Study of Solar Cells by Sem Dark Voltage Contrast

1992 ◽  
Vol 283 ◽  
Author(s):  
S. Mil'Shtein ◽  
S. Iatrolt ◽  
D. Kharas ◽  
R. O. Bell ◽  
D. Sandstrom
Keyword(s):  
Electron Microscopy ◽  
Solar Cells ◽  
Polycrystalline Silicon ◽  
The Other ◽  
Electrical Performance ◽  
Zero Bias ◽  
Junction Area ◽  
Voltage Contrast ◽  
First Time ◽  
Scanning Electron

ABSTRACTFor the first time the Scanning Electron Microscopy (SEM) Dark Voltage Contrast (DVC) technique was used to examine the field distribution in a solar cell made of polycrystalline silicon.The samples were cut off solar cells made of Edge-defined Film-fed Grown (EFG) Silicon and lapped at 2 and 5 degree angles. The DVC measurements were performed at forward, reverse, and zero bias conditions using a Hitachi S-570 SEM and a Kevex-8000 microanalyzer.The I-V curves were recorded to test the electric performance of the samples. We examined two groups of solar cells. One group of cells demonstrated, after regular processing, reasonable electrical performance and abrupt DVC profile. The other group was intentionally doped with titanium, which presumably was agglomerated in the p-n junction area thus degrading completely the electrical performance of the cells and weakening the electric field by a factor of 4–6.

scholarly journals Spinnerets and silk-producing system of Segestria senoculata (Araneae, Araneomorphae, Segestriidae)

2016 ◽  
Vol 48 (3) ◽  
pp. 388 ◽  
Author(s):  
S. Karschová ◽  
J. Hajer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Current Knowledge ◽  
The Other ◽  
Sem Study ◽  
First Time ◽  
Scanning Electron

The spinning apparatus and silk of <em>Segestria senoculata</em> were studied with the use of scanning electron microscopy and light microscopy, which confirmed the presence of four categories of spigots connected with four types of spinning glands (<em>i.e</em>., <em>Glandulae ampullaceae major, Glandulae ampullaceae minor, Glandulae piriformes and Glandulae pseudaciniformes</em>). New data about the morphology of spinnerets and spigots were obtained for both the adults and nymphal stages of both sexes. For the first time the silken threads of retreats, signal threads and attachment discs of the members of <em>Segestria</em> were subjected to a detailed SEM study. The data resulting from studying the spinning apparatus of <em>S. senoculata</em> was compared to current knowledge of the silk producing systems of families belonging to the Dysderoidea superfamily. Silks that are emitted from spigots in the course of retreat construction are not (similarly to the other dysderoids) processed by the spider’s legs during the subsequent process of hardening. Apart from the major ampullate glands/spigots, segestriids also possess developed minor ampullate glands. Minor ampullate threads are used by <em>S. senoculata</em> spiders when making their signal threads.

scholarly journals Effects of miniaturization in the anatomy of the minute springtail Mesaphorura sylvatica (Hexapoda: Collembola: Tullbergiidae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8037 ◽  
Author(s):  
Irina V. Panina ◽  
Mikhail B. Potapov ◽  
Alexey A. Polilov
Keyword(s):  
Electron Microscopy ◽  
Small Body ◽  
The Other ◽  
Small Body Size ◽  
Soil Microarthropods ◽  
Computer Reconstruction ◽  
Organ Systems ◽  
First Time ◽  
The Brain ◽  
Scanning Electron

Smaller animals display pecular characteristics related to their small body size, and miniaturization has recently been intensely studied in insects, but not in other arthropods. Collembola, or springtails, are abundant soil microarthropods and form one of the four basal groups of hexapods. Many of them are notably smaller than 1 mm long, which makes them a good model for studying miniaturization effects in arthropods. In this study we analyze for the first time the anatomy of the minute springtail Mesaphorura sylvatica (body length 400 µm). It is described using light and scanning electron microscopy and 3D computer reconstruction. Possible effects of miniaturization are revealed based on a comparative analysis of data from this study and from studies on the anatomy of larger collembolans. Despite the extremely small size of M. sylvatica, some organ systems, e.g., muscular and digestive, remain complex. On the other hand, the nervous system displays considerable changes. The brain has two pairs of apertures with three pairs of muscles running through them, and all ganglia are shifted posteriad by one segment. The relative volumes of the skeleton, brain, and musculature are smaller than those of most microinsects, while the relative volumes of other systems are greater than or the same as in most microinsects. Comparison of the effects of miniaturization in collembolans with those of insects has shown that most of the miniaturization-related features of M. sylvatica have also been found in microinsects (shift of the brain into the prothorax, absent heart, absence of midgut musculature, etc.), but also has revealed unique features (brain with two apertures and three pairs of muscles going through them), which have not been described before.

