1,252 research outputs found
H-tailored surface conductivity in narrow band gap In(AsN)
Get PDFWe show that the n-type conductivity of the narrow band gap In(AsN) alloy can be increased within a thin (similar to 100 nm) channel below the surface by the controlled incorporation of H-atoms. This channel has a large electron sheet density of similar to 10(18) m(-2) and a high electron mobility (mu > 0.1 m(2)V(-1)s(-1) at low and room temperature). For a fixed dose of impinging H-atoms, its width decreases with the increase in concentration of N-atoms that act as H-traps thus forming N-H donor complexes near the surface. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License
In(AsN) mid-infrared emission enhanced by rapid thermal annealing
No full textWe report a substantial increase in the quality and photoluminescence (PL) emission efficiency of In(AsN)
dilute nitride alloys grown on both p-type InAs and semi-insulting GaAs substrates, in response to rapid
thermal annealing. At 4 K the PL emission efficiency increases by 25 times due to a reduction in non-radiative
Shockley–Read–Hall recombination originating from elimination of point defects. For annealing
temperatures up to 500 C the activation energy for thermal quenching increases by a factor of three,
with no change in the residual electron concentration and mobility. Temperature dependent PL, together
with X-ray diffraction measurements, reveals an improvement in compositional uniformity. Our results
are significant for photonic device applications and particularly for the development of cryogenic midinfrared
photodiodes, monolithic detectors and focal plane arrays
Two Velichko-like Theorems for C(X)
No full textThis paper provides two new Velichko-like theorems for the weak counterpart of the locally convex space CkX of all real-valued functions defined on a Tychonoff space X equipped with the compact-open topology τk
Continuous Flow Chemistry Techniques in the Synthesis of Strained Carbo- and Heterocyclic Compounds
No full textIn the pursuit of advancing organic chemistry, this doctoral thesis presents an innovative approach that integrates process chemistry with flow chemistry to synthesize and functionalize strained carbocycles. This approach challenges traditional synthetic paradigms and redefines efficiency, sustainability, and scalability in chemical synthesis. Recognizing the limitations of conventional batch reactions, such as scalability constraints and significant waste production, this research transitions to flow chemistry systems to enhance reaction efficiency, reduce waste, and improve sustainability.
The core of this thesis lies in optimizing traditional synthetic methods into more productive and eco-friendly flow chemistry processes. This transformation leverages the advantages of flow chemistry, including superior reaction control, enhanced safety, and efficient waste management. A key highlight is the development of a multi-step reaction sequence for synthesizing valuable building blocks, starting with the conversion of alkynes to diketones, followed by photocyclization, and culminating in the formation of cyclopropyl-thio-ketones, cyclopropylamines, and γ-lactones through various nucleophilic additions.
The thesis also addresses the challenges of stability and scalability in flow chemistry setups, providing insights into transitioning from batch to flow processes. Through detailed optimization and creative problem-solving, this research establishes a foundation for future advancements in process chemistry, emphasizing its role in steering organic synthesis towards more sustainable and productive practices.
By facilitating the large-scale production of complex organic compounds with minimal environmental impact, this thesis contributes to a more sustainable future in chemical manufacturing. The innovative use of flow chemistry techniques presented in this research marks a significant leap forward in organic synthesis, heralding a new era of greener, safer, and more efficient chemical production.In the pursuit of advancing organic chemistry, this doctoral thesis presents an innovative approach that integrates process chemistry with flow chemistry to synthesize and functionalize strained carbocycles. This approach challenges traditional synthetic paradigms and redefines efficiency, sustainability, and scalability in chemical synthesis. Recognizing the limitations of conventional batch reactions, such as scalability constraints and significant waste production, this research transitions to flow chemistry systems to enhance reaction efficiency, reduce waste, and improve sustainability.
