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Online since: September 2014
Authors: Oded Rabinovitch, Dvir Elmalich
The mechanical properties of the various components are given in Fig. 1c.
(a) Elastic Properties ,, nwall=0.2, ,, n12FRP=0.3 Eadh=0.8 GPa, Gadh=0.307 GPa.
(b) Fig. 1 A strengthened but delaminated wall segment under in-plane shear: (a) geometry and cross sections (adapted from [5]); (b) Elastic properties.
Particularly, it affects the vibratory component of this response.
This multi-layered scheme would allow utilizing the improved properties of the tensed diagonal while providing some support to the compressed one and postponing its premature out-of-plane buckling.
(a) Elastic Properties ,, nwall=0.2, ,, n12FRP=0.3 Eadh=0.8 GPa, Gadh=0.307 GPa.
(b) Fig. 1 A strengthened but delaminated wall segment under in-plane shear: (a) geometry and cross sections (adapted from [5]); (b) Elastic properties.
Particularly, it affects the vibratory component of this response.
This multi-layered scheme would allow utilizing the improved properties of the tensed diagonal while providing some support to the compressed one and postponing its premature out-of-plane buckling.
Online since: June 2009
Authors: Antonio Ruiz, Sheng En Fang, Ricardo Perera
Traditional gradient based
optimizers use aggregating functions approaches based on combining all the objectives into a single
one using either addition, multiplication or any other combination of arithmetical operations by using
some weighting factors.
According to PSO, the behavior of each individual is affected by either the best local or the best global individual to help it fly through a hyperspace.
The updating parameters are the uncertain physical properties of the numerical model.
In fact, nowadays, multicriteria optimization has begun to be applied to the damage identification of aeronautical, mechanical and civil engineering structures.
A large inertia weight factor facilitates global exploration while a small weight factor facilitates local exploration.
According to PSO, the behavior of each individual is affected by either the best local or the best global individual to help it fly through a hyperspace.
The updating parameters are the uncertain physical properties of the numerical model.
In fact, nowadays, multicriteria optimization has begun to be applied to the damage identification of aeronautical, mechanical and civil engineering structures.
A large inertia weight factor facilitates global exploration while a small weight factor facilitates local exploration.
Online since: January 2012
Authors: Yong Ming Xia, Hai Peng Pan, Yang Wang, Wei Zhang
Introduction
Linear oscillatory actuator (LOA) is one kind power conversion installment which can transform directly electrical energy into the mechanical energy.
Moving-magnet motors with the advantage of compact structure, high oscillatory frequency [5-7], but the PM’s support requires to use the non-magnetic- conductivity and non-electrical-conductivity material, the mechanical strength of PM and the oscillation resistance property needs high demanding and processing costs.
These factors are not well considered if employs equivalent magnetic circuit method, but the results obtained by FEM is more accurate.
So as to take advantage of fast calculating for 2-D finite element, on condition that it does not affect the solution precision, neglecting the motor’s iron core saturation, then the problem of analyzing LOA’s electromagnetic field is reduced to 2-D steady-state magnetic field problem.
Howe, “Design optimisation of moving-magnet actuators for reciprocating electro-mechanical systems,” IEEE Transactions on Magnetics, vol. 31, no. 6, pp. 3746-3748, 1995
Moving-magnet motors with the advantage of compact structure, high oscillatory frequency [5-7], but the PM’s support requires to use the non-magnetic- conductivity and non-electrical-conductivity material, the mechanical strength of PM and the oscillation resistance property needs high demanding and processing costs.
These factors are not well considered if employs equivalent magnetic circuit method, but the results obtained by FEM is more accurate.
So as to take advantage of fast calculating for 2-D finite element, on condition that it does not affect the solution precision, neglecting the motor’s iron core saturation, then the problem of analyzing LOA’s electromagnetic field is reduced to 2-D steady-state magnetic field problem.
Howe, “Design optimisation of moving-magnet actuators for reciprocating electro-mechanical systems,” IEEE Transactions on Magnetics, vol. 31, no. 6, pp. 3746-3748, 1995
Online since: November 2011
Authors: Xiao Hong Yang, Yong Lun Song, Guo Wei Ran, Tian Jiao Xiao
Weldline
Fig. 1 Butt-weld finite element mesh
After creation of the finite element mesh, it is necessary to specify the material properties as a function of temperature.
The properties of aluminum alloy 2014 are shown in Fig. 2, in which the Poisson ratio and density may influence very slightly the finite element calculation with the temperature variation, thus, their values are assumed to be constant and are 0.33 and 2.8×10-6kg/mm3, respectively.
