Nature of the high sensitivity of heat-treated steels to stress raisers

1979 ◽  
Vol 11 (2) ◽  
pp. 195-202
Author(s):  
M. Ya. Belkin ◽  
L. M. Belkin
Keyword(s):  
High Sensitivity ◽  
Heat Treated ◽  
Stress Raisers

scholarly journals A multiplex real-time PCR method for differentiation of beef, buffalo meat and pork

2019 ◽  
Vol 18 (01) ◽  
pp. 63-71
Author(s):  
Tan M. Tran
Keyword(s):  
Detection Limit ◽  
Real Time ◽  
Real Time Pcr ◽  
High Sensitivity ◽  
Specific Probe ◽  
Food Authenticity ◽  
Processed Meats ◽  
Buffalo Meat ◽  
Heat Treated ◽  
Pcr Method

The objective of this study was to optimize a multiplex real-time PCR protocol for detection of DNA of beef, buffalo meat and pork, serving for food authenticity. The optimized concentrations were 200 nM primer and 100 nM specific probe for beef/buffalo meat, and 300 nM primer and 150 nM probe for pork. The amplification was performed using initial denaturation at 50oC for 2 min, 95oC for 2 min, followed by 45 cycles of denaturation at 95oC for 15 sec, and annealing and extension at 60oC for 40 sec. This protocol had high sensitivity and specificity. The detection limit of this method was found to be 0.1% in raw and heat-treated meat mix (80 – 121oC/15 min) or 0.005 ng DNA/reaction. The protocol of testing was applied for the commercial products both fresh and processed meats. The results demonstrated that 50% of raw beef sample (6/12) weren't found beef DNA. Eight of twelve beef sausage samples (66.67%) contained buffalo DNA. Beef DNA were found in all 12 samples of beef meatballs, but eight out of the 12 meatball samples were confirmed to have buffalo DNA (66.67%) and two out of the 12 meatball samples (16.67%) also contained porcine DNA.

Stress Corrosion Cracking and Corrosion Fatigue in Cr-Mo Low Alloy Steel

CORROSION ◽  
1978 ◽  
Vol 34 (10) ◽  
pp. 325-331 ◽  
Author(s):  
SIGEKI AIYAMA ◽  
TETSUO SHOJI ◽  
HIDEAKI TAKAHASHI ◽  
MASAHIKO SUZUKI
Keyword(s):  
Crack Growth ◽  
Corrosion Fatigue ◽  
High Sensitivity ◽  
Constant Load ◽  
Frequency Effect ◽  
Dissolution Mechanism ◽  
Growth Enhancement ◽  
Corrosion Fatigue Crack ◽  
Stress Cracking ◽  
Heat Treated

Abstract Corrosion fatigue crack propagation tests were performed below and above KISCC in AISI 4145 steel heat treated to 1230 MN/m2 and 0.1 N H2SO4 system with particular reference to effects of frequency and stress intensity parameters. The crack growth results above KISCC could not be described by simple linear summation hypothesis, and this fact suggested the importance of the synergestic effect term in crack growth rate. This synergestic effect denoted hereafter as the dynamic SCC rate was strongly influenced by frequency and showed the maximum at a particular frequency. This frequency effect on the dynamic SCC rate suggested that crack growth enhancement under cyclic loading would be induced by dissolution mechanism in spite of the fact that the material had high sensitivity to hydrogen stress cracking under constant load.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

1977 ◽  
Vol 35 ◽  
pp. 162-163
Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck
Keyword(s):  
Crystallite Size ◽  
Sedimentary Rocks ◽  
Carbonaceous Material ◽  
Low Grade ◽  
X Ray ◽  
Graphitized Carbon ◽  
Transmission Electron ◽  
Heat Treated ◽  
Commercial Carbon ◽  
Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

Effect of Shock Loading on the Microstructure of Uniloy 326

1974 ◽  
Vol 32 ◽  
pp. 504-505
Author(s):  
K. P. Staudhammer ◽  
L. E. Murr
Keyword(s):  
Grain Size ◽  
Shock Loading ◽  
Current Investigation ◽  
Two Phase ◽  
05 C ◽  
Shock Deformation ◽  
Heat Treated

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.

