The Inhibitive effect of ethanolamine on corrosion behavior of aluminium in NaCl solution saturated with CO2

In this study, the inhibitive effect of ethanolamine on corrosion behavior of aluminium was investigated in 3 wt. % NaCl solution, saturated with CO2. All the experiments were carried out at 20 °C. Ethanolamine was added at different concentrations between 1 mM and 8 mM. In order to determine the corrosion inhibition efficiency of investigated inhibitor and the optimal concentration of inhibitor that provides the lowest corrosion of aluminium, the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), linear sweep voltametry (LSV) measurements, weight loss measurements as well as scanning electron microscopy technique (SEM) were performed. The electrochemical study and weight loss measurements indicated that the minimum corrosion rate and maximum inhibition efficiency was detected for concentration of 5 mM of ethanolamine, as well as the ethanolamine did not change the mechanism of aluminium dissolution. The adsorption of ethanolamine was found to obey Frumkin adsorption isotherm at concentrations up to 5 mM, but further increase in concentration was found to deviate from Frumkin adsorption isotherm. The calculated value for interaction parameter a indicates attractive lateral interactions in the adsorbed inhibitor layer. The obtained value of standard free energy of adsorption, ∆Gads θ , confirms that the adsorption process is favorable, spontaneous physisorption process

The Inhibitive effect of ethanolamine on corrosion behavior of aluminium in NaCl solution saturated with CO2

In this study, the inhibitive effect of ethanolamine on corrosion behavior of aluminium was investigated in 3 wt. % NaCl solution, saturated with CO2. All the experiments were carried out at 20°C. Ethanolamine was added at different concentrations between 1 mM and 8 mM. In order to determine the corrosion inhibition efficiency of investigated inhibitor and the optimal concentration of inhibitor that provides the lowest corrosion of aluminium, the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), linear sweep voltametry (LSV) measurements, weight loss measurements as well as scanning electron microscopy technique (SEM) were performed. The electrochemical study and weight loss measurements indicated that the minimum corrosion rate and maximum inhibition efficiency was detected for concentration of 5 mM of ethanolamine, as well as the ethanolamine did not change the mechanism of aluminium dissolution. The adsorption of ethanolamine was found to obey Frumkin adsorption isotherm at concentrations up to 5 mM, but further increase in concentration was found to deviate from Frumkin adsorption isotherm. The calculated value for interaction parameter a indicates attractive lateral interactions in the adsorbed inhibitor layer. The obtained value of standard free energy of adsorption, ∆Gads θ , confirms that the adsorption process is favorable, spontaneous physisorption process

Morphological description and molecular detection of Pestalotiopsis sp on hazelnut in Serbia

In autumn 2015, hazelnut plants with leaf blight symptoms were noticed in a commercial plantation in the Province of Vojvodina, Serbia. Symptomatic samples were collected and submitted to laboratory analysis. Based on morphological characterization, the fungus isolated from the material was initially identified as Pestalotiopsis sp. Pathogenicity tests showed that two selected isolates infected hazelnut leaves and fruits that developed symptoms after artificial inoculation. The pathogen was re-isolated from diseased leaves and fruits, confirming Koch's postulates. Molecular identification was performed with sequence and phylogenetic analysis of ITS, EF1-alpha, and TUB genomic regions. Phylogenetic analysis confirmed the results of the morphological identification. The detection of Pestalotiopsis sp., a causal agent of leaf blight on hazelnut in Serbia, is one of a few reports of these pathogenic fungi on hazelnut

In vitro procena citotoksičnosti 3D štampanog polimera na bazi epoksi smole namenjenog za upotrebu u stomatologiji

