The use of natural stone as an authentic building material for the restoration of historic buildings in order to test sustainable refurbishment: Case study

This study deals with the integrated process of conservation and restoration of architectural heritage and sustainability. The objective of the research was to define adequate methodologies for the structural restoration of historic buildings, their re-use, and sustainable refurbishment in accordance with modern requirements and conservation standards while maintaining the original visual character by using natural stone as an authentic building material. The main research method was the in-situ observation of the historic structures during the restoration and adaptive re-use, the analysis, and evaluation of the research findings regarding energy efficiency improvements and energy saving in the Haybarn complex within the monastery Hilandar, Mount Athos, Greece. Due to its cultural and natural values, Mount Athos has been inscribed on the UNESCO World Heritage List. The research included the damaged and abandoned agricultural structures that belong to the Haybarn complex and the analysis of the obtained results after the restoration had finished and the abandoned premises had been turned into guest rooms for the visitors of Hilandar monastery. The result section states the findings of the research arranged as recommendations for historic building restoration and re-use, emphasizing their new function in accordance with modern comfort requirements and environmental protection standards. The main contribution of this study is the analysis of the research findings and the possibilities of energy refurbishment of the restored historic buildings, through the use of natural stone as authentic local construction material, in accordance with energy efficiency measures and principles, conservation requirements and cultural heritage conservation standards

Antibacterial activity of Beta vulgaris L. pomace extract

Antibacterial activity of Beta vulgaris L. (beetroot) pomace extract (concentration 100 mg/ml) was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates). Disc diffusion method with 15 µl of extract and agar-well diffusion method with 50 and 100 µl were used. Antibiotic (cefotaxime/clavulanic acid) was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth) appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 µl of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared

Protective effect of Gentiana lutea root and leaf extracts against heterocyclic aromatic amines IQ and PhIP produced in thermally processed meat

During high-temperature cooking of protein rich foods, especially meat and fish, heterocyclic aromatic amines can be formed. These amines are a class of potent mutagens that can cause alterations in the structure of DNA and chromosomes. In recent decades, research has been focused on investigating plants and their phytochemicals as potential antimutagens. The aim of this study was to examine the anti-genotoxic effect of methanolic root and leaf extracts of Gentiana lutea against the food mutagens 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) produced in thermally processed meat. To determine the protective potential of extracts, the alkaline comet assay was applied. The results obtained indicated strong anti-genotoxic effect of both extracts against the tested mutagens. The highest inhibition of IQ-induced genotoxicity was recorded for leaf extract (72%). Regarding PhiP, root extract achieved inhibition of 80% of DNA damage, so was more successful than leaf extract. The data obtained in this study stimulates further research of G. lutea extracts and its constituents as potential dietary supplements in improving human health. © Published under licence by IOP Publishing Ltd.Conference of 60th International Meat Industry Conference, MEATCON 2019 ; Conference Date: 22-25 September 2019; Conference Code:15329

Antioxidant and Antibacterial Activity of the Beverage Obtained by Fermentation of Sweetened Lemon Balm (Melissa offi cinalis L.) Tea with Symbiotic Consortium of Bacteria and Yeasts

Kombucha je napitak koji se tradicionalno dobiva fermentacijom zaslađenog crnog ili zelenog čaja (Camellia sinensis L.) s pomoću simbiotičke kulture bakterija i kvasaca (engl. SCOBY). U ovom je radu za pripremu napitka kombucha kao izvor dušika pri fermentaciji upotrijebljena melisa (Melissa officinalis L.). Tijekom sedmodnevne fermentacije mjereni su sljedeći parametri: pH-vrijednost, titracijska kiselost, udjeli ukupnih fenola i fenolnih spojeva, te sposobnost uklanjanja hidroksilnog (˙OH) i 1,1-difenil-2-pikrilhidrazilnog (DPPH) radikala da bi se utvrdila povezanost trajanja fermentacije s antioksidativnom i antibakterijskom aktivnošću fermentiranog napitka od melise. Određena je optimalna titracijska kiselost od 4 do 4,5 g/L, koju su potvrdili dugogodišnji konzumenti tog napitka. Ispitan je antibakterijski učinak napitaka povećane kiselosti od 8,12 g/L na jedanaest divljih bakterijskih sojeva. Rezultati pokazuju da se u proizvodnji fermentiranog napitka kombucha čaj (C. sinensis) može uspješno zamijeniti melisom. Udjel ukupnih fenola i sposobnost uklanjanja DPPH radikala bili su veći u podlozi s melisom nego u tradicionalnom napitku kombucha. Za biološku je aktivnost napitka kombucha s melisom najvjerojatnije zaslužna ružmarinska kiselina, glavni fenolni spoj u napitku. Vrijednosti EC50 pokazuju da napitak kombucha ima veću antioksidativnu vrijednost od čajnih infuzija C. sinensis L. i M. officinalis L., čemu vjerojatno pridonose metaboliti simbiotičke kulture bakterija i kvasaca. Kombucha s melisom optimalne i povećane titracijske kiselosti imala je izraženi antibakterijski učinak, ponajprije zbog prisustva octene kiseline, ali i zbog drugih sastojaka čaja te prisustva metabolita simbiotičke kulture.Kombucha is a fermented tea beverage which is traditionally prepared by fermenting sweetened black or green tea (Camellia sinensis L.) with symbiotic consortium of bacteria and yeasts (SCOBY). In this study, lemon balm (Melissa offi cinalis L.) was used as the only nitrogen source for kombucha fermentation. During the seven-day fermentation process, pH value, titratable acidity (TA), total phenolic content, phenolic compounds, and antioxidant activity against hydroxyl (˙OH) and 1,1-diphenyl-2-picrylhydrazil (DPPH) radicals were measured to detect the connection between the fermentation time and antioxidant and antibacterial activities of lemon balm kombucha. Antibacterial activity of fi nished beverages with optimum acidity (TA=4–4.5 g/L), the value which is confi rmed by long-time kombucha consumers, and enhanced acidity (TA=8.12 g/L) was tested against eleven wild bacterial strains. The results showed that lemon balm could be successfully used as an alternative to C. sinensis L. for kombucha fermentation. Total phenolic content and antioxidant activity against DPPH radicals of lemon balm fermentation broth were higher than those of traditional kombucha. Rosmarinic acid is the main phenolic compound of the lemon balm-based kombucha that probably provides biological activity of the beverage. Judging from the EC50 values, kombucha beverages exhibited higher antioxidant activities compared with C. sinensis L. and M. offi cinalis L. infusions, which can probably be ascribed to SCOBY metabolites. Lemon balm kombucha with both optimum and enhanced acidity showed antibacterial activity, which can be primarily ascribed to acetic acid, but also to some other tea components and SCOBY metabolites

