2,115 research outputs found
Defect-related degradation of Deep-UV-LEDs
No full textWith this paper we describe an extensive analysis of the electro-optical degradation of deep ultraviolet
Light-Emitting Diodes emitting at 310 nm, submitted to accelerated stress test. The results obtained
within this study indicate that: (i) high current stress can induce a significant decrease in the optical
power emitted by the LEDs; (ii) optical power decrease is more prominent at low measuring current levels,
indicating that degradation is related to an increase in the concentration of defects, with subsequent
decrease in the radiative efficiency of the active layer; (iii) stress can induce a significant increase in the
operating voltage of the LEDs, due to the increase in the resistivity of the ohmic contacts or p-type semiconductor;
and (iv) after stress, LEDs show a significantly increased green parasitic emission. This result
suggest that stress induced an increase in the defectiveness of the active layer. Information on the location
of the degraded region is achieved by the analysis of the Apparent Charge Distribution curves
obtained by capacitance–voltage measurements
Hypothesis of the dimensional-geometric scheme of the Nabta-Playa megalith landscape monument
No full textThe study aimed at identifying a scheme of dimensional and geometric relation-ships that could applied to a famous megalithic monument called “calendar circle”, located in the archaeological area of Nabta Playa. In the revealed sizes, there are repetitions of some prime numbers. A special role in all these cases belongs to the prime number 37, which may be is connected with the sequence of numbers of the “Dome Algorithm” (1, 2, 3, 5, 7, 9, 13, 17, 21, 29, 37, ...) , identified by the author earlier and having a cosmographic sense. Similar dimensional and geometric regularities repeatedly revealed by the author earlier. In particular, one can note in this sense the famous megalith Ales Stenar in Sweden and the Sun Boat of Pharaoh Cheops. The results obtained in this article allow us to state that the creators of “small calendar circle” of Nabta Playa were familiar with both the methods of exact geometric constructions and the ancient Egyptian linear measures system
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Professor E. M. Lazko – an outstanding scientist and patriarch of lviv school of geology and precambrian metallogeny: to the 100th anniversary
No full textMeasurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Fourier integrals and a new representation of Maslov's canonical operator near caustics
No full textWe suggest a new representation of Maslov's canonical operator
in a neighborhood of the caustics using a special class of coordinate systems
(\eikonal coordinates") on Lagrangian manifolds
Essays on Environmental and Agricultural Economics
No full textEvaluating the impacts of outcomes by governments, firms, and individuals is a pivotal component of economic analysis. In this dissertation, I apply ex-ante and ex-post techniques to analyze topics surrounding pollution and agricultural lending.
In the first essay, I estimate reductions in transport-related pollutants following the extension of a light-rail transit line in the Los Angeles region. This study uses an ex-post approach, employing difference-in-differences modeling to estimate reductions in carbon monoxide, nitrogen dioxide, and ozone at treatment locations around the Expo Line extension. The major findings of this essay is that there is a statistically significant reduction in carbon monoxide, potential reductions in nitrogen dioxide, and an increase in ozone. These findings are consistent with outcomes from other studies estimating reductions in these pollutants in other densely populated regions.
In the second essay, I estimate the impact of several characteristics of an agricultural borrower as debt loads increase. I use enterprise production budgets from the Texas A&M AgriLife Extension Service as a base for production inputs and costs, coupled with historical price data and futures price data to estimate a borrower���s Term Debt Coverage Ratio (TDCR). I implement a technique called Principal Components Analysis (PCA) to overcome limitations in the data and use Monte Carlo simulations to estimate the probability that the TDCR is less than 1 for a given Debt to Asset Ratio. The PCA techniques allow this tool to offer versatile applications for a variety of analyses from the perspective of an agricultural lender
Beurling-Landau's density on compact manifolds
No full textGiven a compact Riemannian manifold , we consider the subspace of generated by the eigenfunctions of the Laplacian of
eigenvalue less than . This space behaves like a space of polynomials and we have an analogy with the Paley-Wiener spaces. We
study the interpolating and Marcinkiewicz-Zygmund (M-Z) families and provide necessary conditions for sampling and interpolation in terms
of the Beurling-Landau densities. As an application, we prove the equidistribution of the Fekete arrays on some compact manifolds
Fulfillment of Obligations Prescribed by National Legislation and International Treaties when Deciding on Extradition of Persons for Criminal Prosecution or Sentence Execution
No full textIntroduction: the article analyzes the most important procedural aspects of
extradition of persons for criminal prosecution or execution of a sentence as
a separate area of international cooperation in the field of criminal justice. The
author proceeds from the fact that the extradition procedure is a complex of
interrelated, successive procedural actions that begin from the moment of actual
detention of a person who is on the international wanted list on the initiative of
the requested state and an official notification about it, with a proposal to send
a request for his/her extradition to the Russian Federation. A similar request, but
already on the part of the Russian Federation, is sent by its competent authorities
if the requested person has Russian citizenship or does not have citizenship of the
state on whose territory this person is located. However, it can also be sent when
the requested person is a citizen of a third country or stateless. Purpose: to study
aspects of the functioning of the institution of extradition of offenders and to
propose possible solutions to problematic issues. Methods: the methodological
basis of the research is made up of general scientific methods of cognition,
including the principle of objectivity, consistency, induction, deduction, etc. as well
as private scientific methods: descriptive, linguistic, comparative legal. Results:
having considered the procedure for request forwarding, the author comes to the
conclusion that the main task of extradition of offenders is to ensure inevitability
of the punishment imposed by the court and social rehabilitation of convicts.
At the same time, it is important that criminal prosecution or enforcement of a
sentence against them are carried out in accordance with international law and
domestic legislation of the requesting state. Conclusion: the key obstacle to fullfledged functioning of the institute of extradition is the lack of state responsibility
for non-compliance with the requirements for extradition of the wanted persons
and creation of artificial restrictions in solving these issues. The author’s vision of
the way to solve this problem is proposed
Author's pedagogical systems: historical and pedagogical aspect
No full textУ публікації розглянуто авторські педагогічні системи. Історія української педагогічної думки презентує приклади побудови та реалізації авторських педагогічних систем: В. Біблер, В. Дурдуківський, М. Гузик, О. Захаренко, Д. Лебедєв, А. Макаренко, В. Сухомлинський, Л. Терещенко, І. Ткаченко, М. Чумарна, В. Шаталов, М. Щитинін та ін. Зазначено, що аналіз досвіду організації освітнього процесу педагогами-інноваторами свідчить про значний внесок у розвиток освітніх технологій взагалі та авторських педагогічних систем зокрема. The author's pedagogical systems are considered in the publication. The history of Ukrainian pedagogical thought presents examples of construction and implementation of author's pedagogical systems: V. Bibler, V. Durdukivskyi, M. Guzik, O. Zakharenko, D. Lebedev, A. Makarenko, V. Sukhomlynskyi, L. Tereshchenko, I. Tkachenko, M. Chumarna, V. Shatalov, M. Shchytynin and others. It is noted that the analysis of the experience of organizing the educational process by innovative teachers shows a significant contribution to the development of educational technologies in general and author's pedagogical systems in particular
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