33 research outputs found
Mechanisms of Fractal Formation in Colloidal Carbon-Bearing Natural System
By using the advanced nano-approach processes and phenomena in self-organizing colloidal systems are studied. The conditions of appearance of self-organized phenomena are determined and also ranges of operation of diffusion, capillary, and fractalization mechanisms are found.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3363
3D-Self-Assemblage and Self-Organization on Natural Colloidal Microinclusions in Mineral Sediments
The results of micro- and nanoscale research of fractal structure sediments from mineral water re-ceived by the drop method are given. Qualitative analysis of the underlying physical phenomena, allowed
us to establish the conditions of their 3D-fractalization that consider the size of colloidal nanoparticles, its
location and height from the drop center : rmin Rmax hmax and rmax Rmin hmin. It is shown that the main
contribution to 3D fractalization is due to surface tension forces and the Coulomb force interaction.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3625
Microwave Properties of Carbon Nanotubes Grown by Pyrolysis of Ethanol on Nickel Catalyst
The efficiency of carbon nanotubes produced by CVD-method on a nickel catalyst at a protection from
microwave radiation is shown. These data are confirmed by scanning electron microscopy, energy disper-sive X-ray analysis and spectral analysis of the microwave radiation in the frequency range 26-40 GHz.
The observed value of the transmission coefficient S21, up to – 42.7 dB, is in agreement with considered
possible absorption mechanisms of electromagnetic wave energy in carbon nanoscale systems “CNT-nickel
nanoparticles”. The application of carbon powder materials in shielding of electromagnetic radiation has
been theoretically justified.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3628
Synthesis of the Carbon Nanomaterials Based on Renewable Bioresources
The effectiveness and feasibility of producing nanoscale carbon materials from renewable bioresources
were shown as an example marsh mass. The mechanisms of synthesis of amorphous organic carbon from
sphagnum moss species modified by a liquid peat phase of humic nature are discussed. A fundamentally
new way of producing carbon nanotubes by mechanical activation of amorphous organic carbon is
described.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3627
An external beam technique of PIXE for uranium determination in environmental objects
The possibilities of the determination of the content of uranium in materials of the nuclear fuel cycle and environmental objects using the nuclear-physical methods of analysis based on registration of characteristic X-rays excited by protons (PIXE) are considered. It is shown that the introduction to X-ray emission spectrometer the element with a wave dispersion – a pyrocarbon filter, using Bragg-Wulf reflection from the planes of the crystal lattice, makes it possible to reduce the detection limit of uranium in the presence of interfering impurities to a value of 0.0005 mas.%. The proposed approach can be used to determine Th, Pu, and other actinides.Розглянуто можливості визначення вмісту урану в матеріалах ядерного паливного циклу та об'єктів навколишнього середовища з використанням ядерно-фізичних методів аналізу на основі реєстрації характеристичного рентгенівського випромінювання, збуджуваного протонами (PIXE). Показано, що введення у спектрометр рентгенівського випромінювання елемента з хвильовою дисперсією – пірографітного фільтра, що використовує віддзеркалення Брегга-Вульфа від площин кристалічної решітки, дозволяє знизити межу визначення урану в присутності домішок, що заважають, до значення 0,0005 мас.%. Запропонований підхід може бути використаний для визначення Th, Pu та інших актинідів.Рассмотрены возможности определения содержания урана в материалах ядерного топливного цикла и объектах окружающей среды с использованием ядерно-физических методов анализа на основе регистрации характеристического рентгеновского излучения, возбуждаемого протонами (PIXE). Показано, что введение в спектрометр рентгеновского излучения элемента с волновой дисперсией – пирографитного фильтра, использующего отражение Брэгга-Вульфа от плоскостей кристаллической решетки, позволяет снизить предел определения урана в присутствии мешающих примесей до значения 0,0005 мас.%. Предложенный подход может быть использован для определения Th, Pu и других актинидов
Modernization of the analytical nuclear-physical complex sokil
