I. Ristić, Darko Manjenčić, M. Kostić, N. Vukić, S. Cakić, T. Radusin, V. Teofilović
{"title":"Influence of nanofillers and masterbatch on properties of siloxane materials","authors":"I. Ristić, Darko Manjenčić, M. Kostić, N. Vukić, S. Cakić, T. Radusin, V. Teofilović","doi":"10.5937/savteh2202005r","DOIUrl":"https://doi.org/10.5937/savteh2202005r","url":null,"abstract":"Nanocomposites based on siloxane and silicon(IV)oxide nanoparticles (with a hydrophilic and hydrophobic surface) were synthesized to design the desired final properties of the composite material. Masterbatch, a mixture of siloxane containing vinyl functional groups and reinforcing fillers, was added to improve the mechanical properties and topology of siloxane networks. Silicon(IV)oxide was added in amounts of 1, 5, 10, and 20 wt% and masterbatch in amounts of 5 and 10 wt% to examine the effect of the amounts of fillers and masterbatch in the synthesized samples. Fourier transform infrared spectroscopy was used to analyze the chemical structure of the obtained materials. Transmission electron microscopy (TEM) was used to examine the dispersion of filler particles in siloxane nanocomposites. To examine the thermal stability and phase transition temperature of siloxane materials, thermogravimetric analyzes (TGA) and differential scanning calorimetry (DSC) were performed. The addition of masterbatch did not lead to a significant difference in melting temperature, but stoichiometry was disturbed, which decreased the thermal stability compared to samples without masterbatch. The addition of masterbatch to nanocomposites with hydrophilic fillers increases both elongations at break and tensile strength. According to the results, the combination of masterbatch and nanofillers affects the properties of siloxane materials, which could enable obtaining materials with the desired properties.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82514859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Linear compact localized modes in flux-dressed two-dimensional plus lattice","authors":"A. Mančić, M. Stojanović, M. Stepić","doi":"10.5937/savteh2202036m","DOIUrl":"https://doi.org/10.5937/savteh2202036m","url":null,"abstract":"It was studied a photonic linear two-dimensional plus lattice dressed by the artificial flux and explored the influence of the artificial gauge field on the energy band spectrum. The Aharonov-Bohm effect has caused the appearance of flat zones and for certain values of the flux, the lattice spectrum has been described by two momentum independent, fully degenerated flatbands and three dispersive bands. Three different types of fundamental non-orthogonal compactons have been obtained. The findings presented in this study could be tested in practice and they may be used for probing different artificial flatband systems, e. g. ultracold atoms in optical lattices, polariton condensates etc.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78975745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ivana T. Karabegović, Sandra Stamenkovic-Stojanovic, M. Lazić, Natalija Đorđević, B. Danilović
{"title":"Antimicrobial activity and overall sensory acceptance of fermented goat whey beverage: Process conditions optimization using response surface approach","authors":"Ivana T. Karabegović, Sandra Stamenkovic-Stojanovic, M. Lazić, Natalija Đorđević, B. Danilović","doi":"10.5937/savteh2202026k","DOIUrl":"https://doi.org/10.5937/savteh2202026k","url":null,"abstract":"Even though it contains high levels of many important nutritive compounds, whey has not been widely accepted by consumers due to its unappealing taste and texture. Whey fermentation could improve its sensory properties and result in a functional beverage with appealing characteristics and a clear potential to replace traditional functional milk-based beverages. Therefore, this work aimed to develop a goat whey-based functional beverage fermented with kefir grains and to examine the influence of fermentation temperature and inoculum size on the overall sensorial acceptability of the product and its antimicrobial activity. Response surface methodology along with the central composite design was used to estimate the individual and combined effect of temperature and inoculum size on lactic and acetic acid, ethanol, antimicrobial activity and overall sensory acceptability of the obtained beverage. The experimental data for lactic and acetic acid, antimicrobial activity and overall sensory acceptance of beverage were fitted to a quadratic model, while a linear 2FI model was proposed for the ethanol content. Temperature and inoculum size have been found to affect the quality of the obtained beverage. Multi-response optimization provided an optimum solution for the production of the most acceptable beverage with the highest antimicrobial activity. According to desirability criteria, with overall desirability of 0.79, the following fermentation conditions were proposed for the fermentation of goat whey using kefir: temperature of 27.5 ° C and inoculum size of 7.36%. Proposed values were validated confirming the minimum deviation of experimental and predicted values.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89865740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Maksimov, Sonja Jordeva, Silvana Zhezhova, Longurova Golomeova, D. Andronikov
