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Online since: February 2011
Authors: Abdan Khalina, Aidy Ali, Zahra Dashtizadeh
To take into account these factors, calibration of the system by simulating real operating conditions has to be performed.
The duration of the pulse is variable from ms to s depending to the thickness of material to be probed and its thermal properties[3].
Another observed limitation of the PT is due to the variation in thermal properties inherent to adhesive bonded repairs caused by changes in adhesive or patch thickness [8].
No mechanical contact, no physical coupling nor cooling is required for this technique.
Furthermore, the phase-shift is not dependent on optical properties of the sample or on the heat flux deposition pattern, usual difficulties in thermography[9].
The duration of the pulse is variable from ms to s depending to the thickness of material to be probed and its thermal properties[3].
Another observed limitation of the PT is due to the variation in thermal properties inherent to adhesive bonded repairs caused by changes in adhesive or patch thickness [8].
No mechanical contact, no physical coupling nor cooling is required for this technique.
Furthermore, the phase-shift is not dependent on optical properties of the sample or on the heat flux deposition pattern, usual difficulties in thermography[9].
Online since: January 2014
Authors: Jian Wang, Jin Nan Chen, Jing Li, Jiong Peng
To ensure minimum weight polymer blow molding part has sufficient mechanical properties, the thickness distribution of the polymer part must be strictly controlled.
Gauvin et al. [6] found the minimum part thickness distribution that minimizes the part weight while satisfying mechanical performance constraints such as maximum part deflection or maximum stress for an applied load.
Yousefi et al. [9] studied the effect of rheological properties of HDPE on the parison formation in extrusion blow molding by experiments and numerical simulation.
Mathematical and Physical Models Inflation is the important stage in extrusion blow molding that will eventually affect the quality of the final part.
Fig. 1 Geometric model of the parison and mold Fig. 2 The steady viscosity of HDPE melt with Fig. 3 Frequency dependence of storage modulus G' the shear rate under different temperatures and loss modulus G" at 180 ℃ According to the actual process conditions for extrusion blow molding and the rheological properties of the polymer melt, the following assumptions were made in the simulations: (1) Gravity is negligible; (2) HDPE melt sticks to the mold at the contact; (3) The initial thickness of the parison is uniform.
Gauvin et al. [6] found the minimum part thickness distribution that minimizes the part weight while satisfying mechanical performance constraints such as maximum part deflection or maximum stress for an applied load.
Yousefi et al. [9] studied the effect of rheological properties of HDPE on the parison formation in extrusion blow molding by experiments and numerical simulation.
Mathematical and Physical Models Inflation is the important stage in extrusion blow molding that will eventually affect the quality of the final part.
Fig. 1 Geometric model of the parison and mold Fig. 2 The steady viscosity of HDPE melt with Fig. 3 Frequency dependence of storage modulus G' the shear rate under different temperatures and loss modulus G" at 180 ℃ According to the actual process conditions for extrusion blow molding and the rheological properties of the polymer melt, the following assumptions were made in the simulations: (1) Gravity is negligible; (2) HDPE melt sticks to the mold at the contact; (3) The initial thickness of the parison is uniform.
Online since: February 2012
Authors: Ji Xiang Luo, Da Zhao Deng
It is the matrix-inclusion interfacial damage and the matrix crack propagation damage that resulted in the poor properties above.
And some topology characters, such as different mixed distribution, will directly affect the matrix-inclusion interfacial damage and the matrix crack propagation damage [3-9].
Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 1993, A172(1-2): 63~69 [4] Llorca J.
,Gonzalaez C.Microstructural factors controlling the strength and ductility of Particles-reinforced metal-matrix composites.
The influence of Particles distribution on the mechanical response of a particulate metal matrix composites.
And some topology characters, such as different mixed distribution, will directly affect the matrix-inclusion interfacial damage and the matrix crack propagation damage [3-9].
Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 1993, A172(1-2): 63~69 [4] Llorca J.
