New cuticular morphotypes of Cordaites principalis from the Canadian Carboniferous Maritimes Basin

2000 ◽  
Vol 78 (2) ◽  
pp. 135-148 ◽  
Author(s):  
Erwin L Zodrow ◽  
Zbynek Šimunek ◽  
Arden R Bashforth

Fossil cuticles were extracted from leaves attributed to Cordaites principalis (Germar) Geinitz (Cordaitales) that were collected from Upper Carboniferous strata in Nova Scotia (Sydney and Stellarton sub-basins) and in Newfoundland (Bay St. George sub-basin). The quality of the cuticular preservation is directly related to the thermal maturity and the grain size and angularity of sediments entombing the fossil leaves. Detailed transmitted light and scanning electron microscopy of the cuticles revealed that five distinct cuticular morphotypes could be recognized, demonstrating the variability in epidermal morphology of leaves belonging to one taxon. Two morphotypes show dissimilar and discrete epidermal characteristics, whereas three morphotypes form, more or less, a morphological continuum. Comparison with cuticles from Euramerican and Angaran floral provinces suggests that only one morphotype is in common with cuticles described from Europe, while four morphotypes are new for the Carboniferous.Key words: cuticle, Cordaites, Carboniferous, Canada.

2019 ◽  
Vol 29 (1) ◽  
pp. 1226-1234
Author(s):  
Safa Jida ◽  
Hassan Ouallal ◽  
Brahim Aksasse ◽  
Mohammed Ouanan ◽  
Mohamed El Amraoui ◽  
...  

Abstract This work intends to apprehend and emphasize the contribution of image-processing techniques and computer vision in the treatment of clay-based material known in Meknes region. One of the various characteristics used to describe clay in a qualitative manner is porosity, as it is considered one of the properties that with “kill or cure” effectiveness. For this purpose, we use scanning electron microscopy images, as they are considered the most powerful tool for characterising the quality of the microscopic pore structure of porous materials. We present various existing methods of segmentation, as we are interested only in pore regions. The results show good matching between physical estimation and Voronoi diagram-based porosity estimation.


2017 ◽  
Vol 23 (S1) ◽  
pp. 1266-1267 ◽  
Author(s):  
Barbara Armbruster ◽  
Christopher Booth ◽  
Stuart Searle ◽  
Michael Cable ◽  
Ronald Vane

2012 ◽  
Vol 496 ◽  
pp. 379-382
Author(s):  
Rui Song Yang ◽  
Ming Tian Li ◽  
Chun Hai Liu ◽  
Xue Jun Cui ◽  
Yong Zhong Jin

The Cu0.81Ni0.19 has been synthesized directly from elemental powder of nickel and copper by mechanical alloying. The alloyed Cu0.81Ni0.19 alloy powders are prepared by milling of 8h. The grain size calculated by Scherrer equation of the NiCu alloy decreased with the increasing of milling time. The end-product was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM)


2014 ◽  
Vol 6 ◽  
pp. 752353 ◽  
Author(s):  
Junye Li ◽  
Lifeng Yang ◽  
Weina Liu ◽  
Xuechen Zhang ◽  
Fengyu Sun

In the fields of military and civil uses, some special passages exist in many major parts, such as non-linear tubes. The overall performance is usually decided by the surface quality. Abrasive flow machining (AFM) technology can effectively improve the surface quality of the parts. In order to discuss the mechanism and technology of abrasive flow machining nonlinear tube, the nozzle is picked up as the researching object, and the self-designed polishing liquid is employed to make research on the key technological parameters of abrasive flow machining linear tube. Technological parameters’ impact on surface quality of the parts through the nozzle surface topography and scanning electron microscopy (SEM) map is explored. It is experimentally confirmed that abrasive flow machining can significantly improve surface quality of nonlinear runner, and experimental results can provide technical reference to optimizing study of abrasive flow machining theory.


2018 ◽  
Vol 281 ◽  
pp. 156-162
Author(s):  
Wang Nian Zhang ◽  
Xi Tang Wang ◽  
Zhou Fu Wang

The influence of the light burning temperature on the sintering property of nature dolomite has been investigated by two-step sintering process in the temperature range 1500 °C to 1600 °C. The resulting bulk densities and apparent porosities of the sintered dolomite samples were examined, and analyzing the sintered dolomite by scanning electron microscopy and X-ray diffraction were performed. The results showed light burned at 850 °C for 3 h, the main phases of the dolomite with 3-5 grain size were MgO, CaO and little CaCO3, and then fired at 1600 °C,the density of sintering dolomite reached to 3.38 g/cm3, the apparent property was 1.2 %, the size of MgO grain up to 3.75 μm . However when dolomite light burned at 1050 °C for 3 h, the main phases were MgO and CaO, and then fired at 1600 °C,the density of sintering dolomite only was 3.30 g/cm3, the apparent property was 2.3 %, the size of MgO only was 3.05 μm .


