Neutral particle analysis on ITER: present status and prospects Afanasyev, V.I.; Chernyshev, F.V.; Kislyakov, A.I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2010, Volume:
621, Issue:
1
Journal Article
Peer reviewed
This paper presents the physical basis for measuring the neutral particle fluxes emitted by ITER plasma and describes the instrumentation for that developed in Ioffe Institute (St. Petersburg, ...Russia). Possible mechanisms of the neutralization of the hydrogen and helium ions in the thermal and supra-thermal energy ranges are considered. Numerical simulation results of the neutral fluxes produced by the neutralization processes of the bulk thermal deuterium and tritium ions, the knock-on deuterium and tritium ions and the confined alpha particles are presented.
Presented ITER NPA system consists of low energy neutral particle analyzer (LENPA) and high energy neutral particle analyzer (HENPA). The analyzers provide the measurements in the thermal (10–200
keV) and supra-thermal (0.1–4
MeV) ranges .
Calculation of the counting rates in the analyzer energy channels shows that NPA system will be able to measure D/T ratio both in ITER plasma core (
r<0.4
a) by measuring the neutralized knock-on deuterons and tritons and in plasma medium region (
r>0.4
a) by measuring of the neutralized thermal deuterons and tritons. The possibility of measuring a flux of the neutralized confined alphas is also discussed in the paper.
Lath martensite is important in industry because it is the key strengthening component in many advanced high strength steels. The study of crystallography and chemistry of lath martensite is ...extensive in the literature, however, mostly based on fully martensitic steels. In this work, lath martensite in dual phase steels is investigated with a focus on the substructure identification of the martensite islands and microstructural bands using electron backscattered diffraction, and on the influence of the accompanied tempering process during industrial coating process on the distribution of alloying elements using atom probe tomography. Unlike findings for the fully martensitic steels, no martensite islands with all 24 Kurdjumov-Sachs variants have been observed. Almost all martensite islands contain only one main packet with all six variants and minor variants from the remaining three packets of the same prior austenite grain. Similarly, the martensite bands are typically composed of connected domains originating from prior austenite grains, each containing one main packets (mostly with all variants) and few separate variants. The effect of tempering at ~450 °C (due to the industrial zinc coating process) has also been investigated. The results show a strong carbon partitioning to lath boundaries and Cottrell atmospheres at dislocation core regions due to the thermal process of coating. In contrast, auto-tempering contributes to the carbon redistribution only in a limited manner. The substitutional elements are all homogenously distributed. The phase transformation process has two effects on the material: mechanically, the earlier-formed laths are larger and softer and therefore more ductile (as revealed by nanoindentation); chemically, due to the higher dislocation density inside the later-formed laths, which are generally smaller, carbon Cottrell atmospheres are predominantly observed.
•Lath martensite islands and bands were indexed in variations of dual-phase steels.•Detail insight was obtained by combined EBSD, APT, TEM, nano-indentation analysis.•The islands predominantly consist of one main packet with all six variants.•The bands are composed of connected domains, each largely made of one main packet.•Tempering at ~450 °C causes carbon partition to lath boundaries and dislocation cores.
This review article substantiates the need to take into account internal stresses when predicting mechanical parameters in polymer-composite materials (PCMs) subject to climatic aging. The patterns ...of formation and development of microcracks under cyclic mechanical loads are considered. It is shown that similar microcracks are formed in PCMs due to the action of internal stresses during thermal and thermal-moisture cycling, during the transformation of sorbed water into ice. The nature of microcracking depends on the properties and morphology of polymer matrices and fibers, the number of cycles, the type of stacking, temperature difference, bond strength, the ratio of strength and deformation at the micro- and macrolevels, and other factors. The processes of thermal oxidation and photo-oxidation activate microcracking of polymer matrices in PCMs, proving the need for a profound inquiry into the density of microcracks in open climatic conditions.
Abstract
The sowing quality of seeds is determined by the conditioning properties, one of which is germination. The potential yield depends on the number of germinated seeds, therefore, increasing ...the conditional properties of seeds by pre-sowing treatment is an urgent problem in agriculture. The introduction of an integrated method of pre-sowing seed treatment allows to summarize the positive effect of the electrophysical effects of an electric field and a biological preparation. The article presents the results of the studies carried out to establish the optimal treatment regimes for the treatment of sunflower hybrids NK Neoma, LG 5500, ES Petunia seeds in an integrated way. The parameters of seed treatment were determined - electric field strength 8 kV/cm, exposure 60 seconds, semi-dry etching with Zerebra Agro growth regulator with an aqueous solution in a proportion of 10 ml of the preparation, 1000 ml of water. Laboratory germination in relation to control increased in hybrids NK Neoma and LG 5550 by 10%, in hybrid ES Petunia by 12%.
