Development of the neotropical catfish Rhamdia quelen (Siluriformes, Heptapteridae) incubated in different temperature regimes

Zygote ◽  
2009 ◽  
Vol 18 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Alana Marielle Rodrigues-Galdino ◽  
Camila Valente Maiolino ◽  
Mariana Forgati ◽  
Lucélia Donatti ◽  
Jorge Daniel Mikos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Developmental Stages ◽  
Larval Period ◽  
Early Juvenile ◽  
Temperature Regimes ◽  
Rhamdia Quelen ◽  
Different Temperatures ◽  
Three Stages ◽  
Chemosensory Systems ◽  
Scanning Electron

SummaryThe developmental stages for the embryonic and larval periods of the silver catfish (Rhamdia quelen) kept at different temperatures (21, 24, 27 and 30°C) are described. Fish were analysed under light and scanning electron microscopy. For embryonic development, we described 25 stages, which were grouped into seven periods named zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching periods. For larval development, we defined three stages (early, mid, and late larvae). Additionally, the main ontogenetic events during the post-larvae and early juvenile periods were also described. This species presents a well developped lateral line and chemosensory systems that grow up during the larval period, maturing in the post-larvae. All tested temperatures are viable to R. quelen development, but a shorter incubation period was necessary to complete the development at lower temperatures. However, some malformations (heart edema) were verified at 30°C.

Microstructure and Properties of Nanosemicrystalline Si3N4 Ceramics with Doped Sintering Additives: Part II. Phase Transformation and Microstructural Control

1998 ◽  
Vol 13 (9) ◽  
pp. 2588-2596 ◽  
Author(s):  
K. H. Ryu ◽  
J-M. Yang
Keyword(s):  
Electron Microscopy ◽  
Pressureless Sintering ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Additives ◽  
Different Temperatures ◽  
Si3n4 Ceramics ◽  
Scanning Electron ◽  
Microstructural Control

The low temperature pressureless sintering of a nanosized Si3N4 powder with doped sintering additives was investigated. The microstructural evolution during sintering at different temperatures was analyzed using x-ray diffraction and scanning electron microscopy. The effect of using nanosized Si3N4 powder as a catalyst to accelerate the α→β–Si3N4 transformation of a commercial Si3N4 powder with larger particle sizes was also investigated. Finally, two stage sintering was used to study the feasibility of controlling the microstructure and the mechanical properties of the nanosized silicon nitride.

Characterization of red sternum syndrome in mud crab farms from Thailand

Biologia ◽  
2010 ◽  
Vol 65 (1) ◽  
Author(s):  
Mayuva Areekijseree ◽  
Thanaporn Chuen-Im ◽  
Busaba Panyarachun
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Scylla Serrata ◽  
Mud Crab ◽  
Internal Organs ◽  
Three Stages ◽  
Severity Of The Disease ◽  
Claw Muscle ◽  
Scanning Electron

AbstractSamples of abnormal mud crabs, Scylla serrata (Forskål, 1755) (Decapoda: Portunidae), were collected from crab farms in Samutsongkhram Province, Thailand. These crabs had hard carapaces, red chelipeds and joints, pale hepatopancreas, gills, and soft muscles. They were almost immobile and finally died. The haemolymph revealed three stages of the syndrome, namely orange, orange-white, and milky-white in colors. The haemolymph, integument, hepatopancreas, gills, abdominal and claw muscle, stomach, and heart were dissected and histologically examined using transmission and scanning electron microscopy. Closer examinations found infection with rod-, curve rod-, or coccus-shape bacteria with thin and thick cell walls in all investigated organs and haemolymph. Isolation of the microorganisms from the infected tissues of red sternum syndrome crabs resulted in five types of bacteria. No microorganism growth was observed in normal crabs. Interestingly, the types of isolated bacteria can be classified according to the severity of the disease. Additionally, the degree of bacterial infection found was consistent with the stages of the disease. It was postulated that the bacteria entered the crabs via the gills, and then migrated through circulating haemocytes, before reaching the internal organs.

On The Fatigue Short Crack Behaviors of Directionally Solidified Superalloy DZ4 by In Situ SEM Observations

2010 ◽  
Vol 118-120 ◽  
pp. 289-293
Author(s):  
Xian Feng Ma ◽  
Hui Ji Shi
Keyword(s):  
Electron Microscopy ◽  
Crack Growth ◽  
Short Crack ◽  
Directionally Solidified ◽  
Crack Initiation And Propagation ◽  
Small Fatigue Crack ◽  
Initiation And Propagation ◽  
Different Temperatures ◽  
Scanning Electron

Small fatigue crack behaviors in a nickel-based directionally solidified superalloy DZ4 were studied by in situ scanning electron microscopy. The crack initiation and propagation manners were identified under different temperatures, i.e. 25oC, 350oC, 700oC. Crack growth showed to be associated with the configuration and relative direction of carbide. The anomalous short crack growth was pronounced at 25oC, 350oC and not evident at 700oC, which was analyzed by in situ examining the effect of microstructure.

