scholarly journals Interface Design in Lightweight SiC/TiSi2 Composites Fabricated by Reactive Infiltration Process: Interaction Phenomena between Liquid Si-Rich Si-Ti Alloys and Glassy Carbon

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3746
Author(s):  
Donatella Giuranno ◽  
Sofia Gambaro ◽  
Grzegorz Bruzda ◽  
Rafal Nowak ◽  
Wojciech Polkowski ◽  
...  
Keyword(s):  
Contact Angle ◽  
Glassy Carbon ◽  
Interface Design ◽  
Point Of View ◽  
Operating Conditions ◽  
Eutectic Region ◽  
Infiltration Process ◽  
Reactive Infiltration ◽  
Ti Alloys ◽  
Si Content

To properly design and optimize liquid-assisted processes, such as reactive infiltration for fabricating lightweight and corrosion resistant SiC/TiSi2 composites, the extensive knowledge about the interfacial phenomena taking place when liquid Si-rich Si-Ti alloys are in contact with glassy carbon (GC) is of primary importance. To this end, the wettability of GC by two different Si-rich Si-Ti alloys was investigated for the first time by both the sessile and pendant drop methods at T = 1450 °C. The results obtained, in terms of contact angle values, spreading kinetics, reactivity, and developed interface microstructures, were compared with experimental observations previously obtained for the liquid Si-rich Si-Ti eutectics processed under the same operating conditions. As the main outcome, a different Si content did not seem to affect the final contact angle values. Contrarily, the final developed microstructure at the interface and the spreading kinetics were observed as weakly dependent on the composition. From a practical point of view, Si-Ti alloy compositions with a Si content falling in the simple eutectic region of the Si-Ti phase diagram might be potentially used as infiltrating materials of C- and SiC-based composites.

scholarly journals Interfaces Design in Lightweight SiC/TiSi2 Composites Fabricated by Reactive Infiltration Process: Interaction Phenomena between Liquid Si-rich Si-Ti Alloys and Glassy Carbon

2021 ◽  
Author(s):  
Donatella Giuranno ◽  
Sofia Gambaro ◽  
Grzegorz Bruzda ◽  
Rafal Nowak ◽  
Wojciech Polkowski ◽  
...  
Keyword(s):  
Contact Angle ◽  
Glassy Carbon ◽  
Point Of View ◽  
Operating Conditions ◽  
Eutectic Region ◽  
Infiltration Process ◽  
Reactive Infiltration ◽  
Ti Alloys ◽  
Si Content ◽  
First Time

To design properly and optimizate liquid-assisted processes such as reactive infiltration for fabricating light weight and corrosion resistant SiC/TiSi2 composites, the interfacial phenomena taking place when liquid Si-rich Si-Ti alloys are in contact with glassy carbon (GC) were investigated for the first time by wetting tests performed by both the sessile and pendant drop methods at T = 1450°C. Specifically, two different Si-rich Si-Ti alloys were selected, and the obtained results in terms of contact angle values, spreading kinetics, reactivity, and developed interface microstructures were compared with experimental observations previously obtained for the liquid Si-rich Si-Ti eutectics processed under the same operating conditions. The increase of the Si content did not affected the final contact angle values. Contrarily, the final developed microstructure at the interface as well as the spreading kinetics were observed as weakly dependent on the composition. From the practical point of view, Si-Ti alloy compositions with a Si-content falling in the simple eutectic region of the phase diagram might be potentially used as infiltrant materials of C- and SiC-based composites.

scholarly journals Interfacial Phenomena between Liquid Si-rich Si-Zr Alloys and Glassy Carbon

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1194
Author(s):  
Donatella Giuranno ◽  
Wojciech Polkowski ◽  
Grzegorz Bruzda ◽  
Artur Kudyba ◽  
Javier Narciso
Keyword(s):  
Glassy Carbon ◽  
Sessile Drop ◽  
Point Of View ◽  
Operating Conditions ◽  
Interfacial Phenomena ◽  
Reactive Infiltration ◽  
Design And Optimization ◽  
Si Content ◽  
First Time ◽  
Zr Alloys

