نتایج جستجو برای: cracking

تعداد نتایج: 10846  

2013
Farouq Twaiq

The kinetics of palm oil catalytic cracking over aluminum containing mesoporous silica Al-MCM-41 (5% Al) was investigated in a batch autoclave reactor at the temperatures range of 573 – 673 K. The catalyst was prepared by using sol-gel technique and has been characterized by nitrogen adsorption and x-ray diffraction methods. Surface area of 1276 m/g with average pore diameter of 2.54 nm and por...

2005
Keijo M.J. Haataja

This report describes the details of two new proof-of-concept Bluetooth security analysis tools and two new attacks against Bluetooth security. On-Line PIN Cracking script is a security analysis tool for on-line Bluetooth device PIN cracking. Brute-Force BD ADDR Scanning script is a security analysis tool for brute-force discovery of the addresses of Bluetooth devices that want to be private. S...

2004
S. QU Y. HUANG H. JIANG C. LIU P. D. WU K. C. HWANG

In a remarkable series of experiments, Elssner et al. (1994) and Korn et al. (2002) observed cleavage cracking along a bimaterial interface between Nb and sapphire. The stress required for cleavage cracking is around the theoretical strength of the material. Classical plasticity models fall short to reach such a high stress level. We use the conventional theory of mechanism-based strain gradien...

2008
L. Daigle D. Cusson Z. Lounis

High performance concrete (HPC) bridge decks are prone to premature cracking if movement is restrained. Internal curing (IC) can reduce shrinkage cracking in concrete structures, thus improving their performance and service life. However, there is very limited information available in the literature on the possible extension of service life due to internal curing. This paper addresses this ques...

Journal: :international journal of civil engineering 0
p. ghoddousi a.m. raiss ghasemi t. parhizkar

plastic shrinkage is one of the most important parameter which must be considered in hot weather concreting. if plastic shrinkage is not prevented, cracking will be significant, especialy if silica fume is used in the mix. in this paper, the effect of silica fume in bleeding and evaporation was investigated in laboratory. the results showed that in restrained shrinkage, beside relative humidity...

2000
X. Tan Z. Xu J. K. Shang

In situ transmission electron microscopy study of electric field-induced cracking has been conducted on ^001& oriented 0.65Pb~Mg1/3Nb2/3!O3 – 0.35PbTiO3 crystal. Fracture of the 90° domain boundary was directly observed in the tetragonal area under both static and alternating electric fields. The field strength required to induce domain boundary cracking was lower for alternating electric field...

Journal: :Computers & Chemical Engineering 2012
Guihua Hu Honggang Wang Feng Qian Kevin M. Van Geem Carl M. Schietekat Guy B. Marin

A coupled reactor/furnace simulation has been conducted for a 100 kt/a SL-II naphtha cracking furnace containing both long-flame and radiation burners. The computational fluid dynamics approach was used to simulate the flow, combustion and radiative heat transfer in the furnace. The software packages COILSIM1D and SimCO were used to account for the cracking process in the reactor coils. The sim...

2014
Hongfang Ma Jianwen Li Haitao Zhang Qiwen Sun Weiyong Ying

Catalytic cracking of butene to propylene was carried out in a continuous-flow fixed-bed reactor over HZSM-5 catalysts modified by nickel and phosphorus. The structure and acidity of catalysts were measured by N2 adsorption, NH3-TPD and XPS. The results revealed that surface area and strong acid sites both decreased with increasing phosphorus loadings. The increment of phosphorus loadings reduc...

2003
Leena Lepistö Iivari Kunttu Jorma Autio Ari Visa

Surface reflection can be used as one quality assurance procedure to inspect the defects, cracking, and other irregularities occurring on a polished surface. In this paper, we present a novel approach to the detection of defects based on analysis of surface reflection images. In this approach, the surface image is analyzed using texture analysis based on Gabor-filtering. Gabor-filters can be us...

2016
Lei Wang Lizhao Dai Xuhui Zhang Jianren Zhang

The filling of strand corrosion products during concrete crack propagation is investigated experimentally in the present paper. The effects of stirrups on the filling of corrosion products and concrete cracking are clarified. A prediction model of crack width is developed incorporating the filling proportion of corrosion products and the twisting shape of the strand. Experimental data on cracki...

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