Poly (vinylcaprolactam)-based Microgels to Improve Gloss Properties of Different Natural Fibres

2014 ◽  
Vol 18 (1) ◽  
pp. 50-63 ◽  
Author(s):  
A.G. Hassabo ◽  
S. Schachschal ◽  
C. Cheng ◽  
A. Pich ◽  
C. Popescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Itaconic Acid ◽  
Natural Fibres ◽  
Different Temperatures ◽  
Scanning Electron

Three different thermo-sensitive microgels obtained by the copolymerisation of vinylcaprolactam) (VCL) and various monomers (vinylimidazole(VIm), acetoacetoxyethyl methacrylate (AAEM) and itaconic acid(IA)) are used to coat different fibre surfaces. Two different pHs and two different temperatures, 25°C and 50°C respectively are chosen for the deposition of the microgels. The scanning electron microscopy of the treated fibre shows good distribution of the particles onto the fibres especially at increasing temperatures. The gloss index for the treated fibres has been measured, and showed that it may be controlled for all of the fibres with the treatment parameters (pH and temperature) and the microgel structure.

Comparative Development of Some Taxonomically Critical Floral Inflorescence Features in Cyperaceae

1991 ◽  
Vol 39 (2) ◽  
pp. 119 ◽  
Author(s):  
JJ Bruhl
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Floral Morphology ◽  
Developmental Studies ◽  
Comparative Development ◽  
Inflorescence Morphology ◽  
The Family ◽  
Scanning Electron

Morphology at different developmental stages was investigated by dissection and by scanning electron microscopy (SEM) in five sedges: Eleocharis (three species) and Schoenoplectus (both Cyperoideae, Scirpeae), and Lepidosperma (Caricoideae, Schoeneae). In each case all the perianth segments (scales or bristles) were positioned outside the staminal primordia or stamens, consistent with classical interpretations of flowers. Putative exceptions and previous alternative interpretations of floral morphology in the Cyperaceae are discussed. SEM developmental studies of Hypolytreae (e.g. Scirpodendron) are needed for further clarification of interpretative floral/inflorescence morphology in the family.

Morphology of Sintered Cr-Mo Porous Materials

2015 ◽  
Vol 825-826 ◽  
pp. 838-843
Author(s):  
Moritz Boehm ◽  
Thomas Schmoelzer ◽  
Reinhard Simon ◽  
Christian Gierl-Mayer
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Linear Expansion ◽  
Solid Phase ◽  
Phase Region ◽  
Miscibility Gap ◽  
Liquidus Boundary ◽  
Different Temperatures ◽  
Scanning Electron

Chromium and molybdenum exhibit continuous solubility in the solid phase region at temperatures of 908°C and above [1]. At lower temperatures, the system exhibits a miscibility gap. Furthermore a congruent minimum in the liquidus boundary exists at 1854°C. Chromium and molybdenum powders with different particle morphologies were mixed and porous green parts were produced by pressing. Sintering experiments were performed at different temperatures and for different chromium to molybdenum ratios. To investigate the evolution of the microstructure, sintering was interrupted at different temperatures and points in time. The microstructure and morphology of the sintered parts was investigated by scanning electron microscopy as well as light optical microscopy. It was found that during sintering, a Cr-Mo solid solution is formed. Depending on the molybdenum content, this induces either shrinking or swelling of the porous parts. Samples exhibited a linear expansion of up to 10% and final porosities of up to 65%.

scholarly journals 738 Text ANATOMICAL DESCRIPTION OF THE FRUIT-RECEPTACLE DETACHMENT AREA IN CAYENNE PEPPER

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 538f-538
Author(s):  
Kay P. Gersch ◽  
Carl E. Motsenbocker ◽  
Grezory A. Lang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Histochemical Staining ◽  
Distinct Region ◽  
Cell Type ◽  
Mature Fruit ◽  
Cell Layers ◽  
Or Organization ◽  
Scanning Electron

Two genotypes of cayenne pepper, Capsicum annuun, have been previously identified which differ significantly in ease of fruit detachment force. Both greenhouse- and field-grown plants of these genotypes, Cajun1-9027 and Cap-9004, were investigated for differences in cell type or organization where the fruit and receptacle join. Scanning electron microscopy revealed that mature fruit of genotype Cajun1-9027, which does not separate, exhibits a distinct region of sclerified cells that extend from the periphery of the fruit into the receptacle for at least 15 cell layers. In contrast, mature fruit of the more readily detachable genotype, Cap-9004, had fewer sclerified cells at the point of detachment. Neither genotype exhibits a well-defined abscission zone prior to, or at, maturity. Interpretation of histochemical staining of fruit-receptacle sections following ethylene treatment at different fruit developmental stages will be discussed.

scholarly journals Synthesis and Catalase Mimic Activity of MnO2 Nano Powder Prepared by Hydrothermal Process

2019 ◽  
Vol 27 (2) ◽  
pp. 228-237 ◽  
Author(s):  
Rashed T. Rasheed ◽  
Sariya D. Al-Algawi ◽  
Rosul M. N.
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Annealing Temperature ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Atomic Force ◽  
Different Temperatures ◽  
Scanning Electron

Manganese dioxide (MnO2) nanopowder has been synthesized by hydrothermal method. MnO2 was annealed at different temperatures (250, 400, 550, 700˚C). The crystal structure and surface morphology of these nanostructures were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM). The catalase mimic activity (catalytic activity) of MnO2 against hydrogen peroxide (H2O2) was studied by using the new method and found that 400˚C is the best annealing temperature.

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