scholarly journals ANALYSIS OF THERMAL EFFECTS WITH MULTI-FOCI STRUCTURING

2021 ◽  
pp. 89-99
Author(s):  
A.V. Kolesnikov ◽  
◽  
S.V. Semenova ◽  
V.N. Vyrovoy ◽  
V.Ya. Kersh ◽  
...  
Keyword(s):  
Structure Formation ◽  
Thermal Imaging ◽  
Thermal Effects ◽  
Thermal Sensitivity ◽  
Thermal Processes ◽  
Composite Binder ◽  
Indirect Response ◽  
Heterogeneous Processes ◽  
Exothermic Process ◽  
High Plastic

Abstract. The possibility of a thermal imaging technique for studying the setting of composite materials in the light of the paradigm of multifocal structure formation is analyzed. Since thermal violated observations are characterized by a high thermal sensitivity to temperature gradients up to hundredths of degrees, they make it possible to distinguish the temperature differences arising in the adjacent sections of the hardening binding. A technique for obtaining thermal images (thermograms) of a hardening composite binder is implemented. A series of thermograms of setting processes was obtained, for two of them a quantitative study was carried out, including the temperature gauge and the construction of several types of graphic mappings of the obtained patterns ‒ the normalized frequency of the distribution of the area of the binder for those temperatures and two types of densitograms ‒ radial and circular, allowing to visualize the structure of thermal foci arising in a binder. The hardening of binding materials is considered as a multistage exothermic process, in which hydration processes is accompanied by heating. The speed of heterogeneous processes associated with hydration depends, in turn, on the characteristics of the forming structure of binding materials. The observed thermal processes are considered as an indirect response, "shadow" of structure formation processes. The information consisting in this indirect response, however, is enough to make a number of conclusions on the nature of the emerging structure. The study revealed a high probability of the formation of foci near the macroscopic boundaries of the section (walls and bottom of the form), inconsistency of the structural processes, the occurrence of diverse foci of structure formation corresponding to temperature foci. The interpretation of the data obtained is the conclusion about formation of the regions of high plastic deformations near the boundaries of the contact of the foci. This regions are considered as a cluster of microscopic boundaries of the section, cracks and pores, which give rise to the structure of the destruction of the hardened material. The emergence of such areas is associated with nonynchronouspassage of structuring in different parts of the binder.

scholarly journals On thermal effects of early structure formation of fluorogypsum composite binder

2020 ◽  
Vol 1611 ◽  
pp. 012048
Author(s):  
L A Anikanova ◽  
O V Volkova ◽  
A I Kudyakov ◽  
V A Lotov ◽  
E Danilova ◽  
...  
Keyword(s):  
Structure Formation ◽  
Thermal Effects ◽  
Composite Binder

The Thermal Processes within Polyethylene in Mixtures with a High Content of Inorganic Components after Plastic Deformation under High Pressure

2018 ◽  
Vol 45 (3) ◽  
pp. 79-86 ◽  
Author(s):  
V.A. Zhorin ◽  
M.R. Kiselev
Keyword(s):  
Differential Scanning Calorimetry ◽  
Plastic Deformation ◽  
High Pressure ◽  
Thermal Effects ◽  
Germanium Dioxide ◽  
Thermal Processes ◽  
Scanning Calorimetry ◽  
Interphase Interaction ◽  
Enthalpy Of Melting ◽  
Inorganic Components

Mixtures of polyethylene and 80% germanium dioxide, magnesium, magnesium oxide, and sodium chloride were subjected to plastic deformation under a pressure of 0.5–4.0 GPa, and were then investigated by differential scanning calorimetry. The enthalpy of melting of the polymer in certain mixtures reached 300 J/g. On thermograms of deformed mixtures, exothermic processes were observed. The observed thermal effects are possibly due to interphase interaction at the phase boundary.

Investigation on the thermal effects of NaYF4:Er under 1550 nm irradiation

2017 ◽  
Vol 19 (12) ◽  
pp. 8465-8470 ◽  
Author(s):  
Hong Wang ◽  
Xiumei Yin ◽  
Mingming Xing ◽  
Yao Fu ◽  
Ying Tian ◽  
...  
Keyword(s):  
Laser Diode ◽  
Thermal Imaging ◽  
Thermal Effects ◽  
Imaging Method ◽  
Infrared Thermal Imaging

The thermal effects of NaYF4:Er microcrystals under 1550 nm laser diode irradiation were investigated using an infrared thermal imaging method.