Phase Transformation In Ti-6al-4v Alloys

1972 ◽  
Vol 30 ◽  
pp. 584-585
Author(s):  
Shiro Fujishiro
Keyword(s):  
Phase Transformation ◽  
Grain Boundary ◽  
Cryogenic Temperature ◽  
Β Phase ◽  
Heat Treated ◽  
Mixed Microstructure ◽  
Ductile Behavior

The Ti-6 wt.% Al-4 wt.% V commercial alloys have exhibited an improved formability at cryogenic temperature when the alloys were heat-treated prior to the tests. The author was interested in further investigating this unusual ductile behavior which may be associated with the strain-induced transformation or twinning of the a phase, enhanced at lower temperatures. The starting materials, supplied by RMI Co., Niles, Ohio were rolled mill products in the form of 40 mil sheets. The microstructure of the as-received materials contained mainly ellipsoidal α grains measuring between 1 and 5μ. The β phase formed an undefined grain boundary around the a grains. The specimens were homogenized at 1050°C for one hour, followed by aging at 500°C for two hours, and then quenched in water to produce the α/β mixed microstructure.

Microstructural Evolution in Reduced TiO2

1981 ◽  
Vol 39 ◽  
pp. 74-75
Author(s):  
W. T. Donlon ◽  
S. Shinozaki ◽  
E. M. Logothetis ◽  
W. Kaizer
Keyword(s):  
Microstructural Evolution ◽  
Point Defects ◽  
Extended Defects ◽  
Small Deviations ◽  
Controlled Atmospheres ◽  
Limited Solubility ◽  
Thin Foils ◽  
Heat Treated ◽  
Porous Polycrystalline ◽  
Crystallographic Shear

Since point defects have a limited solubility in the rutile (TiO2) lattice, small deviations from stoichiometry are known to produce crystallographic shear (CS) planes which accomodate local variations in composition. The material used in this study was porous polycrystalline TiO2 (60% dense), in the form of 3mm. diameter disks, 1mm thick. Samples were mechanically polished, ion-milled by conventional techniques, and initially examined with the use of a Siemens EM102. The electron transparent thin foils were then heat-treated under controlled atmospheres of CO/CO2 and H2 and reexamined in the same manner.The “as-received” material contained mostly TiO2 grains (∼5μm diameter) which had no extended defects. Several grains however, aid exhibit a structure similar to micro-twinned grains observed in reduced rutile. Lattice fringe images (Fig. 1) of these grains reveal that the adjoining layers are not simply twin related variants of a single TinO2n-1 compound. Rather these layers (100 - 250 Å wide) are alternately comprised of stoichiometric TiO2 (rutile) and reduced TiO2 in the form of Ti8O15, with the Ti8O15 layers on either side of the TiO2 being twin related.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Formation Mechanisms for Multiply Twinned Particles During Nucleation in the Au/MICA System

1975 ◽  
Vol 33 ◽  
pp. 84-85
Author(s):  
Eal H. Lee ◽  
Helmut Poppa
Keyword(s):  
Deposition Time ◽  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Formation Mechanisms ◽  
Heat Treated ◽  
Cluster Density ◽  
Diffraction Patterns ◽  
Crystal Particle ◽  
Multiply Twinned Particles

The formation of thin films of gold on mica has been studied in ultra-high vacuum (5xl0-10 torr) . The mica substrates were heat-treated for 24 hours at 375°C, cleaved, and annealed for 15 minutes at the deposition temperature of 300°C prior to deposition. An impingement flux of 3x1013 atoms cm-2 sec-1 was used. These conditions were found to give high number densities of multiple twin particles and are based on a systematic series of nucleation experiments described elsewhere. Individual deposits of varying deposition time were made and examined by bright and dark field TEM after "cleavage preparation" of highly transparent specimens. In the early stages of growth, the films generally consist of small particles which are either single crystals or multiply twinned; a strong preference for multiply twinned particles was found whenever the particle number densities were high. Fig. 1 shows the stable cluster density ns and the variation with deposition time of multiple twin particle and single crystal particle densities, respectively. Corresponding micrographs and diffraction patterns are shown in Fig. 2.

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