scholarly journals The influence of activation and relaxation time on the synthesis of cordierite ceramics

2006 ◽  
Vol 71 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Natasa Djordjevic ◽  
Ljubica Pavlovic
Keyword(s):  
Relaxation Time ◽  
Specific Surface ◽  
Ftir Spectroscopy ◽  
Sintering Temperature ◽  
Mechanochemical Activation ◽  
Component System ◽  
Temperature Changes ◽  
Bet Method ◽  
Cordierite Ceramics ◽  
Induced Changes

Due to its properties, cordierite, 2MgO.2Al2O3 .5SiO2, is nowadays an attractive ceramic material for various applications. Mechanochemical activation of the initial components was used in order to decrease the sintering temperature. Changes in the specific surface area of the activated components were determined by the BET method. The TG and DTA methods were used to monitor the temperature induced changes in the analyzed three-component system. The influence of the relaxation time on the activated components was analyzed by FTIR spectroscopy of both the initial components and the activated mixture after 24 h and 24 months relaxation periods. .

Olfactory bulbectomy-induced changes in phospholipids and protein profiles in the hippocampus and prefrontal cortex of rats. A preliminary study using a FTIR spectroscopy

2016 ◽  
Vol 68 (3) ◽  
pp. 521-528 ◽  
Author(s):  
Joanna Depciuch ◽  
Magdalena Sowa-Kućma ◽  
Paulina Misztak ◽  
Bernadeta Szewczyk ◽  
Gabriel Nowak ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Ftir Spectroscopy ◽  
Olfactory Bulbectomy ◽  
Protein Profiles ◽  
Preliminary Study ◽  
Induced Changes

Preparation of Porous Wollastonite Ceramics for Filtration

2007 ◽  
Vol 336-338 ◽  
pp. 1102-1104 ◽  
Author(s):  
Ming Sheng He ◽  
Jian Bao Li ◽  
Bo Wen Li ◽  
Hong Lin ◽  
Xiao Zhan Yang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sintering Temperature ◽  
Porous Ceramics ◽  
Holding Time ◽  
Starting Material ◽  
Sintering Method

Wollastonite powder was selected as a starting material with carbonate as pore-forming agent and binder added. The porous ceramics were prepared at different temperature by sintering method. The process includes batching, granulating, pressing molding, drying and sintering. It is discussed the influence of sintering temperature, dosage of binder, dosage of pore-forming agent, pressure of molding and holding time on the performance of porous ceramics. According to the principle of particles stack, the porous wollastonite ceramics for filtration with various diameters, shapes and porosity were fabricated by serial experiments. These products have 1 to 10 microns in pore size, 30.04 to 66.15% in porosity, 2.82 m2/g in specific surface area.

Stability of sepiolite in neutral and alkaline media at room temperature

Clay Minerals ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 225-232 ◽  
Author(s):  
S. Martinez-Ramirez ◽  
F. Puertas ◽  
M. T. Blanco-Varela
Keyword(s):  
Specific Surface ◽  
Crystallite Size ◽  
Structural Stability ◽  
Chemical Stability ◽  
Structural Changes ◽  
Alkaline Media ◽  
Bet Method ◽  
Water Ph ◽  
Kinetic Test ◽  
Neutral Media

AbstractThe chemical and structural stability of a Spanish sepiolite from Vallecas, Spain, was studied in 0.04 n NaOH (pH = 12.6), a saturated solution of Ca(OH)2 (pH = 12.6) and deionized/distilled water (pH = 7). The chemical stability was evaluated by determining the concentrations of Mg, Si and Ca in the solid residues during the kinetic test. The structural stability was studied by determining the changes in specific surface area and ‘crystallite’ size. The specific surface was determined by the BET method and the ‘crystallite’ size by the profile of the X-ray diffraction line. The main conclusion was that sepiolite is a material with high chemical stability in neutral and alkaline media, with no significant structural changes. However, in alkaline media, greater dissolution of silica was observed than in neutral media, the silica being derived from the most external tetrahedra attached to the OH− groups.

