The spores of Dryopteris clintoniana and its relatives

1972 ◽  
Vol 50 (10) ◽  
pp. 2027-2029 ◽  
Author(s):  
D. M. Britton
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Diploid Species ◽  
Ancestral Species ◽  
The Individual ◽  
Scanning Electron

The perispore morphology of two diploid species, Dryopteris goldiana (Hook.) A. Gray and D. ludoviciana (Kunze) Small; two allotetraploids, D. celsa (Palmer) Small and D. cristata (L.) A. Gray; and the allohexaploid D. clintoniana (D. C. Eaton) Dowell, was examined with the scanning electron microscope. The contributions of the individual genomes of each species as shown by the morphology of the perine were shown, and an attempt was made to extrapolate the contribution to perine phenotype of genome B from an unknown ancestral species B.

scholarly journals Preparation and Characterization of Chitosan/Agar Blended Films: Part 1. Chemical Structure and Morphology

2012 ◽  
Vol 9 (3) ◽  
pp. 1431-1439 ◽  
Author(s):  
Esam A. El-hefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Smooth Surface ◽  
Chemical Structure ◽  
Structure And Morphology ◽  
The Individual ◽  
Main Component ◽  
Scanning Electron

Chitosan/agar (CS/AG) films were prepared by blending different proportions of chitosan and agar (considering chitosan as the main component) in solution forms. The chemical structure and the morphology of the obtained blended films were investigated using Fourier transform infrared (FTIR) and field emission scanning electron microscope (FESEM). It was revealed that chitosan and agar form a highly compatible blend and their films displayed homogenous and smooth surface properties compared to the individual pure components.

scholarly journals SEM imaging and XPS characterization of doped PVDF fibers

2021 ◽  
Vol 270 ◽  
pp. 01011
Author(s):  
Tereza Smejkalová ◽  
Ştefan Ţălu ◽  
Rashid Dallaev ◽  
Klára Částková ◽  
Dinara Sobola ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Analytical Methods ◽  
Polyvinylidene Fluoride ◽  
X Ray ◽  
Xps Characterization ◽  
Good Biocompatibility ◽  
The Individual ◽  
Scanning Electron

Polyvinylidene fluoride (PVDF) is one of the most promising electroactive polymers; it exhibits excellent electroactive behaviours, good biocompatibility, excellent chemical resistance, and thermal stability, rendering it an attractive material for biomedical, electronic, environmental and energy harvesting applications. This work aims to further improve its properties by the inclusion of powders of piezoactive materials. Polyvinylidene fluoride was formed by electrospinning into fibres with a thickness of 1.5-0.3 µm and then examined in a scanning electron microscope. The work offers a description of the current procedure in the preparation of samples and their modification for examination in a scanning electron microscope, characterizes the individual components of doped fibres and deals with specific instruments used for various analytical methods. The work contains a theoretical introduction to the analytical methods to which the samples will be further subjected, such as energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS). The obtained excellent properties of doped PVDF could be used in the design of sensors.

scholarly journals Twisting of Fibers Balancing the Gel–Sol Transition in Cellulose Aqueous Suspensions

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 873 ◽  
Author(s):  
Dmitry Zlenko ◽  
Sergey Nikolsky ◽  
Alexander Vedenkin ◽  
Galina Politenkova ◽  
Aleksey Skoblin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cellulose Fibers ◽  
Film Production ◽  
3D Scaffold ◽  
Friction Forces ◽  
Practical Applications ◽  
Exponential Increase ◽  
The Individual ◽  
Scanning Electron

Cellulose hydrogels and films are advantageous materials that are applied in modern industry and medicine. Cellulose hydrogels have a stable scaffold and never form films upon drying, while viscous cellulose hydrosols are liquids that could be used for film production. So, stabilizing either a gel or sol state in cellulose suspensions is a worthwhile challenge, significant for the practical applications. However, there is no theory describing the cellulose fibers’ behavior and processes underlying cellulose-gel-scaffold stabilizing. In this work, we provide a phenomenological mechanism explaining the transition between the stable-gel and shapeless-sol states in a cellulose suspension. We suppose that cellulose macromolecules and nanofibrils under strong dispersing treatment (such as sonication) partially untwist and dissociate, and then reassemble in a 3D scaffold having the individual elements twisted in the nodes. The latter leads to an exponential increase in friction forces between the fibers and to the corresponding fastening of the scaffold. We confirm our theory by the data on the circular dichroism of the cellulose suspensions, as well as by the direct scanning electron microscope (SEM) observations and theoretical assessments.

Scanning electron microscopy of the sporosorus in Polymyxa betae (Plasmodiophoromycetes)

1988 ◽  
Vol 66 (12) ◽  
pp. 2518-2522 ◽  
Author(s):  
G. Clafardini ◽  
B. Marotta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Direct Contact ◽  
Host Cells ◽  
Polymyxa Betae ◽  
Resting Spores ◽  
The Individual ◽  
Scanning Electron

Results are reported for observations of sporosori of Polymyxa betae Keskin made with the scanning electron microscope on sugar-beet roots. Sporosori were extracted from the host cells 15, 20, and 30 days after inoculation, purified, and observed with the scanning electron microscope. The morphology of sporosori differs, depending on their stage of maturation. Immature resting spores (cysts) are polyhedral and characterized by a wall rich in folds that converge towards the upper portion in six ridges arranged regularly in a spoke fashion. During maturation the walls of the individual resting spores unfold and come into direct contact with each other. Towards the end of maturation the resting spores become rounded and, after their walls split, germination takes place. After germination the sporosori still conserve their structure as a result of the effect of a cementing substance that keeps the walls united. Details are given of the system used to extract and purify the sporosori for observation using the scanning electron microscope.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

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.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

Characterization of Sputtered Films using the Scanning Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 44-45
Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Sputtered Films ◽  
Plasma Sputtering ◽  
Microelectronic Devices ◽  
Control Film ◽  
Scanning Electron

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.

Field Emission SEM Equipped With Noise Compensator

1973 ◽  
Vol 31 ◽  
pp. 302-303
Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Contrast ◽  
Probe Current ◽  
High Resolution Images ◽  
Scanning Electron

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.

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