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Online since: October 2018
Authors: Yu.Yu. Galkin, S.A. Udodov
In reference [23] this fact is deemed to be related with compaction under compression and reduction of porosity [24]; this is seen as a result of moisture diffusion to unhydrated cement grains and increase of degree of hydration in other writings [25-27].
In this regard, the study posed the following tasks: · obtain data on the intensity of peaks of mineral crystallization when the load is applied at different stages of hardening of the samples; · establish differences in peaks of hydration products of high-aluminate cement subjected to prolonged compression at different stages of hardening; · using a cement paste with a different water-cement ratio to determine the influence of this characteristic on the morphology of the hydration products formed under compression.
It is indicated by reduction of C2AH8 peak at 2Θ=34.56° (its intensity was much higher in the Fig.1) and appearance of peaks of cubical hydroaluminates (2Θ=31.88°; 38.06°; 66.66°).
This conclusion correlates well with the above-noted increase in recrystallization (when comparing data in Figures 1 and 3), which is characterized by increasing porosity and a redistribution of some water [2.6-7.9].
Kosolapov, Formation of the structure of cement stone in concrete during short-term reduction, Izvestiya vuzov.
In this regard, the study posed the following tasks: · obtain data on the intensity of peaks of mineral crystallization when the load is applied at different stages of hardening of the samples; · establish differences in peaks of hydration products of high-aluminate cement subjected to prolonged compression at different stages of hardening; · using a cement paste with a different water-cement ratio to determine the influence of this characteristic on the morphology of the hydration products formed under compression.
It is indicated by reduction of C2AH8 peak at 2Θ=34.56° (its intensity was much higher in the Fig.1) and appearance of peaks of cubical hydroaluminates (2Θ=31.88°; 38.06°; 66.66°).
This conclusion correlates well with the above-noted increase in recrystallization (when comparing data in Figures 1 and 3), which is characterized by increasing porosity and a redistribution of some water [2.6-7.9].
Kosolapov, Formation of the structure of cement stone in concrete during short-term reduction, Izvestiya vuzov.
Online since: February 2019
Authors: L.V. Radionova, Viacheslav V. Shirokov, Sergei R. Faizov, Maxim A. Zhludov
Also the reason of tool stability reduction at high-speed drawing can be increasing resistance to plastic metal deformation by means of increase in strain rate [4].
Given data Mother pipe diameter, mm 6.50 Diameter of ready wire, mm 3.00 Temporary stock tear resistance, MPa 1158 Carbon content, % 0.70 Calculated results Pass number 1 2 3 4 5 6 7 Drawing route 5.993 5.293 4.674 4.128 3.692 3.303 3 Degree of single deformation, % 15 22 22 22 20 20 17.48 Total deformation degree, % 78.7 Reduction ratio 1.176 1.282 1.282 1.282 1.250 1.250 1.212 Total reduction 4.69 Temporary tear resistance, MPa 1206 1283 1366 1453 1536 1625 1705 Wire-die half-angle, deg. 6 6 6 6 4 4 4 Friction coefficient 0.030 0.030 0.030 0.030 0.030 0.030 0.030 Drawing pressure, N/mm2 342.6 498.3 530.2 564.2 557.1 589.1 546.8 Drawing amplification, N 9658 10956 9094 7547 5963 5044 3863 Drawing speed, m/min 120 124 159 198 253 319 398 Power consumed by electric drives, kWt 21.46 25.16 26.78 27.67 27.94 29.8 28.47 Electric energy consumption, kWt/h 143.56 Productivity, t/h 1.316 With a help of a mathematical model of temperature speed drawing mode on FIFO drawing mills wire temperature
Conclusion From this perspective to achieve drawing speeds stipulated by the drawing machine data sheet and increase stability of the drawing tool the approach to selecting the following process parameters on modern drawing machines must be changed: the single deformation (strain) degree and wire-die half-angle.
