PROPERTIES OF TWO FRAGIPAN SOILS IN NOVA SCOTIA INCLUDING SCANNING ELECTRON MICROGRAPHS

1974 ◽  
Vol 54 (2) ◽  
pp. 159-170 ◽  
Author(s):  
CHANG WANG ◽  
J. L. NOWLAND ◽  
H. KODAMA
Keyword(s):  
Electron Microscope ◽  
Nova Scotia ◽  
Hydraulic Conductivity ◽  
Scanning Electron Microscope ◽  
Clay Fraction ◽  
Fine Sand ◽  
Scanning Electron Micrographs ◽  
Moderate Amount ◽  
High Bulk ◽  
Scanning Electron

About 250,000 acres of soil with fragipan have been mapped in Nova Scotia. The fragipan horizons of two soils (Tormentine and Debert) reported in this paper are typical for the province. They have high bulk densities and low saturated hydraulic conductivity. They are also low in organic carbon and free oxides. They are high in fine sand and silt but low in clay, and the fragments of fragipan are readily slaked in water. Mica, chlorite, vermiculite, and kaolinite were found in the clay fractions of both soils throughout the two profiles. A moderate amount of smectite was found in the clay fractions of the Ae horizon of Debert but not in the Tormentine profile. A significant amount of clay increase in both fine and total clay fraction was found in the Bf horizon of the Tormentine soil and the Bmgj and Btx horizons of the Debert soil, and results from translocation or lessivage. The brittleness and other associated properties of the fragipans were attributed to clay bridges linking coarser particles, which were shown in the scanning electron microscope pictures.

Occurrence of Heteropolaria lwoffi (Fauré-Fremiet, 1943) and Apiosoma piscicola Blanchard, 1885 (Ciliata) on Salvelinus fontinalis (Mitchill) in Nova Scotia, Canada

1987 ◽  
Vol 65 (10) ◽  
pp. 2426-2429 ◽  
Author(s):  
D. K. Cone ◽  
P. H. Odense
Keyword(s):  
Electron Microscope ◽  
Nova Scotia ◽  
North America ◽  
Scanning Electron Microscope ◽  
Salvelinus Fontinalis ◽  
Fish Farm ◽  
Mucous Cells ◽  
First Report ◽  
Scanning Electron

Heteropolaria lwoffi (Fauré-Fremiet, 1943) and Apiosoma piscicola Blanchard, 1885 (Ciliata) are reported from fry of Salvelinus fontinalis (Mitchill) at a fish farm in Nova Scotia. The specimens were examined with a scanning electron microscope. Heteropolaria lwoffi attached to pore walls of mucous cells. Apiosoma piscicola had an affinity for the attached scopula of H. lwoffi. Bacterial microcolonies were associated with the adhesive substance secreted by the scopulas but there was no evidence of colony expansion into the underlying skin. The study represents the first specific identifications of stalked peritrichs from salmonids in North America and the first report of A. piscicola on the continent.

scholarly journals Studies in Oberonia, 9: Lessons from excess names in Oberonia for Orchidaceae systematics, including a revision of the Oberonia Sect. Scytoxiphium

Lankesteriana ◽  
2021 ◽  
Author(s):  
Daniel L. Geiger
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Electron Micrographs ◽  
21St Century ◽  
Expert Advice ◽  
Scanning Electron Micrographs ◽  
Palabras Clave ◽  
Microscope Images ◽  
Typological Thinking ◽  
Scanning Electron

