Shape-restricted inference for Lorenz curves using duality theory

We propose a new methodology for estimating curves under a convexity restriction based on Fenchel duality and wavelet approximations. In contrast to approaches where a possibly non-convex estimator is convexified at a second stage, our procedure allows us to construct directly an estimator with a convex shape. The method is applied to the estimation of the Lorenz curve. Applications to estimation of average value at risk, as well as multivariate generalisations to Lorenz surfaces are mentioned. We show asymptotic efficiency which demonstrates that the convexity is achieved at no extra cost.     

New Polylactic Acid Composites for Packaging Applications: Mechanical Properties,Thermal Behavior,and Antimicrobial Activity

The interest in antimicrobial packaging materials based on polylactic acid (PLA) polymers has increased due to the need to improve food safety and environment quality and also to find alternatives to synthetic polymers made from petrochemicals. PLA films by addition of different fillers (grape wastes and celery fibers) were obtained. The mechanical, thermal, surface, and antimicrobial properties of the films were evaluated. The incorporation of inexpensive fillers into the PLA matrix could reduce costs and the studied formulations offer approaches to realize composites with high performances and antimicrobial response, suitable for film food-active packaging materials, especially by use of grape wastes.     

Method for the evaluation of elastomeric seals by compression stress relaxation

A method is described whereby elastomer O-ring performance can be evaluated by compression stress relaxation in a simulated gas turbine lubrication system. The O-ring retained sealing force is measured in real-time during high temperature ageing and during transients to lower temperatures, thus simulating the temperature regimes experienced in an operational gas turbine. In addition to this, the O-rings are exposed to a flow of realistically aged turbine lubricant, producing a realistic level of chemical degradation during testing. The results from this work have demonstrated significant differences between elastomer behaviour due to O-ring material and also due to the temperature regimes subjected to during compression stress relaxation. Taken as a whole, this work represents a considerable improvement on current elastomer O-ring test methods as applied to gas turbine lubricant system seals.     

An improved method for analysis of In-EDTA,I− and Br− used as activable tracers in hydrological studies

Neutron activation analysis combined with chemical preconcentration of the elements in water samples can give a high sensitivity in the determination of concentrations for In-EDTA, I^– and Br^– used as activable tracers in hydrological studies. The authors have developed an improved method of analysis which is sensitive, selective and applicable to a wide range of underground and surface water samples including those having a high concentration of manganese ions.     

Multielemental determination in some water samples by neutron activation method

A method was developed for the determination of element concentrations in structured water samples (water with high oligoelements content). Sixteen elements (As, Br, Ca, Ce, Co, Cr, Eu, Fe, K, La, Lu, Na, Sb, Sc, Sm, Zn) were determined in 4 structured water samples and one taken from the water tap. The samples were preconcentrated evaporating 1 1 at atmospheric pressure and obtaining 100–500 mg of dry residue. Measurement accuracy by -spectroscopy was 3–30% and it can be improved by increasing the measurement time. The method allows simultaneous multielement analysis of various water sources and may successfully be used in environmental pollution control.     

Behavior patterns of observables in quantum-classical limit

It is shown that in the quantum-classical limit (QCL) the observables have different behavior patterns connected with the preservation or loss of their role of significant variables and of their stochasticity.This result rectifies the traditional belief of a unique behavior pattern associated with the disappearance of uncertainties.     

Essential oils of Satureja species: insecticidal effect on Culex pipiens larvae (Diptera: Culicidae)

The chemical composition of the essential oils of the wild growing plants of Greek S. spinosa L., S. parnassica subsp. parnassica Heldr.& Sart ex Boiss., S. thymbra and S. montana were determined by GC and GC/MS analysis. The larvicidal activities of the essential oils were assayed against Culex pipiens biotype molestus. The analytical data indicated that various monoterpene hydrocarbons and phenolic monoterpenes constitute the major constituents of the oils, but their concentration varied greatly among the oils examined. The bioassay results indicated that the oils possess significant larvicidal activities and represent an inexpensive source of natural substances mixture that exhibit potentials for use to control the mosquito larvae.     

Edgeworth expansion for the kernel quantile estimator

Using the kernel estimator of the pth quantile of a distribution brings about an improvement in comparison to the sample quantile estimator. The size and order of this improvement is revealed when studying the Edgeworth expansion of the kernel estimator. Using one more term beyond the normal approximation significantly improves the accuracy for small to moderate samples. The investigation is non- standard since the influence function of the resulting L-statistic explicitly depends on the sample size. We obtain the expansion, justify its validity and demonstrate the numerical gains in using it.     

Development of a cellular biosensor for the detection of 2,4,6-trichloroanisole (TCA)

2,4,6-trichloroanisole (TCA) is a microbial metabolite formed from chlorophenols through the activity of several natural fungal strains present on the cork oak bark. TCA is the primary compound responsible for the mousty/mould off-odour known as “cork taint” present in cork stoppers, wine, water and alcoholic beverages. Chromatographic and electrochemical methods are currently used for the determination of TCA, however its detection at low concentrations remains a technical challenge. The aim of this study was the development of a rapid novel biosensor system based on the Bioelectric Recognition Assay (BERA). The sensor measured the electric response of cultured membrane-engineered fibroblast cells suspended in an alginate gel matrix due to the change of their membrane potential in the presence of the analyte. Membrane-engineered cells were prepared by osmotic insertion of 0.5 μg/l of specific TCA antibodies into the membrane of the cells. The BERA-based sensor was able to detect TCA in a few minutes (3-5 min) at extremely low concentrations (10⁻¹ ppt), thus demonstrating higher sensitivity than the human sensory threshold. In addition, the assay was quite selective against other haloanisoles and halophenols structurally related to or co-occurring with TCA. Finally the sensor was tested against real white wine samples from cork soaks. At this real test, the BERA sensor was able to detect TCA from cork soaks rapidly (3-5 min) at very low concentrations (1.02-12 ng/l), covering the whole range for the detection threshold for wines (1.4-10 ng/l). Therefore, this novel biosensor offers new perspectives for ultra-rapid, ultra-sensitive and low-cost monitoring of TCA presence in cork and wine and possibly also other food commodities.     

Kinetic studies for the esterification of acetic acid with epichlorohydrin over an anion exchange resin catalyst

The kinetics of the esterification reaction between acetic acid and epichlorohydrin catalysed by Purolite A-520E strong basic anion exchange resin was studied. The effects of certain parameters such as stirring speed, particle diameter, temperature, catalyst amount and molar ratio between reactants were experimentally determined. It was found that the overall reaction rate is intrinsically kinetically controlled. The partial orders of reaction with respect to catalyst, acetic acid and epichlorohydrin were determined. A reaction mechanism is proposed. Based on chromatographic data and taking into account the partial orders of reaction, a more detailed kinetic model is suggested.