Factors Affecting the Pore Size in Porous Hydroxyapatite Produced by Stir-Froth-Polymerization Method

2007 ◽  
pp. 1571-1573
Author(s):  
Jie Zhang ◽  
Xiao Shan Ning ◽  
Qun Fang Xiao ◽  
Lei Yang ◽  
Ke Xin Chen ◽  
...  
Keyword(s):  
Pore Size ◽  
Porous Hydroxyapatite ◽  
Factors Affecting ◽  
Polymerization Method

Factors Affecting the Pore Size in Porous Hydroxyapatite Produced by Stir-Froth-Polymerization Method

2007 ◽  
Vol 336-338 ◽  
pp. 1571-1573
Author(s):  
Jie Zhang ◽  
Xiao Shan Ning ◽  
Qun Fang Xiao ◽  
Lei Yang ◽  
Ke Xin Chen ◽  
...  
Keyword(s):  
Cell Size ◽  
Porous Ceramics ◽  
Ceramic Powders ◽  
Average Cell Size ◽  
Average Cell ◽  
Porous Hydroxyapatite ◽  
Factors Affecting ◽  
Polymerization Method ◽  
Highly Porous ◽  
Aqueous Slurry

Stir-froth-polymerization is a novel technique for producing highly porous ceramics, in which bubbles are formed by a mechanical frothing in aqueous slurry of ceramic powders. Many work had be done about the porosity, the permeability and the mechanical strength of the porous ceramics derived from this method, but there are still a lot of things remain unclear. This paper focuses on the mechanism of frothing, and the influence of parameters in the mechanical frothing. It was found that the stir time, the stir speed and the viscosity of the slurry have influence on the average cell-size and the distribution of them respectively. The average cell-size can be controlled in the range from 60 to 160 μm by adjusting the parameters.

scholarly journals The nylon bag technique in the determination of ruminal feed protein degradation

1983 ◽  
Vol 55 (1) ◽  
pp. 1-78 ◽  
Author(s):  
Jouko Setälä
Keyword(s):  
Particulate Matter ◽  
Pore Size ◽  
Control Sample ◽  
Sample Treatment ◽  
Sample Weight ◽  
Factors Affecting ◽  
Experimental Animals ◽  
Incubation Periods ◽  
Feed Protein

The investigation included experiments in which factors affecting the reliability of the nylon bag method were studied. The possibility of applying the feed protein degradabilities to practical feeding conditions was also examined. In the experiments concerning reliability, such factors as bag porosity, sample weight, sample treatment, washing procedure, diets, and differences between animals and incubation days were studied. The feed protein degradabilities were also determined by using as incubation periods the ruminal retention times for particulate matter of different feeds, evaluated as a function of DM intake/100 kg liveweight in different diets. A nylon bag, with a pore size of 40 µm and internal dimensions of 6 X 12 cm was selected for the degradability determinations. The sample weight used in incubations was 57 —60  mg DM/cm2. In the determination of feed protein degradability, when sheep are used as experimental animals, it is recommended that for routine determinations only one animal be used, analyzing the contents of two bags for each incubation period during two successive days. A control sample of which degradability is determined in advance in many sheep, should be used in all incubations in order to control the digestive processes in the rumen of the experimental sheep. The actual degradabilities analyzed by the bag method are applicable in practise, if they are determined using animals at similar feeding levels and on diets similar to those prevailing under the conditions in which the degradabilities are going to be used.

Hydroxyapatite-Collagen Composite Made from Coral and Chicken Claws for Bone Implant Application

2019 ◽  
Vol 966 ◽  
pp. 145-150
Author(s):  
Siswanto ◽  
Dyah Hikmawati ◽  
Aminatun ◽  
Miranda Zamawi Ichsan
Keyword(s):  
Compressive Strength ◽  
Pore Size ◽  
Functional Groups ◽  
Strength Test ◽  
Precipitation Method ◽  
Cytotoxicity Test ◽  
Bone Implant ◽  
Porous Hydroxyapatite ◽  
Collagen Formation ◽  
Compressive Strength Test

