Starch‐capped sulphur nanoparticles synthesised from bulk powder sulphur and their anti‐phytopathogenic activity against Clavibacter sepedonicus

Water‐soluble, stable nanoparticles of elemental sulphur with a size of 9‐52 nm have been synthesised using the stabilising potential of starch. Sulphide anions were used as sulphur precursors that were generated earlier from the bulk powder sulphur in the base‐reduction system NaOH‐N₂H₄·H₂O followed by their oxidation with molecular oxygen to element sulphur atoms. Using a set of modern spectral and microscopic methods (XRD, optical spectroscopy, DLS, TEM), the phase state, elemental composition of the nanocomposites and their nanomorphological characteristics have been investigated. It was found that nanocomposites are formed as sulphur particles with the shape which is nearly spherical dispersed in the polysaccharide starch matrix with a pronounced tendency to cluster into ring formations. Water solubility and stability of the obtained nanoparticles is ensured by sorption of starch macromolecules on the surface of sulphur nanoparticles, with the thickness of the stabilising shell in a range of 10‐171 nm. In vitro experiments were carried out to study the anti‐microbial activity of the obtained sulphur nanocomposite (1.6% S) using the propidium iodide fluorescent dye staining method and the diffusion method. It showed that the water solution of the starch‐capped sulphur nanoparticles at the concentration of 6.25 µg/ml had a pronounced anti‐phytopathogenic activity against the potato ring rot pathogen Clavibacter michiganensis subsp. sepedonicus.     

Evaporation of water from particles in the aerodynamic lens inlet: an experimental study

The extremely high particle transmission efficiency of aerodynamic lens inlets resulted in their wide use in aerosol mass spectrometers. One of the consequences of transporting particles from high ambient pressure into the vacuum is that it is accompanied by a rapid drop in relative humidity (RH). Since many atmospheric particles exist in the form of hygroscopic water droplets, a drop in RH may result in a significant loss of water and even a change in phase. How much water is lost in these inlets is presently unknown. Since water loss can affect particle size, transmission efficiency, ionization probability, and mass spectrum, it is imperative to provide definitive experimental data that can serve to guide the field to a reasonable and uniform sampling approach. In this study, we present the results of a number of highly resolved measurements, conducted under well-defined conditions, of water evaporation from a range of particles, during their transport through an aerodynamic lens inlet. We conclude that the only sure way to avoid ambiguities during measurements of aerodynamic diameter in instruments that utilize low-pressure aerodynamic lens inlets is to dry the particles prior to sampling.     

Oxidation Stability and Tribological Behavior of Vegetable Oil Hydraulic Fluids

The new generation of vegetable oil hydraulic fluids has a price advantage and provides field longevity comparable to synthetic esters at moderate temperature.

This article investigates the oxidation stability and tribological behavior of fully formulated vegetable oil hydraulic fluids. Differences in origin (canola, soybean, and sunflower oil) and the degree of unsaturation are studied. Modified ASTM D943 (Dry TOST) was found reliable to evaluate the impact on oxidative stability of various additive packages in vegetable oils. Tribological testing utilized laboratory hydraulic pumps such as the Vickers V 104C, Vickers 20VQ, and Vickers PFB-5 under a variety of temperatures, pressures, pump outputs, and speeds. The conditions of aging fluids were monitored by evaluation of TAN, viscosity, wear rate, and depletion of antioxidants. Voltammetric technique was applied to determine the concentration of antioxidant in systems. Based on analysis of antioxidant consumption, the main degenerative process in vegetable oils under demanding pump operations is similar to pyrolytic degradation, rather than oxidation.

By selecting the appropriate synergistic additive packages, a remarkable pump longevity can be obtained for each vegetable base stock studied.     

Protective Coatings on Heat-Resistant Nickel Alloys (Review)

The literature on materials for protective coatings on heat-resistant nickel alloys and methods for their production is reviewed in order to generalize the results and determine the principal directions for solution of the problem under consideration. It is shown that a promising approach is the development of layered composite ceramic coatings which, thanks to a graded variation of properties, are able to provide an optimal combination of adherence, mechanical strength, and corrosion and heat resistance. The methods of physical vapor deposition, plasma spraying, and electron-beam deposition remain the principal industrial processes for coating deposition.     