To succeed in the design and optimization of liquid-assisted processes such as reactive infiltration for the fabrication of tailored refractory SiC/ZrSi2 composites, the interfacial phenomena that occur when Si-rich Si-Zr alloys are in contact with glassy carbon (GC) were investigated for the first time by the sessile drop method at T = 1450 °C. Specifically, two different Si-rich Si-Zr alloys were selected, and the obtained results in terms of wettability, spreading kinetics, reactivity, and developed interface microstructures were compared with experimental observations that were previously obtained for the liquid Si-rich, Si-Zr, near-eutectic composition (i.e., Si-10 at.%Zr) that was processed under the same operating conditions. The increase of the Si content only weakly affected the overall phenomena that were observed at the interface. From the practical point of view, this means that even Si-Zr alloys with a higher Si content, with respect to the near eutectic alloy, may be potentially used as infiltrant materials.

scholarly journals Interfacial Phenomena between Liquid Si-Rich Si-Zr Alloys and Glassy Carbon

2020 ◽  
Author(s):  
Donatella Giuranno ◽  
Wojciech Polkowski ◽  
Grzegorz Bruzda ◽  
Artur Kudyba ◽  
Javier Narciso
Keyword(s):  
Glassy Carbon ◽  
Sessile Drop ◽  
Point Of View ◽  
Operating Conditions ◽  
Interfacial Phenomena ◽  
Equilibrium Contact Angle ◽  
Reactive Infiltration ◽  
Si Content ◽  
Key Steps ◽  
Zr Alloys

To design and optimize liquid-assisted processes such as reactive infiltration for fabricating refractory SiC/ZrSi2 composites, basic investigations on the interfacial phenomena occurring when liquid Si-based alloys are in contact with C and SiC substrates, are key steps. Indeed, targeted wettability studies may provide helpful indications for finding the suitable set of operating conditions to succeed the fabrication of composites via the reactive infiltration and for predicting the key influencing mechanisms. The wettability of glassy carbon (GC) by two different Si-rich Si-Zr alloys as a function of the Si-content has been investigated by the sessile drop method at T = 1450°C. The more relevant results obtained in terms of equilibrium contact angle values, spreading kinetics, reactivity and developed interface microstructures are reported in the paper and compared with the behaviour previously observed in the Si-27Zr/GC system. The increase of Si-content only weakly affected the overall phenomena observed at the interface, which from the practical point of view means that even the Si-Zr alloys with higher Si-content, as respect to the eutectic alloy (Si-27Zr), could be potentially used as infiltrant materials.

Tertiary Nitrification Pilot Plants on Parisian Waste Water

1990 ◽  
Vol 22 (1-2) ◽  
pp. 347-352 ◽  
Author(s):  
C. Paffoni ◽  
B. Védry ◽  
M. Gousailles
Keyword(s):  
Waste Water ◽  
Metropolitan Area ◽  
Fixed Bed ◽  
Point Of View ◽  
Operating Conditions ◽  
Research Center ◽  
Daily Output ◽  
Practical Point ◽  
Fixed Bed Reactors

The Paris Metropolitan area, which contains over eight million inhabitants, has a daily output of about 3 M cu.meters of wastewater, the purification of which is achieved by SIAAP (Paris Metropolitan Area Sewage Service) in both Achères and Valenton plants. The carbon pollution is eliminated from over 2 M cu.m/day at Achères. In order to improve the quality of output water, its tertiary nitrification in fixed-bed reactors has been contemplated. The BIOFOR (Degremont) and BIOCARBONE (OTV) processes could be tested in semi-industrial pilot reactors at the CRITER research center of SIAAP. At a reference temperature of 13°C, the removed load is approximately 0.5 kg N NH4/m3.day. From a practical point of view, it may be asserted that in such operating conditions as should be at the Achères plant, one cubic meter of filter can handle the tertiary nitification of one cubic meter of purified water per hour at an effluent temperature of 13°C.