The core of this thesis lies in optimizing traditional synthetic methods into more productive and eco-friendly flow chemistry processes. This transformation leverages the advantages of flow chemistry, including superior reaction control, enhanced safety, and efficient waste management. A key highlight is the development of a multi-step reaction sequence for synthesizing valuable building blocks, starting with the conversion of alkynes to diketones, followed by photocyclization, and culminating in the formation of cyclopropyl-thio-ketones, cyclopropylamines, and γ-lactones through various nucleophilic additions.
The thesis also addresses the challenges of stability and scalability in flow chemistry setups, providing insights into transitioning from batch to flow processes. Through detailed optimization and creative problem-solving, this research establishes a foundation for future advancements in process chemistry, emphasizing its role in steering organic synthesis towards more sustainable and productive practices.
By facilitating the large-scale production of complex organic compounds with minimal environmental impact, this thesis contributes to a more sustainable future in chemical manufacturing. The innovative use of flow chemistry techniques presented in this research marks a significant leap forward in organic synthesis, heralding a new era of greener, safer, and more efficient chemical production
Peculiarities of the hydrogenated In(AsN) alloy
Get PDFThe electronic properties of In(AsN) before and after post-growth sample irradiation with increasing doses of atomic hydrogen have been investigated by photoluminescence. The electron density increases in In(AsN) but not in N-free InAs, until a Fermi stabilization energy is established. A hydrogen epsilon(+/-) transition level just below the conduction band minimum accounts for the dependence of donor formation on N, in agreement with a recent theoretical report highlighting the peculiarity of InAs among III-V compounds. Raman scattering measurements indicate the formation of N-H complexes that are stable under thermal annealing up to similar to 500 K. Finally, hydrogen does not passivate the electronic activity of N, thus leaving the band gap energy of In(AsN) unchanged, once more in stark contrast to what has been reported in other dilute nitride alloys
The Biography of Samoilo Velychko, the Author of the Famous Cossack’s Chronicle
No full textIn this article our imaginary and true knowledge of the biography of the author of the well-known
Cossack chronicle Samoilo Velichko are investigated. On the basis of the analysis of a historiography the
history of emergence of myths, and also the most famous versions of the biography of Velichko is shown. For
example, we study the circumstances of the termination of his service in General office of Zaporizhian Army.
The author introduces new archival documents from the Russian governmental archive of ancient arts and
from the archive of the Institute of History of Russian Academy of Art in St. Petersburg and represents own
interpretations of various facts. As a result, we obtain more exact data on study, a social origin, marital status,
and also the «misfortune» which has happened to Velichko and put an end to his career of the army bureaucrat.
Contrary to the most popular opinion in the historiography it is now possible to take for granted that Velichko
didn’t lose his position after V. Kochubey’s disgrace, but remained on service up to his capture in December,
1708. And moreover, he was in army of the hetman I. Mazepa after he joint Swedes. The detailed analysis
of the military company of November–December, 1708 allow to make the assumption of circumstances of
«misfortune» which happened to S. Velichko. Most likely, he was taken prisoner in Romnakh, during the
urgent departure of I. Mazepa’s troops from there. Besides, the revealed documents confirm availability of
close ties of Velichko with Zaporizhian Host and in particular with the Host’s clerk G. Bovguley. And it is
only the myth that S. Velichko taught V. Kochubey’s children
Effect of dietary fat on the activity of palmitic acid elongase in the blood serum and liver of rats
No full textEffect of dietary fat on the activity of palmitic acid elongase in the blood serum and liver of rats / A. P. Levitsky, V. V. Velichko, I. A. Selivanska, A. P. Lapinska, I. P. Dvulit // Збірник тез доповідей 82-ї наукової конференції викладачів університету, Одеса, 26–29 квіт. 2022 р. / Одес. нац. технол. ун-т ; під заг. ред. Б. В. Єгорова. – Одеса : ОНТУ, 2022. – P. 34–36 : tabl. – Ref.: 3 tit
CLIL or EMI? Confusion, Implementation and Success of EMI in the Department of Economics and Management at the University of Ferrara: A Case Study
No full textCLIL and EMI programmes are among the most important teaching methodologies, which have increasingly gained attention worldwide in countries where English is not the native language of instruction (Rigg 2013). The rise of English-medium programmes in European higher and tertiary education is influenced by processes of globalization (and internationalization) as well as Europeanization (Phillipson 2008).