New modifications that have been used at the analytical nuclear-physics complex (ANPC) Sokil in recent years are described. They concerned an ion accelerator with an increase in the energy of accelerated ions and the separation of ⁴He²⁺ and H²⁺ beams. A system for irradiating materials science samples with a beam of gas ions with the possibility of choosing the irradiated target space has been created. The use of electrostatic beam deflection made it possible to increase the service life of the foil for beam release into the atmosphere. The use of a pyrocarbon filter in the analysis of monoelements or objects with a high X-ray output of one or several elements changed the form of the spectrum. These modifications made it possible to improve the operation of the complex and obtain new possibilities in solving problems by analytical nuclear physics methods in the study of materials for nuclear power engineering and ecology.Описано нові модифікації, які застосовувалися на аналітичному ядерно-фізичному комплексі Сокіл в останні роки. Вони стосувалися прискорювача іонів зі збільшенням енергії прискорених іонів і розділенням пучків ⁴He²⁺ і H²⁺. Створено систему опромінення матеріалознавчих зразків пучком іонів газу із можливістю вибору опромінюваного простору мішені. Використання електростатичного відхилення променя дозволило збільшити термін служби фольги для виходу променя в атмосферу. Використання піровуглецевого фільтра при аналізі моноелементів або об’єктів з високим рентгенівським випромінюванням одного або кількох елементів змінило форму спектра. Ці модифікації дозволили удосконалити роботу комплексу та отримати нові можливості вирішення задач аналітичними методами ядерної фізики при дослідженні матеріалів для атомної енергетики та екології
Influence of the Ratio of Metal Composed Nanocomposites Fe-Co / C on Phase Composition
Metalcarbon nanocomposites based on polyacrylonitrile and nickel chloride are synthesized under the influence of infrared heat. The resulting materials represent a system of carbon matrix formed during the carbonization of PAN, and distributed in it nickel nanoparticles. The average size of the nanoparticles in the nanocomposite was 15-25 nm. It was found that the distribution of nickel nanoparticles sizes is determined by temperature synthesis nanocomposite. Thus with increasing temperature, the predominant average particle size of the metal increases, and the distribution is spread and shifted toward larger sizes.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3360
Computation of response function of multi-detector device for gamma radiation angular distribution measuring
Simulation model, which represents properly measurement of angular distribution of γ-radiation with the help of
a device ShD-1, has been developed. Comparison of response function computations with calibrating measurement
results is presented.Розроблено імітаційну модель, що адекватно відтворює процес вимірювання кутових розподілів гаммавипромінювання за допомогою установки ШД-1. Надано порівняння розрахунків з результатами
калібровочних вимірювань.Разработана имитационная модель, адекватно отображающая процесс измерения угловых распределений
гамма-излучения с помощью установки ШД-1. Представлено сравнение расчетов с результатами калибровочных измерений
Coronal Shock Waves, EUV waves, and Their Relation to CMEs. I. Reconciliation of "EIT waves", Type II Radio Bursts, and Leading Edges of CMEs
We show examples of excitation of coronal waves by flare-related abrupt
eruptions of magnetic rope structures. The waves presumably rapidly steepened
into shocks and freely propagated afterwards like decelerating blast waves that
showed up as Moreton waves and EUV waves. We propose a simple quantitative
description for such shock waves to reconcile their observed propagation with
drift rates of metric type II bursts and kinematics of leading edges of coronal
mass ejections (CMEs). Taking account of different plasma density falloffs for
propagation of a wave up and along the solar surface, we demonstrate a close
correspondence between drift rates of type II bursts and speeds of EUV waves,
Moreton waves, and CMEs observed in a few known events.Comment: 30 pages, 15 figures. Solar Physics, published online. The final
publication is available at http://www.springerlink.co
Justification of the algorithm of personnel selection for the maintenance of automated technological processes in agricultural production
The current stage of strengthening and development of market relations is characterized by increased competition in all spheres of the economy, including agriculture. To strengthen competitive positions, agricultural producers use high-tech equipment complete with elements of automation and microprocessor technology. Only highly qualified specialists with knowledge in the field of both information technology and agriculture can maintain such equipment and manage its operation. The article presents the justification for the structure and content of the algorithm for performing the professional selection of candidates for specialists in the maintenance of high-tech equipment containing elements and mechanisms of microprocessor technology. A description of a specialized digital platform is given that allows for a formalized assessment of the candidate’s compliance with the requirements for a number of characteristics: qualification coefficient, time spent on managing changes in the system, and response time of the specialist to the tasks set. It is noted that according to the results of the presented development, a certificate of state registration of the computer program was obtained