The effect of simulated acid rain on metal desorption from cetraria islandica

In this paper the possibility of extracting metals: K, Al, Ca, Mg, Fe, Cu, Ba, Zn, Mn and Sr, from Cetraria islandica lichen with solutions simulating acid rain (H2SO4- HNO3-(NH4)2SO4), pH 2.00 (1) and 3.28 (2) has been investigated. The results obtained suggest that the investigated elements can be classified into ones where the highest percentage was extracted with the first extraction (K, Al, Mg, Ba, Zn and Mn) and others where the extraction percentage is relatively uniform (Ca and Fe). This indicated different bonding methods in lichen that is in accordance with literature data where two cation bonding methods in lichen were shown.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Study of a long term processes in d.c. argon arc plasma by square power modulation with variable low current period

U-shaped d.c. argon stabilized arc with aerosol supply was investigated by current modulation between 9 and 3 A level and low current period lasting from 0.05 to 40 ms. The variable low current period has great influence on delayed line intensity response that provides information about a recombination and transport processes in plasma. The obtained results indicate that plasma slowly reaches stationary state and that processes related to changes in atom concentration play important role. Character of temporal responses strongly depends on first ionization energy of analyte.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Study of the spatial redistribution of the analyte spectral emission in dc arc plasma induced by external oscillating magnetic field

Monochromatic digital imaging technique was developed for studying the spatial emission intensity distribution of atmospheric pressure dc arc plasma with aerosol supply. Arc plasma was imposed to external oscillating magnetic fields of strengths up to 12 mT and frequency of 50 Hz. This plasma was studied in a laterally resolved manner and at selected observation heights. The intensity enhancement and spatial redistribution of the analyte emission was evaluated and compared to the steady state plasma. The intensity enhancements were correlated with the attained speeds of plasma core movement. Spatial regions in the arc plasma with maximal emission enhancement are identified and clarified. The effect of the electrode polarity was also investigated.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Software tools for simultaneous data visualization and T cell epitopes and disorder prediction in proteins

We have developed EpDis and MassPred, extendable open source software tools that support bioinformatic research and enable parallel use of different methods for the prediction of T cell epitopes, disorder and disordered binding regions and hydropathy calculation. These tools offer a semi-automated installation of chosen sets of external predictors and an interface allowing for easy application of the prediction methods, which can be applied either to individual proteins or to datasets of a large number of proteins. In addition to access to prediction methods, the tools also provide visualization of the obtained results, calculation of consensus from results of different methods, as well as import of experimental data and their comparison with results obtained with different predictors. The tools also offer a graphical user interface and the possibility to store data and the results obtained using all of the integrated methods in the relational database or flat file for further analysis. The MassPred part enables a massive parallel application of all integrated predictors to the set of proteins. Both tools can be downloaded from http://bioinfo.matf.bg.ac.rs/home/downloads.wafl?cat=Software. Appendix A includes the technical description of the created tools and a list of supported predictors

Software tools for simultaneous data visualization and T cell epitopes and disorder prediction in proteins

We have developed EpDis and MassPred, extendable open source software tools that support bioinformatic research and enable parallel use of different methods for the prediction of T cell epitopes, disorder and disordered binding regions and hydropathy calculation. These tools offer a semi-automated installation of chosen sets of external predictors and an interface allowing for easy application of the prediction methods, which can be applied either to individual proteins or to datasets of a large number of proteins. In addition to access to prediction methods, the tools also provide visualization of the obtained results, calculation of consensus from results of different methods, as well as import of experimental data and their comparison with results obtained with different predictors. The tools also offer a graphical user interface and the possibility to store data and the results obtained using all of the integrated methods in the relational database or flat file for further analysis. The MassPred part enables a massive parallel application of all integrated predictors to the set of proteins. Both tools can be downloaded from http://bioinfo.matf.bg.ac.rs/home/downloads.wafl?cat=Software. Appendix A includes the technical description of the created tools and a list of supported predictors

Desorption of metals from Cetraria islandica (L.) Ach. Lichen using solutions simulating acid rain

