3,949 research outputs found
Prestwich A.A. Records of Parrots bred in captivity. London, The Author, 1950-1952
No full textBourlière François. Prestwich A.A. Records of Parrots bred in captivity. London, The Author, 1950-1952. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 7, n°2, 1953. p. 124
Characterization of Unbound Granular Materials for Pavements
No full textThis research is focused on the characterization of the mechanical behavior of unbound granular road base materials (UGMs). An extensive laboratory investigation is described, in which various methods for determination of the mechanical properties of granular materials are examined for their applicability, particularly in developing countries. Further, the mechanical behavior of unbound granular materials as a function of the moisture content and the degree of compaction is investigated. A study into the modeling of the stress dependent mechanical behavior of granular materials is presented. Finally, verification and validation of a relatively simple characterization technique, the repeated load CBR test (RL-CBR), by the results of cyclic load triaxial testing are provided and overall practical implications of the research are presented. The laboratory investigation involves a large range of granular materials, mainly (sub-)tropical road base and subbase materials. The performed tests yield fundamental parameters that describe the strength, stiffness and resistance to permanent deformation of the materials tested. In addition to the (sub-)tropical road base and subbase materials, a recycled mix-granulate widely used in pavement construction in the Netherlands and a base course and frost protection material from Austria are incorporated to a limited extent in the laboratory testing program. Most roads in developing countries are either unpaved or have a thin asphalt surfacing, and as a consequence the granular base and subbase layers provide the bulk of the bearing capacity. Although the important structural contribution of these unbound granular layers is understood, engineering practice still greatly relies on tests which mainly give index properties of these materials. Pavement structures are designed based on empirical design methods related to a single design chart, restricting the incorporation of marginal materials or new materials for which the empirical data sets are not available. The reasons that pavement design and construction in developing countries rely on empirical design procedures that are basically developed for completely different conditions are: - the affordability and complexity of the cyclic triaxial tests required to determine the stress dependent mechanical behavior of granular materials; - the perceived complexity and unfamiliarity with the computational tools (non-linear multilayer or finite element analysis) required to model the performance of pavements using this mechanical behavior despite the availability of powerful digital computers and their penetration even to remote places. In order to promote the introduction of Mechanistic-Empirical design methods in developing countries, this research was set up with two goals: i. to make the characterization technique for the mechanical behavior of granular road base materials more accessible to practice through the development of a simple and effective characterization technique; ii. to further develop the understanding of the stress dependent mechanical behavior of unbound (sub-)tropical base and subbase materials. To achieve the first aim an innovative and relatively simple testing procedure, the RL-CBR test, is developed to characterize the mechanical behavior of the UGMs. RL-CBR testing is performed on the various granular materials in steel moulds without and with strain gauges. With the strain gauges the confining condition and hence the stress state of the specimen is estimated through mould deformation measurements. The finite element method (FEM) is used to model the RL-CBR testing and interpret the test results into mechanical behavior. Due to the non-uniform complex stress distribution in the RL-CBR compared to the triaxial test, fundamental material properties such as the stiffness modulus are less easy to determine. Extensive triaxial testing on the various granular materials is performed to realize the second goal. The result of this investigation is also used to validate and verify the results of the RL-CBR tests. Moreover, the effect of influence factors such as moisture content, degree of compaction, material type etc. on the mechanical behavior is investigated. For the unbound granular road base materials, particularly the natural gravels, the effect of the moisture content on the mechanical behavior was found to be more significant than the effect of the degree of compaction. Relative to the failure and permanent deformation behavior the resilient deformation behavior is less affected by the moisture content and the degree of compaction. The RL-CBR testing serves well its purpose to get a good estimate of the fundamental mechanical properties of granular road base materials from a rather simple characterization technique. The practical accessibility of characterizing the mechanical behavior of UGMs can therefore be enhanced through RL-CBR testing. This is proven by the fact that good correlations have been found between the stiffness results of the two characterization techniques, i.e. the complex triaxial test and the newly developed repeated load CBR test.Design and ConstructionCivil Engineering and Geoscience
A.A. Gromyko and Security Policy: Helsinki compromise (to the 115th anniversary of A.A. Gromyko)
No full textThe article continues the study of the role of the Minister of Foreign Affairs of the USSR A.A. Gromyko in the formation, development and maintenance of security policy, its principles and structural elements. The subject of the article is the research of the preparation, content and prospects of the development of the Helsinki Compromise. On August 1, 1975, this compromise was enshrined in the final act of the Conference on Security and Cooperation in Europe. The article consists of four sections. The first section is dedicated to the problem of the connections between the Western interpretation of progress and the possible influence on the Western world. This problem will be scientifically examined in further articles. In the second section, the author proves that the main task of A.A. Gromyko in 1975 was to agree on the compromise as quickly as possible and then to begin with the main directions of cooperation between states. In the third section, the author analyzes the content of the compromise. In addition, the most important peculiarity (no existence of a common and specific project for all countries) is highlighted. In the fourth section, the author characterizes A.A. Gromyko's ideas about the prospects of the development of the Helsinki compromise. What is new is the interpretation of the CSCE decisions in 1975, the interpretation of the meaning and contradictions in the Gromyko system. The sources of the article are published documents of the Foreign Office of the Federal Republic of Germany, the use of which can be explained methodologically. It was important for the author to conduct the analysis on the basis of the foreign partners' assessment of the statements made by the Soviet Foreign Minister during official negotiations (outer reflection). The author's reasoning should be understood in the context of his earlier article in the journal