,Gonzalaez C.Microstructural factors controlling the strength and ductility of Particles-reinforced metal-matrix composites.
The influence of Particles distribution on the mechanical response of a particulate metal matrix composites.
Online since: February 2012
Authors: Ji Xiang Luo
It is the matrix-inclusion interfacial damage and the matrix crack propagation damage that resulted in the poor properties above.
And some topology characters, such as Depth-width ratio and Direction angle, will directly affect the matrix-inclusion interfacial damage and the matrix crack propagation damage [3-9].
Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 1993, A172(1-2): 63~69 [4] Llorca J.
,Gonzalaez C.Microstructural factors controlling the strength and ductility of fiber-reinforced metal-matrix composites.
The influence of fiber distribution on the mechanical response of a particulate metal matrix composites.
And some topology characters, such as Depth-width ratio and Direction angle, will directly affect the matrix-inclusion interfacial damage and the matrix crack propagation damage [3-9].
Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 1993, A172(1-2): 63~69 [4] Llorca J.
,Gonzalaez C.Microstructural factors controlling the strength and ductility of fiber-reinforced metal-matrix composites.
The influence of fiber distribution on the mechanical response of a particulate metal matrix composites.
Online since: January 2016
Authors: Samer Al Martini, Mohamed Al Khatib
Self-consolidating concrete (SCC) has recently drawn attention to the construction industry in hot weather countries, due to its high fresh and mechanical properties.
As a result of the extreme environmental factors, SCC may arrive to construction site with low fresh quality.
The SCC mixtures were mixed for 2 hours under hot weather conditions and the fresh and mechanical properties were measured and evaluated.
Dubey, Influence of superplasticizer dosages on fresh properties of self-consolidating concrete, Proceedings of the fifth north American conference on fresh properties of self-consolidating concrete, Chicago, Illinois, USA, May 12-15,2015
Diawara, Influence of combined transportation time and temperature on flow properties of self-consolidating concrete," ASCE Journal of materials in Civil Engineering, 2014
As a result of the extreme environmental factors, SCC may arrive to construction site with low fresh quality.
The SCC mixtures were mixed for 2 hours under hot weather conditions and the fresh and mechanical properties were measured and evaluated.
Dubey, Influence of superplasticizer dosages on fresh properties of self-consolidating concrete, Proceedings of the fifth north American conference on fresh properties of self-consolidating concrete, Chicago, Illinois, USA, May 12-15,2015
Diawara, Influence of combined transportation time and temperature on flow properties of self-consolidating concrete," ASCE Journal of materials in Civil Engineering, 2014
Online since: September 2014
Authors: Hong Gang Li, Hui Zeng Tang, Fuan Chen
Introduction
With the improvement of the voltage transmission level, GIS Switchgear is gradually popular for its compact, small footprint, being not affected by the external environment, high reliability, long maintenance cycle, etc[1].
As the questions of the insulation material defects and installation process failure in the process of GIS manufacture and the factors of the overvoltage infringement and the GIS internal overheating in the running of GIS under 1000kV influence, which results in GIS produces inside burr, free metal particles, defective insulation and other issues, so that the GIS partial discharge is generated that leads to insulation fault of GIS, which reduces the service life of GIS [2,3].In all kinds of GIS failure, insulation failure accounts for a large proportion, partial discharge is an important parameter reflecting insulation properties of GIS equipment.So through the GIS partial discharge detection, we can find the internal defects in the GIS timely and effectively, thus avoid a major accident.The common detection methods of partial discharge include: optical detection, chemical detection, acoustic detection, pulse current detection method and UHF detection method.This article analyzes the operational
The frequency of acoustic waves produced by partial discharge and mechanical vibration caused by metal filing hitting against the shell ranges between thousands and tens of thousands of Hertz, to remove interference from other sound sources, the 1~20kHz frequency detection sensor is generally selected
The disadvantage is that in addition to the partial discharge on site, there are many factors that may cause the vibration of the shell, and any of the vibration is very intense, however, different vibration frequency characteristics caused by different reasons, band-pass filter may be used to reduce the external impact
Charged running with long time, because of during the production process the conductor surface sporadic sharp burrs or mixed foreign particles, otherwise the electrical, thermal, chemical and mechanical stress combine effect, causing resin localized cracking and gradually developed, which will eventually lead throughout the discharge breakdown, pot burst, causing power outages occur.
