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Online since: April 2025
Authors: Iryna Glikina, Marat Glikin, Eugene Zubcov
Thermal and mechanical stability of the porous structure of the carrier are considered the main operational characteristics of the industrial catalyst on the carrier.
Further studies of aerosol nanocatalysis technology allowed us to draw the following conclusions: · the direction of movement of the flow component (bottom-up or top-down) does not affect the result; · the concentration of the catalyst without a carrier in the volume of the reactor is extremely small; · the catalyst aerosol fills the entire volume of the reactor.
In 1988, it was experimentally proven that fine aerosol particles of a catalytically active substance have the property of increasing the rate of a chemical reaction by 104-106 times compared to traditional catalysis, based on the mass of the catalyst.
When comparing all factors, it was noted that the aerosol nanocatalysis technology has no analogues in the world.
Catalysts, 5, 2015, pp. 145-269 https://doi.org/10.3390/catal5010145 [5] Yoshihisa Sakata, Yuki Tamauraa, Hayao Imamuraa, Masaya Watanabeb, Preparation of a New Type of CaSiO3 with High Surface Area and Property as a Catalyst Support, Studies in Surface Science and Catalysis, 162, 2006, pp.331-338 https://doi.org/10.1016/S0167-2991(06)80924-9 [6] Graham J.
Further studies of aerosol nanocatalysis technology allowed us to draw the following conclusions: · the direction of movement of the flow component (bottom-up or top-down) does not affect the result; · the concentration of the catalyst without a carrier in the volume of the reactor is extremely small; · the catalyst aerosol fills the entire volume of the reactor.
In 1988, it was experimentally proven that fine aerosol particles of a catalytically active substance have the property of increasing the rate of a chemical reaction by 104-106 times compared to traditional catalysis, based on the mass of the catalyst.
When comparing all factors, it was noted that the aerosol nanocatalysis technology has no analogues in the world.
Catalysts, 5, 2015, pp. 145-269 https://doi.org/10.3390/catal5010145 [5] Yoshihisa Sakata, Yuki Tamauraa, Hayao Imamuraa, Masaya Watanabeb, Preparation of a New Type of CaSiO3 with High Surface Area and Property as a Catalyst Support, Studies in Surface Science and Catalysis, 162, 2006, pp.331-338 https://doi.org/10.1016/S0167-2991(06)80924-9 [6] Graham J.
Online since: May 2010
Authors: Martin Hunkel, Robert C. Wimpory, Jeremy Epp, Thomas Hirsch
Introduction
Residual stresses are well-known influencing factors in the distortion of parts and their effects
have been studied since many decades, particularly within the framework of the collaborative
research center "Distortion Engineering" at the University Bremen, Germany [1- 3].
Beside the already well known positive influence of case hardening on fatigue properties by inducing compressive residual stresses in surface layers, the effect of the generated stresses on the distortions may also be of importance.
In a third step the mechanical behavior (stresses and strains) was simulated.
A second way is to realize a stress-relief heat treatment of a second sample, but this may affect the microstructure and induce 2 nd order residual stresses during cooling of different phases with different thermal expansion coefficients [4].
Beside the already well known positive influence of case hardening on fatigue properties by inducing compressive residual stresses in surface layers, the effect of the generated stresses on the distortions may also be of importance.
In a third step the mechanical behavior (stresses and strains) was simulated.
A second way is to realize a stress-relief heat treatment of a second sample, but this may affect the microstructure and induce 2 nd order residual stresses during cooling of different phases with different thermal expansion coefficients [4].
Online since: June 2013
Authors: Chin Kian Liew, T.J. Shelley
Liew1,b
1School of Mechanical and Mining Engineering, 2nd Floor Building 43 Cooper Road, The University of Queensland, Brisbane, QLD, Australia
at.shelley@uq.edu.au, bc.liew@uq.edu.au (corresponding author)
Keywords: composites, impact damage, structural health monitoring, ultrasonic guided waves, wavelet analysis.
As has already been mentioned during discussions about Plate 1, Plate 2 contains larger impact damage; this was seen to affect the impact damage response signals shown in Fig. 9 and Fig. 10 in comparison with their baseline signals.
Due to a number of factors including time consuming testing and signal processing procedures, as well as the cost of producing numerous plates, only two plates were used for this study.
