scholarly journals Enhancement the Mycosynthesis of Selenium Nanoparticles by Using Gamma Radiation

Dose-Response ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 155932582110593
Author(s):  
Basma H. Amin ◽  
Hanaa Y. Ahmed ◽  
Eman M. El Gazzar ◽  
Monda M. M. Badawy
Keyword(s):  
Gamma Radiation ◽  
Gamma Ray ◽  
Uv Spectroscopy ◽  
Living System ◽  
Selenium Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Different Doses ◽  
Biogenic Selenium Nanoparticles

Selenium is a fundamental trace element of the living system. Microorganisms play a crucial role in the selenium cycle, both in the environment and in life. Biogenic selenium nanoparticles have shown promising prospects for use in medicine as an antioxidant and anticancer agent. In this study, SeNPs were biosynthesized by Penicillium citrinum. The spore suspension which was previously prepared was exposed to different doses of gamma radiation (10, 20, 30, 50, and 60 Gy). SeNPs were then produced by an irradiated P citrinum. UV spectroscopy, transmission electron microscopy, X-ray diffraction, and GSH content were assayed to evaluate the probability of P citrinum synthesizing SeNPs. In conclusion, irradiation of P citrinum by gamma ray enhances the mycosynthesis of SeNPs.

Preparation and Spectral Properties of PVP-Modified ZnO Nanorods

2008 ◽  
Vol 368-372 ◽  
pp. 329-332 ◽  
Author(s):  
Yang Feng Huang ◽  
Han Ning Xiao ◽  
Shu Guang Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Uv Spectroscopy ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Emission ◽  
Transmission Electron ◽  
Light Region ◽  
Uv Absorption Spectrum

ZnO nanorods were prepared by a hydrothermal reaction in the presence or absence of PVP (polyvinyl pyrrolidone). The obtained products were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, UV-Vis absorption (UV) spectroscopy and photoluminescence (PL) spectroscopy. The results suggest that PVP plays an important role in the preparation of ZnO nanorods. The UV absorption spectrum showed PVP increases the UV-shielding ability but doesn’t influence the transparency in the visible light region. A weak UV emission at 353 nm of PL spectra exhibit the surface of ZnO nanorods is passivated and oxygen-related defects is supplied by PVP.

Temperature Effect on the Thermoluminescent Signal Induced by Gamma Radiation in NaCl

2015 ◽  
Vol 1769 ◽  
Author(s):  
Demetrio Mendoza Anaya ◽  
Pedro R. González Martínez ◽  
María E. Fernández García ◽  
Gilberto Mondragón Galicia ◽  
Claudia E. Gutiérrez Wing
Keyword(s):  
Electron Microscopy ◽  
Gamma Radiation ◽  
Gamma Ray ◽  
Irradiation Time ◽  
Low Cost ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Linear Dependency ◽  
Scanning Electron

ABSTRACTThe effects of thermal treatments on the thermoluminescent (TL) signal of NaCl (ACS reagent) induced by gamma radiation were investigated. Samples of NaCl were thermally treated at 500, 800 and 1000 °C and characterized by X-Ray diffraction and scanning electron microscopy. After their exposure 0.1 to 150 Gy of gamma radiation from a gamma-ray source of 60Co, a TL curve for each temperature of treatment was obtained. We observed a different TL behavior on the irradiated samples as a function of the temperature applied during the thermal treatments. For the sample treated at 500 °C, three peaks centered at 102, 133 and 228 °C were observed. Samples treated at 800 and 1000 °C showed two main peaks at 128 and 220 °C and 136 and 219 °C, respectively; however, the highest TL intensity signal was observed for the sample at 800 °C. All samples showed a linear dependency of the integrated TL intensity from the signal emitted as function of the irradiation time. This is an important advantage because NaCl could be applied as a very low cost thermoluminescent dosimetric material. A comparison between the TL signal induced by gamma radiation in pure and Eu doped NaCl is also reported.

scholarly journals Potent antibacterial action of phycosynthesized selenium nanoparticles using Spirulina platensis extract

2021 ◽  
Vol 10 (1) ◽  
pp. 49-60
Author(s):  
Basant E.F. ElSaied ◽  
Amany M. Diab ◽  
Ahmed A. Tayel ◽  
Mousa A. Alghuthaymi ◽  
Shaaban H. Moussa
Keyword(s):  
Spirulina Platensis ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Selenium Nanoparticles ◽  
Bacterial Cells ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Bioactive Agents ◽  
Size Diminution

