Supercritical fluid extraction of soybean oil from the surface of spiked quartz sand - modelling study

The extraction of soybean oil from the surface of spiked quartz sand using supercritical CO2 was investigated. Sand as solid was used; it is not porous material so the internal diffusion does not exist, all the soluble material is in the surface of the particles. Sovová’s model has been used in order to obtain an analytical solution to develop the required extraction yield curves. The model simplifies when the internal diffusion can be neglected. The external mass transfer coefficient was determined by fitting the theoretical extraction curve to experimental data. According to the external mass transfer coefficient, a new Sherwood correlation was developed in terms of the dimensionless groups: Reynolds and Schmidt number. It was found that this correlation give superior results when compared to experimental data

Protection of stored plant products from rodent pests using chlorophacinone

Apart from some preventive measures, advisably taken during construction of storage facilities or at the time of product storage, treatments with chemical rodenticides have been the most widely practiced method of controlling commensal rodents. Their control in storages is normally carried out after animal presence has been observed, and treatments from early autumn onwards, throughout the season, provide the best effect. The paper shows the effects of baits with lower content of the active ingredient chlorophacinone than recommended for protecting stored plant products from rodents. The experiments were set up using the relevant OEPP/EPPO method. Different contents (0.005% and 0.0075%) of the active ingredient chlorophacinone were used in a ready for use (RB) paste bait formulation. Baits were laid in boxes along rodent routes, underneath pallets with sacks and in places where major damage was observed. Baits for house mice were placed at a rate of 10-20 g per 1-3 m, while 30-50 g of baits for brown rats were laid at specific points. Daily bait intake was monitored over a period of 10 d and the portions were replaced with new ones as needed. Placebo baits were laid in identical boxes for 4 d before the experiment began. The abundance of house mice was estimated based on the highest and lowest daily intake of bait divided by the species’ daily food requirement. The data in this experiment show that 0.005% and 0.0075% chorophacinone contents in RB baits changed neither palatability nor bait efficacy in controlling house mouse and brown rat indoors. The average efficacy of chorophacinone was 87-93% against house mouse and 90-100% against brown rat. Keywords: Chlorophacinone, Rodent, Storage, Efficac

The possibility of use of some essential oils in rodenticidal baits

Jokić, G., Vukša, M., Đedović, S., Stojnić, B., Kataranovski, D

Improving the economic performances of the beet-sugar industry

General trend of free trade at the regional level as well as in the direction of European Union has motivated sugar factories located in Serbia to invest into technologies that are more efficient in order to make their products more competitive in the markets of Europe. Until 2005, the project of energy efficiency improvement in Serbian sugar factories was conducted in Crvenka and Žabalj. Now, they have energy consumption around 1 MJ/kg beet, in contrast to the previous consumption of 1.2 up to 1.5 MJ/kg beet. Further improvements are possible but investments would be high. A result of measurements taken during 2006, after the sugar factory "Donji Srem" - Pećinci was reconstructed showed that a considerable saving has been achieved. The first set of measurements showed that the energy consumption was 1.01 MJ/kg beet, which was 20% higher than intended, but at the same time energy savings were about 30% lower with respect to the values before the reconstruction

The application of hydrogen-palladium electrode for potentiometric acid-base determinations in tetrahydrofuran

The application of the hydrogen-palladium electrode (H2/Pd) as the indicator electrode for the determination of relative acidity scale (Es, mV) of tetrahydrofuran (THF) and the potentiometric titrations of acids in this solvent was investigated. The relative acidity scale tetrahydrofuran was determined from the difference half-neutralization potentials of perchloric acid and tetrabutylammonium hydroxide (TBAH), which were measured by using both H2/Pd-SCE and glass-SCE electrode pairs. The experimentally obtained value of Es scale THF with a H2/Pd-SCE electrode pair was 1155 mV, and those obtained with glass-SCE electrode pair 880 mV. By using a H2/Pd indicator electrode, the individual acids (benzoic acid, palmitic acid, maleic acid, acetyl acetone, α-naphthol) and two component acid mixtures (benzoic acid + α-naphthol, palmitic acid + α-naphthol, maleic acid + α-naphthol and maleic acid + ftalic acid) were titrated with a standard solution of TBAH. In addition, sodium methylate and potassium hydroxide proved to be very suitable titrating agents for titrating of the individual acids and the acids in mixtures, respectively. The relative error of the determination of acids in mixture was less than 3%. The results are in agreement with those obtained by a conventional glass electrode. The advantages of H2/Pd electrode over a glass electrode in potentiometric acid-base determinations in tetrahydrofuran lie in the following: this electrode gives wider relative acidity scale THF, higher the potential jumps at the titration end-point and relatively fast response time; furthermore, it is very durable, simple to prepare and can be used in the titrations of small volumes. [Projekat Ministarstva nauke Republike Srbije, br.172051