Thermal sensitivity of DASH interferometers: the role of thermal effects during the calibration of an Echelle DASH interferometer

2013 ◽  
Vol 52 (33) ◽  
pp. 8082 ◽  
Author(s):  
Kenneth D. Marr ◽  
Christoph R. Englert ◽  
John M. Harlander ◽  
Kenneth W. Miller
Keyword(s):  
Thermal Effects ◽  
Thermal Sensitivity

scholarly journals Coordinated Control of Pressure Difference and Rising Velocity for Stratospheric Airship with Thermal Effects

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Luhe Hong ◽  
Hui-Yu Jin ◽  
Xianwu Lin ◽  
Weiyao Lan
Keyword(s):  
Solar Radiation ◽  
Pressure Difference ◽  
Thermal Effects ◽  
Coordinated Control ◽  
Thermal Processes ◽  
Reference Trajectory ◽  
Stratospheric Airship ◽  
Control Scheme ◽  
Thermal Disturbance ◽  
Trajectory Simulations

Ascending control of stratospheric airship is a challenging control problem, especially if both the rising velocity and the pressure difference between the inside and outside of the airship are required to be controlled simultaneously during ascending. In this paper, a coordinated scheme to control pressure difference and rising velocity of stratospheric airship with vector thrust is presented. With the control scheme, the airship maintains the pressure difference by exhausting air with feedback control. At the same time, the supplemental thrust is generated to compensate the buoyancy fluctuation caused by exhausting air so that the airship’s vertical velocity can track a given reference trajectory. Simulations show that the coordinated control scheme ensures that the airship rises to the altitude of 20 km steadily and rapidly while the pressure difference is always in the safe range. Furthermore, the control scheme is robust enough to the thermal disturbance caused by solar radiation and other thermal processes, which is calculated with partial differential equations.

Examination of thermal processes and structure formation in twin‐arc servicing of wagon wheels using computer modelling

2000 ◽  
Vol 14 (8) ◽  
pp. 642-647
Author(s):  
S N Kiselev ◽  
N N Voronin ◽  
G D Kuz'mina ◽  
E L Makarov ◽  
A A Kulikov
Keyword(s):  
Structure Formation ◽  
Computer Modelling ◽  
Thermal Processes

scholarly journals Heat production in a feeding matrix formed on carrion by communally breeding beetles

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Szymon Matuszewski ◽  
Anna Mądra-Bielewicz
Keyword(s):  
Heat Production ◽  
Thermal Imaging ◽  
Thermal Effects ◽  
Development Time ◽  
Thermal Component ◽  
Larval Phase ◽  
The Matrix ◽  
New Form ◽  
Carrion Beetles ◽  
Insect Fitness

AbstractInsects regulate their body temperature mostly behaviourally, by changing posture or microhabitat. Usually they use heat that is already present in the environment. Sometimes, however, they may manipulate the environment to affect, focus or benefit from thermogenesis. Carrion beetles create a feeding matrix by applying to cadaver surface anal or oral exudates. We tested the hypothesis that the matrix, which is formed on carrion by communally breeding beetle Necrodes littoralis L. (Silphidae), produces heat that enhances insect fitness. Using thermal imaging we demonstrate that heat produced in the matrix formed on meat by adult or larval beetles is larger than in meat decomposing without insects. Larval beetles regularly warmed up in the matrix. Moreover, by comparing matrix temperature and larval fitness in colonies with and without preparation of meat by adult beetles, we provide evidence that formation of the matrix by adult beetles has deferred thermal effects for larval microhabitat. We found an increase in heat production of the matrix and a decrease in development time and mortality of larvae after adult beetles applied their exudates on meat in the pre-larval phase. Our findings indicate that spreading of exudates over carrion by Necrodes larvae, apart from other likely functions (e.g. digesting carrion or promoting growth of beneficial microbes), facilitates thermoregulation. In case of adult beetles, this behaviour brings distinct thermal benefits for their offspring and therefore may be viewed as a new form of indirect parental care with an important thermal component.