Synthesis of porous hydroxyapatite-collagen composites for bone implant applications has been carried out. Hydroxyapatite synthesized from coral by the precipitation method, while Collagen synthesized from chicken claws. Collagen formation was carried out by freeze-dry technique with variations in freezing time of 2, 4 and 6 hours at -80 ° C. The next process was by drying in a lyophilizer. Characterization of samples was carried out using Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy (SEM), compressive strength test and cytotoxicity test with Microtetrazolium (MTT) assay. FTIR results proved that collagen uptake and hydroxyapatite combine chemically. This is indicated by the absorption of functional groups that did not coincide between collagen and hydroxyapatite functional groups with composites. SEM observations showed that the largest pore size was obtained at freezing for 2 hours which was 774 μm and the smallest in freezing for 6 hours was 640 μm. This pore size was an important parameter of the bone implant because it played a role in the osteoinductive process. The composite compressive strength test results for freezing 2 hours, 4 hours and 6 hours respectively was 737 KPa, 842 KPa and 707.7 KPa. The results of the cytotoxicity test with MTT showed the percentage of cell viability above 100%. This means that the Hydroxyapatite-collagen composite is non-toxic. So, the sample formed has qualified as a bone implant candidate.

Effects of Pore Size on Osteoconduction at the Porous Hydroxyapatite

1999 ◽  
Vol 34 (1) ◽  
pp. 37 ◽  
Author(s):  
Sung Soo Chung ◽  
Kug Sun Hong ◽  
Hyuk Joon Youn ◽  
Bong Soon Chang ◽  
Jin Sup Yeom ◽  
...  
Keyword(s):  
Pore Size ◽  
Porous Hydroxyapatite

Effect of Biomass-Based Catalyst in Walnut Shell/Polypropylene to BTX

2021 ◽  
pp. 11-28
Author(s):  
Yanan Guo ◽  
Xin Pan ◽  
Qingjiao Zhu ◽  
Jingjing Ma ◽  
Qingjie Guo
Keyword(s):  
Pore Size ◽  
Catalytic Effect ◽  
Cycling Performance ◽  
Cycle Performance ◽  
Walnut Shell ◽  
Mass Yield ◽  
Key Factors ◽  
Factors Affecting ◽  
Benzene Toluene ◽  
Catalyst Carriers

Four biomass-based catalyst carriers with different pore structures were prepared by using a carbonization-activation method, followed by employment in the copyrolysis of Walnut Shell/Polypropylene (WNS/PP) to produce Benzene, Toluene and Xylene (BTX). Ten cycles were performed in each copyrolysis test in a bench-scaled tube furnace to determine the suitable pore size of the catalyst and excellent cycling performance for BTX production. In addition, Zn, Ni, and Ce were loaded with the selected catalyst carriers to synthesize the most suitable biomass-based catalyst. Results showed that the pore size and active center of the catalyst were the key factors affecting the WNS/PP catalytic copyrolysis. Biomass-based carrier with a pore size in the range of 0.55-1.2 nm was the most suitable to produce BTX in the optimal 10 cycle performance; it realized a relative BTX content of 9-20 area%, and a BTX mass yield of 23-67 mg/(graw) in the liquid-phase products from the WNS/PP copyrolysis. A catalyst loaded with 10 wt% Zn possessed the best catalytic effect with a relative BTX content of 39.49 area%, and a BTX yield of 111.13 mg/(graw)

Microstructure Designing of Porous β-Tricalcium Phosphate for Control of Reactions in the Bone

2007 ◽  
Vol 361-363 ◽  
pp. 989-992 ◽  
Author(s):  
Koji Ioku ◽  
Masanobu Kamitakahara ◽  
Giichiro Kawachi ◽  
Yoshinori Gonda ◽  
Takatoshi Okuda ◽  
...  
Keyword(s):  
Particle Size ◽  
Bone Graft ◽  
Porous Materials ◽  
Pore Size ◽  
Hydrothermal Method ◽  
Tricalcium Phosphate ◽  
Molar Ratio ◽  
Graft Material ◽  
Porous Hydroxyapatite ◽  
Unique Method

