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Online since: October 2012
Authors: Xiang Ren, Rong Zhao, Hua Juan Yuan
Tertiary sandstone and mudstone red layer ( N2 ): brown, pale yellow, medium-fine grained sandstone interbedded with red green gray mudstone, located at both sides of the river mouth alluvial fan, formed into piedmont relatively flat platform.
Table 1 The outcropping granite along the route Stake umber Stratigraphic lithology Lithology Rock mass characteristics K5+000~ K8+400 Low-grade metamorphic granite Gray shallow metamorphic granite, metamorphic quartz leptynite and medium - coarse granular at local section 2~3 sets of joints: 300°~325°/∠60°~80°,200°~263°/∠80° ~85°,290°~300°/∠20°~30°,Block structure K8+400~ K11+700 Migmatite mainly is composed of of biotite monzonite gneiss, quartz schist, biotite schist, slate, diabase veins and pegmatite dikes, intestinal -like structure at K8+400 3 sets of joints: 335°~350°/∠63°~77°,50°~ 75°/∠55°~80°, 175°~230°/∠13°~25°, block, Sub - block structure K11+700~ K32+988 Granite Brown, red meat , fine grained or porphyritic texture, pegmatite and quartz vein is visible. 3 sets of joints: 290°~330°/∠75°~77°,44°~65°/∠57°~74°,260°~290°/∠17°~25°, Sub–block, Fractured structure Table 2 Parameters list of the granite Ithology Degree of weathering Bulk density /g·cm-3 Pressive strength
Table 4 The ranked slope stability by the Ministry of Railways Stable(Ⅰ) Basically stable (Ⅱ) Unstable (Ⅲ) Time Excavation - the operational stability may be unstable when operation Instability after the excavation Failure mode Stable and no damage, spalling, chip off-falling individually, a small amount of crumbling Basically stable, without significant disruption, crumbling, a small amount of chip off-falling,local slumping, Large-scale slump Bedding slump, tilt, collapse Engineering measures Directly excavation Sprayed anchor, pointing , grouting, embedded in fill , Protection of slopes, and local support retaining all ,opencut tunnel, anchor piles , change the line Table 5 Maximum recording flood level along the route Number A-A' B-B' C-C' D-D' Stake number along the route K5+100 K8+280 K12+070 K26+410 Riverbed width /m 42 11.5 4 32 Flood level above the riverbed height /m 1.6 5.0 13.0 1.0 In addition, the requirements for flood control at road embankment along the river of
Table 1 The outcropping granite along the route Stake umber Stratigraphic lithology Lithology Rock mass characteristics K5+000~ K8+400 Low-grade metamorphic granite Gray shallow metamorphic granite, metamorphic quartz leptynite and medium - coarse granular at local section 2~3 sets of joints: 300°~325°/∠60°~80°,200°~263°/∠80° ~85°,290°~300°/∠20°~30°,Block structure K8+400~ K11+700 Migmatite mainly is composed of of biotite monzonite gneiss, quartz schist, biotite schist, slate, diabase veins and pegmatite dikes, intestinal -like structure at K8+400 3 sets of joints: 335°~350°/∠63°~77°,50°~ 75°/∠55°~80°, 175°~230°/∠13°~25°, block, Sub - block structure K11+700~ K32+988 Granite Brown, red meat , fine grained or porphyritic texture, pegmatite and quartz vein is visible. 3 sets of joints: 290°~330°/∠75°~77°,44°~65°/∠57°~74°,260°~290°/∠17°~25°, Sub–block, Fractured structure Table 2 Parameters list of the granite Ithology Degree of weathering Bulk density /g·cm-3 Pressive strength
Table 4 The ranked slope stability by the Ministry of Railways Stable(Ⅰ) Basically stable (Ⅱ) Unstable (Ⅲ) Time Excavation - the operational stability may be unstable when operation Instability after the excavation Failure mode Stable and no damage, spalling, chip off-falling individually, a small amount of crumbling Basically stable, without significant disruption, crumbling, a small amount of chip off-falling,local slumping, Large-scale slump Bedding slump, tilt, collapse Engineering measures Directly excavation Sprayed anchor, pointing , grouting, embedded in fill , Protection of slopes, and local support retaining all ,opencut tunnel, anchor piles , change the line Table 5 Maximum recording flood level along the route Number A-A' B-B' C-C' D-D' Stake number along the route K5+100 K8+280 K12+070 K26+410 Riverbed width /m 42 11.5 4 32 Flood level above the riverbed height /m 1.6 5.0 13.0 1.0 In addition, the requirements for flood control at road embankment along the river of
Online since: February 2016
Authors: Evgeniy Valerjevich Korolev, Alexandr Sergeevich Inozemtcev, Alexandr Evstigneev
The system is decomposed in parts; then, both number of parts and number of cross-dependencies between them are minimized.