Structure Formation Features of Non-Autoclaved Gas Concrete Matrix on the Basis of Composite Binders with Various Mineral Additives

2019 ◽  
Vol 974 ◽  
pp. 249-254
Author(s):  
Michail V. Absimetov ◽  
Mikhail Yurievich Elistratkin ◽  
Marina S. Ageeva
Keyword(s):  
Structure Formation ◽  
Mutual Influence ◽  
Strength Properties ◽  
Mass Concrete ◽  
Composite Binder ◽  
Viscosity Change ◽  
Molding Compound ◽  
Scale Levels ◽  
Good Potential ◽  
Cellular Concrete

One of the effective ways to reduce the material consumption of structures, to save all types of resources due to this, is the transition to porous constructional materials instead of traditional dense materials. In this regard, non-autoclaved gas concrete is of great interest. This material has a high manufacturability and has a good potential for improving the strength properties due to the replacement of traditional portland cement by special composite binders. Available publications confirm the effectiveness and prospects of this direction. An important disadvantage of such works is the fact that the binder indicators and the final cellular concrete characteristics are considered mainly independently. In our opinion, it is more correct to consider at least two structure-forming processes proceeding in parallel and sequentially at different scale levels. Micro level is a stone structure formation based on the composite binder; macro-level is a gas porization of cellular mass concrete. These processes have a great mutual influence on each other, and therefore this article attempts to observe the gassing products effect on the stone hardening based on composite binders, as well as the composite binder makeup on the viscosity change of the molding compound, as an important condition for the formation of high-quality less defective pore structure of cellular concrete.

scholarly journals Modeling Thermal Effects in Metals Irradiated by Copper Nanoclusters

2018 ◽  
Vol 173 ◽  
pp. 06001 ◽  
Author(s):  
Balt Batgerel ◽  
Stefka Dimova ◽  
Temenujka Kupenova ◽  
Igor Puzynin ◽  
Taisia Puzynina ◽  
...  
Keyword(s):  
Thermal Effects ◽  
Structural Changes ◽  
Condensed Matter ◽  
Thermal Processes ◽  
Thermal Spike ◽  
Copper Nanoclusters ◽  
Thermal Spike Model ◽  
Spike Model ◽  
Wave Effects ◽  
Dynamics Method

One of the promising areas in condensed matter physics is the study of the interaction of nanoclusters with various metallic targets. In this paper we investigate the thermal processes in metals irradiated with nanoclusters by the molecular dynamics method. In the framework of this method wave effects of the heat transfer are obtained, a feature which is absent in the thermal spike model. We repost results of computer simulation of the structural changes in irradiated copper targets of different sizes depending on the energy (in the range of 10–50 eV/atom) of copper nanoclusters.

scholarly journals CEMENT STONE STRUCTURE COMPACTION WITH COMPOSITE BINDER

2019 ◽  
pp. 195-206 ◽  
Author(s):  
R. S. Fediuk ◽  
A. V. Baranov ◽  
D. V. Khromenok ◽  
I. R. Zelenskiy ◽  
S. V. Kim
Keyword(s):  
Portland Cement ◽  
Silicon Dioxide ◽  
Structure Formation ◽  
Quartz Sand ◽  
Strength Properties ◽  
Planetary Mill ◽  
Cement Stone ◽  
Composite Binder ◽  
Silica Additive

The aim of the paper is to improve the strength properties of cement stone via control for structure formation. The composite binder composition includes the type CEM I 42.5N (58–70%) Portland cement, active silica additive (25–37%), quartz sand (2.5–7.5%) and limestone crushed waste (2.5–7.5%). The optimum technology of mechanochemical activation is proposed for the cement stone. The optimization of the structure formation process is provided by the mineral-mineral modifier, crushed together with Portland cement in a planetary mill to a specific surface of 550 m2/kg. The amorphous phase of silicon dioxide in the composition of the modifier intensifies the calcium hydroxide binding forming during alite hydration. It contributes to the growth in low-basic calcium silicate and lowers the cement stone basicity, while reducing the amount of portlandite. The crystalline phase of β-quartz silicon dioxide plays the role of crystallization centers new formations and the cement stone microstructure compaction. Limestone particles contribute to the formation of calcium hydrocarbonate and act as a microfiller together with fine ground quartz sand clogging the pores in the cement stone.

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