Thermal Diffusivity of Sintered 12CaOx7Al2O3

Poster presented at the 14th International Conference on Photoacoustic and Photothermal Phenomena, Cairo, Egypt, January 6-9, 200

Vjerojatnost ispada koreliranih SIR prijemnika sa SSC raznolikosti putem kanala s kompozitnim K_G slabljenjem/zasjenjivanjem signala

In this paper, the effects of multipath fading and shadowing over the propagation channel are observed through the performance analysis of switch and stay selection combining (SSC) technique. The short term fading (multipath fading) in conjunction with the long term fading (shadowing) are both modeled by Generalized-K (K_G) distribution. The proposed system is considered as interference-limited system in correlated fading environment. The probability density function (PDF) of signal-to-interference ratio (SIR) at the output of SSC receiver is derived in form of Meijer G functions. According to this new expression, the outage probability is considered and the effects of fading and shadowing parameters and correlation coefficients on the performance gain are analyzed.U radu su razmatrana djelovanja višeputnog slabljenja i zasjenjivanja signala u propagacijskom kanalu pomoću analize SSC prijemnika raznolikosti (prekidački prostorni kombinator raznolikosti). Kompozitni utjecaj brzog (višeputnog) i sporog slabljenja signala (zasjenjivanja) modeliran je poopćenom-K (K_G) razdiobom. Predloženi sustav razmatran je kao sustav s ko-kanalnom interferencijom kao dominantnom smetnjom i koreliranim slabljenjem signala. Funkcija gustoće razdiobe (PDF) odnosa signal/smetnja (SIR) SSC izlaza prijemnika izvedena je u obliku Meijer G funkcija. Na osnovu ovog izraza, razmatra se vjerojatnost ispada te analiziraju učinci parametara i korelacijskih koeficijenata slabljenja i zasjenjivanja signala na unaprijeđenje performansi sustava

Thermal diffusivity of sintered 12CaO×7AI2O3

Poster presented at the 14th International Conference on Photoacoustic and Photothermal Phenomena, Cairo, Egypt, January 6-9, 2007Paper: [http://dx.doi.org/10.1140/epjst/e2008-00423-7

Thermal diffusivity of sintered 12CaO×7AI2O3

The thermal diffusivity and free carrier diffusion coefficient of 12CaO×7 Al2O3 (C12A7) sintered for different times in air or hydrogen followed by treatment with UV light were determined from photoacoustic phase and amplitude spectra obtained using the photoacoustic method with a transmission detection configuration. The influence of the sintering time on the values of the obtained parameters was analyzed and also the different sintering procedures. © EDP Sciences/Societé Italiana di Fisica/Springer-Verlag 2008.Poster: [https://hdl.handle.net/21.15107/rcub_dais_312

Chemical Composition, Antimicrobial andAntioxidant Activity of Birch (Betula pendula Roth.) Buds Essential Oil

The essential oil from birch (Betula pendula Roth.) buds was obtained by Clevenger-type hydrodistillation. Its qualitative and quantitative composition was determined by gas chromatography in combination with mass spectrometry (GC/MS) and flame ionization detection (GC/FID), respectively. Twenty-seven compounds, mainly sesquiterpene hydrocarbons (78.7%) and oxygenated sesquiterpenes (14.8%), were identified comprising 93.5% of total identified components in the essential oil. The most abundant compounds were germacrene D (21.7%) and -cadinene (17.0%). Antimicrobial activity of isolated essential oil against Gram-positive and Gram-negative bacteria as well as fungus Candida albicans was determined using the disc-diffusion method. The isolated essential oil has shown antimicrobial activity against the following microorganisms: Proteus vulgaris, Bacillus luteus and Klebsiella pneumoniae. Antioxidative activity of the essential oil was determined using the DPPH assay, after adding DPPH radical and after 20min, 30min and 60min incubation with radical. Essential oil showed antioxidant activity

Antimicrobial P(HEMA/IA)/PVP semi-interpenetrating network hydrogels

New semi-interpenetrating networks (semi-IPNHs) (P(HEMA/IA)/PVP) were prepared by free radical crosslinking copolymerization of 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA, 5 mol%), in the presence of poly(vinyl pyrrolidone) (PVP, 2, 5, and 10 mol%), as an interpenetrating agent. The structure of the semi-IPNHs was confirmed by Fourier transform infrared spectroscopy, and morphology study was performed by scanning electron microscopy, which revealed the characteristic porous morphology. The results obtained by dynamic mechanical analysis showed the improvement of mechanical properties with increasing PVP content in semi-IPNs. The maximum swelling was observed for all studied systems at a slightly acidic media (around pH 6), so it can be said that the content of PVP has no influence on the swelling behavior, in the PVP range investigated. Along with the pH sensitivity, which was expected due to the presence of IA, semi-IPNHs showed temperature-sensitive swelling properties, with the lower critical solution temperature value around 41 degrees C, which is in the physiologically interesting interval. The antimicrobial activity of the samples was tested using E. coli, S. aureus, and C. albicans pathogens. It was noticed that the antimicrobial potential depends on type of microbes, time of exposure, and PVP content in the samples. Due to their good antimicrobial and mechanical properties these stimuli-sensitive semi-IPNHs have potential to be used as biomaterials for the applications in medicine and pharmacy

Fertile transgenic Lotus corniculatus resistant to the non-selective herbicide phosphinothricin

