Evaluation of Transport Capacity through Liquid Membranes of Some Crown Ether‐Siloxane Copolymers

The complexation ability of some linear crown ether‐siloxane copolymers of ester or amide type with cations as K⁺ and NH₄⁺ was investigated spectrophotometrically in order to select the polysiloxane receptors that achieve good ion transport ability by bulk liquid membrane systems. The transport properties of the potassium picrate through a liquid membrane using siloxane‐crown ether polyamide as carrier were discussed.     

A NOVEL METHOD FOR DIRECT NONDESTRUCTIVE DIAGNOSIS OF CARIES AFFECTED TOOTH SURFACES BY LASER MULTIPHOTON IONIZATION

A new nondestructive analytical method for diagnosis of tooth caries is presented. The method is based on the Multiphoton Ionization (MPI) fast conductivity signals measured from tooth surfaces. The signals are acquired for a series of laser wavelengths, thus obtaining full MPI spectra. The results indicate a good correlation between the MPI results and the degree of severity of the caries, as diagnosed using traditional inspection. Moreover, the spectral information can be reduced (using least squares fitting) to a single parameter that provides an objective quantitative estimation of the caries severity. The MPI data can be obtained for tiny points on the dental surface and it is suggested that mapping is possible by scanning method.     

Emotion regulation and decision making under risk and uncertainty.

It is well established that emotion plays a key role in human social and economic decision making. The recent literature on emotion regulation (ER), however, highlights that humans typically make efforts to control emotion experiences. This leaves open the possibility that decision effects previously attributed to acute emotion may be a consequence of acute ER strategies such as cognitive reappraisal and expressive suppression. In Study 1, we manipulated ER of laboratory-induced fear and disgust, and found that the cognitive reappraisal of these negative emotions promotes risky decisions (reduces risk aversion) in the Balloon Analogue Risk Task and is associated with increased performance in the prehunch/hunch period of the Iowa Gambling Task. In Study 2, we found that naturally occurring negative emotions also increase risk aversion in Balloon Analogue Risk Task, but the incidental use of cognitive reappraisal of emotions impedes this effect. We offer evidence that the increased effectiveness of cognitive reappraisal in reducing the experience of emotions underlies its beneficial effects on decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dental Enamel Caries (Early) Diagnosis and Mapping by Laser Raman Spectral Imaging

Abstract

A method for estimating the extent of tooth caries and providing imaging information based on Raman Spectral Imaging is suggested. This non‐destructive optical method is able to characterize and differentiate between normal enamel tooth surface, and initial and advanced tooth caries. Images and corresponding spectra were acquired from various tooth sites, and it was demonstrated that normal, white opaque, brown discoloured, and pitted tooth surfaces all have different distinct spectral features which characterize the different degrees of dental caries. Spectral analysis allows for detection of early changes in the surfaces of carious teeth, and the associated mapping capability allows for morphological characterization. It was found that the emission at 960 cm^?1, which corresponds to PO stretching in the hydroxyapatite bond, is the most significant and can be used for diagnosis of caries. The emissions at 1070 cm^?1 and at 590 cm^?1 can also be applied, but are less accurate. The results suggest that this technique may be further developed and applied for clinical diagnosis of initial and more advanced demineralization processes of the enamel tooth surfaces.     

Synthetic adipic complex tetraesters as eco‐friendly lubricants

The paper presents results concerning the synthesis and characterisation as lubricants with biodegradability potential of some complex tetraesters realised on the basis of adipic acid and different glycols such as (mono) ethylene, 1,3‐propylene, 1,4‐butylene, 1,5‐pentamethylene, 1,6‐hexamethylene, diethylene and triethylene glycol, respectively, along with oleic acid used, considered as an end, final segment or as a capping element. On the basis of a regular alternation or successive distribution principle of the polar and nonpolar chemical functions equally distributed, shared out on the length of a sufficient, satisfactorily long, large molecule, valuable synthetic complex tetraester lubricants considered as eco‐friendly base oils with biodegradability potential were performed. These products showed very good tribological properties, such as high viscosity indices and high flash points, and also very good lubricity features. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of working parameters on surface finish in ball-burnishing of hardened steels

Burnishing is a chipless finishing method, which employs a rolling tool, pressed against the workpiece, in order to achieve plastic deformation of the surface layer. Recent developments made possible burnishing of heat-treated steel components up to 65 HRC. Features of burnishing include a good roughness (comparable to grinding), as well as improvement of mechanical characteristics of the surface (fatigue strength, corrosion resistance, and bearing ratio), due to implementation of compressive stresses into the surface layer. This paper will present influences of certain burnishing parameters upon roughness, for a hardened steel component (64 HRC).     

Investigation of Mixed Mode I/II Brittle Fracture Using ASCB Specimen

Using the asymmetric semi-circular bend specimen (ASCB) with vertical crack, a series of mixed mode I/II fracture tests were performed on two different rigid polyurethanes materials. The experimental results obtained for brittle fracture are compared with the theoretical predictions based on MTS and SED criteria. The results demonstrate that the SED criterion gives better results for mode II loading conditions, while for mode I and predominantly mode I both criteria are accurate.     

New unsymmetrical complex diesters of adipic acid considered as tribological fluids

The paper presents results concerning the synthesis and characterisation of some unsymmetrical diesters of adipic acid with a mixed, complex structure in order to produce synthetic ester oils with specific tribological properties. These complex diesters have been synthesised by taking into account medium and superior aliphatic alcohols, such as n‐butanol, n‐hexanol, 2‐ethyl‐hexanol, isodecanol and isotridecanol along with special alcohols of a complex alkyl–aryl nature, namely 2‐phenoxy‐ethanol, 2‐([o‐sec butyl] phenoxy) ethanol and 2‐([p‐nonyl] phenoxy) ethanol, respectively. By varying the length of the aliphatic alcohols and also by modifying the length and position of the alkyl pendant group on the aromatic ring of the complex alkyl–aryl alcohols, three series of products have been realised. On the basis of this programme, it has been possible to obtain fluid products that show valuable tribological features with adequate and versatile characteristics. Copyright © 2010 John Wiley & Sons, Ltd.