1,427 research outputs found
Dielectric rod waveguide components at sub-THz frequencies
Full text linkThis thesis is focused on the development of dielectric rod waveguide (DRW) components at sub-THz frequencies. DRWs proved themselves as low loss transmission lines at sub-millimeter wave and THz frequencies; they can be well matched with rectangular metal waveguides, and also used as antennas. In addition, the DRW allows integration of various components using standard microfabrication techniques, e.g. the bolometric power sensor can be integrated in the center of the DRW and measure the power travelling in the DRW, and a phase shifter based on a high impedance surface (HIS) can be manufactured on the surface of the DRW and can change the phase of the propagating wave inside the DRW.
In the first part of this thesis the narrow band and wide band DRW antennas were designed, manufactured and tested. The DRW antennas are lightweight, compact and easy to manufacture. The narrow band DRW antenna proved to operate in the range of 220 – 325 GHz. The wideband DRW antenna showed a constant performance over the band of 75 – 1100 GHz according to numerical simulations and over the band of 75 – 325 GHz experimentally. The radiation patterns of the antenna were measured in co- and cross-polarization. The co-polarization radiation patterns are nearly independent of frequency. The 3 dB beamwidth is 50º - 60º, and the 10 dB beamwidth is about 95º. The return loss of the antenna is better than 15 dB.
In the second part of this thesis the bolometric power sensor integrated into DRW was designed, manufactured and tested at frequencies 75 – 1010 GHz. The power sensor consists of a metallic antenna -like structure in the center of the DRW in E-plane suspended on a membrane over an airgap to improve the thermal insulation. The power sensor showed good matching with the rectangular metal waveguides and constant responsivity over the wide band of frequencies, as well as a linear responsivity up to 500 mW applied power.
In the third part of this thesis the microelectromechanical system (MEMS) tunable HIS was developed for integration on to the surface of a DRW using suspended carbon nanotube (SWCNT) film as a movable element of the HIS. The implementation of a SWCNT network as a material for movable suspended film allows to significantly simplify the fabrication process of the HIS due to a simple technique of the SWCNT film deposition by dry transfer, and additionally it allows to reduce the actuation voltage of the HIS due to the low Young's modulus of the SWCNT network. The unique deposition technique of the SWCNT film allows to design a HIS phase shifter directly on the surface of the DRW. The suspended SWCNT film structure showed the tunability of the capacitance of 100% at 0 – 10 V applied bias voltage. Such properties allow to create a SWCNT MEMS HIS with a phase shift of 260° at 0 – 7 V bias voltage
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Saltikov-Shedrin's traditions in literary creation of Andrey Platonov
No full textIn this article the author throws light on connections between the creative work of Andrey Platonov and satire of Mikhail Saltikov-Shedrin. Author deduces similarity of the destinies of two Great Russian writers; she notifies likeness of their literary stylistics, unity of their literary characters and vehicles
In memory of Andrey A. Aleksandrov (1946?2015)
Full text linkOn March, 17th, 2015 professor Andrey A. Alexandrov, the chief of functional cardiology department at Endocrinology Research Centre passed away. Andrey A. Alexandrov graduated from 2nd Moscow Medical Institute in 1971. In 1979 finished his PhD and in 1989 his doctoral research on topic ?Hormonal regulation and carbohydrate metabolism in patients with heart attack?. From 1999 to present time was the Chief of cardiology department at Endocrinology Research Centre. Alexandrov is the author of more than 420 publications, he supervised 13 PhDs and 1 doctoral research. We will remember him as a high level professional, great scientist, talented teacher and charming person.
Andrey Kiselev: the life and the legend
Full text linkThis article is devoted to Andrey Kiselev, probably the most well-known Russian author of mathematics textbooks. His books remained in schools for nearly one hundred years, and his name became legendary, symbolizing the “good old days” when all was supposedly well with mathematics education. Meanwhile, even in Russia, let alone abroad, many aspects of Kiselev’s life are little known. Their study facilitates a better understanding of the complicated nature of the development of Russian and Soviet mathematics education, including the connection between them and seemingly distant social-political issues. The present article undertakes such a study. The author draws on his Russian publications, materials from Russian archives, and other primary sources
BOOK REVIEW “DIARY OF AN INVASION, BY ANDREY KURKOV (2022)”
Full text linkDiary of An Invasion is a book written by Ukrainian author Andrey Kurkov in 2022. Written mostly during the first semester of 2022, the book is a chronological and personal diary that recounts Kurkov’s experience in Ukraine, during the initial months of the Russian invasion
Andrey Muraviev’s The Russian Vilnius
No full textThe article is an attempt to present the impressions of Andrey Muraviev, religious writer,
theologian, poet, playwright, church and state activist, from his stay in Vilnius in 1863, on the basis of his work entitled The Russian Vilnius. It consists of six essays on Vilnius religious monuments: the Chapel of Our Lady of Ostra Brama, St. Paraskeva Orthodox church, Orthodox cathedral of Our Most Holy Lady, Orthodox church of translation of St Nicholas’ relics, Holy Trinity cathedral, Holy Spirit church and monastery complex. The author was only interested in monuments which would document the city’s connections to Russia and Orthodox Christianity. His reflections might be considered as a literary justification for the program of Russification of the north-west country, developed by the writer’s brother, Mikhail, who went down in Polish historical memory as Veshatiel
Andrey Muraviev’s "The Russian Vilnius"
Full text linkThe article is an attempt to present the impressions of Andrey Muraviev, religious writer,
theologian, poet, playwright, church and state activist, from his stay in Vilnius in 1863, on the basis
of his work entitled
The Russian Vilnius
. It consists of six essays on Vilnius religious monuments:
the Chapel of Our Lady of Ostra Brama, St. Paraskeva Orthodox church, Orthodox cathedral of Our
Most Holy Lady, Orthodox church of translation of St Nicholas’ relics, Holy Trinity cathedral, Holy
Spirit church and monastery complex. The author was only interested in monuments which would
document the city’s connections to Russia and Orthodox Christianity. His reflections might be con
-
sidered as a literary justification for the program of Russification of the north-west country, devel
-
oped by the writer’s brother, Mikhail, who went down in Polish historical memory as Veshatiel
Andrey Bely: A Critical Review
Full text linkAndrey Bely, novelist, essayist, theoretician, critic, and poet, was a central figure in the Russian Symbolist movement of the 1920s, the most important literary movement in Russia in this century. Bely articulated a Symbolist aesthetic and originated a new approach to the study of Russian metrics and versification, giving rise to a new scholarly discipline that still thrives in the West.
Although regarded by some critics, including Vladimir Nabokov, as the author of the greatest Russian novel of this century, Bely has been nearly forgotten in his native country for ideological reasons. In the West he remains little known and generally under-valued. But with recent English translations of Kotik Letaev and his masterpiece, Petersburg, interest in Bely is increasing. Janecek\u27s book brings together some of the best modern scholarship on Bely and the Russian Symbolist movement of the 1920s.
Gerald Janecek is associate professor of Russian at the University of Kentucky.https://uknowledge.uky.edu/upk_slavic_languages_and_societies/1001/thumbnail.jp
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