Search results for "SCOPE"

Hydrolytic action of phospholipase A2 in monolayers in the phase transition region: direct observation of enzyme domain formation using fluorescence …

1990

Phospholipase A2, a ubiquitous lipolytic enzyme highly active in the hydrolysis of organized phospholipid substrates, has been characterized optically in its action against a variety of phospholipid monolayers using fluorescence microscopy. By labeling the enzyme with a fluorescent marker and introducing it into the subphase of a Langmuir film balance, the hydrolysis of lipid monolayers in their liquid-solid phase transition region could be directly observed with the assistance of an epifluorescence microscope. Visual observation of hydrolysis of different phospholipid monolayers in the phase transition region in real-time could differentiate various mechanisms of hydrolytic action against …

Pectin biopolymer mechanics and microstructure associated with polysaccharide phase transitions.

2019

Polysaccharide polymers like pectin can demonstrate striking and reversible changes in their physical properties depending upon relatively small changes in water content. Recent interest in using pectin polysaccharides as mesothelial sealants suggests that water content, rather than nonphysiologic changes in temperature, may be a practical approach to optimize the physical properties of the pectin biopolymers. Here, we used humidified environments to manipulate the water content of dispersed solution of pectins with a high degree of methyl esterification (high-methoxyl pectin; HMP). The gel phase transition was identified by a nonlinear increase in compression resistance at a water content …

Phase transitions and upconversion luminescence in oxyfluoride glass ceramics containing Ba4Gd3F17 nanocrystals

2017

This is the peer reviewed version of the following article: G. Krieke, A. Sarakovskis, R. Ignatans, J. Gabrusenoks "Phase transitions and upconversion luminescence in oxyfluoride glass ceramics containing Ba4Gd3F17 nanocrystals", Journal of the European Ceramic Society, 2017, 37 (4), which has been published in final form at https://www.sciencedirect.com/science/article/abs/pii/S0955221916306768 This article may be used for non-commercial purposes in accordance with Elsevier Terms and Conditions for Sharing and Self-Archiving.

Narrowing the Theory’s or Study’s Scope May Increase Practical Relevance

2019

Photoelectrochemical Evidence of Cu2O/TiO2 Nanotubes Hetero-Junctions formation and their Physicochemical Characterization

2014

Cu2O/TiO2 nanotubes heterojunctions were fabricated by electrochemical deposition of cuprous oxide on TiO2 nanotubes arrays grown by anodizing. X-ray diffraction and Raman Spectroscopy analysis allows for identification of Cu2O, whose morphological features were studied by Scanning Electron Microscopy as a function of the charge circulated during the electrodeposition step. Photoelectrochemical measurements in aqueous solutions evidenced a red shift of the light absorption threshold of TiO2 nanotubes due to the presence of cuprous oxide even for very low circulated charges, while electrochemical impedance measurements proved a significant reduction of the electrode impedance due the presenc…

A photoelectrochemical investigation of conversion coatings on Mg substrates

2005

Abstract The structure, morphology and composition of conversion coatings grown in stannate bath on pure Mg were studied using potential–time, polarization curves, X-ray diffraction, scanning electron microscopy and photocurrent spectroscopy. The coating is manly constituted by crystalline magnesium–tin hydroxide, whose morphology and distribution depends on the conversion bath composition and temperature. The photoelectrochemical investigation allowed to estimate the band gap value of MgSn(OH) 6 and flat band potential. A sketch of the metal/passive film/electrolyte junction formed during conversion on the metal substrate is reported to account for the overall photoelectrochemical behaviou…

Photocurrent enhancement in thin a-Si:H solar cells via plasmonic light trapping

2014

Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping is investigated, and correlated with the morphology and the optical properties of the selfassembled silver nanoparticles incorporated in the cells' back reflector. © 2014 OSA.

On-line monitoring of one-step laser fabrication of micro-optical components

2002

The use of an on-line monitoring method based on photoelasticity techniques for the fabrication of micro-optical components by means of controlled laser heating is described. From this description it is possible to show in real time the mechanical stresses that form the microelement. A new parameter, stressed area, is introduced that quantifies the stresses of a microelement during its fabrication, facilitating a deeper understanding of the physical phenomena involved in the process as well as being a useful test of quality. It also permits the stress produced in the manufacturing process and the optical properties of the final microelement to be correlated. The results for several microlen…

A critical assessment of automatic photoelastic methods for the analysis of edge residual stresses in glass

2014

The measurement of residual stresses is of great importance in the glass industry. The analysis of residual stresses in the glass is usually carried out by photoelastic methods since the glass is a photoelastic material. This article considers the determination of membrane residual stresses of glass plates by digital photoelasticity. In particular, it presents a critical assessment concerning the automated methods based on gray-field polariscope, spectral content analysis, phase shifting, RGB photoelasticity, “test fringes” methods and “tint plate” method. These methods can effectively automate manual methods currently specified in some standards.

Magnetic Domain Imaging of Thin Metallic Layers Using PEEM

2001

Photoemission electron microscopy (PEEM) in combination with resonant excitation by circularly polarized soft X-rays has proven to be a powerful analytical tool for the study of magnetic microstructures and multilayers. In this type of electron microscope the lateral intensity distribution of the emitted low-energy secondary or photoelectrons is imaged by an electron-optical system. Owing to its fast parallel image acquisition, its wide zoom range allowing fields of view from almost 1 mm down to a few µm combined with a high base-resolution of the order of 20 nm, the method offers a unique access to many aspects in surface and thin film magnetism on the mesoscopic length scale. Magnetic con…