scholarly journals A new method for the analysis of compaction processes in high-porosity agglomerates

2007 ◽  
Vol 10 (2) ◽  
pp. 89-91 ◽  
Author(s):  
L. -O. Heim ◽  
H. -J. Butt ◽  
J. Blum ◽  
R. Schräpler
2007 ◽  
Vol 544-545 ◽  
pp. 789-792 ◽  
Author(s):  
Li Zhang ◽  
Yu Bao Li ◽  
Pu Jiang Shi ◽  
Yi Zuo ◽  
Lan Wu

A novel nano-hydroxyapatite/chitosan (n-HA/CS) composite scaffold with high porosity was developed by a new method of emulsion-foaming/freeze-drying process and was characterized by means of infrared spectroscopy (IR), scanning electronic microscopy (SEM) and universal material testing machine. In addition, the porosity and density of the scaffold were also calculated. IR result shows that the characteristic absorption peaks belonging to both CS and HA are present in their composite, and the slight band-shifts and peak-decrease suggest that some interactions have taken place between the two phases of CS and n-HA in the composite. SEM photo displays that, with the dosage increase of Tween-80, the prepared scaffold shows highly porous and interconnected structure, in which macropores and micropores coexist. The calculated data demonstrate that the porosity of the scaffold is proportional to the content of the emulsifier, while the compressive strength is inversely. When 15wt% emulsifier used, the porosity of the scaffold can be up to 90% and the density is 0.453g/cm3, while the corresponding compressive strength is about 2.4MPa. The newly developed n-HA/CS composite scaffolds may serve as a good 3-D substrate for cell attachment and migration in bone tissue engineering.


1997 ◽  
Vol 152 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Kei-ichi Koizumi ◽  
Yoshiteru Watanabe ◽  
Kumiko Morita ◽  
Naoki Utoguchi ◽  
Mitsuo Matsumoto
Keyword(s):  

Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.


Author(s):  
H. M. Kerch ◽  
R. A. Gerhardt

Highly porous ceramics are employed in a variety of engineering applications due to their unique mechanical, optical, and electrical characteristics. In order to achieve proper design and function, information about the pore structure must be obtained. Parameters of importance include pore size, pore volume, and size distribution, as well as pore texture and geometry. A quantitative determination of these features for high porosity materials by a microscopic technique is usually not done because artifacts introduced by either the sample preparation method or the image forming process of the microscope make interpretation difficult.Scanning electron microscopy for both fractured and polished surfaces has been utilized extensively for examining pore structures. However, there is uncertainty in distinguishing between topography and pores for the fractured specimen and sample pullout obscures the true morphology for samples that are polished. In addition, very small pores (nm range) cannot be resolved in the S.E.M. On the other hand, T.E.M. has better resolution but the specimen preparation methods involved such as powder dispersion, ion milling, and chemical etching may incur problems ranging from preferential widening of pores to partial or complete destruction of the pore network.


1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document