Fig.2 Material properties of AA2014 Finally, the suitable heat source after checking, surface convection, radiation and boundary conditions can be loaded so as to carry out the finite element calculation.
Therefore, it can be considered that the molten zone may correspond to the temperature being more than 507℃ and the heat affected zone (HAZ) may correspond to the temperature being lower than 507℃.
Fig. 6 shows that the heating curves corresponding to the heating rates and the heating temperatures by applying three welding processes; the relation between the heating rate vH and the heating temperature can be in the linear function for the laser welding and the laser-TIG hybrid welding; the slope factors are -7.33 and -5.53 for the former and the later respectively.
The properties of aluminum alloy 2014 are shown in Fig. 2, in which the Poisson ratio and density may influence very slightly the finite element calculation with the temperature variation, thus, their values are assumed to be constant and are 0.33 and 2.8×10-6kg/mm3, respectively.
Fig.2 Material properties of AA2014 Finally, the suitable heat source after checking, surface convection, radiation and boundary conditions can be loaded so as to carry out the finite element calculation.
Therefore, it can be considered that the molten zone may correspond to the temperature being more than 507℃ and the heat affected zone (HAZ) may correspond to the temperature being lower than 507℃.
Fig. 6 shows that the heating curves corresponding to the heating rates and the heating temperatures by applying three welding processes; the relation between the heating rate vH and the heating temperature can be in the linear function for the laser welding and the laser-TIG hybrid welding; the slope factors are -7.33 and -5.53 for the former and the later respectively.
Online since: June 2015
Authors: Kiichi Kamimura, Tsuyoshi Horikawa, Yukimune Watanabe, Noriyasu Kawana
The defects formed by an ion implantation process and an activation (recovery) annealing in a device process also affect the characteristics of the devices.
The lower melting point of the silicon substrate is one of serious limiting factors for the process of the device fabricated on the 3C-SiC heteroepitaxial layer.
It was found that those defects influenced the peculiar fluctuation of properties of MOSFETs.
The surface of the epitaxial film was planarized by chemical mechanical polishing (CMP) processing.
The results shown in Fig. 2 indicated the promising property of 3C-SiC, considering that crystal defects of the order of 108 /cm2 were detected in the 3C-SiC layer used as the substrate of those devices.
The lower melting point of the silicon substrate is one of serious limiting factors for the process of the device fabricated on the 3C-SiC heteroepitaxial layer.
It was found that those defects influenced the peculiar fluctuation of properties of MOSFETs.
The surface of the epitaxial film was planarized by chemical mechanical polishing (CMP) processing.
The results shown in Fig. 2 indicated the promising property of 3C-SiC, considering that crystal defects of the order of 108 /cm2 were detected in the 3C-SiC layer used as the substrate of those devices.
Online since: October 2012
Authors: Guang Hua Zhang, Long Liu, Jun Guo Li, Fang Zhao
In this study, the purified HA was used as raw material, the sulfonation and copolymerization reactions were used to increase the hydrophilic property and molecular weight of HA, so a new type of dispersant for CWS, sulfonated humic acid-acrylic acid resin (SHA) was obtained.
The certain-mount aqueous solutions of sodium humate, sodium sulfite and sulfuric acid were mixed in a reactor flask equipped with temperature-controlled electric heating device, mechanical stirrer, thermometer and reflux condenser.
The rheological properties were also measured employing the rheometer mentioned above.
Zeta potential, indicating coal interparticle electrostatic repulsion, and thereby, directly affects apparent viscosity.
Steric hindrace and electrostatic repulsion are the main factors influencing the stability of CWS [5].
The certain-mount aqueous solutions of sodium humate, sodium sulfite and sulfuric acid were mixed in a reactor flask equipped with temperature-controlled electric heating device, mechanical stirrer, thermometer and reflux condenser.
The rheological properties were also measured employing the rheometer mentioned above.
Zeta potential, indicating coal interparticle electrostatic repulsion, and thereby, directly affects apparent viscosity.
Steric hindrace and electrostatic repulsion are the main factors influencing the stability of CWS [5].
Online since: August 2025
Authors: Victor Hugo Ferreira Gonçalves, Sabrina Bento, José Carlos Dutra Filho, Ailton de Souza Gomes, João Arthur Ferreira Lunau Batalha
The dynamic properties of the material were evaluated, and correlated to microscopic morphology and physico-chemical properties.
The NMP/DMSO (0,3/0,7 %(v/v)) solvent mixture formed the film with the best properties, under hydrated conditions.
Such parameters, in theory, take into account the decomposition of the total vaporization energy of a compound into various individual factors.
On the other hand, the greatest disadvantage for these samples was mechanical properties.
