Mg,Al-mixed oxide system: Synthesis under hydrothermal conditions, physico-chemical characterisation and application as an efficient catalyst for imidazole methylation

2005 ◽  
Vol 292 ◽  
pp. 208-214 ◽  
Author(s):  
Hanna Grabowska ◽  
Mirosław Zawadzki ◽  
Ludwik Syper ◽  
Włodzimierz Miśta
Keyword(s):  
Mixed Oxide ◽  
Oxide System ◽  
Hydrothermal Conditions ◽  
Efficient Catalyst ◽  
System Synthesis ◽  
Physico Chemical

Mechanical, thermal and physico-chemical behavior of virgin and hydrothermally aged polymeric pipes

2020 ◽  
pp. 089270572096216 ◽  
Author(s):  
Houcine Jemii ◽  
Dalila Hammiche ◽  
Abid Boubakri ◽  
Nader Haddar ◽  
Noamen Guermazi
Keyword(s):  
Aging Temperature ◽  
Accelerated Aging ◽  
Pipe Material ◽  
Hydrothermal Conditions ◽  
Hydrothermal Aging ◽  
Aged Material ◽  
Physico Chemical ◽  
Aging Response ◽  
Strength And Stiffness ◽  
Composite Pipes

In this paper, an experimental study was conducted to characterize industrial PVC pipes and to investigate the effect of hydrothermal aging on their physico-chemical, thermal, and mechanical behavior. Three temperature (25°C, 60°C and 90°C) and full immersion in distilled water were retained as accelerated hydrothermal conditions. Kinetic of water absorption was examined and Fickian behavior was observed. The aging temperature was found to influence the water uptake behavior of PVC samples. Thermogravimetric analysis (TGA) has proved that the pipe material is not pure, while it consists of PVC reinforced with calcium carbonate (CaCO3). After exposure to accelerated aging, TGA and FTIR analysis exhibit preliminary signs of degradation of PVC samples under the retained conditions. Changes affecting the shape and the color of aged samples were examined. Mechanical properties have been characterized, after immersion of 30 days, with an improvement of strength and stiffness of the aged samples, in particular at elevated aging temperature. However, the aging response is accompanied by a loss of ductility for the aged material. These results, even for brief exposure, could help to understand the behavior of PVC composite pipes under hydrothermal conditions.

Ca-Sr-Ga-Nb mixed oxide system for high temperature superconductor substrate applications

1994 ◽  
Vol 139 (1-2) ◽  
pp. 54-66 ◽  
Author(s):  
S. Erdei ◽  
L.E. Cross ◽  
F.W. Ainger ◽  
A. Bhalla
Keyword(s):  
High Temperature ◽  
Mixed Oxide ◽  
High Temperature Superconductor ◽  
Oxide System

Mössbauer studies in thermally treated iron-samarium mixed oxide system

1994 ◽  
Vol 186 (6) ◽  
pp. 455-462
Author(s):  
R. Garg ◽  
V. K. Garg ◽  
I. Czakó-Nagy ◽  
S. Nagy ◽  
E. Kuzmann ◽  
...  
Keyword(s):  
Mixed Oxide ◽  
Oxide System ◽  
Mössbauer Studies ◽  
Thermally Treated

Features of Ferroelectric States in the Simple-Perovskite Mixed-Oxide System (1−x)Pb(Zn1/3Nb2/3)O3–xPbTiO3 with Lower Ti Contents

2016 ◽  
Vol 85 (3) ◽  
pp. 034708 ◽  
Author(s):  
Hirofumi Tsukasaki ◽  
Yuka Uneno ◽  
Shigeo Mori ◽  
Yasumasa Koyama
Keyword(s):  
Mixed Oxide ◽  
Oxide System ◽  
System 1

LDH-derived catalysts for complete oxidation of volatile organic compounds

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 67-77 ◽  
Author(s):  
K. Bahranowski ◽  
E. Bielańska ◽  
R. Janik ◽  
T. Machej ◽  
E. M. Serwicka
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Copper Chromite ◽  
Oxide System ◽  
High Catalytic Activity ◽  
Commercial Catalyst ◽  
Volatile Organic ◽  
Double Hydroxides ◽  
Very High

AbstractThe Cu,Cr-, Zn,Cr- and Cu,Al-layered double hydroxides have been synthesized by the coprecipitation method and characterized by elemental analysis, PXRD, SEM/EDS and BET. The mixed oxide materials obtained upon calcination at 873 K show very high catalytic activity for the combustion of toluene and ethanol. The best sample is derived from the Cu,Cr-LDH precursor with a Cu:Cr ratio of 2, composed of copper oxide and copper chromite. This catalyst gave 50% conversion of toluene and ethanol at temperatures of 45 and 15 K lower, respectively, than the reference commercial catalyst. Catalytic tests with a mechanical mixture of CuO and CuCr2O4 demonstrate that the use of an LDH precursor is essential for optimum results. The importance of the simultaneous presence of both Cu and Cr, the influence of the Cu:Cr ratio on the catalytic activity and the role of the interface boundaries in the CuO-CuCr2O4 mixed oxide system are discussed.

Physico-chemical study on the state of cobalt in a precipitated cobalt-aluminum oxide system

2002 ◽  
Vol 4 (17) ◽  
pp. 4236-4243 ◽  
Author(s):  
Alexander A. Khassin ◽  
Vladimir F. Anufrienko ◽  
Vladimir N. Ikorskii ◽  
Lyudmila M. Plyasova ◽  
Galina N. Kustova ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
Chemical Study ◽  
Oxide System ◽  
The State ◽  
Physico Chemical

Ce–Ni mixed oxide as efficient catalyst for H2 production and nanofibrous carbon material from ethanol in the presence of water

RSC Advances ◽  
2012 ◽  
Vol 2 (25) ◽  
pp. 9626 ◽  
Author(s):  
Wenhao Fang ◽  
Cyril Pirez ◽  
Mickaël Capron ◽  
Sébastien Paul ◽  
Thirumalaiswamy Raja ◽  
...  
Keyword(s):  
Mixed Oxide ◽  
Carbon Material ◽  
H2 Production ◽  
Efficient Catalyst ◽  
Nanofibrous Carbon
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