Resistance to the non-selective herbicide dl-phosphinothricin (PPT) was introduced into commercial Lotus corniculatus cv. Bokor by co-cultivation of cotyledons with Agrobacterium tumefaciensAGL1 harbouring the binary vector pDM805 which contains the bialaphos resistance gene (bar) from Streptomyces hygroscopicus encoding phosphinothricin acetyltransferase (PAT) and the uidA gene encoding -glucuronidase. The half-cotyledon explants were precultured on regeneration Murashige and Skoog's (MS) medium supplemented with 6-benzyladenine (BA) and 1-naphthaleneacetic acid (NAA) at 0.5mgL(-1) each, 3days prior to infection. Upon co-cultivation, the explants were cultured on PPT-free regeneration medium for 10days, and then subcultured on regeneration/selection media with increasing PPT concentrations (5-7mgL(-1)) for about 18weeks. Out of 480 initially co-cultivated explants, 272 regenerated shoots survived the entire PPT selection procedure. Resistant shoots were grown further, multiplied by tillering that was additionally promoted by PPT and rooted on hormone-free MS medium containing 5mgL(-1) PPT. Established shoot cultures, continuously maintained on the same medium, have preserved PPT resistance up to now (more than 2years). Transformed plants assessed in vitro and in a greenhouse were tolerant to the herbicide PPT at 300mgL(-1) equivalent to more than twofold the recommended field dosage for weed eradication. Applied PPT treatment did not affect the activities of glutamine synthetase (GS; EC 6.3.1.2) and NADH-dependent glutamate dehydrogenase (NADH-GDH; EC 1.4.1.2) in transformed plants. However, PPT did increase the mobility of glutamine synthetase isoforms GS1 and GS2 as well as the inhibition of an additional high mobility GS (hmGS) activity. In untransformed plants, PPT treatment reduced total GS activity by 4.4-fold while contrary the activity of NADH-GDH was increased by ninefold. All transformed herbicide-resistant plants were phenotypically normal and exhibited genomic stability, as were the untransformed plants analysed by flow cytometry. Under greenhouse conditions, they grew to maturity, flowered and set seeds. Stable integration and expression of the bar gene in T0 and T1 plants were confirmed by Southern and Western blot analysis, while integration of the reporter uidA gene did not occur. The bar gene was inherited in a Mendelian fashion by the progeny, as detected by PPT resistance. The production of PPT-resistant plants may have significant practical applications in weed control in fields of L. corniculatus

Far infrared study of impurity local modes in palladium-doped PbTe and PbSnTe

PbTe and Pb0.85Sn0.15Te single crystals, doped with Pd, were grown using the Bridgman method. Far infrared spectra were measured in the temperature range between 10 K and 300 K. The experimental spectra were numerically analyzed using first the Kramers-Krönig method and then a fitting procedure, based on the plasmon-phonon interaction model, and the optical parameters were calculated. Since the electronic structure of the ionized state for Pd, Ni and Pt is of the same type, and the influence of d-shells is very strong, special attention was paid to the influence of the electronic structure of dopants on the final properties PbTe and PbSnTe crystals. © 2008 Elsevier B.V. All rights reserved

Fertile transgenic Lotus corniculatus resistant to the non-selective herbicide phosphinothricin

Resistance to the non-selective herbicide dl-phosphinothricin (PPT) was introduced into commercial Lotus corniculatus cv. Bokor by co-cultivation of cotyledons with Agrobacterium tumefaciensAGL1 harbouring the binary vector pDM805 which contains the bialaphos resistance gene (bar) from Streptomyces hygroscopicus encoding phosphinothricin acetyltransferase (PAT) and the uidA gene encoding -glucuronidase. The half-cotyledon explants were precultured on regeneration Murashige and Skoog's (MS) medium supplemented with 6-benzyladenine (BA) and 1-naphthaleneacetic acid (NAA) at 0.5mgL(-1) each, 3days prior to infection. Upon co-cultivation, the explants were cultured on PPT-free regeneration medium for 10days, and then subcultured on regeneration/selection media with increasing PPT concentrations (5-7mgL(-1)) for about 18weeks. Out of 480 initially co-cultivated explants, 272 regenerated shoots survived the entire PPT selection procedure. Resistant shoots were grown further, multiplied by tillering that was additionally promoted by PPT and rooted on hormone-free MS medium containing 5mgL(-1) PPT. Established shoot cultures, continuously maintained on the same medium, have preserved PPT resistance up to now (more than 2years). Transformed plants assessed in vitro and in a greenhouse were tolerant to the herbicide PPT at 300mgL(-1) equivalent to more than twofold the recommended field dosage for weed eradication. Applied PPT treatment did not affect the activities of glutamine synthetase (GS; EC 6.3.1.2) and NADH-dependent glutamate dehydrogenase (NADH-GDH; EC 1.4.1.2) in transformed plants. However, PPT did increase the mobility of glutamine synthetase isoforms GS1 and GS2 as well as the inhibition of an additional high mobility GS (hmGS) activity. In untransformed plants, PPT treatment reduced total GS activity by 4.4-fold while contrary the activity of NADH-GDH was increased by ninefold. All transformed herbicide-resistant plants were phenotypically normal and exhibited genomic stability, as were the untransformed plants analysed by flow cytometry. Under greenhouse conditions, they grew to maturity, flowered and set seeds. Stable integration and expression of the bar gene in T0 and T1 plants were confirmed by Southern and Western blot analysis, while integration of the reporter uidA gene did not occur. The bar gene was inherited in a Mendelian fashion by the progeny, as detected by PPT resistance. The production of PPT-resistant plants may have significant practical applications in weed control in fields of L. corniculatus.Ministry of Education, Science and Technological Development of the Republic of Serbia [ON173015, ON173024, ON173005