An alternative method to improve the settleability of gas-vacuolated cyanobacteria by collapsing gas vesicles

2016 ◽  
Vol 16 (6) ◽  
pp. 1552-1560 ◽  
Author(s):  
Helayaye Damitha Lakmali Abeynayaka ◽  
Takashi Asaeda ◽  
Kyoko Tanaka ◽  
Kimie Atsuzawa ◽  
Yasuko Kaneko ◽  
...  
Keyword(s):  
Applied Pressure ◽  
Water Layer ◽  
Control Culture ◽  
Gas Vesicles ◽  
Morphological Variations ◽  
Gas Vacuoles ◽  
Transmission Electron ◽  
Pseudanabaena Galeata ◽  
Microscopy Images ◽  
Maximum Removal

This study estimated the ability of pressurization to collapse gas vesicles and thereby enhance the settleability of fresh water cyanobacteria. Settling velocities of Pseudanabaena galeata and Microcystis aeruginosa were measured at 11 different pressure values from 0 to 0.5 MPa. The morphological variations that occurred in the gas vacuoles according to the applied pressure were investigated using transmission electron microscopy images. The settleability of both cyanobacteria species increased statistically significantly (P = 0.000) with increasing pressure, whereas the gas-vacuolated area of both species decreased significantly (P = 0.000) with the magnitude of the applied pressure. The removal ability of cyanobacterial cells from the water layer increased with high pressure treatment. The maximum removal efficiency observed of P. galeata and M. aeruginosa cells relative to the control culture were 82% and 95%, respectively, at the maximum tested pressure value of 0.5 MPa.

A Transmission Electron Microscopical Investigation of Phase Transformations in TiNi

1980 ◽  
Vol 38 ◽  
pp. 340-341
Author(s):  
P. Moine ◽  
G. M. Michal ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Phase Transformations ◽  
Applied Stress ◽  
Structural Changes ◽  
Microscopical Investigation ◽  
Temperature Range ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Diffraction Effects ◽  
Microscopy Images

Premartensitic effects in near equiatomic TiNi have been pointed out by several authors(1-5). These include anomalous contrast in electron microscopy images (mottling, striations, etc. ),diffraction effects(diffuse streaks, extra reflections, etc.), a resistivity peak above Ms (temperature at which a perceptible amount of martensite is formed without applied stress). However the structural changes occuring in this temperature range are not well understood. The purpose of this study is to clarify these phenomena.

Formation of Luminescent Si Nanocrystals by High-Temperature Annealing of Ion-Beam-Sputtered Si/SiO2 Multilayers

2003 ◽  
Vol 775 ◽  
Author(s):  
Suk-Ho Choi ◽  
Jun Sung Bae ◽  
Kyung Jung Kim ◽  
Dae Won Moon
Keyword(s):  
Quantum Confinement ◽  
Radiative Recombination ◽  
Ion Beam ◽  
Quantum Confinement Effect ◽  
Visible Range ◽  
Ion Beam Sputtering ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Beam Sputtering ◽  
Microscopy Images

AbstractSi/SiO2 multilayers (MLs) have been prepared under different deposition temperatures (TS) by ion beam sputtering. The annealing at 1200°C leads to the formation of Si nanocrystals in the Si layer of MLs. The high resolution transmission electron microscopy images clearly demonstrate the existence of Si nanocrystals, which exhibit photoluminescence (PL) in the visible range when TS is ≥ 300°C. This is attributed to well-separation of nanocrystals in the higher-TS samples, which is thought to be a major cause for reducing non-radiative recombination in the interface between Si nanocrystal and surface oxide. The visible PL spectra are enhanced in its intensity and are shifted to higher energy by increasing TS. These PL behaviours are consistent with the quantum confinement effect of Si nanocrystals.

scholarly journals Green Synthesis of Feather-Shaped MoS2/CdS Photocatalyst for Effective Hydrogen Production

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Liu ◽  
Hongtao Yu ◽  
Xie Quan ◽  
Shuo Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Production ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Sulfur Source ◽  
X Ray ◽  
Transmission Electron ◽  
Microscopy Images ◽  
Effective Hydrogen ◽  
Better Than