Microfiltration of distillery stillage: Influence of membrane pore size

Stillage is one of the most polluted waste products of the food industry. Beside large volume, the stillage contains high amount of suspended solids, high values of chemical oxygen demand and biological oxygen demand, so it should not be discharged in the nature before previous purification. In this work, three ceramic membranes for microfiltration with different pore sizes were tested for stillage purification in order to find the most suitable membrane for the filtration process. Ceramic membranes with a nominal pore size of 200 nm, 450 nm and 800 nm were used for filtration. The influence of pore size on permeate flux and removal efficiency was investigated. A membrane with the pore size of 200 nm showed the best filtration performance so it was chosen for the microfiltration process

Porcelain veneers - preparation design: A retrospective review

This paper discusses the preparation of tooth design for porcelain veneers. It follows the literature more than three decades back in the past. From the very beginning, porcelain veneers were placed to no/minimally prepared tooth substance, showing different problems in clinical use. Later, the technique of etching the porcelain and controlling the reduction of tooth structure, presented the great steps forward in porcelain veneers accepting. A special accent concerning the preparative design was placed on variations of incisal edge preparation - the problem, which is still present in current practice. Additionally, the paper emphasizes the extremely demanding protocols in making the porcelain veneers as well as their expanded clinical indications

Prilog poznavanju suzbijanja sivog pacova (Rattus norvegicus) na farmi mlečnih krava

Rattus norvegicus is a synanthropic species living almost exclusively around facilities for keeping domestic animals. This three-year research focused on options for reducing economic damage caused by this rodent species in stables for heavy milking cows by testing preparations with active substances of various origin. It involved an environmentally friendly product based on sodium selenite 0.1%, a cholecalciferol-based natural product 0.75%, as well as anticoagulant rodenticides containing the active substances bromadiolone 0.005% and brodifacoum 0.005%. These preparations were formulated as granules, plate bait or grain bait. The environmentally friendly sodium selenite product achieved 76.2% efficacy in the first year of research, 70% in the second, and 67.5% in the third. The synthetic products based on bromadiolone and brodifacoum demonstrated high efficacy in all of the three experimental years and in all three formulations. The cholecalciferol rodenticide had 71.4% efficacy in the first year, 68% in the second, and 67.7% in the third. The data show that the environmentally safe product had a lower efficacy due to high rodent abundance and inadequate epidemiological conditions existing on the farm of heavy milking cows, while the bromadiolone and brodifacoum-based products achieved high efficacy.Rattus norvegicus gotovo uvek živi u objektima namenjenim za gajenje domaćih životinja i kao sinanotropna vrsta prisutan je u čovekovoj najbližoj okolini. Predmet naših trogodišnjih istraživanja je alternativa smanjenja ekonomskih šteta koju pričinjava ovaj glodar u stajama farmi visoko-mlečnih krava, primenom preparata na bazi aktivnih materija različitog porekla. U eksperimentima je korišćen ekološko prihvatljivi preparat na bazi natrijum-selenita (0,1%), preparat prirodnog porekla na bazi holekalciferola (0,75%) i antikoagulantni rodenticidi na bazi bromadiolona (0,005%) i brodifakuma (0,005%). Primenjeni preparati su formulisani u obliku granula, obloženog i zrnastog mamka. Ekološko prihvatljivi preparat na bazi natrijum-selenita je ispoljio efikasnost od 76,2% u prvoj godini istraživanja, u drugoj 70% i u trećoj godini 67,5%. Sintetisani preparati na bazi bromadiolona i brodifakuma pokazali su visoku efikasnost u sve tri godine ispitivanja za sve tri navedene formulacije. Rodenticid na bazi holekalciferola je ispoljio efikasnost od 71,4% u prvoj godini, u drugoj 68% i u trećoj 67,7 %. Rezultati istraživanja ukazuju da je zbog velike brojnosti glodara i neadekvatnih epidemioloških uslova na farmi visoko-mlečnih krava ispoljena slabija efikasnost ekološko prihvatljivog preparata dok su preparati na bazi bromadiolona i brodifakuma ispoljili visoku efikasnost

Supplementary material for the article: Jevtić, S.; Stefanović, A.; Stanković, D. M.; Pergal, M. V.; Ivanović, A. T.; Jokić, A.; Petković, B. B. Boron-Doped Diamond Electrode — A Prestigious Unmodified Carbon Electrode for Simple and Fast Determination of Bentazone in River Water Samples. Diamond and Related Materials 2018, 81, 133–137. https://doi.org/10.1016/j.diamond.2017.12.009

Supplementary material for: [https://doi.org/10.1016/j.diamond.2017.12.009]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2081]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3177