EMI, in particular, seems to have gained more and more attention on behalf of European universities in response to changes in the international education system over the last two decades.
As far as the European university context is concerned, Italy seems to be a relative newcomer to EMI. In 2012, the OECD classified Italy as a country offering ‘no or nearly no programmes in English’, based on data from 2010. Although Italy is undoubtedly lagging behind many northern European countries, it is worth noting that English Taught Programmes are increasing fast. The Department of Economics and Management of the University of Ferrara has recently begun to implement EMI in postgraduate courses. After the initial confusion between CLIL and EMI, professors decided to implement EMI in an attempt to increase international openness, attractiveness, and competitiveness to varying degrees. Three important issues are particularly explored in this study, namely: 1) changes carried out to suit the lecture format to the EMI lectures, as compared to traditional lecture formats delivered in Italian for the same subject matter, 2) level of language proficiency of both EMI lecturers and students and 3) opinions about EMI implementation by both lecturers and students
Armenian nationalism according to velichko and chavchavadze
No full textErmenilerin Kafkasya’da Türkler dısındaki diger komsusu olan Gürcülerle olan iliskilerinde Ermeni milliyetçiliginin ve bu ülkeye yönelik toprak iddialarının izlerini bulmak mümkündür. Gürcüler, Ermenilerin Gürcü topraklarını eski Ermeni vilayetleri olarak adlandırdıgını ve Gürcistan’ın büyük bir bölümü ile birlikte Tiflis’in çok eski zamanlardan itibaren Ermenilere ait oldugunu iddia ettiklerini belirtirler. Bir Gürcü kontu olan $. G. Çavçavadze, kendi tarihlerinin tahrif edilmesine yönelik rahatsızlıgını “Ermeni Alimleri ve Feryat Eden Taslar” adlı eserle dile getirir. Uzun yıllar Kafkasya’da gazetecilik yapan V. L. Veliçko ise 19. yüzyılda Kafkasya’da yasayan halkları ve son derece kritik olan bölgenin siyasi ve sosyal durumunu inceleyerek Kafkasya adlı eserinin Ermenilere ayırdıgı bölümünde dikkat çekici hususlara deginmistir. Günümüzde hala tartısılan “Büyük Ermenistan” veya “Denizden Denize Büyük Ermenistan” idealinin anlasılması, Ermeni milliyetçiliginin tarihi boyutlarının çok yönlü bilinmesi ve kavranması ile mümkündür. Bu çerçevede, gerek Çavçavadze’nin gerekse Veliçko’nun Ermeni milliyetçiligine yönelik görüsleri bu çalısmada irdelenecektir.Embedded territorial claims on Georgia can be found in Armenian nationalism. Some Georgian historians emphasized in their chronicles that the Armenians recognized the Georgian lands as ancient Armenian provinces. They also underlined the Armenians claim on a large part of Georgia including Tbilisi. G. Chavchavadze, a Georgian prince, expressed his resentment on the distortion of their own history in his book “Armenian Scholars and Crying Stones”. Additionally, V. L. Velichko who was a Russian journalist in the Caucasus for many years examined the people living in the Caucasus during the 19th century and the critical political and social situation of the region, and provided valuable information on Armenians in his book entitled “The Caucasus”. The idea of “Greater Armenia” which is still relevant to current debates can be only comprehended by looking at historical aspects of Armenian nationalism. In this framework, both Chavchavadze’s and Velichko’s thoughts on Armenian nationalism will be analyzed in this study
Supplemental Material - Tracing the evolution of personality cognition in early human civilisations: A computational analysis of the Gilgamesh epic
No full textSupplemental Material for Tracing the evolution of personality cognition in early human civilisations: A computational analysis of the Gilgamesh epic by Ronald Fischer, Johannes A. Karl, Velichko Fetvadjiev, Markus Luczak-Roesch, Reinhard Pirngruber, and Amy He Du in European Journal of Personality</p
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