scholarly journals СРАВНИТЕЛЬНОЕ ИССЛЕДОВАНИЕ МОРФОЛОГИИ СПОР РОДОВ ПОДСЕМЕЙСТВА CRYPTOGRAMMOIDEAE

2016 ◽  
Vol 6 (3) ◽  
pp. 333-346
Author(s):  
A. V. Vaganov
Keyword(s):  
Comparative Study ◽  
Morphological Characters ◽  
Equatorial Position ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Spore Form ◽  
Distal Side

<p>Using the method of scanning electronic microscopy (SEM), a comparative study of twelve representatives of subfamily <em>Cryptogrammoideae </em>S.Linds. family <em>Pteridaceae </em>E.D.M.Kirchn. was carried out. A comparative study of morphological characters of investigated spores has revealed characters that allow considering the relatedness of the studied species to one subfamily – Cryptogrammoideae. These characters include: spore form is roundish-triangular, lociniate in proximal-polar and distal-polar positions; spore contour is low-crenate to smooth; distal side of the spore in an equatorial position is convex; rays of laesura are straight, raised over a sporoderm surface; exosporium is clearly defined from fine-granulate to verrucate.</p>

scholarly journals Spore morphology of Vaginularia Fée species (Pteridaceae) from South-Eastern Asia A.

2017 ◽  
Vol 7 (4) ◽  
pp. 231-233
Author(s):  
A. V. Vaganov ◽  
I. I. Gureyeva ◽  
A. A. Kuznetsov ◽  
R. S. Romanets
Keyword(s):  
Comparative Study ◽  
Smooth Surface ◽  
Polar Axis ◽  
Spore Morphology ◽  
Scanning Electronic Microscopy ◽  
Eastern Asia ◽  
Electronic Microscopy ◽  
South Eastern ◽  
Equatorial Diameter ◽  
Axis Length

A comparative study of spores of two species of Vaginularia (Vittarioideae, Pteridaceae) from South-Eastern – Vaginularia paradoxa (Fée) Mett. ex Miq. and V. trichoidea Fée – was performed by the method of scanning electronic microscopy (SEM). Spores are tetrahedral, trilete; they are very similar to each other in smooth surface and relatively narrow laesura arms. Differences between species are in shape of spores in proximal position (triangular with narrowly-rounded corners and concave sides in V. paradoxa and triangular with broadly-rounded corners and slightly concave sides in V. trichoidea), in length of laesura arms relative to the radius of the spore (laesura arms are about 0.75 of spore radius in V. paradoxa, and riches corners of spore in V. trichoidea) and in size of spore (spore of V. paradoxa are about 1.5 times more in equatorial diameter and 1.7 times more in polar axis length).

scholarly journals Spore morphology of Haplopteris C. Presl species (Vittarioideae, Pteridaceae) from China

2017 ◽  
Vol 7 (4) ◽  
pp. 290-294
Author(s):  
A. V. Vaganov ◽  
I. I. Gureyeva ◽  
A. A. Kuznetsov ◽  
R. S. Romanets
Keyword(s):  
Comparative Study ◽  
Spore Morphology ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy

A comparative study of spores of four species of Haplopteris C. Presl, H. amboinensis (Fée) X.C. Zhang, H. forrestiana (Ching) E.H. Crane, H. linearifolia (Ching) X.C. Zhang, and H. mediosora (Hayata) X.C. Zhang, from China was performed using the method of scanning electronic microscopy (SEM). Spores of Haplopteris species are bilateral monolete ellipsoidal or ellipsoidal, but slightly narrowed in the middle. Perispore thin, easily breakable, smooth; exospore smooth, its surface is finely granulate or finely undulate (as seen at higher magnification). Haplopteris amboinensis have the largest spores (79.5×34.3×40.9 μм), H. mediosora – the smallest one 49.2×24.5×24.9 μм).

scholarly journals Tribological Performance of CoCrMo Alloys with Boron Additions in As-Cast and Heat-Treated Conditions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 355
Author(s):  
Marco A. L. Hernandez-Rodriguez ◽  
Diego E. Lozano ◽  
Gabriela M. Martinez-Cazares ◽  
Yaneth Bedolla-Gil
Keyword(s):  
Boron Content ◽  
Tribological Performance ◽  
Secondary Phases ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Hardness Tests ◽  
Heat Treated ◽  
Cocrmo Alloys ◽  
Cast Condition ◽  
Ball On Disc

The present study evaluates the effect of boron additions on the tribological performance of CoCrMo alloys. The alloys were prepared with boron ranging from 0.06 to 1 wt%. The materials were characterized using metallographic techniques, scanning electronic microscopy, and roughness and hardness tests. Tribological evaluation was made by means of ball-on-disc tests for sliding distances of 4, 8 and 12 km. The samples were in the as-cast condition and after a heat treatment at 1200 °C for 1 h, finished by water quenching. The results showed that wear resistance was influenced by the microstructure and the number of secondary phases. The volume loss decreased as the boron content increased. Due to hard phases, abrasion wear was observed. Delamination fatigue was also detected after long sliding distances. Both wear mechanisms diminished in higher boron content alloys.

scholarly journals IMPROVEMENT OF MICROMERITIC, COMPRESSIBILITY AND SOLUBILITY CHARACTERISTICS OF LINEZOLID BY CRYSTALLO-CO-AGGLOMERATION TECHNIQUE

2017 ◽  
Vol 9 (4) ◽  
pp. 47 ◽  
Author(s):  
Atul M. Kadam ◽  
Shitalkumar S. Patil
Keyword(s):  
Drug Release ◽  
Methyl Cellulose ◽  
Mechanical Deformation ◽  
Angle Of Repose ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Time Required ◽  
Good Flow

