Conformal Modulus of the Exterior of Two Rectilinear Slits

We study moduli of planar ring domains whose complements are linear segments and establish formulas for their moduli in terms of the Weierstrass elliptic functions. Numerical tests are carried out to illustrate our results

Loop-mediated isothermal amplification (LAMP) method for fast detection of Campylobacter spp in meat food products and environmental objects of a processing plant’s

There is constant necessity of developing the accurate and fast methods for detection of foodborne pathogens. Microorganisms of Campylobacter genus are one of the main causes of foodborne diseases worldwide. Fast identification of Campylobacter at all stages of the food life cycle is an efficient strategy to control foodborne campylobacteriosis. This article the authors evaluated a commercial loop-mediated isothermal amplification (LAMP) system with bioluminescence, called as the 3M™ Molecular Detection Analysis (MDA), which was used to find Campylobacter in food products with the help of a certain standard method, which is referred to as the reference method. The results of this study showed that the commercial LAMP based method is as efficient as the reference method, and features high specificity and minimum determinability (sensitivity). The LAMP based method has been shown to be a fast and reliable method for detection of Campylobacter spp. scarce presence (10 CFU/25 g) in meat, meat products, as well as carcass swabs and production facilities’ environment. The LAMP analysis required about 24–27 hours to achieve a result. However the LAMP based method will facilitate the detection of Campylobacter, as it provides much easier and faster detection of Cam  pylobacter spp., including Campylobacter jejuni/Campylobacter coli, than standard microbiological methods. The LAMP based method is an efficient tool to prevent the spreading of Campylobacter spp. contamination in food products.There is constant necessity of developing the accurate and fast methods for detection of foodborne pathogens. Microorganisms of Campylobacter genus are one of the main causes of foodborne diseases worldwide. Fast identification of Campylobacter at all stages of the food life cycle is an efficient strategy to control foodborne campylobacteriosis. This article the authors evaluated a commercial loop-mediated isothermal amplification (LAMP) system with bioluminescence, called as the 3M™ Molecular Detection Analysis (MDA), which was used to find Campylobacter in food products with the help of a certain standard method, which is referred to as the reference method. The results of this study showed that the commercial LAMP based method is as efficient as the reference method, and features high specificity and minimum determinability (sensitivity). The LAMP based method has been shown to be a fast and reliable method for detection of Campylobacter spp. scarce presence (10 CFU/25 g) in meat, meat products, as well as carcass swabs and production facilities’ environment. The LAMP analysis required about 24–27 hours to achieve a result. However the LAMP based method will facilitate the detection of Campylobacter, as it provides much easier and faster detection of Cam  pylobacter spp., including Campylobacter jejuni/Campylobacter coli, than standard microbiological methods. The LAMP based method is an efficient tool to prevent the spreading of Campylobacter spp. contamination in food products

Investigação das propriedades físico-químicas e características estruturais do produto da pirólise de resíduos de madeira