A.A. BRUSILOV - FULL GENERAL OF RUSSIAN ARMY AND LAST COMMANDER OF RUSSIAN TSAR
No full textThe article analyzes the biography of Russian full general A.A. Brusilov − the hero of World War I, whose name is associated with the term “Brusilov Offensive”. The author exa-mines his views on the new situation which developed in Russia during the two revolutions of 1917, and then in the Soviet period. The author highly appreciates the theoretical preparation level of A.A. Brusilov, who got full military education in tsarist Russia; reveals the pre-sence of numerous analogous episodes in the biographies of A.A. Brusilov and A.V. Suvorov. He focuses on the similar origin of two Russian heroes, whose families belonged to the military dynasties of imperial Russia. The author concludes that the continuity of generations is very important in the issue of effective army’s functioning. This tradition was preserved in the new Soviet state
High-k fluoropolymers dielectrics for low-bias ambipolar organic light emitting transistors (Olets)
No full textFunding Information: Author Contributions: Conceptualization, A.A. and C.S.; methodology, A.A. and C.S.; validation, A.A., K.G.-R., and C.S.; data curation, A.A., K.G.-R., and C.S.; writing—original draft preparation, A.A. and C.S.; writing—review and editing, A.A., K.G.-R., and C.S.; supervision, C.S.; project administration, C.S.; funding acquisition, C.S. All authors have read and agreed to the published ver-sion ofFunding:the manuThescript.authors acknowledge the support from the Academy of Finland Flagship Program (Grant No.: 320167, PREIN) and the Aalto seed funding scheme. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Organic light emitting transistors (OLETs) combine, in the same device, the function of an electrical switch with the capability of generating light under appropriate bias conditions. In this work, we demonstrate how engineering the dielectric layer based on high-k polyvinylidene fluoride (PVDF)-based polymers can lead to a drastic reduction of device driving voltages and the improvement of its optoelectronic properties. We first investigated the morphology and the dielectric response of these polymer dielectrics in terms of polymer (P(VDF-TrFE) and P(VDF-TrFE-CFE)) and solvent content (cyclopentanone, methylethylketone). Implementing these high-k PVDF-based dielectrics enabled low-bias ambipolar organic light emitting transistors, with reduced threshold voltages (<20 V) and enhanced light output (compared to conventional polymer reference), along with an overall improvement of the device efficiency. Further, we preliminary transferred these fluorinated high-k dielectric films onto a plastic substrate to enable flexible light emitting transistors. These findings hold potential for broader exploitation of the OLET platform, where the device can now be driven by commercially available electronics, thus enabling flexible low-bias organic electronic devices.Peer reviewe
Continuous representation for shell models of turbulence
No full textIn this work we construct and analyze continuous hydrodynamic models in one space dimension, which are induced by shell models of turbulence. After Fourier transformation, such continuous models split into an infinite number of uncoupled subsystems, which are all identical to the same shell model. The two shell models, which allow such a construction, are considered: the dyadic (Desnyansky--Novikov) model with the intershell ratio and the Sabra model of turbulence with . The continuous models allow understanding various properties of shell model solutions and provide their interpretation in physical space. We show that the asymptotic solutions of the dyadic model with Kolmogorov scaling correspond to the shocks (discontinuities) for the induced continuous solutions in physical space, and the finite-time blowup together with its viscous regularization follow the scenario similar to the Burgers equation. For the Sabra model, we provide the physical space representation for blowup solutions and intermittent turbulent dynamics
A.A. Gromyko and Security Policy: Conflict of Strategies after Helsinki
No full textThe article continues the study of the role of the Minister of Foreign Affairs of the USSR A.A. Gromyko in the formation, development and maintenance of security policy, its principles and structural elements. The subject of the article is the analysis and comparison of the strategies of A.A. Gromyko and the Western countries in 1976–1977 after the signing of the Helsinki Final Act. The article consists of three parts. In the first part, the author analyzes the strategic course of A.A. Gromyko and proves that the Soviet Foreign Minister understood détente as a three-level process. For this reason, he wanted to agree on the common content of détente and to build cooperation between states of different status in the system of international relations that would be beneficial for all participants. The second part describes the West’s strategic course. The author shows that the West hoped to weaken the USSR, lure the country into a foreign policy game, «keep the Soviets in good spirits» and obtain voluntary concessions from the country. The Helsinki Final Act was as a «provisional high point» that would lead to a fight for what had been achieved. In the third part, the positions of A.A. Gromyko and the Western political elite were compared. For the first time in historiography, the thesis about a real possibility of dialogue between the USSR and the United States on the legal formalization of the status of the great powers was presented. The author recommends taking into account the proposals of A.A. Gromyko in the modern system of international relations. The sources of the article are published documents of the Foreign Office of the Federal Republic of Germany, the use of which can be explained methodologically. It was important for the author to conduct the analysis on the basis of the foreign partners' assessment of the statements made by the Soviet Foreign Minister during official negotiations (outer reflection). The author's reasoning should be understood in the context of his earlier article in the journal
Hamiltonian formalism for weak turbulence of inertial waves in rotating fluids
No full textWe present the Hamiltonian description of incompressible rotating fluid by using the Clebsch variables. We find the transformation which allows us to present the three-wave interaction Hamiltonian in normal variables in simple explicit form. We analyze the three-wave interaction amplitude and find new anisotropic spectra. Finally we study the convergence of integrals and present the kinetic equation
Paralegal work: a community-based approach to fisheries law enforcement ni Negros Occidental, Philippines
No full textFishery management, Legal aspects
Philosophical, pedagogical and sociological conception of A.A. Zinoviev
No full textThe paper focuses on A.A. Zinoviev's philosophical and pedagogical conception within his sociological doctrine. The author analyses communality of the educational process, the mechanism of pedagogical stuff functioning as well as relations within a “communal cell” and the ideological element of contemporary Russian education
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