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Search Results: 1 - 10 of 1003 matches for " Jozef Mikulec "
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COMPARISON OF RUTHENIUM CATALYSTS SUPPORTED ON BETA AND MORDENITE IN THE HYDROCYCLOALKYLATION OF BENZENE
Milan Kralik,Zuzana Vallusova,Jan Laluch,Jozef Mikulec
Petroleum and Coal , 2008,
Abstract: One way of conversion of benzene into a valuable component of motor fuel is hydrocycloalkylation producing cyclohexylbenzene (CHB) and dicyclohexylbenzene (DCHB). Two catalysts containing 0.2 wt. % of ruthenium were prepared using mordenite (Ru/M) and beta (Ru/B) zeolites as supports. Catalytic tests were carried out in a batch reactor at 175 and 200 oC and hydrogen pressure of 2 MPa at maximum. Cyclohexane was used as a solvent. Better results were obtained with Ru/B catalyst, which corresponds with better accessibility of the interior space. Selectivity to sum of CHB and DCHB varied from 60 down to 40 % at the conversion of benzene 30 and 80 %. Obtained results should motivate further technological investigation of the process.
Catalytic Transformation of Tall Oil into Biocomponent of Diesel Fuel
Jozef Mikulec,Andrea Kleinová,Ján Cvengro?,L'udmila Joríková,Marek Bani?
International Journal of Chemical Engineering , 2012, DOI: 10.1155/2012/215258
Abstract: One of the conventional kraft pulp mills produce crude tall oil which is a mixture of free fatty acids, resin acids, sterols, terpenoid compounds, and many others. This study is devoted to the issue of direct transformation of crude tall oil in a mixture with straight-run atmospheric gas oil to liquid fuels using three different commercial hydrotreating catalysts. Diesel fuel production is an alternative to incineration of these materials. High catalytic activity was achieved for all tested catalysts in temperature range 360–380°C, under 5.5?MPa hydrogen pressure and ratio H2/feedstock 500–1000 l/l. Crude tall oil can be converted to diesel oil component via simultaneous refining with straight-run atmospheric gas oil on NiMo/Al2O3 and NiW/Al2O3-zeolite catalysts. All tested catalysts had very good hydrodenitrogenation activity and high liquid yield were at tested conditions. 1. Introduction One of the modes of reducing the share of green house gases (GHG) emissions at energy production lies in the utilization of biomass and wastes. In the initial step, the known technological processes and feedstock commonly applied in foodstuff processing industry were utilized to produce first generation biocomponents. The use of fatty acid esters, bioalcohol, and ETBE is common at present. First-generation biocomponents are usually more expensive when compared to petroleum-based fuels. Competition with foodstuff production is questionable as well. The actual system based on indicative targets of reaching the total energy content or volume of biocomponents does not support priorities of biocomponents utilization with low-cost GHG emission decrease. The regulatory mechanisms should be stipulated in a way that allow finds a possible reduction in the GHG emission for various biofuels and foodstuffs. Biofuels should be supported through an efficiency increase of current biocomponents and development of new improved procedures. The regulatory mechanism should not act as a barrier for new biofuel types. One of the possible solutions is represented by the introduction of second generation biocomponents originated from wastes. Crude tall oil (CTO) [1] is a byproduct of paper production from coniferous wood by the Kraft pulping process. As an average, 20–30?kg tall oil/ton wood is produced. It contains 30–50% wt. of free fatty (mainly oleic and linolic) acids, 40–60% of rosin acids (abietic and pimaric acids), and 10–15% of unsaponifiables containing 2–4% of sterols, fatty alcohols, phenols and hydrocarbons. Free fatty acids (FFAs) and rosin acids (RAs) can be separated by
Search for Direct CP Violation in K+-->pi+-pi+pi- Decays by NA48/2
I. Mikulec
Physics , 2005,
Abstract: First preliminary measurement of the direct CP-violating parameter Ag by the NA48/2 experiment at CERN SPS is presented. Using more than 1.6 billions of charged kaon decays into three charged pions, the charge asymmetry in the K+-->pi+-pi+pi- Dalitz plot slope, Ag, has been measured to Ag = (0.5 +- 3.8) x 10^-4. This result is more than an order of magnitude more precise than results of previous experiments.
Kaon Physics
I. Mikulec
Physics , 2004,
Abstract: The most recent progress and future prospects in kaon physics are reviewed. Main results are the first observation of the rare decays KS->pi0ee and KS->pi0mumu by NA48, new K+->pinunu event observed by E949 and new precision measurements of K0->pienu decays by KTeV, KLOE and NA48 made in an effort to resolve the slight deviation from the unitarity in the CKM matrix, involving the |Vus| coupling.
Optoelectrical Method of Measuring the Aircraft Track Velocity Vector
V. Ricny,J. Mikulec
Radioengineering , 1992,
Abstract: This article deals with new principal and basic algorithm of the optoelectronics measuring method of aircraft track velocity vector using digital processing of video signals of CCD line sensors.
Cloning, expression, purification and characterization of replication protein from plasmid pGP2 from Acetobacter estunensis  [PDF]
Peter Grones, Jozef Grones
Advances in Bioscience and Biotechnology (ABB) , 2010, DOI: 10.4236/abb.2010.15055
Abstract: The Acetobacter estunensis Rep34 protein participates in the replication of bacterial plasmid pGP2. The Rep34 protein of the A. estunensis, was cloned to the expression vector, that ensure fusion with a His-tag sequence (Rep34 His-tagged), over-expressed in Escherichia coli and purified by metal-affinity chromatography to yield a highly purified and active protein. On this purified protein number different activities and motifs were detected. DNA band-shift assays showed that the Rep34 His-tagged protein bound to the regulation region for replication on the linear double-stranded DNA. In the protein was determined phosphatase activity, ATPase activity and protein is possible to unwind double strand DNA.
