Study of the efficacy of new systems for reducing the combustibility of polypropylene based on polycyclic organic compounds

Incorporation of a flame retardant system (FRS) consisting of the ammonium salt of amino-trismethylenephosphonic acid and a condensed tetranuclear heterocycle — 2,7-diamino-4,9-dihydroxypyridotetrahydrophenanthrene-5,10-dione — in a polypropylene melt during spinning increases the oxygen index of the polymer, yield of carbonized residue, intensive decomposition temperature, and other parameters. The ratio of the components of the FRS and FRS content in the polymer affect these parameters.     

Effect of the conditions of spinning viscose textile fibres on their properties

Rigorous respect of the standard character and purity of the spinning solution, spinning bath parameters, and orientation draw ratio ensures obtaining a complex fibre homogeneous over the length. By varying the flow rate of viscose from the spinneret and disk rotation, it is possible to vary the fibre tension, strength, elongation, and shrinkage within wide limits and ensure a high capacity for uniform dyeing. The limits of the overall draw ratio of viscose textile fibres of varying assortment without elementary fibre breakage and formation of nap were established. __________ Translated from Khimicheskie Volokna, No. 6, pp. 28–31, November–December, 2005.     

Fabrication of materials for medical applications from solutions of biocompatible polymers

Technologically easy incorporation of biologically active compounds in a polymeric material in spinning from a compatible solution or dispersion in a polymer solution creates the conditions for directed regulation of the structure and fabrication of composite and porous materials. Additional modification in the stage of fabrication of spinning compositions or finished polymer articles allows regulating the kinetics of separation of the biologically active compounds. __________ Translated from Khimicheskie Volokna, No. 6, pp. 21–24, November–December, 2005.     

New Fluorine-Containing Polymers for Modification of the Surface Properties of Chemical Fibres

A series of polymers was made from new fluoroalkyl acrylates and the effect of the structure of their fluoroalkyl radical on the decrease in the wettability of fibre materials was investigated. It was found that polymers with long fluoroalkyl radicals of linear structure are characterized by the highest effectiveness. Chain branching and incorporation of an oxygen atom in the fluoroalkyl chain decrease the nonwettability effect of the modified fibres.__________Translated from Khimicheskie Volokna, No. 2, pp. 3–5, March–April, 2005.     

Spring pollen and related allergies in southern Spain

Over the last 10 years, there has been an increase in pollen allergies throughout Europe; this trend is clearly reflected in this study carried out in Córdoba (southern Spain) over 7 consecutive years, which recorded important increases in the concentrations of certain pollen types of particular interest in this city, together with an increase in the number of patients with pollinosis visiting the Allergy Unit at Córdoba's Reina Sofía University Hospital. The purpose of this study was to ascertain whether these two trends were related. Sampling was carried out from 1984 to 1990, using a Burkard spore trap placed at a height of approximately 15 m on a building situated in the city center. The trend towards an annual increase in the concentration of pollen grains was positive in all cases, although very slight for Quercus and very marked for Olea europaea. However, a different pattern of behavior was recorded with respect to the correlation between pollen concentration and cases of pollinosis, a correlation which varied according to taxa.     

Enantiospecific drug analysis via the ortho-phthalaldehyde/homochiral thiol derivatization method

Pre-column derivatization with o-phthaldialdehyde and an optically active thiol has hitherto been used mainly for liquid-chromatographic chiral separation of amino acids. Chiral separation of non-amino-acid primary amines, especially of pharmaceuticals, via this approach has been largely ignored. We have therefore examined the applicability of the method to the chiral resolution of several pharmaceutical amines. o-Phthaldialdehyde and four commercially available homochiral thiols were used to study the separation of the enantiomers of amphetamine, p-hydroxyamphetamine, p-chloroamphetamine, 3-amino- 1-phenylbutane, 3-amino-1-(4-hydroxyphenyl)-butane, mexiletine, tocainide, tranylcypromine and rimantadine. The resulting highly fluorescent isoindole derivatives were resolved on a Waters Nova-Pak C18 column using mobile phases consisting of mixtures of methanol, a sodium acetate buffer and acetonitrile, and the column effluent was monitored using fluorescence or UV detection. In some cases the fluorescence and/or the UV absorbance of the two diastereomers were unequal. It was found that the resolution of most of the amines could be optimized by varying the homochiral thiol in the derivatization step. This method of chiral separation may have wide applicability in enantiospecific drug analysis of non-amino-acid primary amines due to its simplicity and the high sensitivity it provides.     

A multiagent update process in a database with temporal datadependencies and schema versioning

Temporal data dependencies are high-level linguistic constructs that define relationships among values of data-elements in temporal databases. These constructs enable the support of schema versioning as well as the definition of consistency requirements for a single time-point and among values in different time-points. In this paper, we present a multiagent update process in a database with temporal data dependencies and schema versioning. The update process supports the evolution of dependencies over time and the use of temporal operators within temporal data dependencies. The temporal dependency language is presented, along with the temporal dependency graph-which serves as the executable data structure. A thorough discussion of the feasibility, performance, and consistency of the presented model is provided     

Efficient mode transformations of degenerate Laguerre-Gaussian beams

We present an approach for efficient conversion of a single-high-order-mode distribution from a laser to a nearly Gaussian distribution and vice versa. It is based on dividing the high-order mode distribution into equal parts that are then combined together coherently. We implement our approach with several optical arrangements that include a combination of discrete elements and some with single interferometric elements. These arrangements are analyzed and experimentally evaluated for converting the TEM01 mode distribution with Mx(2) = 3 to a nearly Gaussian beam with Mx(2) = 1.045 or Mx(2) = 1.15. The basic principle, design, and experimental results obtained with several conversion arrangements are presented. The results reveal that conversion efficiency is typically greater than 90%, compared with theoretical ones. In addition, some arrangement is exploited for converting the fundamental Gaussian-beam distribution into the TEM01 mode distribution.