Zhijie, "Impact Damage Modes and Residual Flexural Properties of Composites Beam," Journal of Reinforced Plastics and Composites, vol. 27, p. 13, 2008.
As has already been mentioned during discussions about Plate 1, Plate 2 contains larger impact damage; this was seen to affect the impact damage response signals shown in Fig. 9 and Fig. 10 in comparison with their baseline signals.
Due to a number of factors including time consuming testing and signal processing procedures, as well as the cost of producing numerous plates, only two plates were used for this study.
Zhijie, "Impact Damage Modes and Residual Flexural Properties of Composites Beam," Journal of Reinforced Plastics and Composites, vol. 27, p. 13, 2008.
Online since: January 2010
Authors: Ivone Figueiredo, Luis Guerra Rosa
The reason for using
ML method is because it is considered a very robust method, yielding estimators with good
statistical properties.
In fact, fractographic analysis of ceramic specimens indicates that, in many cases, two concurrent populations of critical flaws are important factors: the intrinsic and the extrinsic flaws.
The use of these samples does not affect the rationale of the work and it allows to attain the targeted objectives of the present investigation.
[2] EN 843-5: 2006, Advanced technical ceramics - Monolithic ceramics - Mechanical tests at room temperature - Part 5: Statistical analysis
In fact, fractographic analysis of ceramic specimens indicates that, in many cases, two concurrent populations of critical flaws are important factors: the intrinsic and the extrinsic flaws.
The use of these samples does not affect the rationale of the work and it allows to attain the targeted objectives of the present investigation.
[2] EN 843-5: 2006, Advanced technical ceramics - Monolithic ceramics - Mechanical tests at room temperature - Part 5: Statistical analysis
Online since: October 2015
Authors: Robert C. Pullar
Dielectric properties are independent of the particle size or anisotropy of the fibre material, but for other properties which are so affected, such as magnetisation, this must also be accounted for.
The fibres with >32% SrSiO3 appear smooth and dense, with improved mechanical properties.
Morkoc, “Microwave ferrites, part 1: fundamental properties”, J.
Kelly, "Properties of Fibre Composites", Conf.
Hale, “Physical-properties of composite-materials“, J.
The fibres with >32% SrSiO3 appear smooth and dense, with improved mechanical properties.
Morkoc, “Microwave ferrites, part 1: fundamental properties”, J.
Kelly, "Properties of Fibre Composites", Conf.
Hale, “Physical-properties of composite-materials“, J.
Online since: August 2013
Authors: Pierre Ricco, Stanislav Hahn
Control of wall turbulence by spinning discs
Pierre Ricco1,a, Stanislav Hahn,2,b
1Department of Mechanical Engineering, The University of Sheffield, Mappin Street, S1 3JD
Sheffield, United Kingdom
2Honeywell Turbo Technologies, Turanka 100/1236, Brno, Czech Republic
ap.ricco@sheffield.ac.uk, bstanislav.hahn@honeywell.com
Keywords: flow control, turbulence control, spinning discs
Abstract.
The urms is affected the most as the peak is reduced by about 15% and shifts upward from y+≈15 to y+≈20.
Along the dashed zero-R line in figure 2, both ⟨udvd⟩ and ⟨utvt⟩ increase and balance each other as W grows, leaving the drag unchanged.0 20 40 60 80 100 120 140 160 0 0.5 1 1.5 2 2.5 3 3.5 4 y+ u+d,rms v+d,rms w+d,rms ⟨udvd⟩ + ring patterns � �� x-elongated bands ��� δ+ 6 0 20 40 60 80 100 120 140 160 180 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 y+ ud + ut ut ut,s u+rms w+rms ⟨uv⟩ + Fig. 7: Left: wall-normal profiles of r.m.s. of ud components and of ⟨udvd⟩ + (the latter multiplied by a factor of 6); the disc-flow boundary layer thickness δ is shown.
In case of failure, the rotating discs would not lead to off-design drag increase, as for compliant surfaces because of undesired changes of mechanical properties, or for suction and ribletted surfaces because of dirt deposition, caused in the latter case by the very small maximum riblet height in flight conditions, about 0.15 mm [20].
The urms is affected the most as the peak is reduced by about 15% and shifts upward from y+≈15 to y+≈20.
