Silica in Woody Stems

1974 ◽  
Vol 22 (2) ◽  
pp. 211 ◽  
Author(s):  
G Scurfield ◽  
CA Anderson ◽  
ER Segnit
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Xylem Parenchyma ◽  
X Ray ◽  
Woody Perennial ◽  
Internal Surfaces ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells ◽  
Scanning Electron

Scanning electron microscopy has been used to examine silica isolated by chemical means from the wood of 32 species of woody perennial. The silica consists of aggregate grains lying free in the lumina or in ray and xylem parenchyma cells in 24 of the species. It occurs as dense silica in the other species, filling the lumina or lining the internal surfaces of vessels (and fibres) in all cases except Gynotroches axillaris where it is deposited in ray parenchyma cells. Infrared spectra and X-ray diffraction diagrams, obtained for specimens of both sorts of silica, are indistinguishable from those for amorphous silica. Aggregate grain and dense silicas are also alike in that their differential thermal analysis curves show a rather broad endothermic peak between 175° and 205°C. The results are discussed in relation to possible modes of deposition of the two sorts of silica and the tendency for silica in ray parenchyma cells to be associated with polyphenols.

scholarly journals Effect of Surfactant Addition on Bi2Te3 Nanostructures Synthesized by Hydrothermal Method

2017 ◽  
Vol 62 (2) ◽  
pp. 1005-1010 ◽  
Author(s):  
Peyala Dharmaiah ◽  
C.H. Lee ◽  
B. Madavali ◽  
Soon-Jik Hong
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Figure Of Merit ◽  
Bulk Sample ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coarse Grains ◽  
Scanning Electron ◽  
Nanostructured Sample

AbstractIn the present work, we have prepared Bi2Te3nanostructures with different morphologies such as nano-spherical, nanoplates and nanoflakes obtained using various surfactant additions (EG, PVP, and EDTA) by a hydrothermal method. The shape of the nanoparticles can be controlled by addition of surfactants. The samples were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that the minority BiOCl phase disappears after maintained pH at 10 with EG as surfactant. SEM bulk microstructure reveals that the sample consists of fine and coarse grains. Temperature dependence of thermoelectric properties of the nanostructured bulk sample was investigated in the range of 300-450K. The presence of nanograins in the bulk sample exhibits a reduction of thermal conductivity and less effect on electrical conductivity. As a result, a figure of merit of the sintered bulk sample reached 0.2 at 400 K. A maximum micro Vickers hardness of 102 Hv was obtained for the nanostructured sample, which was higher than the other reported results.

INHIBITION OF WATER CONDUCTIVITY CAUSED BY WATERMARK DISEASE IN SALIX SACHALINENSIS

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Yasuaki Sakamoto ◽  
Yuzou Sano
Keyword(s):  
Wood Anatomy ◽  
High Moisture ◽  
Water Conductivity ◽  
X Ray ◽  
Salix Sachalinensis ◽  
Water Conduction ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
High Moisture Level ◽  
Ray Parenchyma Cells

Water conduction and wood anatomy of Salix sachalinensis attacked by watermark disease were investigated. The internal symptom, the watermark, appeared as a brown to brown-black stained zone in sapwood. Dye injection tests revealed that water conduction did not take place in the watermark. However, soft X-ray photography and cryo-scanning electron microscopy revealed that the watermark had a high moisture level. In the watermark, some of the vessels were plugged with tyloses and masses of bacteria, and some of the ray parenchyma cells caused necrosis. Hence, the non-conductive watermark in sapwood can be considered similar to discoloured wood or wetwood.

Wood Anatomy of Bhesa Sinica (Celastraceae)

IAWA Journal ◽  
1990 ◽  
Vol 11 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Zhang Xinying ◽  
Pieter Baas ◽  
Alberta M. W. Mennega
Keyword(s):  
Wood Anatomy ◽  
The Other ◽  
Anatomical Character ◽  
The Family ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Parenchyma Cells

The wood anatomy of Bhesa sinica (Chang ' Liang) Chang ' Liang, the only species of the genus occurring in China, is described in detail and compared with other Celastraceae. Bhesa sinica closely resembles other species of the genus, in e. g. vessels mainly in radial multiples, exclusively scalariform perforations, large and (almost) simple vessel-ray pits; parenchyma in fine irregular bands, in long (over 8-celled) strands; thick-walled, non septate libriform fibres; 1-5-seriate heterocellular rays, and prismatic crystals in chambered axial and ray parenchyma cells. This combination of characters is not known to occur in any of the other genera of the Celastraceae, and most individual wood anatomical character states of Bhesa are also unusual within the family. The isolated position of the genus in the Celastraceae is discussed.

Influence of NaCl on Mechanical Properties and Microstructure of Cement Stone

2013 ◽  
Vol 700 ◽  
pp. 136-139
Author(s):  
Xin Tang ◽  
Jin Huang
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Crystalline Phase ◽  
The Other ◽  
Cement Stone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Crystalline Phase ◽  
Gel Phase ◽  
Scanning Electron

The mechanical properties and microstructure of cement stone containing different sodium chloride (NaCl) have been investigated. Uni-axial compression experiments were used to study mechanical properties. The main crystalline phase composition of cement specimens was determined by means of X-ray diffraction (XRD). Surface morphology of cement stone was observed by using scanning electron microscopy (SEM). The obtained results showed that compared with the other samples, the sample incorporated 14% sodium chloride was quite different, whose compressive strength was higher and microstructure was denser. The sodium chloride crystalline phase and the hydration (C-S-H) gel phase co-existed.

