scholarly journals Micromorphological Studies of the Loranthaceae, Phragmanthera capitata (Sprengel) Balle

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Franklin Uangbaoje Ohikhena ◽  
Olubunmi Abosede Wintola ◽  
Anthony Jide Afolayan

Phragmanthera capitata (Sprengel) Balle is a mistletoe of the Loranthaceae family that has been explored for its therapeutic properties in folklore for ages. However, there had been an alarming increase in misidentification of species in this family. This may be due in part to the lack of species taxonomic information. Hence, this study wishes to highlight the range of micromorphological features which could complement the information database of this species. Scanning electron, light, and energy dispersive X-ray (EDX) microscopies were used for this study. The result revealed a paracytic type of stomata with mean abaxial and adaxial density of 225.42±3.67 mm2 and 137.21±5.65 mm2, respectively, and mean guard cell length of 26.45±0.02 μm. Oval-shaped lenticels with a mean length of 34.29±0.26 μm were observed. They were arranged in parallel on the epidermal cells of the abaxial midrib. Densely packed stellate trichomes were revealed on the abaxial epidermis with a density of 63.32±3.70 mm2. Tracheary elements, which are tightly packed with granules believed to be proteins, were observed in the cross sections of the twig. Deposits chiefly composed of silicon, aluminium, potassium, and iron were recorded in the EDX analysis. This study revealed detailed descriptive micromorphological structures which could serve as a source of information and reference for the taxonomic description of P. capitata.

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.


2011 ◽  
Vol 239-242 ◽  
pp. 2942-2945 ◽  
Author(s):  
Jin Chen ◽  
Li Li Wang ◽  
Guang Cheng Yang ◽  
Zhi Qiang Qiao ◽  
Fu De Nie

Flower-like LLM-105 three-dimensional microstructures, which consisted of LLM-105 microrods with rectangular cross-sections, were prepared via a smiple template- and surfactant-free recrystallization process using [Bmim]CF3SO3as good solvent and water as poor solvent. A tentative mechanism for the growth of the flower-like LLM-105 three-dimensional microstructures was proposed on the basis of the analysis of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Comparing with LLM-105 raw material, the thermal decomposition took place at lower temperature and the weight loss has increased for the flower-like three-dimensional microstructures in the differential scanning calorimetric/thermogravimetric (DSC/TG) measurements.


2013 ◽  
Vol 21 (1) ◽  
pp. 149-160 ◽  
Author(s):  
I. M. Zougrou ◽  
M. Katsikini ◽  
F. Pinakidou ◽  
E. C. Paloura ◽  
L. Papadopoulou ◽  
...  

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities,e.g.Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the FeK-edge X-ray absorption fine structure (XAFS) spectra. Finally, SrK-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1or Ca2unit-cell site occupation.


2011 ◽  
Vol 284-286 ◽  
pp. 1397-1400
Author(s):  
Huai Yao ◽  
Yong Zhi Wang ◽  
Bo Xu

The high pressure and high temperature sintering of α-Si3N4 and γ-Si3N4 with Y2O3-Al2O3-La2O3 as additives were studied under pressures of 5.4 GPa and temperatures of 1420-1770 K. The effects of sintering temperatures and pressures on properties of sintered ceramic samples were investigated with X-ray diffraction and scanning electron microscopy. The results show that γ-Si3N4 and α-Si3N4 is transformed to β-Si3N4 completely. The highest relative densities and Vickers hardness (HV) of sintered samples are 98.71 and 21.76GPa, respectively. The sintered samples were composed of elongated β-Si3N4 rod crystals with disordered orientation and had intergranular interlocks and uniform and compact microstructure. Pulled out crystal grains on the fractured cross sections were obviously observed by SEM.


Author(s):  
A.G. Fitzgerald ◽  
S.M. Potrous

The diffusion of silver in amorphous chalcogenides is the basis for high-resolution lithographic applications. Previous studies of the diffusion of silver on contact with chalcogenide films has been studied by Auger depth profiling and the effects of photodoping on chemical bonding have been studied by x-ray photoelectron spectroscopy. Electron lithographic effects have been studied in the transmission electron microscope.The objective of the investigation described here has been to determine the degree of diffusion of silver in the amorphous chalcogenides, As2S3, As2Se3, GeS and GeSe when these films are in contact with thin silver films. The silver distribution has been determined by x-ray microanalysis of film cross-sections in the scanning electron microscope (SEM). Electron beam induced conductivity (EBIC) at points in these films has also been investigated.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 695 ◽  
Author(s):  
Marek Bara ◽  
Mateusz Niedźwiedź ◽  
Władysław Skoneczny