Abstract Selenium nanoparticles (SeNPs) are reinforced safe forms of the essential micronutrient selenium (Se) which take a lead in countless biotechnological and biomedical applications. The phycosynthesis of SeNPs was successfully investigated using cell-free extract of the microalgae, Spirulina platensis. The phycosynthesized S. platensis-SeNPs (SpSeNPs) were characterized using several characterization techniques such as UV-Visible, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and energy dispersive X-ray. They were effectually achieved using different concentration from sodium selenite (Na2SeO3) (1, 5, and 10 mM) to give size means of 12.64, 8.61, and 5.93 nm, respectively, with spherical shapes and highly negative zeta potentialities. The infrared analyses revealed the involvement of many phycochemials in SpSeNPs production. The antibacterial properties of SpSeNPs were confirmed, qualitatively and quantitatively, against foodborne microorganisms (Staphylococcus aureus and Salmonella typhimurium); the antibacterial activity was correlated and increased with SeNPs’ size diminution. The scanning micrographs of S. typhimurium cells treated with SpSeNPs indicated the severe action of nanoparticles to destroy bacterial cells in time-dependent manners. The innovative facile phycosynthesis of SeNPs using S. platensis is recommended to generate effectual bioactive agents to control hazardous bacterial species.

scholarly journals Modified Chitosan-Clay Nanocomposite as a Drug Delivery System Intercalation andIn VitroRelease of Ibuprofen

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Rehab Abdeen ◽  
Nehal Salahuddin
Keyword(s):  
Uv Spectroscopy ◽  
Drug Carrier ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Chitosan ◽  
Release Drug ◽  
Transmission Electron ◽  
Release Processes

The present paper focused on the intercalation of ibuprofen into sodium montmorillonite, chitosan, and chitosan montmorillonite nanocomposites as a sustained release drug carrier. The compounds were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The basal spacing of montmorillonite increased from 9.6 Å to 19.6 Å indicating the intercalation of modified chitosan and ibuprofen between lamellar layers. UV spectroscopy was employed to monitor thein vitrodrug release processes in both pH 5.4 and 7.8 solutions. The results revealed that ibuprofen was released from MMT, CS, and Mod-CS/MMT steadily and was pH dependent.

Atomic Structure of PtRu Nanoparticle Catalysts and Their Methanol Oxidation Activity

2007 ◽  
Vol 1056 ◽  
Author(s):  
Hiroaki Nitani ◽  
Yusuke Honda ◽  
Ryo Horioka ◽  
Kosuke Ohara ◽  
Takuya Kawaguchi ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Gamma Ray ◽  
Bimetallic Nanoparticles ◽  
Clear Correlation ◽  
X Ray Diffraction ◽  
Oxidation Activity ◽  
X Ray ◽  
Nanoparticle Catalysts ◽  
Transmission Electron ◽  
Gamma Ray Irradiation

ABSTRACTPtRu bimetallic nanoparticles supported on carbon nanoparticle (PtRu/C) catalysts were synthesized with radiation irradiation. The samples were structural analyzed by techniques of X-ray absorption fine structure (XAFS), transmission electron microscope (TEM) and X-ray diffraction (XRD). The results indicated that PtRu/C catalysts which prepared by an electron beam irradiation had more homogeneous atomic arrangement than that prepared by a gamma-ray irradiation. We found a clear correlation between the atomic structure and the catalytic activity of PtRu/C catalysts. These results supported the bi-functional mechanism.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

A TEM investigation of a hyper-eutectic lead-tin alloy

1988 ◽  
Vol 46 ◽  
pp. 562-563
Author(s):  
John A. Sutliff
Keyword(s):  
Volume Diffusion ◽  
Eutectic Mixture ◽  
Precipitation Reaction ◽  
Directionally Solidified ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffusion Controlled ◽  
Discontinuous Precipitation Reaction ◽  
Controlled Precipitation

Near-eutectic Pb-Sn alloys are important solders used by the electronics industry. In these solders, the eutectic mixture, which solidifies last, is the important microstructural consituent. The orientation relation (OR) between the eutectic phases has previously been determined for directionally solidified (DS) eutectic alloys using x-ray diffraction or electron chanelling techniques. In the present investigation the microstructure of a conventionally cast, hyper-eutectic Pb-Sn alloy was examined by transmission electron microscopy (TEM) and the OR between the eutectic phases was determined by electron diffraction. Precipitates of Sn in Pb were also observed and the OR determined. The same OR was found in both the eutectic and precipitation reacted materials. While the precipitation of Sn in Pb was previously shown to occur by a discontinuous precipitation reaction,3 the present work confirms a recent finding that volume diffusion controlled precipitation can also occur.Samples that are representative of the solder's cast microstructure are difficult to prepare for TEM because the alloy is multiphase and the phases are soft.

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