SCANNING ELECTRON MICROSCOPE: POSSIBILITIES FOR STUDYING KIDNEY DISEASES

2020 ◽  
pp. 176-182
Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Filtration Rate ◽  
Kidney Diseases ◽  
First Time ◽  
Scanning Electron

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.

scholarly journals Labellum and gynostemium micromorphology in Polystachya (Orchidaceae)

2020 ◽  
Vol 307 (1) ◽  
Author(s):  
Mytnik Joanna ◽  
Davies L. Kevin ◽  
Narajczyk Magdalena ◽  
Łuszczek Dorota ◽  
Kubiak Joanna ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sub Saharan Africa ◽  
Capitate Trichomes ◽  
Sub Saharan ◽  
First Time ◽  
Scanning Electron

AbstractPolystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy (SEM). Our results show the scale of infrageneric diversity of trichomes and papillae relative to the sampled sections. They also demonstrate the taxonomic value of labellar micromorphology at the sectional level. The study revealed seven types of papillae and five types of trichomes (uni- and multi-cellular) in Polystachya, some of which, are described here for the first time. Clavate trichomes are the most common and are present in 60% of the species studied. Moniliform trichomes mainly occur in sect. Polystachya and are strongly characteristic of the section. Pseudopollen is formed by fragmentation of moniliform trichomes or the detachment of other trichomes as bicellular units. We provide, for the first time, evidence for the detachment of the terminal cells of capitate trichomes.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

Scanning Electron Microscopy Coupled with Energy Dispersive Spectrometric Analysis Reveals for the First Time Weddellite and Sylvite Crystals on the Surface of Involucral Bracts and Petals of two Xeranthemum L. (Compositae) Species

2017 ◽  
Vol 23 (3) ◽  
pp. 679-686 ◽  
Author(s):  
Milan Gavrilović ◽  
Suzana Erić ◽  
Petar D. Marin ◽  
Núria Garcia-Jacas ◽  
Alfonso Susanna ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Glandular Trichomes ◽  
Energy Dispersive ◽  
Spectrometric Analysis ◽  
Eds Analysis ◽  
Taxonomic Studies ◽  
First Time ◽  
Tetragonal Bipyramid ◽  
Scanning Electron

AbstractIn this work, weddellite and sylvite crystals are identified for the first time on the involucral bracts and petals of Xeranthemum annuum and Xeranthemum cylindraceum using scanning electron microscopy coupled with energy dispersive spectrometric (SEM-EDS) analysis. Well-developed crystals of weddellite (CaC2O4·2H2O) occur in the form of a tetragonal bipyramid (hhl), rarely in combination of a bipyramid and tetragonal prism (h00). Indumentum of involucral bracts of X. cylindraceum consists of nonglandular and glandular trichomes. Sylvite (KCl) crystals are observed only on the petal surface of X. cylindraceum. The crystals of sylvite occur in the form of perfect cubes (hexahedrons), but some crystals are deformed, i.e., partially elongated. Taxonomic significance of investigated microcharacters as well as the use of SEM-EDS analysis in taxonomic studies of plants are discussed.

scholarly journals Capture and scanning electron microscopy of individual snow crystals

1994 ◽  
Vol 40 (134) ◽  
pp. 195-197
Author(s):  
E. W. Wolff ◽  
A. P. Reid
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Liquid Nitrogen Temperature ◽  
Experimental Methods ◽  
Snow Crystal ◽  
Snow Crystals ◽  
First Time ◽  
Scanning Electron

AbstractA snow crystal has been successfully collected on to a scanning electron microscope (SEM) stub in central Greenland. It was preserved at liquid-nitrogen temperature for 5 months, prior to examination in the SEM. This is believed to be the first time a snow crystal has been observed directly in the SEM and offers some new experimental methods for understanding crystals and their chemistry.

Ascospore sculpturing and generic concepts in the Testudinaceae (syn. Zopfiaceae)

1979 ◽  
Vol 57 (2) ◽  
pp. 91-99 ◽  
Author(s):  
D. L. Hawksworth
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Combination ◽  
The Family ◽  
First Time ◽  
Scanning Electron

Generic concepts in the Testudinaceae (Ascomycotina, Loculoascomycetes) are reviewed with particular emphasis on the sculpturing of the ascospores which has been examined by scanning electron microscopy (SEM) for the first time. A key to the nine genera accepted in the family is provided of which two are described as new: Ulospora for U. bilgramii comb.nov. (= Zopfia bilgramii D. Hawksw. et al.), the ascospores of which have three to six deep fissures in each cell, and Zopfiofoveola for Z. punctata comb.nov. (= Zopfia punctata D. Hawksw. & C. Booth), with distinctly and regularly foveolate ascospores. One further new combination is made: Rechingeriella boudieri comb.nov. (= Zopfia boudieri Arnaud). The positions of three additional genera referred to the family by earlier authors but which are excluded from it here are also briefly discussed.

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