Survey of Some Canadian Lakes for the Presence of Ultrastructurally Discrete Particles in the Colloidal Size Range

1979 ◽  
Vol 36 (8) ◽  
pp. 906-921 ◽  
Author(s):  
A. Massalski ◽  
Gary G. Leppard
Keyword(s):  
Electron Microscopy ◽  
Size Range ◽  
Trophic Levels ◽  
Clay Particles ◽  
Air Interface ◽  
Transmission Electron ◽  
Different Depths ◽  
Thin Section Analysis ◽  
Almost All ◽  
Section Analysis

Water samples from nine Canadian lakes were centrifuged and the pellets were analyzed by transmission electron microscopy. The pellets included small organisms, organic colloids, and clay particles. In almost all the samples, colloids were the major component revealed following thin-section analysis. When viewed at high magnification, much of each pellet consisted of morphologically discrete particles, some of which were readily categorized. Electron-opaque fibrils of colloidal size were frequently encountered (1) at different depths, (2) as a coating on the surface of algae and bacteria, (3) overlaying the sediments, (4) as an apparent adhesive between a variety of particles, and (5) as a component of froth at the water–air interface. They were common at all times and in lakes of various trophic levels and sizes. Key words: water, colloids, fibrils, lakes, electron microscopy

scholarly journals Facile synthesis of Au/ZnO/Ag nanoparticles using Glechoma hederacea L. extract, and their activity against leukemia

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Renata Dobrucka ◽  
Aleksandra Romaniuk-Drapała ◽  
Mariusz Kaczmarek
Keyword(s):  
Electron Microscopy ◽  
Ag Nanoparticles ◽  
Mononuclear Cells ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Mtt Test ◽  
Transmission Electron ◽  
Almost All ◽  
Glechoma Hederacea

AbstractMetal combinations have been attracting the attention of scientists for some time. They usually exhibit new characteristics that are different from the ones possessed by their components. In this work, Au/ZnO/Ag nanoparticles were synthesized biologically using Glechoma hederacea L. extract. The synthesized Au/ZnO/Ag nanoparticles were characterized by UV-Vis, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Atomic Force Microscopy (AFM). The microscopic methods confirmed the presence of spherical nanoparticles of 50–70 nm. The influence of biologically synthesized Au/ZnO/Ag nanoparticles on the vitality of human cells was evaluated in vitro with the use of established human Acute T Cell Leukemia cell line, Jurkat (ATCC® TIB-152™), as well as mononuclear cells isolated from peripheral blood (PBMC) of voluntary donors. Cell survival and the half-maximal inhibitory concentration index (IC50) were analyzed by the MTT test. The studies showed that the total loss of cell viability occurred at the Au/ZnO/Ag nanoparticle concentration range of 10 µmol–50 µmol. The use of Au/ZnO/Ag nanoparticles at the concentration of 100 µmol eliminated almost all living cells from the culture in 24h. The above observation confirms the result obtained during the MTT test.

Ultrastructural karyology of Spongospora subterranea (Plasmodiophoromycetes)

1992 ◽  
Vol 70 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Electron Microscopy ◽  
Single Unit ◽  
Spongospora Subterranea ◽  
Unit Membrane ◽  
Potato Tubers ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes ◽  
Transmission Electron ◽  
Host Parasite ◽  
Section Analysis

Sporogenic (cystogenous) stages of development of Spongospora subterranea (Wallroth) Lagerheim f.sp. subterranea Tomlinson infecting potato tubers were examined with transmission electron microscopy. Volume of nuclei in transitional Plasmodia was 28.2 ± 8.3 μm3. Serial section analysis revealed 37 synaptonemal complexes, hence the haploid chromosome number was considered to be 37. Total length of synaptonemal complexes per nucleus was 74.6 ± 1.4 μm, with individual synaptonemal complexes ranging in length from 1.34 ± 0.07 μm to 3.48 ± 0.17 μm. No polycomplexes were observed in transitional nuclei. Electron-opaque thickenings of lateral elements occurred irregularly. Additional ultrastructural features of sporogenic plasmodia included end-to-end paired centrioles defining the poles of the nuclei and a host–parasite boundary of a single unit membrane. Key words: karyotype, Plasmodiophoromycetes, Spongospora, synaptonemal complex.