{"title":"Qualitative and quantitative analysis of the pre-consumer textile waste in North Macedonia","authors":"S. Maksimov, Sonja Jordeva, Silvana Zhezhova, Longurova Golomeova, D. Andronikov","doi":"10.5937/savteh2201088m","DOIUrl":"https://doi.org/10.5937/savteh2201088m","url":null,"abstract":"Textile waste in North Macedonia participates with 4.7% in the total composition of the municipal solid waste which is completely landfilled. The purpose of this paper is investigation of the textile waste quantity and quality as a pre-condition for its further management. The results obtained show domination of the apparel cutting waste, the total amount has an average value of 2792.7 tons per year. The further analysis shows that cotton waste is the most represented with 46.4%, then waste from artificial and synthetic fibres with 41.4%. During the research period (2015-2020), 1.42 kg/capita (on average) of pure pre-consumer textile waste with retained physical and mechanical properties is generated annually.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83049397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natalija Đorđević, Stojan Mančić, Ivana T. Karabegović, D. Cvetković, J. Stanojević, D. Savić, B. Danilović
{"title":"The effect of distillation methods on the yield, composition and biological activity of basil (Ocimum basilicum L.) essential oil","authors":"Natalija Đorđević, Stojan Mančić, Ivana T. Karabegović, D. Cvetković, J. Stanojević, D. Savić, B. Danilović","doi":"10.5937/savteh2202016d","DOIUrl":"https://doi.org/10.5937/savteh2202016d","url":null,"abstract":"Basil (Ocimum basilicum L.) is an aromatic plant, well known for its characteristic scent and healing properties, which has a wide application, from cooking to alternative medicine. The objective of this work was to evaluate the chemical composition, antimicrobial and antioxidant activity of basil essential oil obtained by hydrodistillation, microwave-assisted hydrodistillation and solvent-free microwave-assisted hydrodistillation. Gas chromatography analysis showed that the main components present in all three essential oils were linalool (30.3-58.2%) and epi-a-cadinol (5.6-7.3%). The distillation method mainly affected the content of terpenes, and aromatic compounds. The essential oils expressed good antimicrobial activity, most effective against Escherichia coli ATCC 25922, while the Pseudomonas aeruginosa ATCC 27853 was the most resistant strain. Good antioxidant activity was established after 120 min of incubation for all obtained essential oils with a significant difference regarding the applied distillation method. The results showed a great influence of the distillation method on the chemical composition, detected compounds, as well as antioxidant potential and antimicrobial activity of basil essential oils. The use of microwave assisted hydrodistillation has shown a significant difference in oil yield, energy consumption and environmental impact, which makes it a more suitable distillation process compared to conventional hydrodistillation.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77811806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Nikodijević, S. Konstantinović, Marija Kodrić, D. Đorđević
{"title":"Advantages of dyeing wool fibers at 60 °C after previous modification with alcohol","authors":"M. Nikodijević, S. Konstantinović, Marija Kodrić, D. Đorđević","doi":"10.5937/savteh2202062n","DOIUrl":"https://doi.org/10.5937/savteh2202062n","url":null,"abstract":"This research work describes the advantages of dyeing wool fibers at 60 °C after pre-treatment with alcohol. Wool is a natural fiber. This fiber can be dyed with acid, metal-complex and other dyes. Acid dyes should be soluble in water and most commonly used for dyeing wool, silk and nylon. Wool fibers with 100 % chemical composition were used in this study. The wool fiber was pre-treated in alcohol (npentanol) at a temperature of 60 °C for 30 minutes. Pre-treated wool fibers were dyed with Supramin Blau acid dye. The time for dyeing samples of wool fibers was 5, 10, 20, 30, 40, 50 and 60 minutes. The process of dyeing wool fibers with acid dye at 60 °C showed a higher degree of exhaustion and adsorption capacity when wool was pre-treated with n-pentanol compared to wool that was not pre-treated with n-pentanol. A constant increase in the degree of dye exhaustion on the pretreated wool fiber was observed during the increase in initial dye concentration. A longer dyeing time for pre-treated wool results in a higher degree of dye exhaustion. Models Weber-Morris and Elovich are applicable for describing the adsorption flow because there is very little scatter around the ideal curve, so functional straight lines cover most points very well.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72708896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"UHPLC-DAD-ESI-MS analysis of the 'Centaurium erythraea' infusion","authors":"V. Nikolić, J. Zvezdanović, S. Konstantinović","doi":"10.5937/savteh2201013n","DOIUrl":"https://doi.org/10.5937/savteh2201013n","url":null,"abstract":"Chemical composition was estimated in a tea sample, i.e. infusion prepared from dried aerial herb of Centaurium erythraea. The plant was harvested in the Stara Planina mountain (Serbia, 42°43'00\"N; 24°55'04\"E) during the flowering stage. The flowering tops of the plant were dried to the moisture content of 7.89 (w/w) in a dark place. Qualitative analysis was done by Ultrahigh performance liquid chromatography-diode array detector-electrospray mass spectrometry (UH-PLC-DAD-ESI-MS/MS) method. The aim of this study was to detect and identify phytochemicals in the infusion prepared in a traditional way and present it as a good source of biologically active substances and bio-antioxidants. The analysis of C. erythraea infusion primarily indicated the presence of secoiridoid glycosides (sweroside, gentiopicroside, secologanoside, swertiamarin), xanthones and flavo-noids, which promises good quality of tea from Eastern Serbia.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90601301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katarina Stepic, Radomir Ljupković, Jovana D. Ickovski, A. Zarubica