As the questions of the insulation material defects and installation process failure in the process of GIS manufacture and the factors of the overvoltage infringement and the GIS internal overheating in the running of GIS under 1000kV influence, which results in GIS produces inside burr, free metal particles, defective insulation and other issues, so that the GIS partial discharge is generated that leads to insulation fault of GIS, which reduces the service life of GIS [2,3].In all kinds of GIS failure, insulation failure accounts for a large proportion, partial discharge is an important parameter reflecting insulation properties of GIS equipment.So through the GIS partial discharge detection, we can find the internal defects in the GIS timely and effectively, thus avoid a major accident.The common detection methods of partial discharge include: optical detection, chemical detection, acoustic detection, pulse current detection method and UHF detection method.This article analyzes the operational
The frequency of acoustic waves produced by partial discharge and mechanical vibration caused by metal filing hitting against the shell ranges between thousands and tens of thousands of Hertz, to remove interference from other sound sources, the 1~20kHz frequency detection sensor is generally selected
The disadvantage is that in addition to the partial discharge on site, there are many factors that may cause the vibration of the shell, and any of the vibration is very intense, however, different vibration frequency characteristics caused by different reasons, band-pass filter may be used to reduce the external impact
Charged running with long time, because of during the production process the conductor surface sporadic sharp burrs or mixed foreign particles, otherwise the electrical, thermal, chemical and mechanical stress combine effect, causing resin localized cracking and gradually developed, which will eventually lead throughout the discharge breakdown, pot burst, causing power outages occur.
Online since: October 2014
Authors: Sebastien Remy, Nadège Troussier, Wen Hua Zhu, De Xian Wang
Machine tool is the basic equipment of machinery industry, playing very important role in today's manufacturing, and its variety, quality and processing efficiency directly affects economic benefits and the technology level of the mechanical industry production.
And this paper involves the analysis of movement patterns during assembly, interference detection and evaluation of Human factors in the process, in order to improve the performance of the product.
According to the properties of object, the feasibility analysis can be divided into the geometric feasibility analysis and the mechanical feasibility analysis.
In the actual assembly environment, the mechanical feasibility analysis is generally required.
The mechanical feasibility analysis refers to the assemble ability under certain assembly space, on the condition of considering the assembly staff and the assembly tool.
And this paper involves the analysis of movement patterns during assembly, interference detection and evaluation of Human factors in the process, in order to improve the performance of the product.
According to the properties of object, the feasibility analysis can be divided into the geometric feasibility analysis and the mechanical feasibility analysis.
In the actual assembly environment, the mechanical feasibility analysis is generally required.
The mechanical feasibility analysis refers to the assemble ability under certain assembly space, on the condition of considering the assembly staff and the assembly tool.
Online since: April 2020
Authors: Donanta Dhaneswara, Davino Aditya Dwinanda, Bionolla Shandiana
This coating can also protect the mould while it subjected to thermal, mechanical and physic-chemical reaction while the casting process [1-3].
There are several factors that need to be considered to choose refractory material as filler, which is the heat resistance of the material and the size of the material.
The heat resistance of the material determines the stability of the coating to withstand high temperatures and particle size affecting the mixing of coating components, the particle size should be under 35 micron to prevent the particles settled [1,4].
Senna, Physico-Chemical Properties of Carboxymethyl Cellulose (CMC)/Nanosized Titanium Oxide (TiO2) Gamma Irradiated Composite,48(4), (2015), 44–52
Chen, Thermal Properties of Carboxymethylcellulose and Methyl Methacrylate Graft Copolymers, (September 2011), 1242–1249. https://doi.org/10.1080/00222348.2013.763568 [14] R.