The reasons for excess names in microfloral orchids such as Oberonia Lindl. can be traced to poor scholarship (e.g., failure to review the literature, ignoring expert advice), typological thinking, and erroneous assumption of microendemism. Some extraordinarily poor descriptions, including some from the 21st century, can be termed “taxonomic vandalism”. The outdated reliance on drawings as opposed to z-stacked photographs and scanning electron micrographs poses further problems due to an abundance of demonstrable problems with drawings. The Oberonia sect. Scytoxiphium Schltr. with eight described species is reduced to one species, Oberonia heliophila Rchb.f.; it is illustrated by original drawings, live photographs and scanning electron microscope images. The distribution is extended from Java through Micronesia and Samoa. The species occurs predominantly from 0–500 m, less frequently to 900 m, and possibly to even 1900 m. It flowers throughout the year. Keywords/Palabras clave: Oberonia, Oberonia sect. Scytoxiphium, revision, revisión, synonymies, sinonimias, taxonomic vandalism, vandalismo taxonómico

scholarly journals Morphological and Molecular Characterization of Toxocara apodemi (Nematoda: Ascarididae) from Striped Field Mice, Apodemus agrarius, in Korea

2020 ◽  
Vol 58 (4) ◽  
pp. 403-411
Author(s):  
Hyeon Cheol Kim ◽  
Eui Ju Hong ◽  
Si Yun Ryu ◽  
Jinho Park ◽  
Jeong Gon Cho ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
18S Rrna ◽  
Rrna Gene ◽  
Scanning Electron Micrographs ◽  
Toxocara Cati ◽  
Apodemus Agrarius ◽  
Toxocara Vitulorum ◽  
Field Mice ◽  
Scanning Electron

Adult ascarid worms from the field mice, Apodemus agrarius, were observed with a light and scanning electron microscope, and molecularly analized with 18S rRNA gene. In the scanning electron microscope, 3 prominent labia were present in the anterior end of male and female worms, but the interlabia and gubernaculum were absent. Scanning electron micrographs showed cervical alae as vestigial organs that looked like a slightly uplifted superficial sewing stitch. Total 6 pairs of post-cloacal papillae were observed on the tail of the male worms. The tail of female worms was blunt and conical shape with a spine-like structure, mucron. The eggs were sub-globular, coated with the albuminous layer and 73 by 82 μm in average size. The superficial pits of T. apodemi egg (mean 8.6×6.7 μm) are obviously bigger than those of Toxocara spp. The partial sequence of 18S rRNA showed the sequence homology of Toxocara canis (99.6%), Toxocara cati (99.4%), Toxascaris leonina (99.4%), and Toxocara vitulorum (99.2%). Conclusively, it was confirmed that ascarid nematodes, Toxocara apodemi, recovered from striped field mice in Korea are taxonomically conspecific relationship with genus Toxocara and genetic divergence from other Toxocara species.

The microstructure of the dentition and dermal ornament of three dipnoans from the Devonian of Western Australia: a contribution towards dipnoan interrelations, and morphogenesis, growth and adaption of the skeletal tissues

1977 ◽  
Vol 281 (979) ◽  
pp. 29-72 ◽  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Anterior Part ◽  
Polarized Light ◽  
Scanning Electron Micrographs ◽  
Dental Tissues ◽  
Functional Surfaces ◽  
Current Usage ◽  
First Time ◽  
Scanning Electron

