The Alteration of the Pore Spaces in Sandstones

Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.


Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.


Phytotaxa ◽  
2018 ◽  
Vol 373 (3) ◽  
pp. 169 ◽  
Author(s):  
YUE CAO ◽  
PAN YU ◽  
QINGMIN YOU ◽  
REX L. LOWE ◽  
DAVID M. WILLIAMS ◽  
...  

A new species of Tabularia, Tabularia sinensis, is described from the inland Poyang Lake (Jiangxi Province), the largest lake in China. The description is based on light and scanning electron microscope observations of valve and girdle elements. Given the diversity of forms in the genus, the relationships and status of the genus was investigated in the context of the other known species in the genus and to ascertain if Tabularia, as originally circumscribed, remains monophyletic.


1971 ◽  
Vol 49 (3) ◽  
pp. 371-372 ◽  
Author(s):  
Y. Hiratsuka

Two types of surface markings on the aeciospores of five pine stem rusts occurring in Canada were observed under a scanning electron microscope. Spores of four species, Endocronartium harknessii (J. P. Moore) Y. Hiratsuka (= Peridermium harknessii J. P. Moore), Cronartium coleosporioides Arth. (= P. stalactiforme Arth. & Kern), C. comptoniae Arth., and C. ribicola J. C. Fisch., had annulated processes with five to seven layers and each spore had a smooth area. The smooth area was at the same level as the top layer of the processes. Each species could be distinguished by the shape and size of its processes. Spores of Cronartium comandrae Pk. had no smooth areas and had obtuse or cuspidate processes with no annulations. Different ontogenies were apparent for the two types of spore surface markings.


Author(s):  
N. Ollier ◽  
G. Panczer ◽  
B. Champagnon ◽  
P. Jollivet

Abstract Two types of borosilicate leached SON68-type glasses were studied, one doped with uranium and the other with rare-earth element (Nd, Eu). Photoluminescence and cathodoluminescence properties of U doped samples have been correlated to microscopic features of the corroded glass. Nuclear analysis, Electronic Microprobe and Scanning Electron Microscope investigations revealed the heterogeneous composition of the gels with differentiated phases. Enriched U phases (crystallised or not) and phosphorus precipitated phases in rare earth gel have been detected.


Zootaxa ◽  
2009 ◽  
Vol 2093 (1) ◽  
pp. 1-36 ◽  
Author(s):  
ANNE HELENE S. TANDBERG ◽  
WIM VADER

This paper presents redescriptions of amphipods in the genus Metopa (Stenothoidae) in the type-collections of the Zoological Museum of Copenhagen. For Metopa clypeata and M. abyssalis we redescribe the type-specimens, for M. glacialis and M. groenlandica the redescriptions are based on new material and checked against the type-specimens. For all except M. abyssalis a combination of new line drawings and scanning electron microscope (SEM) pictures is provided, for M. abyssalis, line drawings only. A summary of the other species having earlier been designed to Metopa in the Copenhagen collections is given, with a list of their present taxonomic position.


2020 ◽  
Vol 866 ◽  
pp. 115-124
Author(s):  
Zhan Kui Wang ◽  
Ming Hua Pang ◽  
Jian Xiu Su ◽  
Jian Guo Yao

In this paper, a series of chemical mechanical polishing (CMP) experiments for magnesia alumina (Mg-Al) spinel were carried out with different abrasives, and the materials removal rate (MRR) and surface quality was evaluated to explore their different effects. The scanning electron microscope (SEM) and laser particle size analyzer were also employed to test the micro-shape and size distribution of abrasives. Then, the mechanism of different effects with different abrasives was analyzed in CMP for Mg-Al spinel. Those experimental results suggest that different subjecting pressure ratios of abrasives to polishing pad with different abrasive are the key factors leading to difference polishing performances in CMP.


1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.


Zootaxa ◽  
2018 ◽  
Vol 4434 (1) ◽  
pp. 111
Author(s):  
JOSÉ G. PALACIOS-VARGAS ◽  
AILA SOARES FERREIRA ◽  
DOUGLAS ZEPPELINI

A new diagnosis of Denisiella is provided, based on the revision of most descriptions, including three new species from Brazil. New Brazilian taxa share the presence of 6 + 6 eyes, 4 + 4 serrate spine-like on tibiotarsi III and the polycarinate setae on tibiotarsi II but differ from each other by the shape and size of the sensilla of the tibiotarsi I. Denisiella rhizophorae sp. nov. has the combination of sensilla on tibiotarsi I of rhagidial type and C2 blunt on antennal segment III. Only D. betschi sp. nov. has barbulate spines on head and D. caatingae sp. nov. is the only which males present nasal organ. They are illustrated with drawings and scanning electron microscope photographs. Three different shapes of sensilla in the tibiotarsi I were observed and were compared with other species. 


1982 ◽  
Vol 60 (5) ◽  
pp. 667-673
Author(s):  
Emmeline Vindt-Balguerie

The shoot apex of the bulbil of Huperzia selago (L.) Bernh. (Lycopodium) has been examined by scanning electron microscope. From an ontogenic point of view, changes in shape and size have been observed in the apical meristem. Successive minimal and maximal areas of this meristem are described during a plastochron. Area and cell number are also quantified with the scanning electron microscope. Only one leaf is initiated at the beginning of each plastochron, and the two contact parastichies observed in the shoot apex of the mature bulbil are two foliar helices.


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