In this paper, the object of investigation is a solid product of pyrolysis of wood waste. The structural characteristics and physical-chemical properties of the solid pyrolysis product obtained in the production conditions, characterizing the sorption properties with respect to pollutants contained in aqueous media - the specific area, surface structure, pore size and size distribution are characterized.The specific surface, volume and radius of the pores were determined by capillary condensation of nitrogen. The specific surface area of the pyrolysis product of wood waste is 310.5 m2/ g. The volume and radius of the pores determined by the t-method and the BJH method are 0.229 cc/g and 19.3 A, respectively. The elemental composition and surface structure of the pyrolysis product were studied by scanning electron and x-ray microscopy. The obtained data indicate the presence of sorption properties.According to the definition of the dispersed composition, the pyrolysis product of wood waste mainly contains particles of sizes from 0.1 to 3 mm (86.6%). The specific value of the bulk density of the pyrolysis product is not inferior to that of known adsorbents. And they are 295 g/dm3. The moisture content of wood waste after treatment with pyrolysis does not exceed the normative value and accounts for 2.7%.It is established that utilization of wood waste by low-temperature pyrolysis makes it possible to obtain a sorption material.En este trabajo, el objeto de investigación es un producto sólido de pirólisis de residuos de madera. Se caracterizan las características estructurales y las propiedades físico-químicas del producto de pirólisis sólido obtenido en las condiciones de producción, que caracterizan las propiedades de sorción con respecto a los contaminantes contenidos en medios acuosos: el área específica, la estructura de la superficie, el tamaño de los poros y la distribución de tamaños.La superficie específica, el volumen y el radio de los poros se determinaron mediante la condensación capilar de nitrógeno. El área superficial específica del producto de pirólisis de los residuos de madera es de 310,5 m2 / g. El volumen y el radio de los poros determinados por el método t y el método BJH son 0.229 cc / gy 19.3 A, respectivamente. La composición elemental y la estructura de la superficie del producto de pirólisis se estudiaron mediante microscopía electrónica y de rayos X de barrido. Los datos obtenidos indican la presencia de propiedades de sorción.Según la definición de la composición dispersa, el producto de pirólisis de los desechos de madera contiene principalmente partículas de tamaños de 0,1 a 3 mm (86,6%). El valor específico de la densidad aparente del producto de pirólisis no es inferior al de los adsorbentes conocidos. Y son 295 g / dm3. El contenido de humedad de los residuos de madera después del tratamiento con pirólisis no excede el valor normativo y representa el 2,7%.Se ha establecido que la utilización de residuos de madera mediante pirólisis a baja temperatura permite obtener un material de sorción.Neste trabalho, o objeto de investigação é um produto sólido de pirólise de resíduos de madeira. As características estruturais e propriedades físico-químicas do produto de pirólise sólido obtido nas condições de produção, caracterizando as propriedades de sorção em relação aos poluentes contidos em meio aquoso - a área específica, estrutura superficial, tamanho de poro e distribuição de tamanho são caracterizadas.A superfície específica, volume e raio dos poros foram determinados por condensação capilar de nitrogênio. A área superficial específica do produto da pirólise de resíduos de madeira é de 310,5 m2 / g. O volume e o raio dos poros determinados pelo método t e pelo método BJH são de 0,229 cc / ge 19,3 A, respectivamente. A composição elementar e a estrutura superficial do produto da pirólise foram estudadas por microscopia eletrônica de varredura e de raios-X. Os dados obtidos indicam a presença de propriedades de sorção.De acordo com a definição da composição dispersa, o produto de pirólise de resíduos de madeira contém principalmente partículas de tamanhos de 0,1 a 3 mm (86,6%). O valor específico da densidade aparente do produto de pirólise não é inferior ao dos adsorventes conhecidos. E eles são 295 g / dm3. O teor de umidade dos resíduos de madeira após o tratamento com pirólise não excede o valor normativo e representa 2,7%.Estabelece-se que a utilização de resíduos de madeira por pirólise a baixa temperatura possibilita a obtenção de um material de sorção

Evaluation of approaches to increase the effectiveness of various disinfectants against biofilm communities of different ages

Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms.Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms

Evaluating the effect of various types of disinfectants on bacterial biofilms

Biofilm formation on equipment surfaces is a potential food safety hazard, providing increased resistance and persistence of pathogens and spoilage microorganisms in food production environments. The issue of preventing the biofilm formation is extremely important, since a wide range of disinfectants does not always provide the proper effect. The article discusses the antimicrobial effectiveness of disinfectants with various active ingredients (based on active chlorine, peracetic acid and quaternary ammonium compounds (QAC) with enzymatic substances) on binary biofilms. The objects of the study were the strains of pathogenic and opportunistic microorganisms isolated from abiotic surfaces of food production environments and food products. Different effects of disinfectants on biofilms formed by bacteria have been established. Disinfectant based on peracetic acid and chlorine had the greatest effect on binary biofilms of Brochothrix thermosphacta/Salmonella spp. and Staphylococcus equorum/Salmonella spp. The greatest antimicrobial effect on biofilm of Listeria monocytogenes 12/Pseudomonas azotoformans 6 was shown by a chlorine-based disinfectant. Disinfectants based on chlorine and QAC with enzymatic substances were most effective against the binary biofilm of L. monocytogenes 12/Salmonella spp. 14. However, none of the disinfectants had absolute antimicrobial effectiveness against the studied binary biofilms. Biofilm-forming microorganisms have shown resistance to the recommended concentrations of disinfectants. Therefore, currently, it is extremely important to revise approaches to hygiene at enterprises by finding working concentrations of new antimicrobial agents and new procedure that are effective for destroying biofilms