{"title":"A short review of titania-graphene oxide based composites as a photocatalysts","authors":"Katarina Stepic, Radomir Ljupković, Jovana D. Ickovski, A. Zarubica","doi":"10.5937/savteh2102051s","DOIUrl":"https://doi.org/10.5937/savteh2102051s","url":null,"abstract":"New and effective methods of water purification are necessary to minimize pollution. Many methods have been used in wastewater treatment, but sorption is considered as an easy and economic process. The efficiency of any sorption process mainly depends on the physicochemical properties of the used adsorbent. Since photocatalysts can initiate reactions of decomposition organic contaminants under ultraviolet or sunlight irradiation without using chemicals or producing chemical wastes, photocatalytic reactions are considered a sustainable way to remove a variety of environmental pollutants. Ultraviolet water purification became the most effective method of water disinfection and purification. Heterogeneous semiconductor photocatalysts have recently emerged as an efficient material for purifying water. The crystal structure is crucial for photocatalytic activity and efficiency of semiconductors, thus optimal parameters must be provided during the preparation of photocatalysts. To overcome problems with semiconductors usage, the use of co-catalysts and photocatalyst carriers is one of the solutions. Recently, much emphasis has been placed on using graphene oxide (GO) supported semiconductor photocatalysts. In this paper, a short review of composites of titanium dioxide and graphene oxide-based materials is given.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86873523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Compression properties of knitted fabrics printed by sublimation transfer printing technique","authors":"S. Stojanović, J. Geršak, D. Trajković","doi":"10.5937/savteh2101046s","DOIUrl":"https://doi.org/10.5937/savteh2101046s","url":null,"abstract":"Compression properties of textile materials are useful for determining fullness, softness, smoothness, and stiffness. In addition, compression parameters have significant influence on fabric hand value and quality of textile materials. The present paper reports a study of the sublimation printing process influence on the change in compression properties of knitted fabrics (polyester, cotton, and cotton/ polyester) intended for sportswear manufacturing. For that purpose, the KES-FB3-A Compression Tester was used for measuring compression parameters of knitted fabrics. The parameters, which contributed to the smallest reduction percentage in compression properties of polyester knitted fabrics were yarn linear density and weight. For cotton-rich knitted fabrics sublimation coating powder was used for paper modification to bond disperse dyes to cotton fibres. The analysis of the results showed that the printing process had a smaller influence on the change of compression parameters of polyesters in relation to cotton and cotton/polyester knitted fabrics. It was noted that the printing process had the effect of thickness reduction for all knitted fabrics to varying degrees. Printing process contributed to small decrease in compressibility and specific volume values for polyester knitted fabrics. The modification process contributed to the significant reduction of the compressibility for cotton (from 34.46% to 47.89%) and cotton/polyester (from 38.81% to 50.75%) knitted fabrics. In addition, reduction in specific volume values range from 41.86% to 44.19% for cotton and from 42.37% to 45.75% for cotton/ polyester knitted fabrics was notted.","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90016408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of the nitrogen source type on the growth and consumption of crude glycerol by Streptomyces hygroscopicus CH-7","authors":"S. Ilić, J. Ćirić, G. Gojgić-Cvijović","doi":"10.5937/savteh2101041i","DOIUrl":"https://doi.org/10.5937/savteh2101041i","url":null,"abstract":"In this paper we studied the effect of different amino acids (arginine, tryptophan, tyrosine, and phenylalanine) as nitrogen sources on the growth of actinomycete Streptomyces hygroscopicus CH-7 and the consumption of crude glycerol, obtained as a by-product in the biodiesel production from sunflower oil. The highest biomass concentration (9.5 g/L) was achieved using the basic medium and the medium with tryptophan (9.2 g/L), while the crude glycerol consumption was the highest in the basic medium (5.9 mg/mL) and the medium with phenylalanine (3.3 mg/mL).","PeriodicalId":7216,"journal":{"name":"Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83790354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}