Single-molecule precursor-based approaches to cobalt sulphide nanostructures

2010 ◽  
Vol 368 (1927) ◽  
pp. 4249-4260 ◽  
Author(s):  
Karthik Ramasamy ◽  
Weerakanya Maneerprakorn ◽  
Mohammad A. Malik ◽  
Paul O'Brien
Keyword(s):  
Electron Microscopy ◽  
Single Molecule ◽  
Size Range ◽  
Hexagonal Phase ◽  
Cobalt Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Cobalt Sulphide ◽  
Microscopy Images

Cobalt complexes of 1,1,5,5-tetramethyl-2,4-dithiobiuret, [Co{N(SCNMe 2 ) 2 } 3 ] ( 1 ), and 1,1,5,5-tetraisopropyl-2-thiobiuret, [Co{N(SOCN i Pr 2 ) 2 } 2 ] ( 2 ), have been synthesized and characterized. Both complexes were used as single-molecule precursors for the preparation of cobalt sulphide nanoparticles by thermolysis in hexadecylamine, octadecylamine or oleylamine. The powder X-ray diffraction pattern of as-prepared nanoparticles showed the hexagonal phase of Co 1− x S from complex 1 and mixtures of cubic and hexagonal Co 4 S 3 from complex 2 . Transmission electron microscopy images of material prepared from complex 1 showed spherical and trigonally shaped particles in the size range of 10–15 nm; whereas spheres, rods, trigonal prisms and pentagonally and hexagonally faceted crystallites were observed from complex 2 . This observation is the first of the Co 4 S 3 phase in a nanodispersed form.

Flocculation characteristics of organo-modified clay particles in poly(L-lactide) / montmorillonite hybrid systems

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Pham Hoai Nam ◽  
Atsuhiro Fujimori ◽  
Toru Masuko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrogen Bonding ◽  
Hybrid Systems ◽  
Hydroxyl Groups ◽  
Clay Particles ◽  
Modified Clay ◽  
Modified Montmorillonite ◽  
Transmission Electron ◽  
Ft Ir

Abstract The stacking characteristics of organo-modified montmorillonite particles in poly(L-lactide) / clay hybrids have been investigated through FT-IR measurements and transmission electron microscopy. The clay particles tend to flocculate with hydrogen bonding among the hydroxyl groups of the surfactant, those located at the edge of clay particles, and/or those existing at the ends of polylactide chains.

Characterization of Nanostructured Nickel Aluminate Formation during Mechano-Chemical Recycling of Spent NiO/Al2O3 Catalyst

2011 ◽  
Vol 364 ◽  
pp. 186-190
Author(s):  
Karim Nazemi Mohammad ◽  
Saeed Sheibani ◽  
Fereshteh Rashchi ◽  
Victor Gonzalez De La Cruz ◽  
Alfonso Caballero Martínez
Keyword(s):  
Electron Microscopy ◽  
Size Range ◽  
Spherical Shape ◽  
Research Use ◽  
Chemical Recycling ◽  
X Ray Diffraction ◽  
Nickel Aluminate ◽  
X Ray ◽  
Transmission Electron

In this research, use of mechanical alloying method, as a new and effective route for the recycling of spent NiO/Al2O3catalyst to nanostructured nickel aluminate spinel was investigated. Samples were characterized using different techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). It was found that the formation of NiAl2O4was started between 15 to 20 hours of milling and completed after 60 hours. The final particles had relatively spherical shape with the size range of 5-50 nm.

Novel Method for Preparing Transmission Electron Microscopy Samples of Micrometer-Sized Powder Particles by Using Focused Ion Beam

2017 ◽  
Vol 23 (5) ◽  
pp. 1055-1060 ◽  
Author(s):  
Tae-Hoon Kim ◽  
Min-Chul Kang ◽  
Ga-Bin Jung ◽  
Dong Soo Kim ◽  
Cheol-Woong Yang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Size Range ◽  
Ion Beam ◽  
Preparation Technique ◽  
Simple Method ◽  
Transmission Electron ◽  
Powder Particles ◽  
Novel Method