Detailed descriptions of the microstructure, which includes both histology and ultrastructure, are given for each type of tissue in each of the three species of Australian dipnoan. Most of the tissues have not previously been recorded in this way even for other species within the same genera. The microstructure is interpreted from examination of ground sections in transmitted and polarized light, together with examination of functional, forming and fracture surfaces in the scanning electron microscope. No previous studies of dipnoan dental tissues have been published in which the histology is related to surface morphology as seen in the scanning electron microscope. The histology, microstructure, growth and distribution of buccal denticles are described in Griphognathus whitei and Holodipterus gogoensis , and their morphogenesis and adaptation to function is discussed. It is concluded that the phyletic trend towards macromerism, as shown in chondricthyans and primitive teleostomes, is illustrated in the three species of dipnoan. The continuous layer of dentine of the tooth ridges, lips and covering to the dermal snout is described and found to be similar in the three species and equivalent to the tissue described previously in other dipnoans, sometimes as a form of cosmine. A term not in current usage is suggested for this dentine, namely syndentine. Dentine terminology is reviewed and the relevance to dipnoan dental tissues is discussed with the conclusion that an older term should be reintroduced to eliminate the current anomalies in terminology. Chirodipterus australis is the only species with typical tooth plates. The histology is compared with previous accounts of tooth plates in dipnoans and found to have some similarity with those of Neoceratodus forsteri . The microstructure is reported from examination of the worn functional surfaces and acid-etched functional surfaces with the scanning electron microscope, this information has not previously been reported for dipnoan tooth plates and is presented here as a basis for comparison with other species. New features of cosmine structure are described from scanning electron micrographs of the surfaces and these are related to the probable mode of formation and the involvement of the epithelial cells. The structure is found to compare in some ways with the cosmine of osteolepids. The loss of cosmine and replacement by tubercles in Griphognathus whitei and Holodipterus gogoensis is explained as retention of an ontogenetic potential which is comparable with Ørvig’s theory of cosmine regression in the porolepids. Superpositional growth in the dermal skull bones is described for the first time in dipnoans. It is postulated that the ancestors of dipnoans had superimposed denticles beneath a cosmine covering. The information obtained from the microstructure is used to examine the hypothesis proposed by Miles (1977) in a paper on the phyletic relations within the dipnoans. This confirms that Griphognathus white i has retained a primitive dentition with separate buccal denticles and tooth ridges; Holodipterus gogoensis has retained these features, denticles and lip ridges, together with an advanced feature of tooth cusps which are a divergent specialization phyletically preceding tooth plates; Chirodipterus australis has not retained buccal denticles but has lip ridges on the snout and anterior part of the lower jaw, and the specialized tooth plates. Pleromic dentine is recorded in two of these species and discussed with other observed methods of adaptation to wear.

Cell walls in Cucurbita maxima cotyledons in relation to imbibition

1974 ◽  
Vol 52 (7) ◽  
pp. 1465-1468 ◽  
Author(s):  
John N. A. Lott
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Electron Micrographs ◽  
Propylene Oxide ◽  
Cell Walls ◽  
Scanning Electron Micrographs ◽  
Cucurbita Maxima ◽  
Glutaraldehyde Fixation ◽  
Mesophyll Cells ◽  
Scanning Electron

The scanning electron microscope and the freeze-etch technique were used to demonstrate the presence of corrugated cell walls in cotyledon mesophyll cells from dry squash seeds. These wavy cell walls straightened out during imbibition. In the scanning electron micrographs no wavy cell walls were observed in the smaller epidermal cells. Tissue imbibed for 2 h and then air-dried contained corrugated cell walls, whereas similar imbibed tissue dehydrated in ethanol and propylene oxide contained smooth cell walls. Thus the method of seed dehydration is important in determining the appearance of wavy cell walls. Glutaraldehyde fixation during the 2-h imbibition process did not alter the conditions under which wavy cell walls reappear.

Study on the Morphology of Nano-ZnO in Foam Glass

2011 ◽  
Vol 415-417 ◽  
pp. 598-601
Author(s):  
Fang Yun Yu ◽  
Qing Chi Sun ◽  
Wei Bing Ma ◽  
Dong Sheng Lv ◽  
Xiu Hua Li
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Growth Mechanism ◽  
Porous Glass ◽  
Foam Glass ◽  
Raw Material ◽  
Mass Ratio ◽  
Moderate Amount ◽  
Nano Zno ◽  
Scanning Electron

Nanoscale ZnO has received considerable attention due to its remarkable properties like absorbing wave. Foam glass containing nano-ZnO can enhance the property of wave absorbing. Investigating the morphology of nano-ZnO and researching the moderate amount of Zn filler in the foam glass are important. In the work, Zn filler was added into the porous glass to grow the nano-ZnO with no catalyst by Vapor-Solid mechanism. Foam glasses were fabricated by sintering mixture of pure foam glass raw material and Zn powder. The patterns of nano-ZnO were investigated by scanning electron microscope (SEM). Meanwhile, the detail of the growth mechanism of ZnO in foam glass was analysed. The results indicate that with the content of Zn increased, the granular nano-crystals become more, and the crystal whiskers become less, shorter, and a little thicker in pores. The diameter of the whiskers is about 50 nm. What’s more, the size of pores become small as Zn mass ratio increasing.

