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Prediction of the Impact of Land Use and Soil Type on Concentrations of Heavy Metals and Phthalates in Soil Based on Model Simulation
No full textThe main objective of this study is to determine the possibility of predicting the impact of land use and soil type on concentrations of heavy metals (HMs) and phthalates (PAEs) in soil based on an artificial neural network model (ANN). Qualitative analysis of HMs was performed with inductively coupled plasma-optical emission spectrometry (ICP/OES) and Direct Mercury Analyzer. Determination of PAEs was performed with gas chromatography (GC) coupled with a single quadrupole mass spectrometry (MS). An ANN, based on the Broyden-Fletcher-Goldfarb-Shanno (BFGS) iterative algorithm, for the prediction of HM and PAE concentrations, based on land use and soil type parameters, showed good prediction capabilities (the coefficient of determination (r(2)) values during the training cycle for HM concentration variables were 0.895, 0.927, 0.885, 0.813, 0.883, 0.917, 0.931, and 0.883, respectively, and for PAEs, the concentration variables were 0.950, 0.974, 0.958, 0.974, and 0.943, respectively). The results of this study indicate that HM and PAE concentrations, based on land use and soil type, can be predicted using ANN
Effect of CoMoO4 nanopowders synthesized by glycine nitrate procedure and calcinated at 450 °C on Briggs-Rauscher oscillatory dynamics
No full textCobalt molybdate is of importantce for the development of mobile telecommunication systems, such as mobile phones and high-quality microwave dielectric ceramics for high resonant frequency selectivity in microwave devices. Due to their special catalytic properties, cobalt molybdates have been used as catalysts in many chemical and petrochemical processes. The CoMoO4 nanoparticles ware synthetized in a simple, quick, and inexpensive way, by using a glycine nitrate procedure (GNP), with and without calcination at 450 °C [1], and investigated by applying the Briggs-Rauscher oscillatory reaction method [2]. The complex oscillatory BR reaction is sensitive to different insoluble analyte addition [3]. This feature of BR oscillatory reaction is used to investigate effect of different masses of GNP synthetized (with and without calcination at 450 °C) CoMoO4 samples on oscillatory dynamics. These two samples give the complete different effects in BR reaction. Obtained results strongly suggest that BR oscillatory reaction could be used for distinguishing these two samples, opening new direction in the investigation of ceramics materials
Novi postupak proizvodnje jestive gljive Grifola frondosa baziran na primeni modifikovanog zeolita
No full textUZDUŽNA I POPREČNA EKSPLOATACIONA STABILNOST TRAKTORA SA ASPEKTA BEZBEDNOSTI PRI AGROTEHNIČKIM OPERACIJAMA
No full textModeling, Simulation, and Computer Control of a High-Frequency Wood Drying System
No full textHigh-frequency wood drying is the modern method used in raw wood drying so that treated wood can be used further in various processes. Such systems are used because of the economy, energy efficiency, obtaining of good mechanical properties of the wood after treatment, as well as reducing time consumption. Therefore, it is extremely important to understand each component of such systems and processes. The mentioned systems are implemented using high-frequency generators based on vacuum tubes (VT). Their development and, in particular, optimization are by far more complex than the transistor systems; therefore, the development is now compelled to rely on computer modelling and simulation. In this research, a high-frequency (HF) generator of 20 kW output power and 1.5-15 MHz adjustable frequency based on VT was produced and then, with the corresponding model for VT itself and the rest of the developed circuit, was followed by computer simulation and real-system measurement. The model parameters were adjusted, which provided additional system optimization. An extra match of the results from the simulation and measurement was obtained; thus, the optimization was performed faster and more precisely. In addition, an easier and quicker way of adjusting parameters of the PID controller using a developed software-based control system was attained. The problems of cooling the VT anode under high DC voltage, as well as temperature measurement in the HF electric field, have been solved
Breakthrough Analysis of Chemical Composition and Applied Chemometrics of European Plum Cultivars Grown in Norway
No full textThe aim of this study was to find the chemical parameters for the differentiation of plum cultivars grown along the fjord areas of Western Norway and Eastern Norway, having specific agroclimatic conditions. Chemical analysis of the fruits confirmed the contents of 13 quantified elements, 22 sugar compounds, 11 organic acids, 19 phenolic compounds, and antioxidant activity in 68 plum cultivars. Dominated contents were noted for nitrogen (with the maximum mean value of 3.11%), potassium (8055.80 mg/kg), and phosphorous (7878.88 mg/kg). Averagely, the highest level of sugars was determined for glucose (244.46 g/kg), fructose (197.92 g/kg), sucrose (208.25 g/kg), and sorbitol (98.02 g/kg), organic acids for malic acid (24.06 g/kg), and for polyphenol compounds were 5-O-caffeoylquinic acid (66.31 mg/kg), and rutin (58.06 mg/kg). Applied principal component analysis has been useful for distinguishing the plum cultivars from three areas in Norway where copper, iron, potassium, magnesium, manganese, and sodium; sucrose, ribose, maltose, and raffinose; p-hydroxybenzoic acid, rutin, ferulic acid, kaempferol 7-O-glucoside, p-coumaric acid, and 5-O-caffeoylquinic acid were the most influential. In regard to human health and future breeding work that will have the aim to produce functional food with high health-related compounds, the plum cultivar 'Mallard' should be underlined due to the high level of elements, 'Valor' due to high sugar content, 'Helgoyplomme' due to content of organic acids, and 'Diamond' due to the content of phenolic compounds
A comprehensive approach to chitosan-gelatine edible coating with beta-cyclodextrin/lemongrass essential oil inclusion complex - Characterization and food application
No full textBiopolymer-based films present an ideal matrix for the incorporation of active substances such as antimicrobial agents, giving active packaging a framework of green chemistry and a step forward in food packaging technology. The chitosan-gelatine active coating has been prepared using lemongrass oil as an antimicrobial compound applying a different approach. Instead of surfactants, to achieve compatibilization of compounds, beta-cyclodextrin was used to encapsulate lemongrass oil. The antimicrobial effect was assessed using the dip-coating method on freshly harvested cherry tomatoes artificially contaminated by Penicillium aurantiogriseum during 20 days of cold storage. According to the evaluation of the antimicrobial effect of coating formulation on cherry tomato samples, which was mathematically assessed by predictive kinetic models and digital imaging, the applied coating formulation was found to be very effective since the development of fungal contamination for active-coated samples was observed for 20 days
Chemical Characterization of Beebread from Serbia. UHPLC-QTOF identification of Phenolic Compounds
No full textQSAR and machine learning models of redox potentials of some organic pigments
No full textThe organic pigments offer promising opportunities for developing new sustainable electrode materials for lithium batteries. Some of them have been identified as cathode material with very encouraging reversible lithium ion storage characteristics. One of them is a naturally occurring purpurin extracted from the Madder plant (Rubia tinctorum) for which we confirmed this good electrochemical behavior by cyclic voltammetry. One of the strategies towards obtaining materials with even better characteristics is a structural modification of already existing pigments. Building a theoretical model that could predict the redox properties of these new compounds can be very useful towards achieving that goal. In order to build a 3D QSAR (quantitative structure–activity relationship) model for material redox potential prediction, 9 organic pigments with known redox potentials were extracted from the literature. Based on molecular interaction field (MIF) probes we calculated standard GRIND (grid-independent) descriptors and constructed following principal PLS (partial least squares) model. By validation with the literature data, but also with the obtained experimental data for purpurin, this model proved very reliable in predicting the redox potential. A comparison was also made with the machine learning model that was formed in parallel.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi