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Online since: July 2007
Authors: Bert Verlinden, Joost R. Duflou, Dirk Van Oudheusden, Dirk Cattrysse
Compared to this reference approach, a makespan
reduction and a setup time reduction can be observed.
Future research will focus on expanding the model and verifying its applicability on a larger data-set.
The proposed approach results in both a makespan reduction and a reduction in the number of setups.
For this mathematical model, good results can be obtained as far as makespan reduction, setup time reduction and reduction of the number of toolchanges is concerned.
On average a makespan reduction of 6% is observed.
Future research will focus on expanding the model and verifying its applicability on a larger data-set.
The proposed approach results in both a makespan reduction and a reduction in the number of setups.
For this mathematical model, good results can be obtained as far as makespan reduction, setup time reduction and reduction of the number of toolchanges is concerned.
On average a makespan reduction of 6% is observed.
Online since: November 2016
Authors: Dagoberto Brandão Santos, Paula Oliveira Malta, Iane Dutra Moutinho, Davi Silva Alves, Aline Vasconcelos Ferreira
The Avrami exponent data indicate the occurrence of an unidimensional grain growth due only to high angle boundaries migration, with values ranging between 0.9 and 1.2.
The EBSD data were processed by Orientation Image Microscopy (OIM)™ from the commercial software developed by EDAX Inc.
Vickers Microhardness The softening kinetics was studied through Vickers microhardness measurements for both series, in which the data analysis shows that the softening process proceeds as the annealing time and temperature increase (Fig. 2).
This step is characterized by the reduction of grain boundary energy through their growth [5].
Recrystallization Kinetics The Avrami expoent data indicate the occurrence of an unidimensional grain growth due only to high angle boudaries migration, with values ranging between 0.9 and 1.2.
The EBSD data were processed by Orientation Image Microscopy (OIM)™ from the commercial software developed by EDAX Inc.
Vickers Microhardness The softening kinetics was studied through Vickers microhardness measurements for both series, in which the data analysis shows that the softening process proceeds as the annealing time and temperature increase (Fig. 2).
This step is characterized by the reduction of grain boundary energy through their growth [5].
Recrystallization Kinetics The Avrami expoent data indicate the occurrence of an unidimensional grain growth due only to high angle boudaries migration, with values ranging between 0.9 and 1.2.
Online since: July 2022
Authors: Marion Merklein, Peter Hetz, Martin Kraus
Both force and displacement data are recorded in z-direction.
The displacement data is adjusted with a correction curve that compensates for the stiffness of the universal testing machine and the upsetting tool.
A further reduction to λ = 0.1 does not lead to a continued decrease in the flow stress.
For AA7075-T6, only at λ = 0.1 is there a slight reduction of 3% in the onset of yielding, which corresponds to the reduction of the yield stress level in the flow curve.
The reduction of the yield stress level correlates with the grain size of the materials.
The displacement data is adjusted with a correction curve that compensates for the stiffness of the universal testing machine and the upsetting tool.
A further reduction to λ = 0.1 does not lead to a continued decrease in the flow stress.
For AA7075-T6, only at λ = 0.1 is there a slight reduction of 3% in the onset of yielding, which corresponds to the reduction of the yield stress level in the flow curve.
The reduction of the yield stress level correlates with the grain size of the materials.
Online since: December 2013
Authors: Chun Fa Dong, Xiang Lin Zhang, Chuan Liang Cao, Hao Cai
Synthesis of monodispersed lauric acid capped silver nanoparticles by wet-chemical reduction method
Chunfa Donga, Xianglin Zhang*b, Chuanliang Caoc and Hao Caid
State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
adongchunfa@126.com, bhust_zxl@mail.hust.edu.cn, ccaoliang1102736@126.com dchhust@hust.edu.cn,
Keywords: Lauric acid; Silver nanoparticles; chemical reduction method; nanoparticles
Abstract.
The results showed that monodispersed and stable nanosize silver sol can be prepared by wet-chemical reduction method and the distribution of particle size and the stability of the nano silver sol can be analyzed by UV-visible spectrophotometer.
The peaks are consistent with the data on standard card (JCPDS 04-0783) corresponding face centered cubic crystal system (FCC) elemental silver (111), (200), (220), (311), (222) crystal plane diffraction.There are no other peaks in Figure1, which indicated that the sample is high purity elemental silver .Combined with the Scherrer formula, crystallite size of each crystal face can be calculated.
TEM morphologies of nano-silver particles synthesized at different temperature: (a) 25 °C, (b) 50 °C,(c) 80 °C Conclusions (1)The uniform particle size of nano silver sol is successfully prepared by liquid chemical reduction method with the use of silver ammonium solution as the precursor, lauric acid as capping agent and hydrazine hydrate as reducing agent.
The results showed that monodispersed and stable nanosize silver sol can be prepared by wet-chemical reduction method and the distribution of particle size and the stability of the nano silver sol can be analyzed by UV-visible spectrophotometer.