Given data Mother pipe diameter, mm 6.50 Diameter of ready wire, mm 3.00 Temporary stock tear resistance, MPa 1158 Carbon content, % 0.70 Calculated results Pass number 1 2 3 4 5 6 7 Drawing route 5.993 5.293 4.674 4.128 3.692 3.303 3 Degree of single deformation, % 15 22 22 22 20 20 17.48 Total deformation degree, % 78.7 Reduction ratio 1.176 1.282 1.282 1.282 1.250 1.250 1.212 Total reduction 4.69 Temporary tear resistance, MPa 1206 1283 1366 1453 1536 1625 1705 Wire-die half-angle, deg. 6 6 6 6 4 4 4 Friction coefficient 0.030 0.030 0.030 0.030 0.030 0.030 0.030 Drawing pressure, N/mm2 342.6 498.3 530.2 564.2 557.1 589.1 546.8 Drawing amplification, N 9658 10956 9094 7547 5963 5044 3863 Drawing speed, m/min 120 124 159 198 253 319 398 Power consumed by electric drives, kWt 21.46 25.16 26.78 27.67 27.94 29.8 28.47 Electric energy consumption, kWt/h 143.56 Productivity, t/h 1.316 With a help of a mathematical model of temperature speed drawing mode on FIFO drawing mills wire temperature
Conclusion From this perspective to achieve drawing speeds stipulated by the drawing machine data sheet and increase stability of the drawing tool the approach to selecting the following process parameters on modern drawing machines must be changed: the single deformation (strain) degree and wire-die half-angle.
Online since: January 2010
Authors: Leo A.I. Kestens, Roumen H. Petrov, Orlando León-García
The fracture area of the broken specimens was
calculated by image analysis in order to obtain the reduction of area at fracture and the related true
stress.
The equipment employed for EBSD analysis was a NOVA600 Dual Beam scanning electron microscopy with field-emission gun and equipped with an OxfordHKL EBSD data collection system.
The main difference between both steels is the reduction of area at fracture where the slow cooled sample is characterized by a higher strain localization which is shown in Fig. 2c.
Quenched Slow cooled Tensile strength, [MPa] 723.4 ± 7.1 568 ± 3.8 Deformation at necking, [%] 13.39 ± 0.33 13.69 ± 0.18 Deformation at fracture, [%] 18.19 ± 0.61 17.59 ± 0.3 Reduction of area at fracture, [%] 49.7 ± 1.32 65.3 ± 0.89 True stress at fracture, [MPa] 1236.8 ± 27.4 1260.2 ± 13.9 Vickers microhardness, [VH] 214 ± 5.1 170 ± 4.1 Table 1 Mechanical properties of both DP steels obtained from tensile tests.
In summary, the quenched DP steel exhibits higher void activity than the slow cooled material but in both cases the void density is low and similar to data reported by Ahmad et al. [4].
The equipment employed for EBSD analysis was a NOVA600 Dual Beam scanning electron microscopy with field-emission gun and equipped with an OxfordHKL EBSD data collection system.
The main difference between both steels is the reduction of area at fracture where the slow cooled sample is characterized by a higher strain localization which is shown in Fig. 2c.
Quenched Slow cooled Tensile strength, [MPa] 723.4 ± 7.1 568 ± 3.8 Deformation at necking, [%] 13.39 ± 0.33 13.69 ± 0.18 Deformation at fracture, [%] 18.19 ± 0.61 17.59 ± 0.3 Reduction of area at fracture, [%] 49.7 ± 1.32 65.3 ± 0.89 True stress at fracture, [MPa] 1236.8 ± 27.4 1260.2 ± 13.9 Vickers microhardness, [VH] 214 ± 5.1 170 ± 4.1 Table 1 Mechanical properties of both DP steels obtained from tensile tests.
In summary, the quenched DP steel exhibits higher void activity than the slow cooled material but in both cases the void density is low and similar to data reported by Ahmad et al. [4].
Online since: May 2011
Authors: Xiao Ming Yuan, Rui Sun, Long Wei Chen
Incident of arbitry loading, ag(t), is a discrete data which can be read as,
, j=0, 1,2,3...
