Correlation of structure and intrinsic luminescence of freshly introduced dislocations in GaN revealed by SEM and TEM

2019 ◽  
Author(s):  
O. S. Medvedev ◽  
O. F. Vyvenko ◽  
E. V. Ubyivovk ◽  
S. V. Shapenkov ◽  
M. Seibt
Keyword(s):  
Intrinsic Luminescence ◽  
Sem And Tem

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

The morphology and ultrastructure of pollen grains of Scutasporites nanuki Utting (Sashiniaceae, Coniferales) from the Permian of the East-European Platform

Palaeobotany ◽  
2012 ◽  
Vol 3 ◽  
pp. 5-11
Author(s):  
A. V. Gomankov ◽  
V. F. Tarasevich
Keyword(s):  
East European Platform ◽  
Central Body ◽  
Pollen Grains ◽  
Irregular Shape ◽  
East European ◽  
Sem And Tem

Dispersed bisaccate pollen grains of Scutasporites nanuki were studied by means of LM, SEM and TEM. Sacci ultrastructure of these pollen grains was rather peculiar. Sacci were like a thin fi lmy fringe attached to the central body near the equator. They were fi lled with sporopollenin elements of irregular shape and various dimensions with equally various cavities between them. Such an ultrastructure is called as spongy. The morphology and ultrastructure of S. nanuki is discussed in the context of the evolution of early conifers.

scholarly journals SEM and TEM Cross-section films Study of Chrysanthemum leucanthemum (Asteraceae) Pollen from Costa Rica

2021 ◽  
Vol 27 (S1) ◽  
pp. 1722-1723
Author(s):  
Guillermina González-Mancera ◽  
Laura E. Gómez-Lizarraga ◽  
Joaquin Morales-García
Keyword(s):  
Costa Rica ◽  
Cross Section ◽  
Sem And Tem ◽  
Chrysanthemum Leucanthemum

scholarly journals SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants – a descriptive analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Britta Kuehlmann ◽  
Isabel Zucal ◽  
Clark Andrew Bonham ◽  
Lydia-Marie Joubert ◽  
Lukas Prantl
Keyword(s):  
Descriptive Analysis ◽  
Breast Implants ◽  
Foreign Body Response ◽  
Future Research ◽  
Cellular Mechanisms ◽  
Tem Analysis ◽  
Capsular Fibrosis ◽  
Sem And Tem ◽  
Post Operation ◽  
Bacterial Accumulation

Abstract Background Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM). Results Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules. Conclusions This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

Failure analysis of laser diodes by SEM and TEM

1999 ◽  
Vol 48 (6) ◽  
pp. 791-794 ◽  
Author(s):  
Y. Yabuuchi ◽  
S. Inazato
Keyword(s):  
Failure Analysis ◽  
Laser Diodes ◽  
Sem And Tem

A Novel MEMS-Based Technique for In-Situ Characterization of Freestanding Nanometer Scale Thin Films Inside SEM and TEM

2001 ◽  
Author(s):  
M. A. Haque ◽  
M. T. A. Saif
Keyword(s):  
Thin Films ◽  
Tensile Testing ◽  
Uniaxial Tensile ◽  
Aluminum Specimen ◽  
Sem And Tem ◽  
Uniaxial Tensile Testing ◽  
Testing Facility ◽  
Film Specimen ◽  
On Chip

Abstract We present a MEMS-based technique for in-situ uniaxial tensile testing of freestanding thin films inside SEM and TEM. It integrates a freestanding thin film specimen with MEMS force sensors and structures to produce an on-chip tensile testing facility. Cofabrication of the specimen with force and displacement measuring mechanisms produces the following unique features: 1) Quantitative experimentation can be carried out in both SEM and TEM, 2) No extra gripping mechanism is required, 3) Specimen misalignment can be eliminated, 4) Pre-stress in specimen can be determined, and 5) Specimens with micrometer to nanometer thickness can be tested. We demonstrate the technique by testing a 200-nanometer thick Aluminum specimen in-situ in SEM. Significant strengthening and anelasticity were observed at this size scale.

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