Background/Aim. There is limited published evidence on the cytotoxicity of 3D printed polymer materials for dentistry applications, despite that they are now widely used in medicine. Stereolithography (SLA) is one of the foremost 3D processes used in 3D printing, yet there are only a small number of resin materials reported to be suitable for medical applications. The aim of this study was to investigate, in vitro, the cytotoxic effect of the 3D printed resin in order to establish the suitability for its usage in dentistry and related medical applications such as surgical dental guides, occlusal splits and orthodontic devices. Methods. To examine the cytotoxicity of the 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA), two cell cultures were used: mouse fibroblasts L929, and human lung fibroblasts MRC-5. The cell viability was determined by the Mosmann's colorimetric (MTT) test and the agar diffusion test (ADT). Results. Direct contact of the tested material with the ADT test showed nontoxic effects of tested material in any cell culture. The tested material showed no cytotoxic effect after 3 days of extraction of the eluate by the MTT, but mild cytotoxic effect after 5, 7 and 21 days on both cell lines. The cytotoxicity increased with increasing the time of the eluate extraction. Conclusion. The 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA) is considered appropriate for making surgical dental implant guides according to the cytotoxic behavior. According to the mild level of cytotoxicity after the longer extraction periods, there is a need for further evaluation of biocompatibility for its application for the occlusal splints and orthodontic devices.Uvod/Cilj. Malo je objavljenih dokaza o citotoksičnosti 3D štampanih polimernih materijala za upotrebu u stomatologiji, bez obzira na njihovu sve širu primenu u medicini. Stereolitografija (SLA) jedan je od najvažnijih 3D procesa koji se primenjuje za 3D štampu, ali postoji samo Mali broj materijala na bazi smola za koje je dokazano da su pogodni za medicinsku primenu. Cilj ove studije je bio da se ispita, in vitro, citotoksični efekat 3D štampanog polimera kako bi se utvrdila mogućnost za njegovu upotrebu u stomatologiji i srodnim medicinskim oblastima, kao što su hirurške dentalne vođice, okluzalni splintovi i ortodontski aparati. Metode. Da bi se ispitala citotoksičnost 3D štampanog polimera na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA), korišc'ene su dve c'elijske kulture: fibroblasti miša L929 i humani fibroplasti pluc'a MRC-5. Vijabilnost c'elija utvrđena je Mosmannovim kolorimetrijskim testom (MTT) i testom difuzije agara (ADT). Rezultati. Direktan kontakt testiranog materijala ispitan pomoću ADT pokazao je da materijal nije imao citotoksičan efekat ni na jednu ćelijsku kulturu. Testitrani materijal je imao blag citotoksični efekat posle 5, 7 i 21 dana ekstrakcije eluata primenom MTT na obe ćelijske linije. Citotoksičnost je rasla sa produženjem vremena ekstrakcije eluata. Zaključak. 3D štampani polimer na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA) se može smatrati pogodnim za izradu hirurških dentalnih implantnih vođica sa tačke gledišta njegovog citotoksičnog uticaja. Zbog pokazanih blagih citotoksičnih efekata nakon dužih ekstrakcionih perioda eluata potrebna su dalja istraživanja u oblasti biokompatibilnosti materijala da bi se taj polimer mogao koristiti za izradu okluzalnih splintova i ortodontskih aparata

Valorization of Winery Waste: Prokupac Grape Seed as a Source of Nutritionally Valuable Oil

Valorization of winery waste is a promising solution for waste management with additional benefit of bioactive compounds isolation. The aim of this study was to analyze the nutritional and bioactive potential of oil derived from Serbian autochthonous grape seed variety Prokupac and to compare it with known international grape varieties. Additionally, two extraction methods (ultrasound assisted extraction and cold pressing) were used in order to determine their influence on physico-chemical and nutritive characteristics of grape seed oil. Different methods, including determination of physicochemical properties, content of bioactive compounds, oxidative stability and antioxidative capacity were used for the characterization of grape seed oils. Results indicated that the higher yield was obtained by ultrasound assisted extraction compared to cold pressing. The application of ultrasound assisted extraction resulted in increased α-tocopherol content and better antioxidant capacity and oxidative stability of oil. Significant differences in bioactive composition were observed for Prokupac seed oil compared to the other grape varieties. Oil extracted from Prokupac grape seed had the lowest content of polyunsaturated and the highest content of saturated fatty acids, the highest content of α-tocopherol and consequently, the best antioxidative capacity. Prokupac grape seed has a great potential for isolation of nutritive and bioactive valuable oil

Vegetative compatibility and RFLP analysis of colletotrichum destructivum isolates from alfalfa and red clover

