127 research outputs found

    Quantitative phase analysis of modified hardened cement paste

    Get PDF
    The relevance of this research is stipulated by the opportunity to control the properties of construction materials through introducing nanomodifying additives. The study of structure parameters of the crystalline phase of hardened cement paste modified by microsilica and Ts38 additives is of great scientific and applied importance

    IRAS 19135+3937: An SRd variable as interacting binary surrounded by a circumbinary disc

    Full text link
    Semi-regular (SR) variables are not a homogeneous class and their variability is often explained due to pulsations and/or binarity. This study focuses on IRAS 19135+3937, an SRd variable with an infra-red excess indicative of a dusty disc. A time-series of high-resolution spectra, UBV photometry as well as a very accurate light curve obtained by the Kepler satellite, allowed us to study the object in unprecedented detail. We discovered it to be a binary with a period of 127 days. The primary has a low surface gravity and an atmosphere depleted in refractory elements. This combination of properties unambiguously places IRAS 19135+3937 in the subclass of post-Asymptotic Giant Branch stars with dusty discs. We show that the light variations in this object can not be due to pulsations, but are likely caused by the obscuration of the primary by the circumbinary disc during orbital motion. Furthermore, we argue that the double-peaked Fe emission lines provide evidence for the existence of a gaseous circumbinary Keplerian disc inside the dusty disc. A secondary set of absorption lines has been detected near light minimum, which we attribute to the reflected spectrum of the primary on the disc wall, which segregates due to the different Doppler shift. This corroborates the recent finding that reflection in the optical by this type of discs is very efficient. The system also shows a variable Halpha profile indicating a collimated outflow originating around the companion. IRAS 19135+3937 thus encompasses all the major emergent trends about evolved disc systems, that will eventually help to place these objects in the evolutionary context.Comment: Accepted to MNRA

    Surface structure of commercially pure VT1-0 titanium irradiated by an intense pulsed electron beam

    Get PDF
    It is shown that pulsed electron beam irradiation of commercially pure titanium at a beam energy density of 10 J/cm{2}, pulse duration of 150 [mu]s, number of pulses of N=5 pulses, and pulse repetition frequency of 0.3 Hz with attendant polymorphic [alpha]->[beta]->[ alpha] transformations allows a more than five-fold decrease in the grain and subgrain sizes of the material structure

    DIGITAL EDUCATIONAL ENVIRONMENT AS A TOOL OF SYSTEM CHANGES IN THE TEACHER’S PROFESSIONAL ACTIVITY

    Get PDF
    Purpose: Social and cultural prerequisites of Russia’s transition to an open information society have predetermined new requirements for graduates of modern educational organizations, ready for communicative activities in a digital educational environment. Informatization of education is characterized by increasing virtualization of the educational process and, as a consequence, the predominance of fragmented thinking, and increase in the gap between traditional and innovative educational technologies. Methodology: The basis of the digital educational environment in the context of the use of knowledge management technologies can be specialized knowledge management systems that combine knowledge of related scientific disciplines, which should provide integration, accumulation, and support, as well as the organization of access to knowledge of the educational environment. A distinctive feature of the development of mankind at the present stage is the transition to information society in which information and information processes are becoming one of the most important components of human life and society. Result: The development of the global process of informatization of society leads to the formation of not only the new information environment for people but also new, information way of their life and professional activities. Many researchers as the most acute problem of modern education called the mismatch of software, including for educational purposes, to high technical characteristics of computers, resulting in extremely low efficiency of computer use in training. Critically assessing the effectiveness of the existing software of the educational process and the ways of its development, we see the prospects for a radical change in the situation in the orientation to the use of knowledge management technologies that use software products that can be changed, adapting to the needs of the user and, in particular, to the didactic tasks of training. Applications: This research can be used for universities, teachers, and students. Novelty/Originality: In this research, the model of Digital Educational Environment as a Tool of System Changes in the Teacher’s Professional Activity is presented in a comprehensive and complete manner
    corecore