Objective: The purpose of current study was to improve physicochemical properties such as micrometric, compressibility and solubility of linezolid (LNZ) by preparing crystallo-co-agglomerates (CCA) in the presence of polymer for the enhancement of overall physicochemical performance.Methods: The process of agglomeration involves the use of dichloromethane (DCM) as a good solvent and chloroform as bridging liquid were used to prepare agglomerates. Agglomerates were characterised in the solid state using several techniques such as Scanning electronic microscopy(SEM), Fourier transformation infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRPD) The agglomerates obtained were evaluated for micrometric, mechanical, deformation, compressibility and drug release properties.Results: It was found that micrometric properties and dissolution characteristics of agglomerates were significantly improved than that of pure linezolid. Solubility was found to be increased than pure linezolid. The solubility of crystallo co-agglomerates was found an increase in 5 fold 3 fold and 3.7 fold for PVPK30 (0.5%), PVPK30 (0.25%) and PVPK30 (0.75%) respectively. The angle of repose for all batches was found between 22 ° to 30 °Carrs index was between 12.27±0.6 to 18.73±0.4 and Hausners ratio Near to 1, indicated good flow ability of agglomerates. The time required for drug release over a period of 60 min, is as LA1>LA2>LA3. LA3 shows fast drug release than LA1 and LA2, due to solubilization of drug due to more concentration of PVPK30 and less concentration of talc.Conclusion: Based on the above results, it was revealed that CCA of linezolid prepared with DCM and HPMC (Hydroxypropyl methyl cellulose)/PEG (Polyethylene glycol)/PVP (Polyvinylpyrrolidone) K30 exhibited improved micrometric properties, compressibility and in addition to improving solubility and dissolution rate.

scholarly journals Analysis of the properties of a Cu-Al2-O3 sintered system based on ultra fine and nanocomposite powders

2007 ◽  
Vol 39 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Z. Andjic ◽  
M. Korac ◽  
Z. Kamberovic ◽  
A. Vujovic ◽  
M. Tasic
Keyword(s):  
Mechanical Properties ◽  
Chemical Method ◽  
Elevated Temperatures ◽  
Hydrogen Atmosphere ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Composite Powders ◽  
Nanocomposite Powders ◽  
Final Composition

In this paper synthesis of a composite based on Cu-Al2O3 by a thermo-chemical method is shown along with a comparative analysis of the properties of the obtained nanocomposite sintered samples, which are characterized by a good combination of electric-mechanical properties, suitable for work at elevated temperatures. Ultra fine and nanocrystal powder Cu-Al2O3 is obtained by a chemical method, starting from water solutions of nitrates up to achieving the requested composition with 3 and 5% of Al2O3. Synthesis of composite powders has been developed through several stages: drying by spraying, oxidation of the obtained powder of precursor and then reduction by hydrogen until the final composition of nanocomposite powder is achieved. After characterization of the obtained powders, which comprised examination by the Scanning Electronic Microscopy (SEM) method and X-ray-structure analysis (RDA), the powders were compacted with compacting pressure of 500 MPa. Sintering of the obtained samples was performed in the hydrogen atmosphere in isothermal conditions at temperatures of 800 and 900oC for 30, 60, 90 and 120 minutes. Characterization of the obtained Cu-Al2O3 of the nanocomposite sintered system comprised examination of microstructure by the Scanning Electronic Microscopy (SEM), as well as examining of electric mechanical properties. The obtained results show a homogenous distribution of dispersoides in the structure, as well as good mechanical and electric properties. .

scholarly journals INVESTIGATION OF STRUCTURE OF NANOCOMPOSITES ON THE BASIS OF MIXTURE OF POLYPROPYLENE AND MODIFIED POLYAMIDE WITH USING SCANNING ELECTRONIC MICROSCOPY

2019 ◽  
Vol 2 (1) ◽  
pp. 138-144 ◽  
Author(s):  
V. V. Krasinskyi ◽  
◽  
O. V. Suberlyak ◽  
M. V. Chekailo ◽  
L. Dulebova ◽  
...  
Keyword(s):  
Scanning Electronic Microscopy ◽  
Electronic Microscopy

scholarly journals Removal of Sulphate and Manganese on Synthetic Wastewater in Sulphate Reducing Bioreactor Using Indonesian Natural Zeolite

2017 ◽  
Vol 17 (2) ◽  
pp. 203 ◽  
Author(s):  
Endah Retnaningrum ◽  
Wahyu Wilopo
Keyword(s):  
Natural Zeolite ◽  
Fluidized Bed Reactor ◽  
Synthetic Wastewater ◽  
Particle Analysis ◽  
Support Material ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Manganese Removal ◽  
Ph Values ◽  
Reducing Bacteria

The present research was conducted to investigate sulphate and manganese removal from synthetic wastewater. The continuous laboratory scale of down-flow fluidized-bed reactor (DFBR) using sulphate reducing bacteria (SRB) consortium and Indonesian natural zeolite as a bacterial support material was designed. At 9 days operation, maximum sulphate and manganese removal was observed to be 23% and 15.4%, respectively. The pH values were also changed to neutral. The population of SRB increased which effect on the raising of their activity for removing sulphate and manganese. Using the scanning electronic microscopy (SEM), it was observed that natural zeolite possesses excellent physical characteristics as a bacterial support material in DFBR. The imaging SEM result of SRB consortium on zeolite surface clearly showed the developed SRB biofilm on that particle. Analysis result of EDX confirmed that manganese was precipitated as manganese–sulfides.

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