Search results for "SMIS"

Dislocations in AIIIBVI single crystals

1988

High densities of planar defects are evidenced in various AIIIBVI layer compounds by systematic electron microscopy observations with the dark-field weak-beam image technique. Several samples are analyzed, as obtained from different crystal ingots of InSe grown by the Bridgman-Stockbarger method, and some GaS and GaSe single crystals grown both, from the melt and from the vapour. The observed defects are identified mainly as screw and edge dislocations, the orientation of which is obtained in some cases by the analysis of the Moire fringes. Dislocation densities ranging between 108 and 1010 cm−2 are measured, not uniformly distributed in the various regions of each sample. Finally, the obse…

Radiation damage in zircon

2003

A single, zoned, Sri Lankan zircon exhibits a range of microstructures from crystalline to nearly amorphous that are the result of radiation damage over a dose range of 2.1–10.1·1015 α-decay events/mg (0.16–0.47 dpa). The zones in the crystal were examined at a variety of length scales using optical microscopy, micro-Raman spectroscopy, electron microprobe analysis, and transmission electron microscopy. Birefringence varies linearly with dose: birefringence = −4.71·10−18 /g· D α + 4.86·10−2. Full width at half maximum (FWHM) measurements of the B1g(ν3) peak, as determined by micro-Raman spectroscopy, were used to estimate the extent of radiation damage in each zone. The radiation dose (calc…

Microstructural evolution of mullites produced from single-phase gels

2007

The crystalline microstructure of mullites obtained by heating monophasic gels has been investigated. Gels with alumina to silica molar ratio of 3:2 (as in secondary mullite) and 2:1 (as in primary mullite) were prepared by gelling mixtures of aluminium nitrate and tetraethylorthosilicate. Phase transformations were induced by heating the gel precursors, with different final treatment temperatures between 1173 and 1873 K. The mullites formed as a result of thermal treatment were studied by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The crystalline structure (unit-cell parameters) and microstructure were determined from X-ray diffraction pa…

Growth and defect studies of CdTe particles

2013

The paper reports the epitaxial growth of cadmium telluride (CdTe) particles by thermal deposition on cleaved planes of (001)NaCl and (001)KBr. Using high resolution transmission electron microscopy and electron diffraction it was shown that CdTe particles could have different orientation and phase (cubic or hexagonal) depending on the substrate temperature. Their most common defects are twins and stacking faults.

Ultrastructural and histochemical analysis reveals ethylene-induced responses underlying reduced peel collapse in detached citrus fruit

2010

Fruits from many citrus cultivars develop depressed areas in the flavedo (outer part of the peel) and albedo (inner part) following detachment. Although ultrastructural analysis may provide important information about multiple plant responses to stresses and external stimuli at the cell and tissue levels, and despite the proved efficacy of ethylene in reducing peel damage in citrus fruit, cytological responses of this horticultural crop to protective ethylene concentrations have not yet been reported. We show that applying high ethylene levels (2 mu L L(-1) for 14 days) causes sublethal stress as it favored the alteration of cuticle, vacuole, middle lamella and primary wall, especially in t…

ER stress in human hepatic cells treated with Efavirenz: Mitochondria again

2013

Background & Aims ER stress is associated with a growing number of liver diseases, including drug-induced hepatotoxicity. The non-nucleoside analogue reverse transcriptase inhibitor Efavirenz, a cornerstone of the multidrug strategy employed to treat HIV1 infection, has been related to the development of various adverse events, including metabolic disturbances and hepatic toxicity, the mechanisms of which remain elusive. Recent evidence has pinpointed a specific mitochondrial effect of Efavirenz in human hepatic cells. This study assesses the induction of ER stress by Efavirenz in the same model and the implication of mitochondria in this process. Methods Primary human hepatocytes and Hep3B…

Particulated wisdom teeth as an autologous bone substitute for grafting/filling material in bone defects : case Report

2020

Introduction Bone augmentation material using permanent teeth are confirmed in many articles to provide good histological and clinical results. Advances in osteoconduction and osteoinduction, low cost of material, no risk of disease transmission and elimination of foreign body reaction are important aspects not only to the clinician but to patient as well. Many techniques and devices to obtain graft material for bone augmentation out of teeth are found in the literature. Material and Methods The wisdom teeth crush technique developed in our office and described in this case report is simple and no specific devices for teeth grinding were used. The graft material was obtained from impacted i…

Light and electron microscopy study of D2-40 expression on lymphatics

2008

A DC and small signal AC model for organic thin film transistors including contact effects and non quasi static regime

2017

Abstract We present a compact model for the DC and small signal AC analysis of Organic Thin Film Transistors (OTFTs). The DC part of the model assumes that the electrical current injected in the OTFT is limited by the presence of a metal/organic semiconductor junction that, at source, acts as a reverse biased Schottky junction. By including this junction, modeled as a reverse biased gated diode at source, the DC model is able to reproduce the scaling of the electrical characteristics even for short channel devices. The small signal AC part of the model uses a transmission line approach in order to compute the impedances of the channel and parasitic regions of the device. The overlap capacit…

Structure and Deformations of Pd−Ni Core−Shell Nanoparticles

2005

International audience; Homogeneous collections of Pd−Ni core−shell nanoparticles have been prepared by decomposition of metal−organic compounds and studied by several electron microscopy techniques: transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), energy-filtered microscopy (EFTEM), and by X-ray photoelectron spectroscopy (XPS). The physical and chemical properties of the Pd shell are supposed to depend on its electronic properties, which are influenced by the presence of the Ni core and by the deformation in the Pd lattice. Here, the interfacial structure of Pd/Ni and the lattice deformations in t…