The impact of soil structure and confining stress on the hydraulic conductivity of clays in brine environments

1992 ◽  
Vol 29 (5) ◽  
pp. 730-739 ◽  
Author(s):  
N. Yang ◽  
S. L. Barbour
Keyword(s):  
Electron Microscope ◽  
Sodium Chloride ◽  
Hydraulic Conductivity ◽  
Scanning Electron Microscope ◽  
Soil Structure ◽  
Confining Stress ◽  
Soil Structures ◽  
Initial Soil ◽  
Before And After ◽  
Scanning Electron

Numerous studies have been completed in recent years on the alteration of the hydraulic conductivity of clayey soils as a result of exposure to concentrated organic or inorganic permeants. These hydraulic conductivity changes have been attributed to either changes in microstructure, due to contraction of the diffuse double layer, or to the alteration of the macrostructure, as a result of volume changes leading to shrinkage fractures or fissures. In this paper, the change in hydraulic conductivity of a highly plastic natural clay during exposure to a concentrated sodium chloride (NaCl) solution is described. The performance of samples with three different initial soil structures, prepared by slurry, static compaction, and kneading compaction, were investigated under various levels of confining stress. Hydraulic conductivity tests were carried out before and after the samples were exposed to the NaCl solutions. Scanning electron microscope photography was used to compare the soil structures before and after brine permeation. The test results show that the alteration of hydraulic conductivity is strongly related to the initial soil structure and the level of confining stress. No significant change in the microfabric of the clay was observed; however, the size of the interaggregate pores appeared to increase as a result of the physicochemical volume change that occurred during brine permeation. The increase in hydraulic conductivity that occurred during brine permeation could be prevented by increasing the level of confining stress. The stress levels at which significant increases in hydraulic conductivity occurred appeared to be coincident with low levels of vertical stress which allowed the sample to undergo lateral shrinkage and a subsequent loss of confinement. Key words : hydraulic conductivity, clay soils, osmotic consolidation, sodium chloride brine, soil structure, scanning electron microscope.

Influence of fines on the collapse of loose sands

1994 ◽  
Vol 31 (5) ◽  
pp. 728-739 ◽  
Author(s):  
T.D. Pitman ◽  
P.K. Robertson ◽  
D.C. Sego
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Strain Softening ◽  
Triaxial Compression ◽  
Fine Sand ◽  
Large Strains ◽  
Loose Sand ◽  
Test Program ◽  
Softening Behaviour ◽  
Scanning Electron

A study has been carried out to investigate the influence of fines and gradation on the skeletal collapse behaviour of loosely prepared sand samples. Loose sand samples, formed by moist tamping and consolidated to the same effective stress level, were prepared with varying percentages of both plastic and non-plastic fines (< 74 μm) and non-plastic fine sand (> 74 μm). Samples were isotropically consolidated and subjected to monotonic undrained triaxial compression. Results indicate that increased percentages of fines (< 74 μm) have a pronounced effect on the monotonic undrained behaviour at large strains (> 0.5%). This change is represented by a decreased strain softening behaviour and a shifting of the steady-state line. Variation of the gradation of the host sand appears to have little effect on the monotonic undrained behaviour. A supplemental study, involving use of the scanning electron microscope, was carried out to evaluate the findings of the test program in terms of sand fabric. Key words : collapse, monotonic undrained behaviour, scanning electron microscope, fabric.

Sign in / Sign up

Export Citation Format

Share Document