The coarse-grained structure of constructional mixtures and materials is mainly forming under influence of gravity; this level commonly referred as macrostructure.
The structure of fine-grained part (binder, water and fine filler in case of cement composites; binder and fine filler in case of materials with polymer, bitumen and sulfur matrices) evolved under influence of forces caused by surface effects and surface energies.
The coarse-grained structure of constructional mixtures and materials is mainly forming under influence of gravity; this level commonly referred as macrostructure.
The structure of fine-grained part (binder, water and fine filler in case of cement composites; binder and fine filler in case of materials with polymer, bitumen and sulfur matrices) evolved under influence of forces caused by surface effects and surface energies.
Online since: March 2020
Authors: Lee Chin Mei, Sieo Chin Chin, Norhani Abdullah, Ho Yin Wan
S is the total number of types described.
nj is the number of strains belonging to the jth type Results and Discussion The 16S rRNA gene which was approximately 1.5 kb was amplified from genomic DNA of the 12 Lactobacillus strains and five type strains.
Ventura et al. [14] and Delfederico et al. [13] had also reported that ARDRA analysis was able to differentiate the Lactobacillus isolates from kefir grains, intestine and vagina up to species level.
Semorile, Molecular identification and typing of lactobacilli isolated from kefir grains, J.
nj is the number of strains belonging to the jth type Results and Discussion The 16S rRNA gene which was approximately 1.5 kb was amplified from genomic DNA of the 12 Lactobacillus strains and five type strains.
Ventura et al. [14] and Delfederico et al. [13] had also reported that ARDRA analysis was able to differentiate the Lactobacillus isolates from kefir grains, intestine and vagina up to species level.
Semorile, Molecular identification and typing of lactobacilli isolated from kefir grains, J.
Online since: August 2009
Authors: Ming J. Zuo, Han Xin Chen
It may also be generated by the grain boundaries
in the materials and is randomly distributed in time.
The ultrasonic echoes from grain boundaries and other microstructural inhomogeneities in the material cause major difficulties in detection of small cracks, flaws and other metallurgical defect [4].
The optimal parameters p ,µ, and the number of tap-delay input signal were found to be 0.9, 0.001, and 30, respectively.
Other parameters of the LMS-based Morlet filter includingu , p and the number of the tap-delay input signal were 0.001, 0.9 and 30.
The ultrasonic echoes from grain boundaries and other microstructural inhomogeneities in the material cause major difficulties in detection of small cracks, flaws and other metallurgical defect [4].
The optimal parameters p ,µ, and the number of tap-delay input signal were found to be 0.9, 0.001, and 30, respectively.
Other parameters of the LMS-based Morlet filter includingu , p and the number of the tap-delay input signal were 0.001, 0.9 and 30.
Online since: September 2013
Authors: Camilla Mileto, Antonio Martínez Lluch, Fernando Vegas López-Manzanares, Maria Diodato
This way of emitting the waves only facilitates the penetration of the waves if they are oriented as the grain of the wood.
In the case of the mentioned system, the microwaves are transmitted with circular polarization and therefore come out through the whole surface of the antenna acting on a larger surface, penetrating the wood regardless to the direction of the grain.
The microscopic identification of the Southern Yellow Pine was done by analyzing a number of samples under the optical microscope, with the collaboration of Nicola Macchioni, researcher at CNR-IVALSA, Italy.
Application of the microwave treatment on a timber lintel Results and conclusions The described pilot experiment proved that the proper study, knowledge and diagnosis of a historic timber structure make it possible not only to eliminate the original causes of the damages rather than just fixing the symptoms, but also to reduce the number of treatment.