Porous materials of β-tricalcium phosphate (β-Ca3(PO4)2; β-TCP) were prepared from porous hydroxyapatite (Ca10(PO4)6(OH)2; HA) with calcium deficient composition of Ca/P molar ratio of 1.50 synthesized by hydrothermal method. The porous β-TCP was composed of rod-shaped particles of about 10-20 μm in length. Rod-shaped particles were locked together to make micro-pores, and the size of micro-pores formed by tangling of rod-shaped particles was about 0.1-0.5 μm. The particle size and micro-pore size could be controlled by our unique method. It must be suitable for the bone graft material and as the scaffold of cultured bone.

scholarly journals An experimental study on change of gas permeability depending on pore structures in three species (hinoki, Douglas fir, and hemlock) of softwood

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Eun-Suk Jang ◽  
Jee-Hoon Yuk ◽  
Chun-Won Kang
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Capillary Flow ◽  
Gas Permeability ◽  
Douglas Fir ◽  
International Union ◽  
Factors Affecting ◽  
Novel Method ◽  
Significant Factors

Abstract The purpose of this study is to analyze the pore structure for the heartwood, intermediate wood, and sapwood sections in three species of softwood (hinoki, Douglas fir, and hemlock) and to investigate the correlation of gas permeability depending on pore structure. For this study, gas permeability and pore size were measured by capillary flow porometry, and classification of a novel method was performed to determine the type of pores (through pores, blind pores, and closed pores) based on International Union of Pure and Applied Chemistry (IUPAC). Gas permeability, through pore porosity, and pore size increased from heartwood to sapwood. The results of multiple regression analysis showed that through pore porosity, mean pore size, and bulk density were significant factors affecting gas permeability.

Effective factors on thermal conductivity of stochastic structures open cell metal foams

2020 ◽  
Vol 21 (4) ◽  
pp. 410
Author(s):  
Milad Saljooghi ◽  
Abbas Raisi ◽  
Amir Farahbakhsh
Keyword(s):  
Thermal Conductivity ◽  
Pore Size ◽  
Shape Factor ◽  
Physical Property ◽  
Metal Foams ◽  
Primary Role ◽  
Open Cell ◽  
Factors Affecting ◽  
Pressure Parameter ◽  
Experimental Approaches

Effective thermal conductivity (ETC) is a considerable thermo-physical property in design, manufacturing, and usage of multifunctional equipment that benefit cellular structures such as open-cell metal foams. An accurate understanding of key parameters effecting on ETC is classified by: Analytical, Numerical and Experimental approaches. In this study, a comprehensive investigation based on mentioned approaches is presented and a comparison between various factors affecting ETC including porosity, pore size, temperature, pressure and shape factor is made. Porosity and pore size, as main morphological features of open-cell metal foams, indicate structural characterization of them. Increase of porosity and pore size resulted decrease of ETC. The temperature effects on ETC in case of temperatures lower than 250 °C is ignorable although for temperature higher than 500 °C with change of heat transfer mechanism temperature plays a primary role in determining ETC. Few studies have been made on pressure parameter that illustrated its effect on ETC is insignificant. Multiple manufacturing methods produce different topological structures so; the influence of shape factor on ETC requires more efforts to reach a better understanding. Finally, applicable techniques for measuring ETC are briefly discussed.

scholarly journals Preparation of microfiltration ceramic membranes

2021 ◽  
Vol 57 (1) ◽  
pp. 25-32
Author(s):  
A. I. Ivanets
Keyword(s):  
Tensile Strength ◽  
Pore Size ◽  
Average Pore Size ◽  
Ceramic Membranes ◽  
Porous Ceramics ◽  
Optimal Conditions ◽  
Natural Quartz ◽  
Average Pore ◽  
Factors Affecting ◽  
Water Capacity

The main factors affecting the physicochemical properties of microfiltration ceramic membranes based on natural quartz sand were studied. It was found that samples of large-porous ceramics with a content of 11.0 wt. % of the aluminosilicate binder and 10.0 wt. % of the burning additive are characterized by average pore size of 22±3.02 µm, water capacity of 54±5.0 m3/(h×m2×bar), and tensile strength of 9.0±0.6 bar. The optimal conditions for membrane layers coating were determined, which allowed obtaining microfiltration ceramic membranes with average pore size of 2.3±0.2 µm, water capacity of 26±1.0 m3/(h×m2×bar) and tensile strength of 6.5±0.3 bar.

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