Effect of external electric field upon charge distribution, energy and dipole moment of selected monosaccharide molecules  [PDF]
Jozef Mazurkiewicz, Piotr Tomasik
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.45040
Abstract: External electric field of 0.001, 0.01 and 0.05 a.u. changes distribution of the electron density in α- and β-D-glucose, α- and β-D-galactose, α- and β-fructopyranoses and α- and β-fructofuranoses, α- and β-D-ribofuranoses and α and β-D-xylo- furanoses. Hyper-Chem 8.0 software was used together with the AM1 method for optimization of the conformation of the molecules of monosaccharides under study. Then polarizability, charge distribution, potential and dipole moment for molecules placed in the external electric field of 0.000, 0.001, 0.01 and 0.05 a.u. were calculated involving DFT 3-21G method. Application of the external field induced polarizability of electrons, atoms and dipoles, the latter resulting in eventual reorientation of the molecules along the applied field of the molecules and the electron density redistribution at particular atoms. Increase in the field strength generated mostly irregular changes of the electron densities at particular atoms of the molecules as well as polarizabilities. Energy of these molecules and their dipole moments also varied with the strength of the field applied. Results of computations imply that saccharides present in the living organisms may participate in the response of the living organisms to the external electric field affecting metabolism of the molecules in the body fluids by fitting molecules to the enzymes. Structural changes of saccharide components of the membranes can influence the membrane permeability.
Compositional characteristics of commercial yoghurt based on quantitative determination of viable lactic acid bacteria
Pe?i?-Mikulec Dragana,Niketi? Gordana B.
Acta Periodica Technologica , 2009, DOI: 10.2298/apt0940087p
Abstract: Yoghurt quality is particularly difficult to standardize because of the many forms, varieties, manufacturing methods, ingredients and consumer preferences that exist. Since these factors will always play an important role, it is unlikely that a uniform yoghurt quality concept will ever emerge, such as has been developed for other dairy products. There are a number of common denominators, however that have bearing on yoghurt quality. Since a number of producers are recognized within the broad category entitled yoghurt. This situation makes yoghurt an interesting, challenging, but also a confusing area to work in. The present investigation was undertaken to isolate from commercial yoghurt the strains involved in its manufacture and determine the characteristics of Streptococcus thermophilus and Lactobacillus delbrueckii subsp.bulgaricus. This study is concerned with the lactic acid bacteria (L.delbrueckii subsp. bulgaricus and S. thermophilus) growth in yoghurt from involving different procedures and with the determination of the number of lactic acid bacteria in dependence of the temperature and acidity in the period of storage. Predominant samples of yoghurt were with 11-107/ml lactic acid lactococci (44.28%).
Impact of ecological parameters on presence of yeasts and moulds in raw milk
Pe?i?-Mikulec Dragana,Stojanovi? Lazar
Veterinarski Glasnik , 2005, DOI: 10.2298/vetgl0504445p
Abstract: Ecological parameters such as temperature, humidity and other climatic factors in different geographical regions and ecological factors of food production have a complex impact on the speed of growth and multiplication of mould and yeasts. They enable one type of microorganisms to multiply on account of others. Several factors have an impact on the growth of mould and yeasts in raw milk, and the most important ones are as follows: aw, pH and temperature. The interplay between factors ultimately determines grow of yeasts and moulds in raw milk.
Urban, Suburban, and Rural: Adolescents’ Use and Preferences for Fitness Promotion Technologies across Communities
Erika Mikulec,Natalie Goniu,Megan Moreno
ISRN Obesity , 2013, DOI: 10.1155/2013/324259
Abstract: Introduction. An understanding of adolescents’ use of technology across ages and communities could allow for future targeted obesity intervention strategies. Methods. Focus groups of adolescents from rural, suburban, and urban cities in three states were conducted. Focus groups were led by a trained facilitator to explore how participants used technologies and whether they applied them for fitness purposes. All focus groups were audio recorded and manually transcribed. Analysis was conducted by three investigators using an iterative process. Results. Five focus groups included adolescents between the ages of 12 and 18 years (20 females and 8 males.) Three themes were derived from our data. First, we found age differences regarding technology applied to fitness. Younger participants described technology as a complement to fitness; older participants viewed technology as a motivator for fitness. Second, differences in fitness approaches existed between rural and urban adolescents. Adolescents in rural communities reported focusing on the outdoors for fitness, while urban adolescents relied on fitness-oriented video games. Both rural and urban teens related having a lack of fitness-focused resources in their communities. Conclusions. Our findings indicate differences in adolescents’ application of technology for fitness. Despite adolescents’ differing uses of technology across communities, a common need exists to expand their resources. 1. Introduction The increasing prevalence of child and adolescent obesity is a significant public health concern [1, 2]. Approximately 34% of the population between the ages of 12 and 19 years is at risk of overweight and 17% is currently overweight [3]. Additionally, 12.6% of adolescents between 12 and 19 years were considered obese [4]. Children who are overweight or obese are more likely to stay overweight or obese into adulthood, thereby increasing their risk of insulin resistance, diabetes, hypertension, and cardiovascular disease [5]. Despite significant efforts towards understanding and intervening in children and adolescents’ health behaviors surrounding healthy eating and exercise, obesity remains a significant public health issue. Innovative strategies towards reducing this epidemic are clearly needed. One innovative approach may involve technology. The majority of adolescents are increasingly “connected” in a virtual world, using different technologies on a daily basis. Adolescents are avid Internet users; over 90% report access and most report daily use [6]. Of these Internet-using teens, approximately half use
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