ADVANCED TYPES OF CHECKERWORK OF REGENERATIVE HEAT EXCHANGERS FOR GLASS FURNACES

2021 ◽  
pp. 3-10
Author(s):  
O. Koshelnik ◽  
S. Hoisan
Keyword(s):  
Phase Transition ◽  
Heat Exchangers ◽  
Heat Storage ◽  
Point Of View ◽  
Operating Conditions ◽  
Flue Gases ◽  
Regenerative Heat ◽  
Exchange Processes ◽  
Glass Furnaces ◽  
Refractory Bricks

One of the ways to increase glass furnaces energy efficiency is to apply heat exchangers for flue gases thermal potential utilization. Flue gases losses is up to 25-40 % of the total amount of heat supplied in the furnace. These losses are influences by such factors as fuel type, furnace and burners design and manufactured product type. Regenerative heat exchangers with various types of heat storage packing is more efficient for high-power furnaces. Such types of regenerator checkerwork as Cowper checkerwork, two types of Siemens checkerwork, Lichte checkerwork and combined checkerwork have already been sufficiently researched, successfully applied and widely used for glass furnaces of various designs. All of its are made of standard refractory bricks. Basket checkerwork and cruciform checkerwork that are made of fused-cast molded refractory materials have been widely used recently as well. Further improvement of regenerative heat exchangers thermal efficiency only by replacing the checkerwork does not seem possible unless their size being increased. But this enlarging is not always realizable during the modernization of existing furnaces. From this point of view heat storage elements with a phase transition, where metal salts and their mixtures are used as a fusible agent look promising for glass furnaces. These elements can accumulate additional amount of heat due to phase transition, which allows to increase significantly heat exchanger thermal rating without its size and operating conditions changing. However, it is necessary to carry out additional studies of this type of checkerwork dealing with analysis of complex unsteady heat exchange processes in regenerators and selection of appropriate materials that satisfy the operating conditions of regenerative heat exchangers so that the checkerwork can be widely used for glass furnaces.

scholarly journals STATE ANALYSIS INTERNET OF THINGS DEVICES BASED ON BAGGING

T-Comm ◽  
2020 ◽  
Vol 14 (12) ◽  
pp. 45-50
Author(s):  
Mikhail E. Sukhoparov ◽  
◽  
Ilya S. Lebedev ◽  
Keyword(s):  
Time Series ◽  
Internet Of Things ◽  
The State ◽  
Point Of View ◽  
Operating Conditions ◽  
Process Time ◽  
K Nearest Neighbors ◽  
Computational Point ◽  
Iot Devices ◽  
The Internet Of Things

The development of IoT concept makes it necessary to search and improve models and methods for analyzing the state of remote autonomous devices. Due to the fact that some devices are located outside the controlled area, it becomes necessary to develop universal models and methods for identifying the state of low-power devices from a computational point of view, using complex approaches to analyzing data coming from various information channels. The article discusses an approach to identifying IoT devices state, based on parallel functioning classifiers that process time series received from elements in various states and modes of operation. The aim of the work is to develop an approach for identifying the state of IoT devices based on time series recorded during the execution of various processes. The proposed solution is based on methods of parallel classification and statistical analysis, requires an initial labeled sample. The use of several classifiers that give an answer "independently" from each other makes it possible to average the error by "collective" voting. The developed approach is tested on a sequence of classifying algorithms, to the input of which the time series obtained experimentally under various operating conditions were fed. Results are presented for a naive Bayesian classifier, decision trees, discriminant analysis, and the k nearest neighbors method. The use of a sequence of classification algorithms operating in parallel allows scaling by adding new classifiers without losing processing speed. The method makes it possible to identify the state of the Internet of Things device with relatively small requirements for computing resources, ease of implementation, and scalability by adding new classifying algorithms.

scholarly journals Coordinating activity of independent legal entities: issues of law enforcement in conditions of economy digitalization

2019 ◽  
pp. 60-67
Author(s):  
Yu. Yu. Borisova ◽  
I. V. Akimova
Keyword(s):  
Law Enforcement ◽  
Economic Activity ◽  
Legal Regulation ◽  
Point Of View ◽  
Operating Conditions ◽  
Negative Effects ◽  
Judicial Practice ◽  
Stage Of Development ◽  
Legislative Changes ◽  
The Coordinator