Measurement of functional inability and quality of life in cardiac failure. Transcultural adaptation and validation of the Goldman, Minnesota and Duke questionnaires

Cardiac failure has a big impact on the daily life of patients and this can be evaluated using quality of life questionnaires. The aim of this study was to translate and adapt for the French population and test the validity of two quality of life self-administered-questionnaires: the Duke health Profile, the Minnesota Quality of Life Questionnaire in Cardiac Failure and one function capacity questionnaire, the Goldman Specific Activity Scale. The questionnaires were translated and retranslated then submitted to a committee of experts: the final version was presented to 30 patients. The study of the quantitative properties of the three instruments was performed on a sample of 74 patients with cardiac failure to assess their validity and 26 stable patients after cardiac transplantation to test reproducibility. The results of this study show that these three instruments are valid and reproducible and are comparable to the original documents: Cronbach's Alpha ranging from 0.54 to 0.78 for the Duke, except for the social dimension, and from 0.73 to 0.93 for the Minnesota, except for its incapacity dimension, intraclass correlation coefficient > 0.6 in all dimensions. The validity of convergence with LVEF and the NYHA measured during hospitalisation for decompensation was poor, except for the Goldman. The three instruments provided coherent information. The authors conclude that a structured method allows transcultural adaptation of instruments of evaluation of quality of life, the French version having comparable properties to the original documents: they may be used for clinical research.     

Use of methanol and oxygen in promoting the destruction of deca-chlorobiphenyl in supercritical water

The destruction of the well-known PCB, deca-chlorobiphenyl (10-CB), by oxidation and methanolysis in supercritical water (SCW), has been studied in a micro-reactor hydrothermal diamond-anvil cell (DAC, 50 nL) and in larger batch reactors (6 mL). The DAC was coupled to optical and infrared microscopes. In the DAC experiments, 10-CB proved to be stable under pyrolytic conditions, whereas in water, it was hydrolyzed and actually dissolved at temperatures above 475 °C. When partial oxygen was added to the 10-CB/water system, the solubility of 10-CB increased slightly as compared to the pure water experiments, and 10-CB was further decomposed by oxidation. The addition of methanol resulted in further decomposition by methanolysis, as confirmed by FT-IR spectroscopy, and lowered the dissolution temperature to 419 °C. Both oxygen and methanol (25 vol.%) were then used to destroy 10-CB in batch reactors, in which the supercritical water experiments permitted a detailed study of the reaction products of the 10-CB destruction. In the absence of methanol, more than 12 intermediate products were detected by GC-MS, and 99.2% of the 10-CB was destroyed in the presence of 225% excess oxygen at 450 °C within 20 min. When methanol was used in the absence of any excess oxygen, a destruction rate of 100% was achieved at 450 °C within 10 min and only three intermediate products were detected. The enhanced destruction of 10-CB in the presence of methanol is attributed to the homogenous reaction conditions employed and the generation of free radicals.     

The index of ideality of correlation: hierarchy of Monte Carlo models for glass transition temperatures of polymers

Glass transition temperatures of polymers were modelled by means of the CORAL software available on the Internet (http://www.insilico.eu/coral). The architecture of monomers was represented via simplified molecular input line entry systems (SMILES). Three random splits into the training and validation sets were tested to build up quantitative structure - property relationships (QSPRs). The index of Ideality of Correlation (IIC) represents a new measure of predictive potential. Application of the IIC as the criterion of predictive potential for the calibration set was tested in this work and resulted in correct recommendations for selection of the best model from three different models considered here.     

Thermoelectric spherical shell with fractional order heat transfer

Microsystem Technologies - The model of fractional magneto-thermoelasticity is applied to one-dimensional problems of a thermoelectric spherical shell subjected to an arbitrary thermal loading of...     

Utilization of lignocellulosic fibers in molded polyester composites

Using rice straw, bagasse, and cotton stalk fibers as reinforcing fillers in polyester composite was studied. The effects of fiber loading and fiber size on the modulus of rupture (MOR), modulus of elasticity (MOE), tensile strength, water absorption, and thickness swelling were investigated as well. The effect of esterification using maleic anhydride on the aforementioned properties also was studied. Ultraviolet light resistance and thermal behavior of the produced composites were also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 653–660, 2003