DR. JULIUS KARDINAL DOPFNER - IN MEMORIAM

Kardinal Dopfner je zaista bio čovjek Božji, koji je živio u brizi za sve Crkve i za njih se istrošio

Višejedarna Rhizoctonia sp. - patogen šećerne repe i osetljivost sorti u polju

Sugar beet root rot has severely occurred in our country recently, especially in localities of Pazova, Pećinci, Ruma, Sremska Mitrovica and Šid. From diseased roots as well as from soil collected from the localities where decay occurred, fungal isolates were obtained by bait plant method. Based on their characteristics, they were identified as multinucleate Rhizoctonia sp. During the year of 2004 in Mitrosrem trial field T-11, where the presence of multinucleate Rhizoctonia sp. was confirmed, an experiment under the coordination of Committee for Acknowledgement and Registration of New Cultivars in our country was conducted in order to determine cultivars' tolerance, i.e. their susceptibility and possibility for growing on infested fields. Six cultivars of sugar beet, Laetitia (as standard) and five new ones were included in the investigation. The trial was conducted in accordance with the established and accepted method (Ministry of Agriculture, Forestry and Water Resources, Republic of Serbia). Susceptibility of investigated cultivars was evaluated according to significant production characteristics root yield, sugar content, corrected sugar content, thick juice Q, molasses sugar, content of K, Na and amino-N, polarized sugar yield and white sugar yield, as it was recommended by the method. Conducted investigations have revealed that tested sugar beet cultivars showed different reactions to natural infection with multinucleate Rhizoctonia sp. Concerning root yield as the most important agricultural characteristic, statistically significantly higher yield was obtained with the cultivar under code mark 5 (61.120 kg/ha) whereas the cultivar marked under code 6 had significantly lower yield comparing to the standard (38.100 kg/ha).Poslednjih godina uočeno je masovno propadanje šećerne repe u našoj zemlji i to u lokalitetima Pazove, Pećinaca, Rume, Sremske Mitrovice i Šida. Iz obolelih korenova i iz zemljišta prikupljenog sa terena gde je propadanje uočeno, metodom mamaka izolovana je gljiva koja je po svojim osobinama identifikovana kao višejedarna Rhizoctonia sp. U toku 2004. godine na parceli Mitrosrema T-11 gde je izolacijom dokazano prisustvo višejedarne Rhizoctonia sp., postavljen je ogled u okviru sortne komisije za priznavanje i registraciju novih sorti u našoj zemlji sa ciljem utvrđivanja tolerantnosti, odnosno osetljivosti pojedinih sorti i time njihove pogodnosti za gajenje na infestiranom zemljištu. U ispitivanja je uključeno 6 sorti šećerne repe: Laetitia (kao standard) i još pet novih sorti. Ogled je posejan po utvrđenoj i prihvaćenoj metodi sortne komisije (Ministarstvo poljoprivrede, šumarstva i vodoprivrede Republike Srbije). Osetljivost ispitivanih sorti ocenjivana je na osnovu značajnih proizvodnih osobina: prinos korena, polarizacija, korigovani sadržaj šećera Q gustog soka, sadržaja sećera u melasi, sadržaja K, Na i amino N, prinos polarizacionog šećera i prinos kristalnog šećera, kako to metoda i zahteva. Na osnovu obavljenih istraživanja ustanovljeno je da se ispitivane sorte šećerne repe različito ponašaju u uslovima prirodne zaraze višejedarnom Rhizoctonia sp. U pogledu prinosa, kao najvažnije proizvodne karakteristike, statistički značajno viši prinos od standarda ispoljila je sorta koja se vodi pod šifrom 5 (61.120 kg/ha), dok je sorta koja se vodi pod šifrom 6 imala statistički značajno niži prinos u poređenju sa standardom (38.100 kg/ha)

Pulsed Laser Deposition of BaTiO3 on PVDF substrate

Piezoelectric materials play an important role in development of advanced Micro-electromechanical systems (MEMS) and Nano-electro-mechanical systems (NEMS). Their applications span the aero-space industry, communications, defense systems, national security, health care, information technology and environmental monitoring. Materials used in MEMS/NEMS mustsimultaneously satisfy numerous requirements for chemical, structural, mechanical and electrical properties. Although traditionally MEMS in particular have relied on silicon, the materials used in MEMS/NEMS are becoming more heterogeneous. Taking into account that materials nanostructuring can produce unique mechanical, electrical and piezoelectric properties, in this article the investigation of pulsed laser deposition of BaTiO3 on PVDF substrate has been performed. The titanium-saphire laser operated at 800 nm with 40-fs pulse duration and 1 kHz repetition rate was focused onto a mechanically activated BaTiO3 target. Deposition on PVDF substrate was done at an oxygen partial pressure of 10-7 Torr using a laser pulse frequency of 1 kHz at room temperature. The crystal structure and the microstructure of the films were examined using an X-ray diffractometer and scanning electron microscope, while the surface morphology was observed by atomic force microscopy.It was found that pulsed laser deposition of BaTiO3 on PVDF substrate offers a new set of opportunities for development of advanced flexible piezo-films for the next generation of NEMS