Modulus Reduction during Liquefaction Process.
The physical process of liquefaction is excess pore water pressure increases and results in shear modulus reduction.
The essential of liquefaction process is reduction of the subsoil modulus with increasing pore-water pressure.
Further verification for the reliability of the method proposed in this paper by laboratory testing and in-situ data needs more work.
Modulus Reduction during Liquefaction Process.
The physical process of liquefaction is excess pore water pressure increases and results in shear modulus reduction.
The essential of liquefaction process is reduction of the subsoil modulus with increasing pore-water pressure.
Further verification for the reliability of the method proposed in this paper by laboratory testing and in-situ data needs more work.
Online since: December 2012
Authors: Juan Li, Ning Li, Mei Xiu Li
The key in the reduction of special information by expansion is the design of information structure in actual conversion.
The numbering rules are not consistent with the source formats after round-trip conversion, and if the information is recorded to expansion directly and copied back to source format in reduction, it may cause identifier to conflict.
When OOXML is converted into UOF, the footer information is recorded in expansion; while UOF is converted into OOXML, this part of information should be extracted to realize the reduction of information.
When OOXML is converted into UOF, the slide content should ignore these pictures of which the placeholder are footer, number and data, and then call the conversion module in expansion.
The problem can be solved by adding corresponding steps to reduce the unnecessary data in pre-treatment and post-treatment.
The numbering rules are not consistent with the source formats after round-trip conversion, and if the information is recorded to expansion directly and copied back to source format in reduction, it may cause identifier to conflict.
When OOXML is converted into UOF, the footer information is recorded in expansion; while UOF is converted into OOXML, this part of information should be extracted to realize the reduction of information.
When OOXML is converted into UOF, the slide content should ignore these pictures of which the placeholder are footer, number and data, and then call the conversion module in expansion.
The problem can be solved by adding corresponding steps to reduce the unnecessary data in pre-treatment and post-treatment.
Online since: September 2013
Authors: Guo He Wang, Zhi Ping Wu, Jian Zhong Tan, Rui He Niu, Pei Feng Yin
Investment data and methods.
The cocoon quality presented much more differences because of the shortening of whole instars and the reduction of mulberry leaf consumption.
The results indicated that silk length of trimolter cocoons of the 3rd treatment group was not so different from that of the control group with the relative indexes of 95.43% and 98.86%.The the reason was the reduction of silk filament of trimolters, although the weight of dried cocoon of trimolters of the 3rd treatment group decreased obviously, and they only reached to 59.63% and 74.26% of the control group.
Table 3 Analysis of physical and chemical characters of trimolter and tetramolter cocoons Varieties Treatment group Breaking strength Elongation rate Sericin content cN[dtex] Index[%] Value[%] Index[%] Value[%] Index[%] Liangguang NO.2 3rd instar 0.325 61.21 20.91 91.15 19.42 91.60 4th instar 0.232 43.69 17.29 75.37 21.20 104.64 Control 0.531 100 22.94 100 20.26 100 Qiufeng×Baiyu 3rd instar 0.542 104.84 24.76 117.12 21.63 91.93 4th instar 0.361 69.83 20.72 98.01 21.30 90.53 Control 0.517 100 21.14 100 23.53 100 Note: In the above table, breaking strength and Elongation rate of trimolter cocoons refer to the average data of the 230-460 th meter from outer layer to inner layer.
The sericin content of silkworm variety Liangguang NO.2 in the 4th treatment group reached to 104.64%, which indicating the reduction of transformation efficiency from mulberry to silk.
The cocoon quality presented much more differences because of the shortening of whole instars and the reduction of mulberry leaf consumption.
The results indicated that silk length of trimolter cocoons of the 3rd treatment group was not so different from that of the control group with the relative indexes of 95.43% and 98.86%.The the reason was the reduction of silk filament of trimolters, although the weight of dried cocoon of trimolters of the 3rd treatment group decreased obviously, and they only reached to 59.63% and 74.26% of the control group.