AbstractThe preparation of transmission electron microscopy (TEM) samples from powders is quite difficult and challenging. For powders with particles in the 1–5 μm size range, it is especially difficult to select an adequate sample preparation technique. Epoxy is commonly used to bind powder, but drawbacks, such as differential milling originating from unequal milling rates between the epoxy and powder, remain. We propose a new, simple method for preparing TEM samples. This method is especially useful for powders with particles in the 1–5 μm size range that are vulnerable to oxidation. The method uses solder as an embedding agent together with focused ion beam (FIB) milling. The powder was embedded in low-temperature solder using a conventional hot-mounting instrument. Subsequently, FIB was used to fabricate thin TEM samples via the lift-out technique. The solder proved to be more effective than epoxy in producing thin TEM samples with large areas. The problem of differential milling was mitigated, and the solder binder was more stable than epoxy under an electron beam. This methodology can be applied for preparing TEM samples from various powders that are either vulnerable to oxidation or composed of high atomic number elements.

scholarly journals Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anish Stephen ◽  
Sankar Seethalakshmi
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Reaction Time ◽  
Silver Nanoparticle ◽  
Size Range ◽  
Transmission Electron ◽  
Vis Spectroscopy

This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silver nanoparticles (AgNPs) were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). UV-vis spectroscopy derived spectrum demonstrated a peak of 430 nm which corresponds to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy revealed spherical shaped silver nanoparticles in the size range of 20–40 nm.

Clastic Rock Reservoir Physical Characteristics of Southern Songliao Basin Changling Fault Depression Layer

2013 ◽  
Vol 838-841 ◽  
pp. 1320-1323
Author(s):  
Yun Feng Zhang ◽  
Tian Tian Chu ◽  
Hong Qi Yuan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thin Section ◽  
Secondary Porosity ◽  
Fracture Characteristics ◽  
Clastic Rock ◽  
Mercury Intrusion ◽  
Thin Section Analysis ◽  
Section Analysis ◽  
Scanning Electron

We study the Changling fault depression layer reservoir space type and characteristic of clastic rock reservoirs in the study area, by core observation, thin section analysis, cathodoluminescence analysis, scanning electron microscopy and mercury intrusion method, and discusses the development of secondary porosity and fracture characteristics and formation mechanism.

scholarly journals Synthesis of Lead Nanoparticles by Aspergillus Species

2012 ◽  
Vol 61 (1) ◽  
pp. 61-63 ◽  
Author(s):  
K.V. PAVANI ◽  
N. SUNIL KUMAR ◽  
B.B. SANGAMESWARAN
Keyword(s):  
Electron Microscopy ◽  
Size Range ◽  
Natural Process ◽  
Fungal Strain ◽  
Aspergillus Species ◽  
Material Synthesis ◽  
Green Technologies ◽  
Transmission Electron ◽  
20 Nm ◽  
Scanning Electron

In the context of the current demand to develop green technologies in material synthesis, a natural process in the synthesis of lead particles by Aspergillus species to suit such technology is reported. The fungal strain was grown in medium containing different concentrations of lead (0.2-1.5 mM) to determine its resistance to heavy metals. The organism was found to utilize some mechanism and accumulate lead particles outside and inside the cell. The extracellular presence of lead particles in the range of 1.77-5.8 microm was characterized by scanning electron microscopy. The presence of particles of lead in the 5-20 nm size range was found on the cell surface, in the periplasmic space and in the cytoplasm and was analyzed by transmission electron microscopy.

A combined TEM and SEM study of erosive wear

1978 ◽  
Vol 36 (1) ◽  
pp. 584-585
Author(s):  
T.H. Kosel ◽  
R.O. Scattergood ◽  
A.P.L. Turner
Keyword(s):  
Electron Microscopy ◽  
Material Removal ◽  
Erosive Wear ◽  
Thin Foil ◽  
Original Surface ◽  
Thin Foils ◽  
Transmission Electron ◽  
Sem Study ◽  
Different Depths ◽  
Copper Single Crystals

Mechanisms of erosive wear are being studied using transmission electron microscopy (TEM) to examine the subsurface dislocation structures developed and scanning electron microscopy (SEM) to observe the surface topography. Specimens of recrystallized Ni 200 and copper single crystals have been eroded with 5 to 25μm glass microbeads and with 40 and 150 μm A12O3 particles at 53 m/sec using a slinger type erosion apparatus. Thin foils parallel to the original rough eroded surface and one μm or more below it have been prepared by first electroplating a few microns of nickel on the specimen and then electropolishing it away. Thin foil sections at 45̊ to the original surface have been prepared by sectioning specimens with thick electroplated layers; these allow observations to be made at different depths in the same foil.Material removal during particle impingement erosion at low angles of incidence probably occurs by a cutting or micromachining mechanism similar to that suggested by Finnie (1).

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