The paper presents the influence of the surface anodizing parameters of the aluminum alloy EN AW-5251 on the physicochemical properties of the oxide layers produced on it. Micrographs of the surface of the oxide layers were taken using a scanning electron microscope (SEM). The chemical composition of cross-sections from the oxide layers was studied using energy dispersive spectroscopy (EDS). The phase structure of the Al2O3 layers was determined by the pattern method using X-ray diffractometry (XRD). The nanomorphology of the oxide layers were analyzed based on microscopic photographs using the ImageJ 1.50i program. The energetic state of the layers was based on the surface-free energy (SFE), calculated from measurements of contact angles using the Owens-Wendt method. The highest surface-free energy value (49.12 mJ/m2) was recorded for the sample produced at 293 K, 3 A/dm2, in 60 min. The lowest surface-free energy value (31.36 mJ/m2) was recorded for the sample produced at 283 K, 1 A/dm2, in 20 min (the only hydrophobic layer). The highest average value nanopore area (2358.7 nm2) was recorded for the sample produced at 303 K, 4 A/dm2, in 45 min. The lowest average value nanopore area (183 nm2) was recorded for the sample produced at 313 K, 1 A/dm2, in 20 min.


2019 ◽  
Vol 946 ◽  
pp. 123-128
Author(s):  
O.V. Samoilova ◽  
Evgeny A. Trofimov ◽  
E.R. Vakhitova

An experimental study of the phase composition for nine samples of the Cu–Ni–Ce–La alloys with different content of components was carried out. The nickel concentration in the experimental samples varies from 3 to 40 wt. %, the sum of cerium and lanthanum concentrations was not exceed 7 wt. %. Alloys samples of the system Cu–Ni–Ce–La were studied using scanning electron microscopy and microprobe analysis, as well as X-ray analysis. Also, Vickers micro hardness was measured on the cross sections of the experimental samples. In this work, the conditions of intermetallic compounds formation in the as-cast samples were studied. The results of the work can be used for the technological processes analysis of copper and copper-based alloys production.


1997 ◽  
Vol 3 (S2) ◽  
pp. 883-884 ◽  
Author(s):  
Raynald Gauvin

Conventional quantitative X-ray microanalysis in the scanning electron microscope or in the electron microprobe is valid for specimens of bulk homogeneous composition and with flat and polished surfaces. Quantitative methods, using X-ray microanalysis and Monte Carlo simulations of electron trajectories in solids, have been developed for the chemical analysis of spherical inclusions embedded in a matrix and for multilayered specimens. In this paper, the effect of porosity and of the size of the pores are investigated concerning their effect on X-ray emission using Monte Carlo simulation of electron trajectories in solids since porous materials are of great technological importance.This new Monte Carlo program uses elastic Mott cross-sections to compute electron trajectories and the Joy & Luo modification of the continuous Bethe law of energy loss and the details are given elsewhere. This program assumes that all the pores are spherical and have the same size.


2012 ◽  
Vol 59 (2) ◽  
pp. 69-83
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Magdalena Gantner ◽  
Jadwiga Kostrzewska-Kuczumow

Investigations related to morphological and anatomical traits of leaves of four largefruited hazelnut (<i>Corylus</i> L.) cultivars characterised by different susceptibility to filbert aphid (<i>Myzocallis coryli</i> Goetze) feeding. The following parameters were measured: the thickness of leaf blade, the number of stomata, the length of secretory and mechanical hairs and their density on the leaf, the thickness of adaxial and abaxial epidermis and the thickness of their external cell walls. Observations of cross sections of the leaves were made in a light microscope and the surface of the adaxial epidermis was analysed in a scanning electron microscope. It was shown that leaves of the cultivars susceptible to <i>M. coryli</i> feeding had the thinnest leaf blade, especially in the main vein, and many more stomata. Besides, the cultivar most resistant to filbert aphid feeding, White Filbert, was marked by the largest height of the adaxial epidermis cells and the strongest striation of the cuticle in abaxial epidermis. On leaves of this cultivar, the number of mechanical hairs was the highest, while the lowest number of them was noted on Wonder from Bollwiller, the most susceptible cultivar.


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