scholarly journals On the variation of bi‐periodic waves in the transverse direction

Author(s):  
Diane M. Henderson ◽  
John D. Carter ◽  
Megan E. Catalano
Author(s):  
Kathleen B. Reuter

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.


Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  

Abstract AISI 1141 is a resulfurized carbon steel containing nominally 1.50% manganese and 0.08-0.13% sulfur to give it free-machining characteristics. It has relatively low hardenability. Its ductility and toughness are fairly good in the longitudinal direction but tend to be low in the transverse direction. It is highly recommended for high-production automatic-machine products. Among its many uses are screws, bolts, ball joints, spindles and light-duty gears. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-93. Producer or source: Carbon steel mills.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1022
Author(s):  
Jae Hyung Kim ◽  
Taekyung Lee ◽  
Chong Soo Lee

This work investigated the microstructural effect on stretch flangeability of ferrite–martensite dual-phase (DP) steels. Three types of DP steels with various martensitic structures were prepared for the research: fibrous martensite in water-quenched (WQ) sample, chained martensite in air-quenched (AQ) sample, and coarse martensite in step-quenched (SQ) sample. The WQ specimen exhibited the highest mechanical strength and hole expansion ratio compared to the AQ and SQ samples despite their similar fraction of martensite. Such a result was explained in view of uniform distribution of fine martensite and high density of geometrically necessary dislocations in the WQ specimen. Meanwhile, most cracks initiated at either rolling or transverse direction during the stretch flangeability test regardless of the martensitic morphology. It was attributed to the highest average normal anisotropy in the direction of 45° to rolling direction.


2012 ◽  
Vol 217-219 ◽  
pp. 2381-2387
Author(s):  
Doru Romulus Pascu ◽  
Radu Alexandru Roşu ◽  
Iuliana Duma ◽  
Horia Daşcău

Non-alloyed P355NH steel according to EN 10028-3:2003 belongs to a group of fine-grained steels for pressure vessels being used in welded construction at decompression chamber for divers. Values of the chemical, structural and mechanical characteristics and steel toughness experimentally determined fit the analyzed steel in P355NH steel group according to EN 10028-3:2003. The toughness of the analyzed steel at the test temperature of -30°C is characterized by high values of fracture energy KV in longitudinal direction between 48 and 86 J and on transverse direction between 17 and 34J. Steel toughness at the test temperature of -30°C required by ABS standard (in Section 4/5.3 and Table 1) provides for breaking energy KV of min. 35J, with ductile fracture surfaces, value that is not respected at some lots of the three batches (A, B, C) of steel. Finally, based on the direct correlation established between HV10 hardness of the fine structure and the toughness it was made a selection of the lots of non-alloy steel P355NH which correspond to ABS norm for welded construction of the decompression chamber for divers


2008 ◽  
Vol 47 (2) ◽  
pp. 221-225 ◽  
Author(s):  
C. L. Bai ◽  
H. J. Niu
Keyword(s):  

2013 ◽  
Vol 2013 ◽  
pp. 1-14
Author(s):  
Yun Wu ◽  
Zhengrong Liu

We study the bifurcation phenomena of nonlinear waves described by a generalized Zakharov-Kuznetsov equationut+au2+bu4ux+γuxxx+δuxyy=0. We reveal four kinds of interesting bifurcation phenomena. The first kind is that the low-kink waves can be bifurcated from the symmetric solitary waves, the 1-blow-up waves, the tall-kink waves, and the antisymmetric solitary waves. The second kind is that the 1-blow-up waves can be bifurcated from the periodic-blow-up waves, the symmetric solitary waves, and the 2-blow-up waves. The third kind is that the periodic-blow-up waves can be bifurcated from the symmetric periodic waves. The fourth kind is that the tall-kink waves can be bifurcated from the symmetric periodic waves.


2010 ◽  
Vol 59 (5) ◽  
pp. 345-349 ◽  
Author(s):  
R.-B. Adusumalli ◽  
R. Raghavan ◽  
P. Schwaller ◽  
T. Zimmermann ◽  
J. Michler

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