The reaction mechanism analysis and mechanical properties of large-size Al2O3/ZrO2 eutectic ceramics prepared by a novel combustion synthesis

2018 ◽  
Vol 44 (11) ◽  
pp. 12987-12995 ◽  
Author(s):  
Wanjun Yu ◽  
Yongting Zheng ◽  
Yongdong Yu ◽  
Fengyu Lin ◽  
Xiaoyue Su ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reaction Mechanism ◽  
Combustion Synthesis ◽  
Mechanism Analysis ◽  
Large Size

EFFECT OF ZINC DITHIOCARBAMATES AND THIAZOLE-BASED ACCELERATORS ON THE VULCANIZATION OF NATURAL RUBBER

2012 ◽  
Vol 85 (1) ◽  
pp. 120-131 ◽  
Author(s):  
Md. Najib Alam ◽  
Swapan Kumar Mandal ◽  
Subhas Chandra Debnath
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Reaction Mechanism ◽  
Natural Rubber ◽  
High Performance ◽  
Binary Systems ◽  
Synergistic Activity ◽  
Tetramethylthiuram Disulfide

Abstract Several zinc dithiocarbamates (ZDCs) as accelerator derived from safe amine has been exclusively studied in the presence of thiazole-based accelerators to introduce safe dithiocarbamate in the vulcanization of natural rubber. Comparison has been made between conventional unsafe zinc dimethyldithiocarbamate (ZDMC) with safe novel ZDC combined with thizole-based accelerators in the light of mechanical properties. The study reveals that thiuram disulfide and 2-mercaptobenzothiazole (MBT) are always formed from the reaction either between ZDC and dibenzothiazyledisulfide (MBTS) or between ZDC and N-cyclohexyl-2-benzothiazole sulfenamide (CBS). It has been conclusively proved that MBT generated from MBTS or CBS reacts with ZDC and produces tetramethylthiuram disulfide. The observed synergistic activity has been discussed based on the cure and physical data and explained through the results based on high-performance liquid chromatography and a reaction mechanism. Synergistic activity is observed in all binary systems studied. The highest tensile strength is observed in the zinc (N-benzyl piperazino) dithiocarbamate-accelerated system at 3:6 mM ratios. In respect of tensile strength and modulus value, unsafe ZDMC can be successfully replaced by safe ZDCs in combination with thiazole group containing accelerator.

scholarly journals Discrete Element Simulation Analysis of Biaxial Mechanical Properties of Concrete with Large-Size Recycled Aggregate

2021 ◽  
Vol 13 (13) ◽  
pp. 7498
Author(s):  
Tan Li ◽  
Jianzhuang Xiao
Keyword(s):  
Mechanical Properties ◽  
Stress State ◽  
Strain Curve ◽  
Confining Pressure ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Model ◽  
Large Size

Concrete made with large-size recycled aggregates is a new kind of recycled concrete, where the size of the recycled aggregate used is 25–80 mm, which is generally three times that of conventional aggregate. Thus, its composition and mechanical properties are different from that of conventional recycled concrete and can be applied in large-volume structures. In this study, recycled aggregate generated in two stages with randomly distributed gravels and mortar was used to replace the conventional recycled aggregate model, to observe the internal stress state and cracking of the large-size recycled aggregate. This paper also investigated the mechanical properties, such as the compressive strength, crack morphology, and stress–strain curve, of concrete with large-size recycled aggregates under different confining pressures and recycled aggregate incorporation ratios. Through this research, it was found that when compared with conventional concrete, under the confining pressure, the strength of large-size recycled aggregate concrete did not decrease significantly at the same stress state, moreover, the stiffness was increased. Confining pressure has a significant influence on the strength of large-size recycled aggregate cocrete.

scholarly journals Plant multifunctional nuclease TBN1 with unexpected phospholipase activity: structural study and reaction-mechanism analysis. Corrigendum

2013 ◽  
Vol 69 (6) ◽  
pp. 1192-1192
Author(s):  
Tomáš Koval' ◽  
Petra Lipovová ◽  
Tomáš Podzimek ◽  
Jaroslav Matoušek ◽  
Jarmila Dušková ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Structural Study ◽  
Mechanism Analysis ◽  
Phospholipase Activity

Plant multifunctional nuclease TBN1 with unexpected phospholipase activity: structural study and reaction-mechanism analysis

2013 ◽  
Vol 69 (2) ◽  
pp. 213-226 ◽  
Author(s):  
Tomáš Koval' ◽  
Petra Lipovová ◽  
Tomáš Podzimek ◽  
Jaroslav Matoušek ◽  
Jarmila Dušková ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Structural Study ◽  
Mechanism Analysis ◽  
Phospholipase Activity

scholarly journals 316L WAAM and pressure machining influence

2021 ◽  
Author(s):  
Xinfeng Kan ◽  
Dengcui Yang ◽  
Zhengzhi Zhao ◽  
Jiquan Sun
Keyword(s):  
Mechanical Properties ◽  
316L Stainless Steel ◽  
Additive Manufacture ◽  
Arc Voltage ◽  
Large Size ◽  
Complex Shapes ◽  
Rolling Experiment ◽  
Arc Current ◽  
Favorable Conditions

Abstract Wire arc additive manufacture (WAAM) technology has a good development prospect, and can be used to manufacture large metal components with complex shapes in combination with traditional machining equipment. This paper adjusts the parameters from the perspective of heat input and arc control. It is found that the stacking quality of 316L stainless steel is the best when the arc voltage is 40V and the arc current is 360A. It is proposed to obtain the flat layers by pressure machining after every layer is stacked, which can create favorable conditions for manufacturing large-size components. And through the hot rolling experiment, it is proved that pressure machining can improve the density and uniformity of the microstructure, and thus enhance the comprehensive mechanical properties of components built by WAAM.

Combustion synthesis of Si3N4 powder

1997 ◽  
Vol 12 (3) ◽  
pp. 805-811 ◽  
Author(s):  
Wei-Chang Lee ◽  
Shyan-Lung Chung
Keyword(s):  
Reaction Mechanism ◽  
Combustion Synthesis ◽  
Combustion Temperature ◽  
Fine Particles ◽  
Minor Amount ◽  
Synthesis Reaction ◽  
Experimental Parameters ◽  
Combustion Synthesis Reaction ◽  
A Minor ◽  
Low Nitrogen

A combustion synthesis (SHS) process has been developed for the synthesis of Si3N4 powder under low nitrogen pressures. Si and NaN3 powders were used as the reactants, and NH4Cl powder was added as a catalytic agent. These powders were mixed and pressed into a cylindrical compact. The compact was wrapped up with an igniting agent (i.e., Ti + C), and the synthesis reaction was triggered by the combustion of the igniting agent. Addition of NH4Cl was found necessary for the combustion synthesis reaction under low nitrogen pressures (< 1.2 MPa). The product as synthesized is mostly in the form of agglomerated fine particles (0.1–1 μm in diameter) and is composed mainly of α-phase and a minor amount of β-phase. Effects of various experimental parameters (N2 pressure, NaN3, NH4Cl, and Si3N4 contents) on the product conversion and the combustion temperature were investigated. A possible reaction mechanism was proposed that explains the effects of the experimental parameters on the synthesis reaction.

Sign in / Sign up

Export Citation Format

Share Document