A total of 17 isolates of Colletofrichum from alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) plants with anthracnose symptoms were collected from 11 districts in Serbia during 2005-2010 and tested for variability in vegetative compatibility groups (VCGs) and restriction fragment length polymorphisms (RFLP). Nitrate non utilising (nit) mutants were isolated from each of investigated C. desfructivum isolates by selecting chlorate -resistant sectors on medium with chlorate. The isolates were grouped in five VCGs while one isolate was self -incompatible. No relationship was found between VCGs and geographical origin of the isolates. Restriction Fragment Length Polymorphism (RFLP) analysis of a 900 bp intron of the glutamine synthetase (GS) gene revealed a unique polymorphic profile of C. destructivum isolates, distinct from the profiles of other Colletofrichum species. An identical profile was produced for all C. desfructivum isolates, regardless of their host and geographical origin. PCR-RFLP failed to detect some the Serbian C. desfructivum isolates

Quantile-Zone Based Approach to Normality Testing

Normality testing remains an important issue for researchers, despite many solutions that have been published and in use for a long time. There is a need for testing normality in many areas of research and application, among them in Quality control, or more precisely, in the investigation of Shewhart-type control charts. We modified some of our previous results concerning control charts by using the empirical distribution function, proper choice of quantiles and a zone function that quantifies the discrepancy from a normal distribution. That was our approach in constructing a new normality test that we present in this paper. Our results show that our test is more powerful than any other known normality test, even in the case of alternatives with small departures from normality and for small sample sizes. Additionally, many test statistics are sensitive to outliers when testing normality, but that is not the case with our test statistic. We provide a detailed distribution of the test statistic for the presented test and comparable power analysis with highly illustrative graphics. The discussion covers both the cases for known and for estimated parameters

Quantile-Zone Based Approach to Normality Testing

Normality testing remains an important issue for researchers, despite many solutions that have been published and in use for a long time. There is a need for testing normality in many areas of research and application, among them in Quality control, or more precisely, in the investigation of Shewhart-type control charts. We modified some of our previous results concerning control charts by using the empirical distribution function, proper choice of quantiles and a zone function that quantifies the discrepancy from a normal distribution. That was our approach in constructing a new normality test that we present in this paper. Our results show that our test is more powerful than any other known normality test, even in the case of alternatives with small departures from normality and for small sample sizes. Additionally, many test statistics are sensitive to outliers when testing normality, but that is not the case with our test statistic. We provide a detailed distribution of the test statistic for the presented test and comparable power analysis with highly illustrative graphics. The discussion covers both the cases for known and for estimated parameters

Morphological and molecular identification of Fusarium oxysporum f. sp. narcissi on poet’s daffodil (Narcissus poeticus L.) in Serbia

In autumn 2018, daffodil (narcissus) plants with basal bulb rot were noticed in a plantation in locality Jasika, Serbia. Morphological characterization identified Fusarium oxysporum f. sp. narcissi as the causal agent of bulb rot in daffodil. Three selected isolates were tested for their ability to produce symptoms on daffodil bulbs. Two weeks after artificial inoculation typical symptoms of basal rot developed on inoculated bulbs from which the pathogen was re-isolated fulfilling Koch’s postulates. To further identify the pathogen, a molecular characterization with sequence and phylogenetic analysis of ITS and TEF1 genomic regions was performed. Molecular characterization confirmed the obtained results in morphological identification. The detection of Fusarium oxysporum f. sp. narcissi, a causal agent of basal rot on daffodil in Serbia, is the first report of this pathogen in the country

Inhibition properties of self-assembled corrosion inhibitor talloil diethylenetriamine imidazoline for mild steel corrosion in chloride solution saturated with carbon dioxide

The inhibition effect of talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on corrosion of mild steel in chloride solutions saturated with CO2 was investigated by weight loss measurements (WL) and atomic force microscopy (AFM). Adsorption mechanism and kinetics of self-assembled (TOFA/DETA imidazoline) monolayers formation on gold were studied using the quartz crystal microbalance measurements (QCM). WL and AFM results demonstrated that TOFA/DETA imidazoline can effectively protect mild steel surface from corrosion. QCM measurements shown that the adsorption of TOFA/DETA imidazoline onto gold follows Langmuir adsorption isotherm and further investigation of the adsorption process will be carried out on a corroding metal surface