In the case of the mentioned system, the microwaves are transmitted with circular polarization and therefore come out through the whole surface of the antenna acting on a larger surface, penetrating the wood regardless to the direction of the grain.
The microscopic identification of the Southern Yellow Pine was done by analyzing a number of samples under the optical microscope, with the collaboration of Nicola Macchioni, researcher at CNR-IVALSA, Italy.
Application of the microwave treatment on a timber lintel Results and conclusions The described pilot experiment proved that the proper study, knowledge and diagnosis of a historic timber structure make it possible not only to eliminate the original causes of the damages rather than just fixing the symptoms, but also to reduce the number of treatment.
Online since: August 2014
Authors: Michael E. Fitzpatrick, Jeferson Araujo de Oliveira, Jan Kowal
In time-of-flight instruments, different wavelengths of a pulsed “white” beam of neutrons incident on the residual stressed sample diffract in different grain families and reach the neutron detectors at different times and angles in relation to the incident beam, which correlate to the lattice parameters of these grains based on Bragg`s law.
This feature could be caused by a combination of errors, including the “stress-free” lattice parameter, the elastic constants, the volume fraction of each phase, any texture possibly present in the sample, and/or the strain uncertainties associated with the strains allied to the small number of points measured.
In the case presented, since one RS component shows an overall positive balance and the others show the opposite, the dominant source of error is more likely to be either the high strain uncertainties amplified by the small number of points measured or a possible texture effect, since the other sources would shift all RS components in the same direction.
This feature could be caused by a combination of errors, including the “stress-free” lattice parameter, the elastic constants, the volume fraction of each phase, any texture possibly present in the sample, and/or the strain uncertainties associated with the strains allied to the small number of points measured.
In the case presented, since one RS component shows an overall positive balance and the others show the opposite, the dominant source of error is more likely to be either the high strain uncertainties amplified by the small number of points measured or a possible texture effect, since the other sources would shift all RS components in the same direction.
Online since: September 2018
Authors: Oleg S. Tolkachev, Pavel Moskvin, Yurii F. Ivanov, Olga V. Krysina, Аnatoliy A. Klopotov, Aleksandr I. Potekaev, Olga V. Ivanova, Nikolaii Tsvetkov, Elizaveta A. Petrikova
Taking into account that the diffusion rate of titanium and copper atoms in molten aluminum is several orders of magnitude higher than the diffusion rate in the solid phase of aluminum, the following irradiation modes have been chosen for treatment of the “film (Ti or Cu) / (Al) substrate” system: t = 50 μs; ES = (10, 15, and 20) J/cm2; number of pulses N = 3, pulse repetition rate is 0.3 s-1.
The “film/substrate” system, formed by deposition of a metal film using the vacuum-arc method with evaporation of a cathode, is characterized, as a rule, by the presence of a large number of microdroplets (Fig. 1a).
The grain size varies from 0.5 μm to 7 μm.
Particles of the second phase (aluminides of titanium) are found in the bulk of the grains.
The “film/substrate” system, formed by deposition of a metal film using the vacuum-arc method with evaporation of a cathode, is characterized, as a rule, by the presence of a large number of microdroplets (Fig. 1a).
The grain size varies from 0.5 μm to 7 μm.
Particles of the second phase (aluminides of titanium) are found in the bulk of the grains.
Online since: January 2019
Authors: Giovina Marina La Vecchia, Marialaura Tocci, Lorenzo Montesano, Annalisa Pola, Marcello Gelfi
Many authors reported that this technology offers different combined advantages such as degassing, grain refinement and eutectic Si and Fe-rich compounds modification in aluminum casting alloys [8-11].
Titanium is more widely used than steel as it appears to dissolve more slowly and, when dissolved, it can act as grain refiner [18].
It has to be reminded that the micrographs refer to gravity cast samples; a real semisolid process is characterized by the injection of the alloy into a die, which produces high shear stresses in the slurry, strongly affecting its viscosity and enhancing the formation of a high number of globules with round shape.
The SEM-EDS analyses of the obtained samples clearly show the presence of a high number of Fe-rich intermetallic compounds (Fig. 6) as a consequence of the enrichment of the alloy in Fe, Mn and Cr content due to the dissolution of the horn (Alx(Fe,Mn,Cr)ySiz [26]).
