Compensation of a narrowband interference in an ultrawideband communication system based on chaotic radio pulses

The influence of narrowband signals on incoherent reception of ultrawideband chaotic radio pulses in direct chaotic communication (DCC) system is considered. A method for compensating the influence of narrowband signals on the characteristics of this system after incoherent reception of chaotic radio pulses is proposed. The proposed solution enables one to compensate a narrowband signal, preserving the possibility to determine chaotic radio pulses at corresponding time positions. The dependence of the probability of an error per bit on the spreading ratio of chaotic radio pulses is established.     

Luminescent properties of synthetic opal

We have studied the effect of the photonic band gap on the visible luminescence of opal photonic crystals. The results indicate that the position of the photonic band gap in the luminescence and reflection spectra of opal depends on the photon propagation direction. Optical measurements have been used to determine the refractive index of opal and the diameter of silica spheres. We have assessed the effect of oxygen annealing on the intrinsic luminescence spectra and crystal structure of opal. The emission centers in synthetic opal have been tentatively identified. The visible luminescence intensity in opal is shown to be anisotropic, in accordance with the frequency and angular dispersions of the first photonic band gap in opal. Original Russian Text ? A.N. Gruzintsev, G.A. Emel’chenko, V.M. Masalov, M. Romanelli, C. Barthou, P. Benalloul, A. Ma?tre, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 2, pp. 203–209.     

Glass formation in quaternary systems of group I-IV fluorides

We have studied the glass-forming regions in the lead-fluoride-containing quaternary fluorozirconate systems ZrF₄-PbF₂-LaF₃-NaF (ZPLN), ZrF₄-PbF₂-BaF₂-LaF₃(ZPBL), and ZrF₄-PbF₂-BaF₂-NaF (ZPBN). Their temperature characteristics have been determined by differential thermal analysis, and the most stable glass compositions have been identified.     

Chip curling in metal cutting

Chip curling in metal cutting is considered. A method is proposed for determining the dimensions of the dead zone at the cutter tip on the basis of the chip’s geometric parameters.     

Changes in concentration of aflatoxin M1 during manufacture and storage of skim milk powder

In this study, skim milk powder was produced from cow's milk contaminated artificially with aflatoxin M1 (AFM1) at two different levels, 1.5 and 3.5 microg/liter (ppb), and the effects of process stages on the AFM1 contents were investigated. Pasteurization, concentration, and spray drying caused losses of about 16, 40, and 68%, respectively, in AFM1 content of the milk contaminated with 1.5 microg/liter AFM1, and losses of 12, 35, and 59%, respectively, in the milk contaminated with 3.5 microg/liter AFM1. These losses were found to be statisticially significant at the level of P < 0.01. After 3- and 6-month storage periods, AFM1 content of the skim milk powder produced from milk with 1.5 microg/liter AFM1 decreased by 2 and 5%, respectively, whereas these rates were 2 and 4%, respectively, for the skim milk powders made from milk with 3.5 microg/liter AFM1 (after adjustment for sample weight). Changes in AFM1 content of milk powder samples were found statistically insignificant (P > 0.05 and P > 0.01) for 3- and 6-month storage periods.     

Synthesis and characterization of hydrogels based on poly(2-hydroxyethyl methacrylate) for drug delivery under UV irradiation

The present study aims to create a controlled release system through the preparation and characterization of hydrogels based on 2-hydroxyl ethyl methacrylate (HEMA). In order to investigate the influence of photo-initiators on the drug release behavior of the resulting hydrogels, three different photo-initiators [2,2-dimethoxy-2-phenyl-acetophenone] (Irgacure 651), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184) and 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) were used. In addition, hydroxyapatite (HAp) was employed to modify HEMA hydrogels. The synthesis of hydrogels was confirmed by characterization through Fourier transform infrared spectroscopy, nuclear magnetic resonance (¹³C NMR) spectroscopy and digital microscope. The responsive behaviors were investigated by recording swelling ratios under different conditions. In vitro drug release studies were performed for donepezil hydrochloride-loaded hydrogels at pH 1.2, 6.8 and 7.4. The results indicated that hydrogels synthesized using Irgacure 2959 released the maximum amount of donepezil hydrochloride. Moreover, the release rate decreased in the presence of HAp.     

Filling in the government-pattern dictionary in the analysis of equivalence for sense images of statements

Automatic filling in a language knowledgebase in analysis of the sense equivalence of statements is considered in the framework of an original approach based on a theory that represents language as a sense-to-text converter. Gennadii M. Emel’yanov. Born 1943. Graduated from Leningrad Institute of Electrical Engineering in 1966. Received candidate’s degree in 1971 and doctoral degree in 1990. Head of the Department of Computer Software for Computer Devices and Computerized Systems at Novgorod State University. Scientific interests: construction of problem-oriented computer systems for image processing and analysis. Dmitrii V. Mikhailov. Born 1974. Graduated from Novgorod State University in 1997. Received candidate’s degree in 2003. Staff member of the Department of Computer Software for Computer Devices and Computerized Systems at Novgorod State Unniversity. Member of the Russian Association of Pattern Recognition and Image Analysis since 2002. Scientific interests: computer linguistics and artificial intelligence. Author of 15 papers.     

Creating a high-quality wool-oriented Turkish merino herd and investigation of mechanical and dyeability properties of fabrics produced from Turkish merino in comparison with Australian merino

Today, the need for quality wool suitable for worsted fabric production in the world is mainly met by Australian merino wool. In Turkey, which has a significant sheep population, in addition to domestic breeds, approximately 10% of the total sheep population (around four million head) is composed of merino cross breeds. However, the fleece quality is far from meeting Australian merino wool standards. Therefore, the aim of this study is to ensure a merino herd with high-quality wool in Turkey. For this aim, by carrying out field studies in the Thrace region of Turkey where Turkish Merino sheep are widely bred, sheep with fleece that can meet the demands of the worsted industry were determined. As a result of field studies in which thousands of sheep were examined, it was determined that 43 female and 10 male sheep had fleece that would meet these standards. Then the breeders of the sheep, which had quality fleece, were persuaded and these sheep were purchased, and “Turkey's wool-oriented Turkish (Karacabey) Merino Herd” consisting of 30 sheep and three rams was formed in the farm of Tekirdağ Namık Kemal University. In the second part of this study, a 100% wool fabric produced by using Australian merino was taken as a reference and it was aimed to produce the same fabric from Turkish merino wool. For this aim, the wool-oriented Turkish Merino herd, which was bred at the university farm for 1 year, was shorn in May 2022. Then, Turkish and Australian merino wools were first converted into worsted yarn and then into woven fabric. The results of mechanical (tensile strength, pilling, abrasion resistance, felting shrinkage, Hofmann dimensional change, bending stiffness) and dyeability (dye-uptake, CIE L*a*b* and colour yield (K/S) values; washing, rubbing and light fastness values) properties of fabrics produced from Turkish and Australian merino wool is presented.