Electrical Porcelain Containing Ornamental Rock Waste: Microstructural Development

2010 ◽  
Vol 660-661 ◽  
pp. 692-696 ◽  
Author(s):  
M.A. Silva ◽  
J.N.F. Holanda
Keyword(s):  
Electron Microscopy ◽  
The Other ◽  
Electrical Porcelain ◽  
Microstructural Development ◽  
Chemical Transformations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminous Porcelain ◽  
Physical And Chemical ◽  
Scanning Electron

Aluminous electrical porcelains are used in the production of materials of high voltage insulators. The microstructure plays an important role in the performance of electrical porcelain. On the other hand, the porcelain materials undergo a series of physical and chemical transformations during firing. This makes the understanding of their microstructures rather complex. In this work was studied the microstructural development of electrical porcelain containing up to 35 wt.% of ornamental rock waste. The pieces ceramics were pressed at 50 MPa and sintered at 1300 °C. The porcelain pieces were characterized via X-ray diffraction and scanning electron microscopy. The results indicate that the presence of the ornamental rock waste influenced the microstructural development of the pieces of electrical aluminous porcelain.

scholarly journals Synthesis of Zeolite A employing Amazon kaolin waste

Cerâmica ◽  
2015 ◽  
Vol 61 (360) ◽  
pp. 409-413 ◽  
Author(s):  
S. H. da Silva Filho ◽  
L. Bieseki ◽  
A. R. da Silva ◽  
A. A. B. Maia ◽  
R. A. S. San Gil ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Amorphous Materials ◽  
Mas Nmr ◽  
The Other ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
X Ray ◽  
27Al Mas Nmr ◽  
Scanning Electron

Abstract The synthesis of zeolite A employing kaolin waste from paper coating was studied. The kaolin waste was pre-treated at 550 to 800 ºC. For comparison purposes, a sample of zeolite A was also prepared using the IZA procedure. The materials were characterized by 27Al MAS NMR, X-ray diffraction and scanning electron microscopy using a microprobe. Pretreatment was necessary, and the best temperatures were between 600 and 700 ºC. The zeolite A formation was observed in all the prepared materials, reaching 52% crystallinity. On the other hand, the sodalite phase and amorphous materials were also formed.

Template-Free Synthesis of α-Fe2O3 Hollow Spheres and Nanocubes

2011 ◽  
Vol 361-363 ◽  
pp. 2012-2015
Author(s):  
Chang Yun Chen ◽  
Feng Zhou ◽  
Chun Hua ◽  
Zhao Hui Li ◽  
Huan Pang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hollow Spheres ◽  
Magnetic Characteristic ◽  
The Other ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Template Free ◽  
Scanning Electron

A facile hydrothermal method without any templates has been developed for the preparation of α- Fe2O3nanocubes and hollow spheres. The as-synthesized products is then characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM). The nanocubes have extraordinary unity and we can anticipate its unique magnetic characteristic. On the other hand, the hollow sphere structure has a promising future in the application as carriers for targeting drug delivery. In our opinions, the method is not only very simple, but also is very friendly to the environment.

Effect of Ammonia on the SiO2 Colloidal Particles Synthesized by the Stöber Method

2017 ◽  
Vol 865 ◽  
pp. 25-29 ◽  
Author(s):  
Yun Gao Cai ◽  
Xin Qi Li
Keyword(s):  
Size Distribution ◽  
Room Temperature ◽  
Colloidal Particles ◽  
Size Range ◽  
Tetraethyl Orthosilicate ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Result Show ◽  
Scanning Electron

Various sizes SiO2 colloidal particles in the size range of 260-950 nm were synthesized by the stöber method by adjusting the amount of ammonia from 9.0 ml to 3.0 ml while keeping 20.0 ml tetraethyl orthosilicate (TEOS), 125.0 ml ethanol, 6.0 ml ammonia and 18.0 ml distilled water fixed. In addition, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the crystallinity and morphology of the synthesized SiO2 colloidal particles; the XRD result show that the SiO2 colloidal particles are amorphous at room temperature; the SEM results demonstrated that the amount of ammonia could have significant effects on the size, size distribution and sphericity of the SiO2 colloidal particles. SiO2 colloidal particles were resulted with good monodispersity when the amount of ammonia was in the range of 6.0-90 ml, while SiO2 colloidal particles with double size distribution were obtained when the range is 3.0-4.5 ml; on the other hand, SiO2 spheres were resulted with good sphericity when the ammonia is in the range of 6.0-7.5 ml.

Behavior of Some Tungsten Carbide Coatings in Molten Zinc

1996 ◽  
Author(s):  
A.J. Stavros
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tungsten Carbide ◽  
The Other ◽  
Time To Failure ◽  
X Ray Diffraction ◽  
Molten Zinc ◽  
X Ray ◽  
Carbide Coatings ◽  
Scanning Electron

Abstract Two different W-Co-C powders were used in three deposition devices, the Super D-Gun, Jet Kote, and JP-5000 to produce coatings for laboratory immersion tests in molten zinc and %55Al-Zn. Resistance was evaluated as time to failure. Scanning electron microscopy and X-ray diffraction were used to characterize the structures ssid failure mechanism. All coatings were found to fail when the molten metal breached the coating thickness at weak spots and spread out over the underlying interface to lift the coating away from the underlying 316L substrate. These weak spots were "pits" on one Super D-Gun coating (the most resistant coating) and cracks on all the other coatings. No diffusion of zinc through the tungsten carbide coatings was observed.

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