Propagation of HF radio waves over northerly paths: measurements,simulation and systems aspects

Large deviations in the direction of arrival of ionospherically propagating radio signals from the Great Circle Path (GCP) have serious implications for the planning and operation of communications and radiolocation systems operating within the HF-band. Very large deviations are particularly prevalent in the polar and sub-auroral regions where signals often arrive at the receiver with bearings displaced from the great circle direction by up to ±100° or more. Measurements made over several paths are presented in this paper, and the principle causes of off-great circle propagation outlined. Significant progress has been made in modelling the propagation effects and work is now in hand to incorporate the results into tools to aid the planning and operation of HF radio systems operating at northerly latitudes

Sorption concentration of ions of copper (II) and lead (II) by magnetic sorbent

By a chemical method, using a method offered by Massart, where as the use of initial solutions of chlorous and chloric iron magnetite is produced, possessing sorbate properties in relation to the ions of lead(II) and copper(II). Influence of different factors (pH, temperature, time) on the degree of sorption is investigated. A specific surface area of magnetite is measured by the method of Bruner-Emmet-Teller on the analyzer of NOVA 1000e. Structural parameters and phase composition of standards are investigationed by X-ray fluores-cence energy-dispersive spectrometer of brand «BRA-18». The best values of acidity of environment are de-termined for flowing of sorption process on magnetite. Conducted measurements of ζ -potential before and after the sorption indicate the change of charge of double electric layer at the surface of magnetic iron metal-lics, that is related to adsorption of the positively charged cations of the solution. Influence of the interfering ions is indicated, influence of phosphates and sulfates is set on the sorption of IST. The isotherms of sorption of IST are got on magnetic iron. The offered method is tested on the standards of the melted water of snow-cover in the affected of casting production zone

Cosmogenic 11C production and sensitivity of organic scintillator detectors to pep and CNO neutrinos

Several possible background sources determine the detectability of pep and CNO solar neutrinos in organic liquid scintillator detectors. Among such sources, the cosmogenic 11C nuclide plays a central role. 11C is produced underground in reactions induced by the residual cosmic muon flux. Experimental data available for the effective cross section for 11C by muons indicate that 11C will be the dominant source of background for the observation of pep and CNO neutrinos. 11C decays are expected to total a rate 2.5 (20) times higher than the combined rate of pep and CNO neutrinos in Borexino (KamLAND) in the energy window preferred for the pep measurement, between 0.8 and 1.3 MeV. This study examines the production mechanism of 11C by muon-induced showers in organic liquid scintillators with a novel approach: for the first time, we perform a detailed ab initio calculation of the production of a cosmogenic nuclide, 11C, taking into consideration all relevant production channels. Results of the calculation are compared with the effective cross sections measured by target experiments in muon beams. This paper also discusses a technique for reduction of background from 11C in organic liquid scintillator detectors, which allows to identify on a one-by-one basis and remove from the data set a large fraction of 11C decays. The background reduction technique hinges on an idea proposed by Martin Deutsch, who suggested that a neutron must be ejected in every interaction producing a 11C nuclide from 12C. 11C events are tagged by a three-fold coincidence with the parent muon track and the subsequent neutron capture on protons.Comment: 11 pages, 6 figures; added one section detailing comparison with previous estimates; added reference