have a look in the log-file, and all that action to repeat. In the paper it is show, how this work is made by author. The process '‘'editor-TeX-look' is supported by simple Unix tools: bash script texloop, created by author for these purposes, Xterm terminal and a simple editor, which is able to link to the shortcut key the activation of a system command. The reader could be inspired with the solution and to adapt these tools to his/her own needs. In the paper the function of the texloop script is described, and further the longstanding evolution of the author's relation to text editors is informal elaborated and finally a configuration of Xterm terminal, suitable for the czech environment with both ISO-8859-2 and UTF-8 encoding is introduced. For UTF-8 encoding the TeX format csplain is generated at the end of the paper
Various taxonomic designations of <i>V</i>. <i>ramuliflora</i> by different author.
No full textVarious taxonomic designations of V. ramuliflora by different author.</p
AUTHOR BOOK
No full textVytvořil jsem autorskou knihu o čtyřiceti stránkách s ilustracemi a minimem textu. Kniha je černobílá, dominuje v ní tušová kresba štětcem a perem. Kromě té je v knize ale i text, který slouží jako poetické doplnění ilustrací.
Obsah knihy se zaměřuje na úzký kruh přátel a zároveň vypovídá o autorovi jak vybranými motivy, situacemi tak linkou.
Vyznění knihy je spíše pocitové, má zanechat dojem, ne popisně vysvětlovat.ObhájenoI have created author book that has 40 pages with ilustrations and minimum of text. The book is black and white and contains ink drawings. There is also text poetically coresponding with pictures
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