Along the dashed zero-R line in figure 2, both ⟨udvd⟩ and ⟨utvt⟩ increase and balance each other as W grows, leaving the drag unchanged.0 20 40 60 80 100 120 140 160 0 0.5 1 1.5 2 2.5 3 3.5 4 y+ u+d,rms v+d,rms w+d,rms ⟨udvd⟩ + ring patterns � �� x-elongated bands ��� δ+ 6 0 20 40 60 80 100 120 140 160 180 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 y+ ud + ut ut ut,s u+rms w+rms ⟨uv⟩ + Fig. 7: Left: wall-normal profiles of r.m.s. of ud components and of ⟨udvd⟩ + (the latter multiplied by a factor of 6); the disc-flow boundary layer thickness δ is shown.
In case of failure, the rotating discs would not lead to off-design drag increase, as for compliant surfaces because of undesired changes of mechanical properties, or for suction and ribletted surfaces because of dirt deposition, caused in the latter case by the very small maximum riblet height in flight conditions, about 0.15 mm [20].
Online since: January 2016
Authors: Petra Vrhovnik, Davorin Medaković, Tadej Dolenec, Danijel Karlović, Sanda Rončević, Lovorka Pitarević-Svedružić, Nastja Rogan Šmuc, Matej Dolenec
However, the mechanisms of metal uptake (sorption, incorporation in the lattice) by HAP are still not well understood; in particular, interactions between the contaminants in fish bones and teeth have been scarcely investigated to date, in spite of their potential use as environmental indicators and depolluting substances of areas affected by human activity.
HAP exhibits a specific structural resistance to mechanical pressure because of the incorporation of the numbers of elongated ribbon-like crystals.
HAP often affects or even controls the concentrations of calcium, phosphate, and lead in their environment and interacts with other toxic metals such as zinc and cadmium.
Juračić, Relationship between specific surface area and some chemical and physical properties of particulates: study in the northern Adriatic, Mar.
Sorrell, Some important factors in the wet precipitation process of hydroxyapatite, Materials and Design 24 (2003) 197-202
HAP exhibits a specific structural resistance to mechanical pressure because of the incorporation of the numbers of elongated ribbon-like crystals.
HAP often affects or even controls the concentrations of calcium, phosphate, and lead in their environment and interacts with other toxic metals such as zinc and cadmium.
Juračić, Relationship between specific surface area and some chemical and physical properties of particulates: study in the northern Adriatic, Mar.
Sorrell, Some important factors in the wet precipitation process of hydroxyapatite, Materials and Design 24 (2003) 197-202
Online since: March 2014
Authors: Pierre Ohayon, Khosrow Ghavami
Bamboo presents a tremendous economic potential, as it reaches its full growth in only a few months and its maximum mechanical resistance in a few years, besides the fact that it occurs in abundance in tropical and sub-tropical regions of the globe.
These strategic functions are: to carry out an inventory of technological resources (available technologies, expertise and skills); to evaluate technological resources, their strengths and weaknesses, and their economic potential; to optimize (make the best use of technological resources); to enrich technological resources through investigation, acquisition, alliance, research, development, improvement, innovation, renewal and replacement, as well as to further develop human technological expertise and skills by recruiting, training and team building; to watch developments in the scientific, technological and competitive environment employing an appropriate technological vigilance and intelligence system; to protect technological resources by safeguarding intellectual property, and by preserving human expertise and skills.
Sensitivity to public criticism and the fear of political fallout from selection and evaluation findings are inhibiting factors.
The likelihood/probabilities of these assumptions should be analyzed at the formulation stage and monitored throughout implementation, as it is a decisive factor for taking corrective actions or modifying the work plan. 3.3 NOCMAT R&D Projects Outcomes Evaluation For the elaboration of a NOCMAT project different proposal should be examined.
Each one receives specific inputs generating results that directly affect each respective domain.
These strategic functions are: to carry out an inventory of technological resources (available technologies, expertise and skills); to evaluate technological resources, their strengths and weaknesses, and their economic potential; to optimize (make the best use of technological resources); to enrich technological resources through investigation, acquisition, alliance, research, development, improvement, innovation, renewal and replacement, as well as to further develop human technological expertise and skills by recruiting, training and team building; to watch developments in the scientific, technological and competitive environment employing an appropriate technological vigilance and intelligence system; to protect technological resources by safeguarding intellectual property, and by preserving human expertise and skills.