2011 ◽  
Vol 686 ◽  
pp. 348-354 ◽  
Author(s):  
Shu Tao Xiong ◽  
Fu Sheng Pan ◽  
Bin Jiang ◽  
Xiao Ke Li

In the present work, Al-Ca metallic compound was prepared in Mg-Ca alloys and the effects of Al-Ca metallic compound and different Al/Ca values on the grain refinement of Mg-Ca alloys were investigated by scanning electron microscopy and X-ray diffraction, and the mechanism of grain refinement of Mg-Ca alloys was discussed. The results showed that the grain size of Mg-0.5Ca alloy was obviously reduced from 550μm to 230μm due to the addition of Al. Al2Ca phase existed in these alloys and its morphology evolved from granular to rod-like. It is regarded as the main factor for the grain refinement.


1994 ◽  
Vol 72 (6) ◽  
pp. 1018-1026 ◽  
Author(s):  
Peter Gram Jensen ◽  
Jens T. Høeg ◽  
Susan Bower ◽  
Alexey V. Rybakov

The morphology and disposition of lattice organs, putative sensory structures in the carapace of cyprids, are described with scanning electron microscopy from six rhizocephalan species representing four of the five families in the suborder Akentrogonida: Clistosaccus paguri and Sylon hippolytes (Clistosaccidae), Arcturosaccus kussakini (Duplorbidae), Mycetomorpha vancouverensis (Mycetomorphidae), and Diplothylacus sinensis and Thylacoplethus reinhardi (Thompsoniidae). The disposition of pores and setae on the cyprid carapace is also surveyed. In T. reinhardi, poor quality of the specimens allowed only confirmation that lattice organs are present. Cyprids of all other species except M. vancouverensis have two anterior and three posterior pairs of lattice organs on the carapace, just as in almost all other Cirripedia. Cyprids of C. paguri and S. hippolytes are nearly identical in both general shape, carapace setation, and morphology of the lattice organs. In both species the lattice organs are oval–circular pore fields, except the second pair which is very elongate and match-shaped, a morphology unique to the Clistosaccidae. The similarities in cyprid morphology are interpreted as apomorphies supporting the monophyly of the recently rediagnosed Clistosaccidae. Both thompsoniid species have oval–circular lattice organs, indicating a possible sister-group relationship between the Clistosaccidae and the Thompsoniidae. None of the lattice organs of A. kussakini are oval or match-shaped. In M. vancouverensis there is only a single anterior pair of lattice organs, a probable autapomorphy. But the morphology of the M. vancouverensis cyprid is otherwise very reminiscent of those in the Rhizocephala suborder Kentrogonida, such as in being ornamented with numerous (> 100) carapace setae in no fixed pattern compared with the few (< 80) setae in a fixed disposition seen in the other akentrogonids. In cyprids of all Akentrogonida examined, the lattice organs lack a large terminal pore. By out-group comparison with all other cirripedes and with the Ascothoracida, this is regarded as an apomorphy that supports the monophyly of the Akentrogonida.


2007 ◽  
Vol 539-543 ◽  
pp. 3568-3573
Author(s):  
H. Kumagai ◽  
M. Shibata ◽  
Tomokazu Moritani ◽  
Takao Kozakai ◽  
Minoru Doi ◽  
...  

When the Al/Ge/SiO2 bilayer films are annealed in-situ in a scanning electron microscope (SEM) at the temperatures lower than the crystallization temperature of amorphous Ge itself, the so-called metal-mediated-crystallization (MMC) takes place. In the course of MMC, crystalline Ge aggregates (Ge clusters) form in the bilayer films, which results in the formation and the evolution of impressive fractal patterns with branching on the free surface. In-situ SEM observations of annealed Al/Ge/SiO2 bilayer films indicate that the grain size of polycrystalline Al-layer influences the nucleation of Ge clusters and hence of fractal patterns. For the bilayer films containing larger Al grains, the nucleation rate of fractal patterns (Ge clusters) is faster and the number of patterns is larger.


2008 ◽  
Vol 8 (8) ◽  
pp. 4127-4131 ◽  
Author(s):  
G. S. Okram ◽  
Kh. Namrata Devi ◽  
H. Sanatombi ◽  
Ajay Soni ◽  
V. Ganesan ◽  
...  

Nanocrystalline nickel powders were prepared with grain size 'd' in the range 40–100 nm diameters through polyol method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for characterization. XRD of the prepared samples consistently matched with standard fcc structure of nickel without any impurity peak. Detailed analysis and calculations using Scherrer equation for (111) peak revealed systematic increase in line width and peak shifting towards lower diffraction 2θ angles with decrease in nickel to ethylene glycol mole ratio. Different values of d estimated from various peaks of each sample suggested associated microstrains in the nanograins. Values of d estimated from X-ray diffraction patterns were compared with those obtained from atomic force microscopy and scanning electron microscopy results, and discussed. Observed lattice expansion is explained, on the basis of a theoretical model of linear elasticity.


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