Piezoelectric polymer/ceramic nanostructures for mechanical energy harvesting

Vibration-based mechanical energy is one of the most accessible energy source in the surroundings. Harvesting this type of energy exhibits a great potential for remote/wireless sensing, charging batteries, and powering electronic devices. Piezoelectric and ferroelectric materials, including PZT, BaTiO3, ZnO, polyvinylidene fluoride (PVDF), etc., can be used for converting ambient mechanical energy into electricity. Based on these materials, a variety of micro- or nanoelectromechanical systems can be developed for harvesting energies from random vibrations, mechanical waves, or body movements like walking, running, or typing. Recent investigations on nanocomposites of electroactive ceramics and ferroelectric polymers exploit this approach in order to produce new multifunctional materials for mechanical energy harvesting. Taking into account that mechanical activation is one of the methods for modification of physico-chemical properties of the filler, in this study we investigate the influence of mechanical activation of ZnO particles on structural properties of ZnO/polyvinylidene fluoride nanocomposites. The nanocomposite films were prepared by solution casting method and investigated by X-ray diffraction (XRD) method and Raman spectroscopy, while the microstructure morphology has been analyzed by scanning electron microscope (SEM). Presented results will enable optimization of PVDF processing techniques for the production of new mechanical energy harvesting devices

Crystal structure analysis of Nd-doped ceria solid solutions

This paper deals with Nd-doped ceria solid solutions: Ce1-xNdxO2-d with "x" ranging from 0 to 0.25. Six different powders were synthesized by applying the method based on selfpropagating room temperature reaction (SPRT) between metallic nitrates and sodium hydroxide. The method is known to assure very precise stoichiometry of the final product in comparison with a tailored composition. Rietveld refinement was employed to get structural information on the synthesized powder. An increase of Nd ion concentration increases the unit cell parameters and average bond distances. We have shown that all obtained powders were solid solutions with a fluorite-type crystal structure and all powder particles were of nanometric size (about 3 nm)

Synthesis of crystaline silicon oxynitride composites

Silicon oxynitride / silicon nitride (Si2N2O/Si3N4) ceramics have been prepared from Si3N4 powder and amorphous silica (SiO2) by hot pressing at different temperature. It was found that material sintered at lower temperature exhibit fine composite structure composed of equiaxed α-Si3N4 grains and Si2N2O crystals. At higher temperature the growing of Si2N2O particles as well as phase transformation from α-Si3N4 to β-Si3N4 phase take place.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Structural Investigations of Polyvinyliden Fluoride Thin and Thick Films

Polyvinyliden fluoride (PVDF) is a low-density fluoropolymer that exhibits piezoelectric and pyroelectric properties. It can be used in the chemical, semiconductor, medical and defense industries, as well as in aviation and aerospace applications. Crucial factors that lead to the PVDF ferroelectric properties and determine its piezoelectric, mechanical, optical, electrical and thermal properties are its polar conformations, crystal structure, and crystallinity. These characteristics of the material significantly depend on the conditions used in the processing of polymer films. Therefore, we investigated structure and morphology of thin and thick PVDF films obtained by spin coating and solution casting methods, respectively. Structural investigations of PVDF thin and thick films were performed by the X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectrometry (FTIR) methods, while microstructure morphology has been analyzed by scanning electron microscope (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Present results will enable optimization of PVDF processing techniques for the production of pressure and IR sensors

Targeted Synthesis of Ceramic-Polymer Nanocomposites

It is well known that materials used in nano-electro-mechanical systems (NEMS) must simultaneously satisfy numerous requirements for chemical, structural, mechanical and electrical properties. Taking into account that the application of targeted synthesis principles is fundamental for development of these materials, in this article the results of the investigation of the nano-scale grain size effects, grain/particle size induced structural transformations, the evolution of the particle structure during targeted synthesis process and microstructure modeling of ceramic-polymer nanocomposites, has been presented. The nanocomposite BT,ST/PVDF films were prepared by pulsed laser deposition (PLD) method and investigated by X-ray diffraction (XRD) method and Raman spectroscopy, while the microstructure morphology has been analyzed by scanning electron microscope (SEM). It was found that PLD of BT,ST on PVDF substrate offers a new set of opportunities for development of advanced flexible piezo-films for the next generation of NEMS, which applications span the aero-space industry, communications, defense systems, national security, health care, information technology and environmental monitoring

Structural Investigations of Polyvinyliden Fluoride Thin and Thick Films

Polyvinyliden fluoride (PVDF) is a low-density fluoropolymer that exhibits piezoelectric and pyroelectric properties. It can be used in the chemical, semiconductor, medical and defense industries, as well as in aviation and aerospace applications. Crucial factors that lead to the PVDF ferroelectric properties and determine its piezoelectric, mechanical, optical, electrical and thermal properties are its polar conformations, crystal structure, and crystallinity. These characteristics of the material significantly depend on the conditions used in the processing of polymer films. Therefore, we investigated structure and morphology of thin and thick PVDF films obtained by spin coating and solution casting methods, respectively. Structural investigations of PVDF thin and thick films were performed by the X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectrometry (FTIR) methods, while microstructure morphology has been analyzed by scanning electron microscope (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Present results will enable optimization of PVDF processing techniques for the production of pressure and IR sensors