Table 3 Analysis of physical and chemical characters of trimolter and tetramolter cocoons Varieties Treatment group Breaking strength Elongation rate Sericin content cN[dtex] Index[%] Value[%] Index[%] Value[%] Index[%] Liangguang NO.2 3rd instar 0.325 61.21 20.91 91.15 19.42 91.60 4th instar 0.232 43.69 17.29 75.37 21.20 104.64 Control 0.531 100 22.94 100 20.26 100 Qiufeng×Baiyu 3rd instar 0.542 104.84 24.76 117.12 21.63 91.93 4th instar 0.361 69.83 20.72 98.01 21.30 90.53 Control 0.517 100 21.14 100 23.53 100 Note: In the above table, breaking strength and Elongation rate of trimolter cocoons refer to the average data of the 230-460 th meter from outer layer to inner layer.
The sericin content of silkworm variety Liangguang NO.2 in the 4th treatment group reached to 104.64%, which indicating the reduction of transformation efficiency from mulberry to silk.
Online since: January 2018
Authors: Martin Vyšvařil, Michaela Hegrová, Tomáš Žižlavský
The results were expressed as shear rate vs. shear stress (flow curves) and the Herschel-Bulkley model (Eq. 1) was applied to downward-flow curves to fit the experimental data and used to describe mortars rheological behaviour:
τ=τ0+kγn (1)
where τ is the shear stress, γ is the shear rate, τ0 corresponds to the yield stress, k is the consistency coefficient and n is the fluidity index which characterizes shear-thinning (n < 1) or shear-thickening (n > 1) behaviour of a mortar.
Experimental data were reported in terms of complex modulus, G*, and loss tangent, tan(δ), defined by Eq. 2 and Eq. 3: G*=G'2+G''2 (2) tan(δ)=G''G' (3) The complex modulus (G*) expresses the stiffness of the material; the higher the G* value, the harder the material is.
As proved by the spread reduction, both of the guar ethers had a marked thickening effect, contrary to the native guar gum which reduced the spread of lime mortars by 18% only.
The reduction of spread is much more effective than in the case of cellulose ether or starch ether [11,14,16].
· As proved by the spread reduction, both of the guar ethers had a marked thickening effect, contrary to the native guar gum
Experimental data were reported in terms of complex modulus, G*, and loss tangent, tan(δ), defined by Eq. 2 and Eq. 3: G*=G'2+G''2 (2) tan(δ)=G''G' (3) The complex modulus (G*) expresses the stiffness of the material; the higher the G* value, the harder the material is.
As proved by the spread reduction, both of the guar ethers had a marked thickening effect, contrary to the native guar gum which reduced the spread of lime mortars by 18% only.
The reduction of spread is much more effective than in the case of cellulose ether or starch ether [11,14,16].
· As proved by the spread reduction, both of the guar ethers had a marked thickening effect, contrary to the native guar gum
Online since: June 2008
Authors: Irena Topic, Heinz Werner Höppel, Matthias Göken
Ultrafine-grained materials show superior mechanical properties in terms of strength and
ductility compared to conventionally grained (CG) materials, which makes them especially
interesting for light weight construction in the automobile industry due the high specific strength
and the high potential for cost reduction [3, 4].
Originally developed by Thomas et al. [5, 6] in 1991, FSW has become a highly recognised joining technique due to numerous advantages, including higher weight reduction potential compared to standard mechanical fasteners, easier joining of the hard-to-weld materials such as Al alloys and a lower heat input compared to fusion welding [7, 8, 9, 10].
The surfaces were wire brushed to remove the oxide layer, stacked and rolled together without lubrication using a four high rolling mill (Carl Wezel, Mühlacker) to a 50 % thickness reduction.
Additional tests will be required to confirm the data.
At this stage, the microstructural observations and the bulge test data appear conflicting and the exact reasons for this behaviour are not yet clear.