The magnetic fields of a subterranean source observed on the Earth’s surface or from the orbit of a satellite are studied. We analyze the space of all harmonic functions
g
in the external spherical ...domain, which are defined as series in a standard basis. The functions decrease at infinity; their gradients are normal to the field of directions specified at a boundary sphere, and the field of directions is determined by the gradient of a basis function
f
. The results can be used in the solution of the general problem in which the functions
f
and
g
are assumed to be independent of two spherical coordinates on the boundary sphere. Specific calculations were made only under the assumption of the independence of both
g
and
f
of the longitude coordinate. The known results are refined for the case in which
f
is the dipole or quadrupole harmonic, and a new result is obtained for the case in which
f
is the octupole harmonic.
A broadband quantum noise source based on detection of shot noise of a balanced photodetector is demonstrated. Precise electro-optical tuning of the balanced photodetector circuit was carried out by ...an integrated optical beam splitter constructed in the form of the dual output Mach–Zehnder interferometer on a lithium niobate substrate. The classical component of the detected noise related to the relative intensity noise of a laser diode was suppressed by more than 15 dB. At the maximum laser power of 100 mW, the power spectral density of detected shot noise was 12 dB higher than the level of technical noise of the measuring system in the frequency band above 3 GHz.
—
Refractometric studies of hydrosols containing diamond nanoparticles have been carried out in this work. The samples for the study have been obtained from a statically synthesized diamond powder ...preliminarily subjected to standard purification by washing with strong acids and sonication. After additional repeated washing, centrifugation, sonication, and settling for a month, samples, whose particles contained different fractions of amorphous carbon, have been obtained. The particle size in the obtained samples was smaller than 100 nm. To analyze the data of refractometric measurements, equations have been derived that make it possible to determine the fraction of amorphous carbon in the particles and to calculate the thickness of its layer on the particle surface from the results of studying the refractive index and density of the sols of diamond particles. The data of the refractometric studies have been used to determine the ratios between the fractions of crystalline diamond and amorphous carbon in the particles. The performed studies have shown that the refractometric analysis of particle composition can be used to control the quality of industrially produced nanodiamonds.
The development of functional nano-crystalline cellulose hybrid suspensions has been in the focus of many areas of industry and academia for the past decades. The attention is elucidated from a ...unique biocompatible, mechanical, solution etc. properties of cellulose based systems. Fabrication of functional cellulose hybrids with customized features requires detailed knowledge of their final properties as well as understanding the structure–property relationships between the initial ingredients. The reported study investigates the formation and corresponding fundamental solution and molecular characteristics of highly disperse nano-crystalline cellulose hybrids with aluminum oxide nanoparticles. The characterization of the final complexes and its primary components was performed mainly in solution, using basic complementary hydrodynamic approaches, substantially—sedimentation velocity analysis in the analytical ultracentrifuge and related techniques. The analysis of the solution behavior resolved information about the hydrodynamic size, molar mass, shape, asymmetry and composition of the complexes. Additionally morphology of the cellulose hybrids was investigated by scanning force microscopy. To this end we demonstrate complete structural examination of highly disperse colloidal suspensions of crystal nano-cellulose modified by aluminum nanoparticles using classical solution characterization techniques.
Graphic abstract
Abstract
Currently, the food industry uses frozen semi-finished products in the baking of new products. A new type of frozen semi-finished products used to improve the baking properties of flour is ...widely used in North America, Western Europe, Japan, etc. The use of cryopreservation makes it possible to obtain high quality bakery products. The studies were carried out in the laboratory of the Department of Processing Technologies and Food Security of Volgograd State Agrarian University and Volgogradsky CAS. Raw materials such as peeled rye flour, first grade wheat flour, thick rye sourdough, pressed baker's yeast, table salt, nardek with dried apricots were used. The dough was prepared with a 60:40 ratio of peeled rye and first grade wheat flour (W
starter
= 50%) by the developed recipe. The moisture content in the dough was 49.5%. The dough was prepared in a Diosna machine for 5-7 min. The required amount of salt was added as a saline. Yeast suspension was used. The generalization of these processes, which determine the transformation of recipe components into a finished product, provide the basis for scientific foundations of the baking technology using frozen semi-finished products and contributes to the development of methods for predicting the quality of finished products.
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