The peaks are consistent with the data on standard card (JCPDS 04-0783) corresponding face centered cubic crystal system (FCC) elemental silver (111), (200), (220), (311), (222) crystal plane diffraction.There are no other peaks in Figure1, which indicated that the sample is high purity elemental silver .Combined with the Scherrer formula, crystallite size of each crystal face can be calculated.
TEM morphologies of nano-silver particles synthesized at different temperature: (a) 25 °C, (b) 50 °C,(c) 80 °C Conclusions (1)The uniform particle size of nano silver sol is successfully prepared by liquid chemical reduction method with the use of silver ammonium solution as the precursor, lauric acid as capping agent and hydrazine hydrate as reducing agent.
Online since: December 2013
Authors: Petr Konvalinka, Jan Zatloukal
In available literature, the formulae recommended for load bearing capacity prediction and design are based on empirical approach, mostly resulting from statistically processed experimental data [1,2].
The proposed reduction coefficient obviously has to be related to the reinforcement ratio, as for slightly reinforced sections the reduction in moment capacity induced by member curvature is negligible and for sections with high reinforcement ration, even at the threshold of concrete crushing failure, the reduction may reach levels higher than 15 %.
As the reduction was found to be strongly non-linear, a function with more than one parameter was required to approximate it.
For reinforcement ratios ρ lower than 0.15 %, the reduction should be considered zero.
Still, the proposed moment capacity reduction formula (Eq. 8) is quite simple and comprehensible.
The proposed reduction coefficient obviously has to be related to the reinforcement ratio, as for slightly reinforced sections the reduction in moment capacity induced by member curvature is negligible and for sections with high reinforcement ration, even at the threshold of concrete crushing failure, the reduction may reach levels higher than 15 %.
As the reduction was found to be strongly non-linear, a function with more than one parameter was required to approximate it.
For reinforcement ratios ρ lower than 0.15 %, the reduction should be considered zero.
Still, the proposed moment capacity reduction formula (Eq. 8) is quite simple and comprehensible.
Online since: January 2012
Authors: Yong Hong, Jun Gang Wang
With shear rate increasing, both the peak strengths and the post-peak strength reduction become greater.
According to the data of deformation and pore pressure measured during the tests, there are two patterns of causing the strain softening of the silty clay.
In the case of post-peak strength reduction, the values in the tests of 1cm/s are 45% and 65% respectively greater than those obtained in 0.1cm/s and 0.01cm/s tests.
Consequently, it can be supposed that there maybe two probable patterns of the post-peak strength reduction of the silty clay in this study.
The higher shear rate tests are usually accompanied with greater peak strength and higher post-peak reduction in shear stress.
According to the data of deformation and pore pressure measured during the tests, there are two patterns of causing the strain softening of the silty clay.
In the case of post-peak strength reduction, the values in the tests of 1cm/s are 45% and 65% respectively greater than those obtained in 0.1cm/s and 0.01cm/s tests.
Consequently, it can be supposed that there maybe two probable patterns of the post-peak strength reduction of the silty clay in this study.
The higher shear rate tests are usually accompanied with greater peak strength and higher post-peak reduction in shear stress.
Online since: August 2013
Authors: Xue Fang Bao
Research on the key technology of vegetation roofing energy saving
Bao Xuefang
Department of architecture & urban planning of Anhui institute of Architecture & Industry, China
Email: 984813129@qq.com
Keywords: vegetation roof planting technology energy-saving emission reduction ecological landscape
Abstract: This paper focuses on the key technical requirements of roof vegetation, using contrastive method analysis of vegetation roofing heat preservation, heat insulation performance advantages and energy saving and ecological landscape effect, to study the climate vegetation roofing greening plant key technology and application.
Vegetation roofing energy-saving emission reduction effect Energy saving and economic benefits mainly with insulation in summer and heating in winter in roof greening effect, can effectively overcome the influence of summer extreme climate in hot summer and cold winter area of hot, cold winter, improve the building environment microclimate, save the air-conditioning and heating or cooling load, reduce the pressure of city electricity, energy saving
(1) analysis of roof green insulation, insulation performance Green roofs have "natural air conditioning", has a certain heat preservation, heat insulation and energy saving effect,It likes a warm cover the protection of buildings in winter, roof greening in addition to the insulation layer outside the heat insulation effect, the vegetation layer and the planting soil layer also has the performance of double heat preservation, According to the roof greening Hefei area and control area (cement roof) recording observation data: green roof after the indoor temperature increase compared to 2 ℃, (Fig.4) winter warming effect is obvious, double insulation can basically meet the requirement of thermal comfort in buildings in the area.