Sensitivity to public criticism and the fear of political fallout from selection and evaluation findings are inhibiting factors.
The likelihood/probabilities of these assumptions should be analyzed at the formulation stage and monitored throughout implementation, as it is a decisive factor for taking corrective actions or modifying the work plan. 3.3 NOCMAT R&D Projects Outcomes Evaluation For the elaboration of a NOCMAT project different proposal should be examined.
Each one receives specific inputs generating results that directly affect each respective domain.
Online since: April 2009
Authors: Toshio Maruyama, Mitsutoshi Ueda, Kenichi Kawamura
Mechanical
property of an oxide scale such as
cracking and exfoliation behavior is
strongly influenced by the
microstructure in the scale, for
example,. existence of voids.
d d Xz c B t r L z c B t (35) and the following relation can be obtained 00 00 dd ( )d ( )d dd dd ( )d ( )d dd tt tt L t r t ttr LL L tt tt (36) The ratio of thickness of inner and outer scales is expressed as r L (37) This fact indicates that the ratio is always constant and determined by the kinetic factors at both interfaces. 3.4 Growth rate of the total scale 2 II II 2 I I p-ox MX M M M X X 2 II I d( ) d d () d d d () ab X X k Vk L L z c B z c B t t t L bz L (38) where 2 II II
2 I I MX M M M X X p-ox 2 II I () ab X X Vkz c B z c B k bz (39) Eq. (38) provides the parabolic rate law 2 p-ox ( ) 2L k t (40) Eq.(39) differs from the Wagners one by the factor of 2 II II 2 I I M M M X X II I () X z c B z c B (41) The value of Eq. (41) being larger than unity is the indication of the void formation in the scale. 3.5 Void formation in the scale during oxidation Amount of voids formed in the scale is related to the difference in fluxes which is injected at the interface II and extracted from the interface I.
This fact indicates that grain boundary diffusion strongly affects to the scale growth.
d d Xz c B t r L z c B t (35) and the following relation can be obtained 00 00 dd ( )d ( )d dd dd ( )d ( )d dd tt tt L t r t ttr LL L tt tt (36) The ratio of thickness of inner and outer scales is expressed as r L (37) This fact indicates that the ratio is always constant and determined by the kinetic factors at both interfaces. 3.4 Growth rate of the total scale 2 II II 2 I I p-ox MX M M M X X 2 II I d( ) d d () d d d () ab X X k Vk L L z c B z c B t t t L bz L (38) where 2 II II
2 I I MX M M M X X p-ox 2 II I () ab X X Vkz c B z c B k bz (39) Eq. (38) provides the parabolic rate law 2 p-ox ( ) 2L k t (40) Eq.(39) differs from the Wagners one by the factor of 2 II II 2 I I M M M X X II I () X z c B z c B (41) The value of Eq. (41) being larger than unity is the indication of the void formation in the scale. 3.5 Void formation in the scale during oxidation Amount of voids formed in the scale is related to the difference in fluxes which is injected at the interface II and extracted from the interface I.
This fact indicates that grain boundary diffusion strongly affects to the scale growth.
Online since: November 2016
Authors: Chima Benjamin Njoku, Patrick Gathura Ndungu
Electrochemical Properties.
It should be noted that the morphology of the material, microstructure of the electrodes, the calcination temperature and the change in porosity of the materials will affect the charge transfer properties at the phase boundaries [42].
Kalai Selvan, Structural, electrical and electrochemical properties of co-precipitated SrFeO3−δ.
Baran, Structural chemistry and physicochemical properties of perovskite-like materials.
Lee, Structural analysis and electrochemical properties of cobalt-doped Sr0.9Ce0.1MnO3−δ cathode for IT-SOFCs.
It should be noted that the morphology of the material, microstructure of the electrodes, the calcination temperature and the change in porosity of the materials will affect the charge transfer properties at the phase boundaries [42].
Kalai Selvan, Structural, electrical and electrochemical properties of co-precipitated SrFeO3−δ.
Baran, Structural chemistry and physicochemical properties of perovskite-like materials.
Lee, Structural analysis and electrochemical properties of cobalt-doped Sr0.9Ce0.1MnO3−δ cathode for IT-SOFCs.