RIOFH - Repository of Institute of General and Physical Chemistry
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Novel Technology with Solvent Extraction of Used Timber Railway Ties to Obtain Raw Material
No full textBioactivity and sensory perspective of probiotic yogurt fortified with apple pomace flour
No full textIspitivanje purpurina kao katodnog materijala u vodenim Na-jonskim baterijama
No full textPurpurin je organska boja dobijena kao ekstrakt iz biljke Maddre ubrane na planini Kopaonik. U ovom radu, purpurin je koritšćn kao potencijalna zamena za katodni materijal koji se koristi u komercijalnim Li-jonskim baterijama, baziran na neorganskim komponentama kao što su Co, Ni, Mn i Fe. U poredenju sa navedenim neorganskim supstancama, purpurin je potpuno prirodna organska boja koja ne zagaduje životnu sredinu. Organski rastvarč koji se obično koristi u Li jonskim baterijama je toksičan i zapaljiv, tako da je jedna od ideja ovog rada bila da se ispita ponašanje purpurina u vodenom elektolitu. Pošto je Li slabo rasprostranjen u rudama i teško se dobija, to je time i njegova cena viša, ekperiment je rađen u vodenom rastvoru NaNO3 ne bi li se ispitala zamena Li ekonomičnijim Na. Strukturna odredivanja purpurina vršena su IC-om, dok su elektrohemijska merenja vrtena cikličnom voltametrijom. Dobijeni rezultati pokazuju da vodeni rastvor NaNO3 nije pogodan rastvarč kada je u pitanju vrednost i stabilnost kapaciteta
Chemical composition of essential oils of elderberry (sambucus nigra l.) Flowers and fruits
No full textThe majority of essential oils obtained from medicinal plants have been demonstrated to be effective in the treatment of different kinds of diseases, and they are increasingly used in the diet. Due to their chemical composition, essential oils are a very interesting product of the secondary metabolism of plants, for both consumers and researchers. Among others, elderberry (Sambucus nigra L.) is mostly a woody plant, while it can rarely be found as a herbaceous perennial plant. This plant species has been used in traditional medicine because it is a very rich source of phytochemicals. The aim of this study was to identify and compare the composition of essential oils obtained from flowers and fruits of this plant, collected from the Balkan Peninsula. The oils were obtained using the Clevenger apparatus, and their composition was evaluated by gas chromatography - mass spectrometry (GC-MS). The oil composition was affected by the part of the plants used: the most abundant bioactive compounds in the essential oil of air-dried elderberry fruits were β-damascenone (35.70%) and linalyl anthranilate (24.15%). β-damascenone was the dominant compound in the essential oil of lyophilized elderberry fruits (38.64%), while linalool was detected in the concentration of 32.80%. In the essential oil of air-dried elderflowers, the most abundant compound was carane (13.19%). The essential oils of S. nigra shown substantial chemical composition and could be used as a potential source of natural products in the cosmetics and food industry
A comprehensive study of parameters correlated with honey health benefits
No full textOne hundred honey samples of different floral origin (acacia, sunflower, meadow, and forest) collected from nine European countries (Serbia, Albania, Croatia, Montenegro, Romania, Bulgaria, Bosnia and Herzegovina, North Macedonia and Hungary) were analysed for various physicochemical, sensory, antioxidant and antibacterial parameters. The relative antioxidant capacity index and relative antibacterial index were calculated, integrated and expressed as a new property - Power of Honey, intended to be used to predict the health potential of a honey based on its antioxidant and antibacterial activities. Free acidity and colour coordinates L* and a* were chosen for building an artificial neural network model for the prediction of honey health potential. These were chosen based on the obtained correlations between the investigated parameters and in light of the simplicity of the analysis. This model successfully predicted the Power of Honey with a gained coefficient of determination of 0.856. Forest honey samples exhibited the highest Power of Honey. This novel approach should make it possible for honey producers to predict the honey health potential of a particular honey based on a quick and simple analysis
Modelling of corn kernel pre-treatment, drying and processing for ethanol production using artificial neural networks
No full textTwo artificial neural network (ANN) models were developed to predict the main quality parameters of the corn used for ethanol production. Five Croatian corn hybrids were evaluated in this study (introducing the hybrid type as the first input categorical variable for ANN modelling), grown during three vegetation periods (the second categorical variable), under two levels of agrotechnology (the third categorical variable), dried at four temperatures (the fourth input variable), using two different heating and pressure pre-treatments of corn kernels (the fifth variable for ANN calculation) in order to improve the properties of corn for ethanol production. The first model (ANN1) was used to predict the hectolitre weight, 1000-kernels weight, the gelatinisation rate, and the contents of: glucose, reducing sugars and ethanol during the drying process, according to the type of the corn hybrid and the drying temperature. The ANN2 model was developed to predict the corn weight and moisture during the process, based on the input parameters. The artificial neural network models gave a good fit to experimental data and were able to predict the output variables successfully, showing a reasonably good predictive capability (overall r(2) for the corn kernel weight and moisture was 0.989, while r(2) for other outputs was 0.856). On the basis of a developed ANN models, multi-objective optimization was performed showing the possible practical use in the corn kernel drying process