Van Krevelen, Properties of Polymers, fourth ed., Elsevier, Amsterdan, 2001
The NMP/DMSO (0,3/0,7 %(v/v)) solvent mixture formed the film with the best properties, under hydrated conditions.
Such parameters, in theory, take into account the decomposition of the total vaporization energy of a compound into various individual factors.
On the other hand, the greatest disadvantage for these samples was mechanical properties.
Van Krevelen, Properties of Polymers, fourth ed., Elsevier, Amsterdan, 2001
Online since: February 2006
Authors: C.A. Bellemare-Davis, K. Karan, J.G. Pharoah, G. Zak
Under such conditions, mass transport to catalytic surface may be expected to become a limiting
factor in overall reactor efficiency.
Overall, as evidenced in recent studies, microreactors with catalyst-coated channels promise conversion factors comparable to the packed-bed designs. [1,8,14].
Moreso than other materials, metals experience large heat-affected zones (HAZs) when subject to nanosecond-pulse or continuous-wave lasers, and the primary mode of material removal is thermal ablation: rapid evaporation following liquefaction[7,19].
The fluid used in this simulation has the properties of air heated to 470K.
used to strip thin layers (~2-4μm) of aluminum from the surface at a time, such that local asymmetries and melting have limited opportunity to affect the developing profile over multiple passes.
Overall, as evidenced in recent studies, microreactors with catalyst-coated channels promise conversion factors comparable to the packed-bed designs. [1,8,14].
Moreso than other materials, metals experience large heat-affected zones (HAZs) when subject to nanosecond-pulse or continuous-wave lasers, and the primary mode of material removal is thermal ablation: rapid evaporation following liquefaction[7,19].
The fluid used in this simulation has the properties of air heated to 470K.
used to strip thin layers (~2-4μm) of aluminum from the surface at a time, such that local asymmetries and melting have limited opportunity to affect the developing profile over multiple passes.
Online since: July 2015
Authors: Moo Hwan Cho, Neelima Mahato, Mohd Omaish Ansari
The chapter also deals with the relative merits or pros and cons of the massive and large scale installation of machinery to produce electricity from some of the noteworthy renewable energy resources, such as, wind, water and sun, which is affecting the local environment or natural habitats, flora and fauna; overall influence on the delicate balance of the ecosystem.
A wind turbine is equipped with suitable machinery to generate utilizable energy by converting the kinetic energy of the wind into mechanical energy and mechanical energy into electricity.
Here, the factor ‘D’ is a variable.
The main advantages of marine current power are (1) High load factors due to the huge magnitude of the ocean currents as well as fluid properties, (2) Predictability, (3) Large resources of the untapped energy, (4) Little or no environmental impact unless there is a migration of ocean creatures in the currents, and (5) saving lands.
· Geothermal plant construction and related infrastructure have also been discovered to destabilize the lands and adversely affecting the soil quality.
A wind turbine is equipped with suitable machinery to generate utilizable energy by converting the kinetic energy of the wind into mechanical energy and mechanical energy into electricity.
Here, the factor ‘D’ is a variable.
The main advantages of marine current power are (1) High load factors due to the huge magnitude of the ocean currents as well as fluid properties, (2) Predictability, (3) Large resources of the untapped energy, (4) Little or no environmental impact unless there is a migration of ocean creatures in the currents, and (5) saving lands.
· Geothermal plant construction and related infrastructure have also been discovered to destabilize the lands and adversely affecting the soil quality.
Online since: October 2006
Authors: Joo Yung Jung, Jong Won Lee, In Pil Kang, Gyeong Rak Choi, Kwang Joon Yoon, Sung Ho Hwang, Mark J. Schulz, Yeon Sun Choi
Among several
possible smart nanoscale materials, Carbon Nanotubes (CNTs) have aroused great interest in the
research community because of their remarkable mechanical properties [5], electrical conductivity
[6], electrochemical properties [7], piezoresistance [8], and other physical properties [9-11].
The CNT sensor is versatile and can measure multiple physical properties of a structure as illustrated in Figure 1.
As shown in the above experiments, the CNT sensor is versatile and can measure multiple physical properties of a structure.
The capacitance is not affected by strain.
The neuron measures multiple physical properties, including cracking, corrosion, strains, and the number of stress cycles simultaneously.
The CNT sensor is versatile and can measure multiple physical properties of a structure as illustrated in Figure 1.
As shown in the above experiments, the CNT sensor is versatile and can measure multiple physical properties of a structure.
The capacitance is not affected by strain.
The neuron measures multiple physical properties, including cracking, corrosion, strains, and the number of stress cycles simultaneously.