Desorption of metals K, Al, Ca, Mg, Fe, Ba, Zn, Mn, Cu and Sr from Cetraria islandica (L.) with solutions whose composition was similar to that of acid rain, was investigated. Desorption of metals from the lichen was performed by five successive desorption processes. Solution mixtures containing H2SO4, HNO3 and H2SO4-HNO3 were used for desorption. Each solution had three different pH values: 4.61, 5.15 and 5.75, so that the desorptions were performed with nine different solutions successively five times, always using the same solution volume. The investigated metals can be divided into two groups. One group was comprised of K, Ca and Mg, which were desorbed in each of the five desorption processes at all pH values used. The second group included Al, Fe, Zn, Ba, Mn and Sr; these were not desorbed in each individual desorption and not at all pH values, whereas Cu was not desorbed at all under any circumstances. Using the logarithmic dependence of the metal content as a function of the desorption number, it was found that potassium builds two types of links and is connected with weaker links in lichen. Potassium is completely desorbed, 80% in the first desorption, and then gradually in the following desorptions. Other metals are linked with one weaker link (desorption 1-38%) and with one very strong link (desorption below the metal detection limit). [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. ON 172019

The influence of thermodynamic parameters on alkaline activators of geopolymers and the structure of geopolymers

Thermodynamic parameters (densities, viscosities, speed of sound, and refractive index) of four series of alkaline activators were determined over the temperature range from 15 to 60 degrees C for the process of geopolymerization. Mixtures of Na2SiO3 and NaOH of different molar concentrations ( from 2M to 8M with step 2) were used as an alkaline activator. The sample with the highest NaOH concentration also shows the highest values of all thermodynamic parameters. Metakaolin, obtained by calcination of kaolin at 750 degrees C, was used as the starting material. The samples were characterized by X-ray diffraction (XRD), FTIR and Raman spectroscopy, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray (EDX) Spectroscopy. Results of FTIR analysis correlated with results of Raman Spectroscopy. Due to the polymerization process, the changes in the phonon spectrum were confirmed. The different concentrations of activators do not notably change the Si/Al ratio

Numerical computation and prediction of electricity consumption in tobacco industry

Electricity is a key energy source in each country and an important condition for economic development. It is necessary to use modern methods and tools to predict energy consumption for different types of systems and weather conditions. In every industrial plant, electricity consumption presents one of the greatest operating costs. Monitoring and forecasting of this parameter provide the opportunity to rationalize the use of electricity and thus significantly reduce the costs. The paper proposes the prediction of energy consumption by a new time-series model. This involves time series models using a set of previously collected data to predict the future load. The most commonly used linear time series models are the AR (Autoregressive Model), MA (Moving Average) and ARMA (Autoregressive Moving Average Model). The AR model is used in this paper. Using the AR (Autoregressive Model) model, the Monte Carlo simulation method is utilized for predicting and analyzing the energy consumption change in the considered tobacco industrial plant. One of the main parts of the AR model is a seasonal pattern that takes into account the climatic conditions for a given geographical area. This part of the model was delineated by the Fourier transform and was used with the aim of avoiding the model complexity. As an example, the numerical results were performed for tobacco production in one industrial plant. A probabilistic range of input values is used to determine the future probabilistic level of energy consumption

An experimental study of radial symmetry deviation in dc argon arc plasma by current modulation technique

A current square modulation technique is used to investigate radial asymmetry of plasma column of argon stabilized direct current U-shaped arc. By monitoring the temporal behavior of spectral line intensities (in a millisecond domain) for various elements, it was observed that nonhomogeneous emission was much more pronounced for current modulated arc plasma compared to the stationary regime plasma. The reason for such behavior, for this as well as for other arc sources, lies in a mode the stream of argon with aerosol is introduced into the arc plasma.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Electron and gas temperature difference in low current argon d.c. arc studied by power interruption technique

Atmospheric pure argon plasma without analyte water solution injection has been exposed to power interruption experiments in order to study the difference between electron and gas temperature. The arc plasma was studied in low currents range, between 3 and 10 A. Obtained temperature difference ranges from 3000 to 1500 K, from low to high current. A comparison with previous results, for argon plasma with water aerosol supply, have shown that introduction of water reduces temperature difference.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200