Titanium is more widely used than steel as it appears to dissolve more slowly and, when dissolved, it can act as grain refiner [18].
It has to be reminded that the micrographs refer to gravity cast samples; a real semisolid process is characterized by the injection of the alloy into a die, which produces high shear stresses in the slurry, strongly affecting its viscosity and enhancing the formation of a high number of globules with round shape.
The SEM-EDS analyses of the obtained samples clearly show the presence of a high number of Fe-rich intermetallic compounds (Fig. 6) as a consequence of the enrichment of the alloy in Fe, Mn and Cr content due to the dissolution of the horn (Alx(Fe,Mn,Cr)ySiz [26]).
Online since: July 2016
Authors: Katarzyna Gawdzińska, Cezary Behrendt
The samples selection was carried out randomly, and the number of samples (21) is sufficient and selected in accordance with the applicable rules for the performance of the said structural analysis.
The tested samples include in a ferrite and pearlite grain, where the corrosion pits occur (Fig.7 – point 1-5, chemical composition Table 1 – 2 point 1-5, exemplary samples), numerous non-metallic inclusions, which is a material defect.
Causes of pitting corrosion in the tested boiler Causes and spots where the pitting corrosion occur may be [5]: - jogs (dislocations) caused by stresses (mechanical, thermal), - spots of, other than average, chemical composition caused by segregation, non-metallic inclusions or precipitates, - grain boundary, - mechanical damage spots.
Summary The main conclusions regarding the tests performed may include: - pitting corrosion of the heat exchange surfaces of the tested boiler characterized with high intensity and short time of progress, - the depth of pits equaled even up to 50% of the pipe wall and boiler plates’ thickness, - pits were located only in several spots on the heat exchange surface (5 pits in the furnace cover – Fig.1,3 pits in upper part of the oil-combustion pipe – Fig.2, 6 pits in the smoke tubes), - the quality of the steel used for the construction of the boiler should be determined as low due to a number of inclusions occurred during the steel deoxidation process
The tested samples include in a ferrite and pearlite grain, where the corrosion pits occur (Fig.7 – point 1-5, chemical composition Table 1 – 2 point 1-5, exemplary samples), numerous non-metallic inclusions, which is a material defect.
Causes of pitting corrosion in the tested boiler Causes and spots where the pitting corrosion occur may be [5]: - jogs (dislocations) caused by stresses (mechanical, thermal), - spots of, other than average, chemical composition caused by segregation, non-metallic inclusions or precipitates, - grain boundary, - mechanical damage spots.
Summary The main conclusions regarding the tests performed may include: - pitting corrosion of the heat exchange surfaces of the tested boiler characterized with high intensity and short time of progress, - the depth of pits equaled even up to 50% of the pipe wall and boiler plates’ thickness, - pits were located only in several spots on the heat exchange surface (5 pits in the furnace cover – Fig.1,3 pits in upper part of the oil-combustion pipe – Fig.2, 6 pits in the smoke tubes), - the quality of the steel used for the construction of the boiler should be determined as low due to a number of inclusions occurred during the steel deoxidation process
Online since: August 2016
Authors: Chuang Lu, Li Ping Zhu, Fa Qin Xie
Experimental materials and methods
Al-Si alloy is used as the experimental specimen and its compositions are listed in table 1.In the experiment, phosphorus modifier was utilized to conduct modification on the specimens and the primary silicon grains in tissues were refined using squeezing casting technique.
Large number of voids existed in the coating, among them, some of voids go through the interface between the coating and substrate.
In comparison with wrought aluminum alloy[11],the MAO coating of Al-Si alloy were looser, which was due to the large quantities of the primary silicon grains contained in the substrate of aluminum alloy.
There were the mullite phase with many diffraction peaks and small number of quartz (SiO2).
Large number of voids existed in the coating, among them, some of voids go through the interface between the coating and substrate.
In comparison with wrought aluminum alloy[11],the MAO coating of Al-Si alloy were looser, which was due to the large quantities of the primary silicon grains contained in the substrate of aluminum alloy.
There were the mullite phase with many diffraction peaks and small number of quartz (SiO2).