Effect of mesoporous silica nanoparticles on the properties of polyurethane network composites
No full textNovel polyurethane nanocomposite (PUN) materials containing different surface-functionalized mesoporous silica nanoparticles (MSNs) were prepared by in situ polymerization methodology. Polyurethane network was formed from poly(dimethylsiloxane)-based macrodiol (PDMS), 4,4 '-methylenediphenyldiisocyanate (MDI), and hyperbranched polyester of the second pseudo-generation (BH-20; used as crosslinking agent). PU and PU/MSN nanocomposites contained equal ratios of soft PDMS and hard MDI-BH-20 segments. Non-functionalized and surface-functionalized (with 3-(trihydroxysilyl)propyl methylphosphonate (FOMSN) and 2-[methoxy(polyethyleneoxy)6-9-propyl]trimethoxysilane (PEGMSN)) MSNs were used as the nanofillers at a concentration of 1 wt%. Prepared materials were characterized by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analyses (DMTA), nanoindentation, equilibrium swelling and water absorption measurements. Characteristics of the prepared PUNs when in contact with a biological environment were assessed through testing their biocompatibility, protein adsorption and adhesion of endothelial cells. The favourable influence of MSNs on the physico-chemical and biological characteristics of these novel PUN materials was identified, which evidences their vast applicability potential as coatings for medical devices and implants
Experimental and computational study of the two-fluid nozzle spreading characteristics
No full textSpray nozzles are widely used in processing industry for spreading evenly large amount of fluids. The expansion of fluid depends on the nozzle type, the parameters of the nozzle and the characteristics of the working fluids. The experiments were performed for five fluid types used in food/pharma/animal feed application (glycerol, soybean oil, molasses, hydroxypropyl methylcellulose, tara gum), three diameters of the nozzle (1 mm, 3 mm, 5 mm) and three fluid temperatures (40 degrees C, 50 degrees C and 60 degrees C). An experimentally validated numerical model was developed, based on laminar two-phase flow, investigating different liquids, assuming the ideal gas flow, applying the finite volume method and volume of the fluid model with interface tracking. The effects of liquid parameters, nozzle diameter and liquid temperature on the characteristics of the jet were also analysed by artificial neural network model. The nozzle diameter strongly influenced the spreading characteristics of the jet, while the temperature affected the liquid viscosity. The increase of the temperature also led to the augment of the spreading angle of the fluid passing from the nozzle and also the enhancement of the spaying liquid expansion
Invasive Plant Species Biomass-Evaluation of Functional Value
No full textInvasive plant species (IAS), with their numerous negative ecological, health, and economic impacts, represent one of the greatest conservation challenges in the world. Reducing the negative impacts and potentially exploiting the biomass of these plant species can significantly contribute to sustainable management, protect biodiversity, and create a healthy environment. Therefore, the main objective of this study was to evaluate the nutritional potential, phytochemical status, and antioxidant capacity of nine alien invasive plant species: Abutilon theophrasti, Amaranthus retroflexus, Ambrosia artemisiifolia, Datura stramonium, Erigeron annuus, Galinsoga ciliata, Reynoutria japonica, Solidago gigantea, and Sorghum halepense. Multivariate statistical methods such as cluster and PCA were performed to determine possible connections and correlations among selected IAS depending on the phytochemical content. According to the obtained results, R. japonica was notable with the highest content of vitamin C (38.46 mg/100 g FW); while E. annuus (1365.92 mg GAE/100 g FW) showed the highest values of total polyphenolic compounds. A. retroflexus was characterized by the highest content of total chlorophylls (0.26 mg/g) and antioxidant capacity (2221.97 mu mol TE/kg). Therefore, it can be concluded that the selected IAS represent nutrient-rich plant material with significant potential for the recovering of bioactive compounds
Chemical durability of sintered glass-composite prepared from glass cullet and waste foundry sand
No full textIn this study, the glass-composite was prepared using glass cullet and waste foundry sand as raw materials. The powder technology route was employed. The mixtures containing 10-50 wt% of the sand were sintered at T = 750 degrees C for t =1h. XRD and DTA analyses were performed. The chemical durability of the resulting glass-composite was determined by leaching test in HCl, H2SO4, NaOH and distilled water at T = 95 degrees C for t =1h. It was shown that the sintering process carried out without the crystallization of the glass matrix. The lowest chemical durability was determined in alkali solution of glasscomposite