Vegetation roofing vegetation in the summer, vigorous growth, with luxuriant foliage plant growth, photosynthesis will most of the solar energy into biomass, solar radiation heat and reduce the direct effect on the roof, at the same time, planting grass roof thickness increased, gain ability to resist the external thermal effects, Summer (August) afternoon 14 when the roof greening and the control area of the roof temperature observation data recording, the control area of the common roofing temperature is 50.5 ℃, the green zone temperature is only 35.4 ℃, 15 ℃ floor temperature difference, the indoor temperature 1.5 ℃ contrast decreased (Fig.), so green roof can Fig.4 Vegetation roofing and the common roof and test temperature control effectively reduce the temperature of the roof and the summer indoor temperature, reduce air conditioning load, to achieve the purpose of energy-saving insulation.
(2) vegetation roofing reduction effect Air is the necessary material conditions for human survival, city of oxygen consumption of dense population, the high concentration of carbon dioxide, green plants producing oxygen absorption of carbon dioxide, the ground greening area limited, roof greening of atmospheric oxygen and carbon dioxide balance play an important role.
Vegetation roofing energy-saving emission reduction effect Energy saving and economic benefits mainly with insulation in summer and heating in winter in roof greening effect, can effectively overcome the influence of summer extreme climate in hot summer and cold winter area of hot, cold winter, improve the building environment microclimate, save the air-conditioning and heating or cooling load, reduce the pressure of city electricity, energy saving
(1) analysis of roof green insulation, insulation performance Green roofs have "natural air conditioning", has a certain heat preservation, heat insulation and energy saving effect,It likes a warm cover the protection of buildings in winter, roof greening in addition to the insulation layer outside the heat insulation effect, the vegetation layer and the planting soil layer also has the performance of double heat preservation, According to the roof greening Hefei area and control area (cement roof) recording observation data: green roof after the indoor temperature increase compared to 2 ℃, (Fig.4) winter warming effect is obvious, double insulation can basically meet the requirement of thermal comfort in buildings in the area.
Vegetation roofing vegetation in the summer, vigorous growth, with luxuriant foliage plant growth, photosynthesis will most of the solar energy into biomass, solar radiation heat and reduce the direct effect on the roof, at the same time, planting grass roof thickness increased, gain ability to resist the external thermal effects, Summer (August) afternoon 14 when the roof greening and the control area of the roof temperature observation data recording, the control area of the common roofing temperature is 50.5 ℃, the green zone temperature is only 35.4 ℃, 15 ℃ floor temperature difference, the indoor temperature 1.5 ℃ contrast decreased (Fig.), so green roof can Fig.4 Vegetation roofing and the common roof and test temperature control effectively reduce the temperature of the roof and the summer indoor temperature, reduce air conditioning load, to achieve the purpose of energy-saving insulation.
(2) vegetation roofing reduction effect Air is the necessary material conditions for human survival, city of oxygen consumption of dense population, the high concentration of carbon dioxide, green plants producing oxygen absorption of carbon dioxide, the ground greening area limited, roof greening of atmospheric oxygen and carbon dioxide balance play an important role.
Online since: December 2014
Authors: Xiao Xia Guo, Xiang Sun
Shear modulus reduction and the two shear threshold strains
Dynamic shear modulus reduction are plotted in Fig. 4.
These results are consistent with the data for noncohesive soils obtained indirectly by Hsu and Vucetic[3].
The newly obtained data in Fig. 4 are obviously in broad agreement with the previously published results by Hsu and Vucetic[3].
Comparison between the second threshold shear strain values and shear modulus reduction curves obtained confirms that the soil behavior is considerably nonlinear at.
RELATION BETWEEN SECANT SHEAR MODULUS REDUCTION AND THE TWO SHEAR THRESHOLD STRAINS Conclusions This paper carries on dynamic constitutive modelling by use of thermodynamic approach.
These results are consistent with the data for noncohesive soils obtained indirectly by Hsu and Vucetic[3].
The newly obtained data in Fig. 4 are obviously in broad agreement with the previously published results by Hsu and Vucetic[3].
Comparison between the second threshold shear strain values and shear modulus reduction curves obtained confirms that the soil behavior is considerably nonlinear at.
RELATION BETWEEN SECANT SHEAR MODULUS REDUCTION AND THE TWO SHEAR THRESHOLD STRAINS Conclusions This paper carries on dynamic constitutive modelling by use of thermodynamic approach.
Online since: March 2018
Authors: E. Jaafar, Muhammad Kashif, Siti Kudnie Sahari, Zainab Ngaini
Morphological and optical data confirms that rGO losses the oxygen groups compare to GO.
Thus, GO can be reduced by a chemical reagent, thermal reduction and multistep reduction in order to remove the oxygen containing functional groups [6].
More folded and wrinkled structure is produced when the reduction is stronger [15].
This is due to the reduction of the oxygen functional groups in graphene oxide.
Park, “Simple and cost-effective reduction of graphite oxide by sulfuric acid,” Carbon N.
Thus, GO can be reduced by a chemical reagent, thermal reduction and multistep reduction in order to remove the oxygen containing functional groups [6].
More folded and wrinkled structure is produced when the reduction is stronger [15].
This is due to the reduction of the oxygen functional groups in graphene oxide.
Park, “Simple and cost-effective reduction of graphite oxide by sulfuric acid,” Carbon N.