In article authors investigate questions of the operating legal regulation of coordination of economic activity of independent economic entities, including questions of its legisla- tive definition and signs. Article contains the detailed analysis of the most interesting examples of judicial practice and practice of antimonopoly authorities on the matter. Authors, analyzing the current legal regulation, also give an assessment to the planned changes in the legislation in this part and state the point of view about dependence of legal assessment of actions of the coordinator and the economic entities coordinated by it on operating conditions of commodity markets on which it is carried out. As a result of a research authors drew a conclusion on need of legislative changes in a part of admis- sibility of the forbidden coordination provided that the advantage for consumers of such coordination exceeds negative effects for the competition.A significant amount of works of the modern scientists and experts investigating a per- spective of institutes of the antitrust law is devoted to questions of legal qualification of coordination of economic activity of independent economic entities in legal scientific literature.The matter was also raised in publications and authors of the "Rossiyskoye Konkurent- noye Pravo I Ekonomika" magazine, at the same time, it should be noted that to consid- eration of questions of coordination of activity smaller attention is paid, than, for ex- ample, to questions of cartels.Thus, degree of scientific readiness of the matter in general is rather high, at the same time to authors the relevance of this subject and need of the analysis and assessment of the operating regulation taking into account economic features of the present stage of development of the markets seems to be of high interest.

scholarly journals Tangible Lighting Controls

2021 ◽  
Author(s):  
◽  
Amardeep Mohanlal Dugar
Keyword(s):  
Control Systems ◽  
User Experience ◽  
Interface Design ◽  
End Users ◽  
Point Of View ◽  
Essential Difference ◽  
End User ◽  
Lighting Control ◽  
Control Functions ◽  
New Framework

<p>'Tangible lighting controls' is used as an umbrella term to describe lighting control systems that are easy to understand and pleasurable to use by end-users. The crucial question posed is, what is the nature of interface designs sought by end-users for maximising interaction with lighting control systems? The manner in which this question is posed implies a fundamental assumption that improved usability and end-user experience are the primary goals. The concept of end-user understanding of lighting control interfaces is proposed as a basis for improving the usability and end-user experience of lighting control interfaces. Usability engineering methods involving survey research, experimental mock-ups and prototyping have been used to enable end-users to design and evaluate lighting control interfaces. The essential difference is to include end-users' point of view about ease of understanding control functions and pleasure of performing control tasks along with a technical point of view about meeting required standards. Manufacturers' claims about the effectiveness of existing lighting control interfaces are challenged, and an entirely different way of thinking about interface design is revealed. Such a change of thinking may be seen as a new framework for improved designs of lighting control interfaces as well as evaluation of their usability and end-user experience.</p>

Siliconic and Acrylic Resins Dispersed in Water as Protectives for Stone Surface

1992 ◽  
Vol 267 ◽  
Author(s):  
Guido Biscontin ◽  
P. Maravelaki ◽  
E. Zendri ◽  
A. Glisenti
Keyword(s):  
Contact Angle ◽  
Protective Effect ◽  
Water Absorption ◽  
Water Repellency ◽  
Point Of View ◽  
General Effect ◽  
Pore Filling ◽  
Complete Wetting ◽  
Vapour Permeability ◽  
Acrylic Resins

The aim of the present work is to compare the protective effect of solvent and water dispersed products on marble, Lecce and Istria stones. This choice is justified by the need of products effective also from the ecological and toxicological point of view. To obtain these informations two tests have been chosen: contact angle and water absorption. The contact angle may, in theory, be considered a measure of the water repellency, since complete wetting implies a contact angle of 0° and absolutely no wetting an angle of 180°. This does not apply to the water absorption by capillarity test because the absorption variation may be caused by either the water repellency action of the treatments or by the pore filling. However this test may give practical information about the general effect of the treatments. Moreover, the effect of treatments on permeability was investigated by vapour permeability test. Protective effect was studied after application of the products and at various stages of artificial weathering.

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