MoS2/CdS photocatalyst was fabricated by a hydrothermal method for H2production under visible light. This method used low toxic thiourea as a sulfur source and was carried out at 200°C. Thus, it was better than the traditional methods, which are based on an annealing process at relatively high temperature (above 400°C) using toxic H2S as reducing agent. Scanning electron microscopy and transmission electron microscopy images showed that the morphologies of MoS2/CdS samples were feather shaped and MoS2layer was on the surface of CdS. The X-ray photoelectron spectroscopy testified that the sample was composed of stoichiometric MoS2and CdS. The UV-vis diffuse reflectance spectra displayed that the loading of MoS2can enhance the optical absorption of MoS2/CdS. The photocatalytic activity of MoS2/CdS was evaluated by producing hydrogen. The hydrogen production rate on MoS2/CdS reached 192 μmol·h−1. This performance was stable during three repeated photocatalytic processes.

Error Quantification in Strain Mapping Methods

2007 ◽  
Vol 13 (5) ◽  
pp. 320-328 ◽  
Author(s):  
Elisa Guerrero ◽  
Pedro Galindo ◽  
Andrés Yáñez ◽  
Teresa Ben ◽  
Sergio I. Molina
Keyword(s):  
Electron Microscopy ◽  
Geometric Phase ◽  
Step Response ◽  
Strain Mapping ◽  
Error Quantification ◽  
Transmission Electron ◽  
Mapping Techniques ◽  
Microscopy Images ◽  
Real State

In this article a method for determining errors of the strain values when applying strain mapping techniques has been devised. This methodology starts with the generation of a thickness/defocus series of simulated high-resolution transmission electron microscopy images of InAsxP1−x/InP heterostructures and the application of geometric phase. To obtain optimal defocusing conditions, a comparison of different defocus values is carried out by the calculation of the strain profile standard deviations among different specimen thicknesses. Finally, based on the analogy of real state strain to a step response, a characterization of strain mapping error near an interface is proposed.

Facile Refluxing Synthesis of Hydroxyapatite Nanoparticles

2015 ◽  
Vol 68 (8) ◽  
pp. 1293 ◽  
Author(s):  
Pakvipar Chaopanich ◽  
Punnama Siriphannon
Keyword(s):  
Crystallite Size ◽  
Reaction Times ◽  
Single Step ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Aqueous Mixture ◽  
Diffraction Patterns ◽  
Microscopy Images

Hydroxyapatite (HAp) nanoparticles were successfully synthesized from an aqueous mixture of Ca(NO3)2·4H2O and (NH4)2HPO4 by a facile single-step refluxing method using polystyrene sulfonate (PSS) as a template. The effects of reaction times, pH, and PSS concentration on the HAp formation were investigated. It was found that the crystalline HAp was obtained under all conditions after refluxing the precursors for 3 and 6 h. The longer refluxing time, the greater the crystallinity and the larger the crystallite size of the HAp nanoparticles. The HAp with poor crystallinity was obtained at pH 8.5; however, the well-crystallized HAp was obtained when reaction pH was increased to 9.5 and 10.5. In addition, the X-ray diffraction patterns revealed that the presence of PSS template caused the reduction of HAp crystallite size along the (002) plane from 52.6 nm of non-template HAp to 43.4 nm and 41.4 nm of HAp with 0.05 and 0.2 wt-% PSS template, respectively. Transmission electron microscopy images of the synthesized HAp revealed the rod-shaped crystals of all samples. The synthesized HAp nanoparticles were modified by l-aspartic acid (Asp) and l-arginine (Arg), having negative and positive charges, respectively. It was found that the zeta potential of HAp was significantly changed from +5.46 to –24.70 mV after modification with Asp, whereas it was +4.72 mV in the Arg-modified HAp. These results suggested that the negatively charged amino acid was preferentially adsorbed onto the synthesized HAp surface.

Segmentation of virus particle candidates in transmission electron microscopy images

2011 ◽  
Vol 245 (2) ◽  
pp. 140-147 ◽  
Author(s):  
G. KYLBERG ◽  
M. UPPSTRÖM ◽  
K.-O. HEDLUND ◽  
G. BORGEFORS ◽  
I.-M. SINTORN
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Virus Particle ◽  
Transmission Electron ◽  
Microscopy Images
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