There are several factors that need to be considered to choose refractory material as filler, which is the heat resistance of the material and the size of the material.
The heat resistance of the material determines the stability of the coating to withstand high temperatures and particle size affecting the mixing of coating components, the particle size should be under 35 micron to prevent the particles settled [1,4].
Senna, Physico-Chemical Properties of Carboxymethyl Cellulose (CMC)/Nanosized Titanium Oxide (TiO2) Gamma Irradiated Composite,48(4), (2015), 44–52
Chen, Thermal Properties of Carboxymethylcellulose and Methyl Methacrylate Graft Copolymers, (September 2011), 1242–1249. https://doi.org/10.1080/00222348.2013.763568 [14] R.
Online since: May 2012
Authors: Xiang Feng Zhang, Yi Wang, Yan Yan Jing, Hang Zhou Yuan, Quan Guo Zhang
Experimental study of the coproduction technology of straw and excrement ferment for biogas and organic compound fertilizer
Hangzhou Yuan, Quanguo Zhang, Yanyan Jing, Xiangfeng Zhang, Yi Wang
(College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou, 450002, China)
*Corresponding author: zquanguo@163.com
Keywords: Raw Materials Ratio, fermentation period, Nutritional Elements, Gas Production
Abstract.
Tab. 2.1 shows the properties of after pretreatment straw and mixed raw materials, all the results are base on the above test methods.
The straw content obviously affects the rangability of organic mass content, it decreases with the increasing of straw content.
Fig. 2.4 Nitrogen content changes From the Fig. 2.4 we can see that the nitrogen content of raw materials decreases linearly in the process of anaerobic fermentation and it’s largely affected by straw proportion, it decreases when the straw proportion falls.
[12]Fang Yin, Study on affecting factors of biogas slurry on bacteriostastic activity of fusarium solani[J], China biogas , 2006, 24(2):51-52
Tab. 2.1 shows the properties of after pretreatment straw and mixed raw materials, all the results are base on the above test methods.
The straw content obviously affects the rangability of organic mass content, it decreases with the increasing of straw content.
Fig. 2.4 Nitrogen content changes From the Fig. 2.4 we can see that the nitrogen content of raw materials decreases linearly in the process of anaerobic fermentation and it’s largely affected by straw proportion, it decreases when the straw proportion falls.
[12]Fang Yin, Study on affecting factors of biogas slurry on bacteriostastic activity of fusarium solani[J], China biogas , 2006, 24(2):51-52
Online since: November 2006
Authors: Clodomiro Alves Jr., T.M.P. Frota, R.A. Brito, V. Hajek
The aluminum bronze is one
of the most wanted due its excellent properties in combination with low cost of the raw
materials.
Introduction Sintered aluminum bronze is a porous metal material, which due both the low cost of the raw materials and very interesting properties (such as higher mechanical strength, heat, corrosion and oxidation resistance in comparison to tin bronzes) is one of the most wanted systems for preparation of filters and autolubricating sleeves for sliding bearing [1].
Outside of the porosity factor these porous metal materials possess excellent mechanical properties, good thermal conductivity, shock resistance and relatively low friction coefficient etc. [5].
Outside of the isothermal sintering temperature, very important process factor is heating rate.
Before each treatment, the system was pumped down by a two-stage mechanical pump until a residual pressure below 10 Pa was reached.
Introduction Sintered aluminum bronze is a porous metal material, which due both the low cost of the raw materials and very interesting properties (such as higher mechanical strength, heat, corrosion and oxidation resistance in comparison to tin bronzes) is one of the most wanted systems for preparation of filters and autolubricating sleeves for sliding bearing [1].
Outside of the porosity factor these porous metal materials possess excellent mechanical properties, good thermal conductivity, shock resistance and relatively low friction coefficient etc. [5].
Outside of the isothermal sintering temperature, very important process factor is heating rate.
Before each treatment, the system was pumped down by a two-stage mechanical pump until a residual pressure below 10 Pa was reached.