Effects of SiO2 Particles in Mechanical Properties of Iron Composite

2013 ◽  
Vol 465-466 ◽  
pp. 886-890
Author(s):  
Adibah Amir ◽  
Othman Mamat
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Fine Particles ◽  
Sintering Temperature ◽  
Silica Particles ◽  
Milling Process ◽  
Powder Metallurgy Technique ◽  
Temperature Changes ◽  
Different Temperatures

Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.

Behavior of Cs in Grimsel granodiorite: sorption on main minerals and crushed rock

2016 ◽  
Vol 0 (0) ◽  
Author(s):  
Eveliina Muuri ◽  
Jussi Ikonen ◽  
Minja Matara-aho ◽  
Antero Lindberg ◽  
Stellan Holgersson ◽  
...  
Keyword(s):  
Specific Surface ◽  
Test Site ◽  
Potassium Feldspar ◽  
Distribution Coefficients ◽  
Crushed Rock ◽  
Surface Areas ◽  
Bet Method ◽  
Grimsel Test Site ◽  
Specific Surface Areas ◽  
Phreeqc Modelling

AbstractIn this study the sorption of cesium was investigated on four different minerals; quartz, plagioclase, potassium feldspar and biotite as well as granodiorite obtained from the Grimsel test site in Switzerland. The experiments were conducted in the presence of the weakly saline Grimsel groundwater simulant by determining the distribution coefficients using batch sorption experiments and PHREEQC-modelling across a large concentration range. In addition, the purity of the minerals was measured by XRD and the specific surface areas by BET method using krypton. The distribution coefficients of cesium were largest on biotite (0.304 ± 0.005 m

Relationship between Viscoelastic Properties and Characteristics of Filler-Gel in Filled Rubber System

1999 ◽  
Vol 72 (4) ◽  
pp. 657-672 ◽  
Author(s):  
Fumito Yatsuyanagi ◽  
Hiroyuki Kaidou ◽  
Masayoshi Ito
Keyword(s):  
Relaxation Time ◽  
Viscoelastic Properties ◽  
Rolling Resistance ◽  
Rubber Composites ◽  
Component System ◽  
Filled Rubber ◽  
Wide Line ◽  
Dynamic Storage ◽  
Tan Δ ◽  
Multi Component System

Abstract The wide-line NMR and viscoelastic measurements were carried out for the filled rubber systems. NMR results revealed that the filler-gel in the filled rubber composites had a multi-component system depending on the mobility of rubber molecules. The fraction and the spin-spin relaxation time of each component were well correlated with the viscoelastic properties such as dynamic storage modulus (E′) and loss-tangent (tan δ) of the filled rubber systems. Such findings turned out to be useful in designing new tread materials with well-balanced wet traction and rolling resistance in tires.

The Influence of Sinterng Temperature on the Phase, Microstructure and Textual Properties of Hollow Hydroxyapatite Microspheres

2011 ◽  
Vol 239-242 ◽  
pp. 2274-2279 ◽  
Author(s):  
Ying Chun Wang ◽  
Wen Hai Huang ◽  
Ai Hua Yao ◽  
De Ping Wang
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Sintering Temperature ◽  
Total Pore Volume ◽  
Precipitation Method ◽  
Simple Method ◽  
Air Atmosphere

A simple method to prepare hollow hydroxyapatite (HAP) microspheres with mespores on the surfaces is performed using a precipitation method assisted with Li2O-CaO-B2O3(LCB) glass fabrication process. This research is concerned with the effect of sintering temperature on the microstructure evolution, phase purity, surface morphology, specific surface area, and porosity after sintering process. The microspheres were sintered in air atmosphere at temperatures ranging from 500 to 900 °C. The starting hollow HAP microspheres and the sintered specimens were characterized by scanning electron microscope, X-ray diffractometer, specific surface area analyzer, and Hg porosimetry, respectively. The as-prepared microspheres consisted of calcium deficient hydroxyapatite. The results showed that the as-prepared hollow HAP microspheres had the highest specific surface areas, and the biggest total pore volume. The pore size distribution of the as-prepared hollow HAP microspheres were mainly the mesopores in the range of 2～40 nm. The specific surface area and total pore volume of hollow HAP microspheres decreased with increasing sintering temperature. Whereas the mean pore size increased with increasing sintering temperature. It showed that at 700°C, Ca-dHAP decomposes into a biphasic mixture of HAP and β-calcium phosphate(TCP).

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