Originally developed by Thomas et al. [5, 6] in 1991, FSW has become a highly recognised joining technique due to numerous advantages, including higher weight reduction potential compared to standard mechanical fasteners, easier joining of the hard-to-weld materials such as Al alloys and a lower heat input compared to fusion welding [7, 8, 9, 10].
The surfaces were wire brushed to remove the oxide layer, stacked and rolled together without lubrication using a four high rolling mill (Carl Wezel, Mühlacker) to a 50 % thickness reduction.
Additional tests will be required to confirm the data.
At this stage, the microstructural observations and the bulge test data appear conflicting and the exact reasons for this behaviour are not yet clear.
Online since: May 2012
Authors: Bo Yang, Qiang Liu, Ting Meng, Zhi Pei Zhang
According to the investigation data, the air-raid shelter’s size is a 4×3.2 m model.
The soil layer within the scope of the air-raid Shelter is made an assignment of physical and mechanical parameters, its main basis is the data provided by related engineering geological investigation reports, at the same time referring to Rock Mechanics Parameters Book and the Flac3d software’s principle of parameter and does some appropriate adjustment.
Because the site is planning to build a school, the stability of the shelter seriously affected the stability of the building and the personal safety of the staff, we must consider the reduction of the strength of lining structure on the shelter as time goes on, and the 75% intensity decreased in the engineering use period, the displacement and the stress conditions as below.
Shelter horizontal displacement equivalence value maps(mm) equivalence value maps(mm) The results of long-term stability analysis of the air-raid shelter shows that, time will lead to sharp reduction of the lining structure strength, the deformation of the vault and both sides continues to grow, the areas of damage increase further, the shelter will collapse, thus seriously affects the safe use.
The results of the long-term stability analysis about the site simulation of the shelter show that: time will lead to sharp reduction of the lining structure strength, the deformation of the vault and both sides of the shelter continues to increase and the damage scope increases.
The soil layer within the scope of the air-raid Shelter is made an assignment of physical and mechanical parameters, its main basis is the data provided by related engineering geological investigation reports, at the same time referring to Rock Mechanics Parameters Book and the Flac3d software’s principle of parameter and does some appropriate adjustment.
Because the site is planning to build a school, the stability of the shelter seriously affected the stability of the building and the personal safety of the staff, we must consider the reduction of the strength of lining structure on the shelter as time goes on, and the 75% intensity decreased in the engineering use period, the displacement and the stress conditions as below.
Shelter horizontal displacement equivalence value maps(mm) equivalence value maps(mm) The results of long-term stability analysis of the air-raid shelter shows that, time will lead to sharp reduction of the lining structure strength, the deformation of the vault and both sides continues to grow, the areas of damage increase further, the shelter will collapse, thus seriously affects the safe use.
The results of the long-term stability analysis about the site simulation of the shelter show that: time will lead to sharp reduction of the lining structure strength, the deformation of the vault and both sides of the shelter continues to increase and the damage scope increases.
Online since: November 2011
Authors: Chun Bao Sun, Li Ping Mi, Tao Xu, Hong Jun Liu
It can achieve 95% of turbidity reduction, 98% of TSS removal, 93% of COD reduction.
The maximum percentage removal of 94.65% for SS occurred at the PAC dose of 750g/t, No further appreciable reduction in SS could be observed at higher dose of PAC.
This phenomenon could be confirmed from the data in Fig 3.
Conclusions The following conclusions can be drawn from the data presented above: [1]Among the reagent of PAC, PAFC and N83376, the use of PAC or PAFC alone can’t strengthen the settling obviously, the use of N83376 can enhance the sedimentation greatly, however the turbidity of supernatant is high.
The maximum percentage removal of 94.65% for SS occurred at the PAC dose of 750g/t, No further appreciable reduction in SS could be observed at higher dose of PAC.
This phenomenon could be confirmed from the data in Fig 3.
Conclusions The following conclusions can be drawn from the data presented above: [1]Among the reagent of PAC, PAFC and N83376, the use of PAC or PAFC alone can’t strengthen the settling obviously, the use of N83376 can enhance the sedimentation greatly, however the turbidity of supernatant is high.