Hemijska ispitivanja miskantusa gajenog u Srbiji - potencijalni obnovljiv izvor energije

According to scientific community and professional specialists, urging necessity to increase capacity of sources of energy can be partially achieved by using biomass as a raw material. This approach is justified by both economic and ecological reasons. In this paper the results of chemical study of the biomass Miscanthus × giganteus Greef et Deu. cultivated in the Republic of Serbia in the experimental field of the Institute for Application of Nuclear Energy in Zemun were presented. Study of an amount of ashes, elemental analysis of the biomass, and calorific value of the biomass (both higher and lower), which are critical parameters when estimating the quality of a biofuel, points out the possibility of utilization of the miscantus biomass as a fuel. Samples of the plant material for this study were collected during two harvesting periods: in the fall, when the biological yield is the highest, and at the end of the winter, when a highest quality biomass with respect to the combustion is obtained do to a decrease in moisture content and remobilization of the macro- and micronutrients from the above-ground parts of the plants to the rhizomes. Values of the studied parameters indicate that biomass meets the 'green' energy requirements because the amounts of oxides of nitrogen and sulphur in the combustion products would not threaten current quality of the environment and the amount of carbon dioxide produced would be consumed in the process of photosynthesis. Results of the chemical analyses strongly suggest to a high potential of utilization of the miscantus biomass as a biofuel (renewable source of energy) to generate thermal energy.Delimičan odgovor stručne i naučne javnosti na pitanje kako povećati kapacitete energetskih izvora je upotreba biomase kao sirovine, kako iz ekonomskih, tako i iz ekoloških razloga. U ovom radu su prikazani rezultati fizičko-hemijskih ispitivanja biomase miskantusa (Miscanthus × giganteus Greef et Deu.), gajenog na teritoriji Republike Srbije, oglednom polju Instituta za primenu nuklearne energije, Zemun. Ispitivanjem količine pepela, elementarnog sastava biomase i kalorične vrednosti biomase (donje i gornje), koji su presudni za procenu kvaliteta biogoriva, ukazano je na mogućnost eksploatacije biomase miskantusa kao biogoriva. Prikupljanje uzoraka biljnog materijala za ovo istraživanje izvršeno je u dva žetvena roka: u jesen - vreme maksimuma biološkog prinosa i krajem zime, kada se dobija kvalitetnija biomasa za sagorevanje usled smanjenja sadržaja vlage i remobilizacije makro- i mikrohraniva iz nadzemnih delova rizoma. Vrednosti ispitivanih parametara pokazuju da biomasa ispunjava zahteve 'zelene' energije, jer produkti sagorevanja biomase svojom količinom (oksidi N i S) ne bi ugrožavali postojeći kvalitet životne sredine, a količina nastalog ugljenik (IV) - oksida ne bi predstavljala ekološki problem, jer bi se dalje uključila u proces fotosinteze. Rezultati hemijskih analiza argumentovano ukazuju na veliki potencijal upotrebe biomase miskantusa kao biogoriva (obnovljivog izvora energije) u proizvodnji toplotne energije

Cuticular chemoprofile of the fruit fly drosophila subobscura (diptera, drosophilidae)

In insects, cuticular hydrocarbon (CHC) profile is involved in many important biological functions and may vary in different conditions. Among fruit fly species, Drosophila subobscura is one of the most frequently used in genetic, ecological and evolutionary research, because of its rich chromosomal polymorphism, specific behavioral repertoires and habitat preferences. In this work, we identified and quantified cuticular chemoprofile of D. subobscura. Using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS), 25 chemical compounds were found in males and 23 compounds were found in females. Further, ANOVA confirmed significant sexual dimorphism in cuticular chemoprofile amounts. Knowledge of cuticular chemistry could contribute to further research in D. subobscura, starting from behavioral, up to ecological, since this species is recognized as an important model system for the study and monitoring of global climate changes

Cuticular chemoprofile of the fruit fly drosophila subobscura (diptera, drosophilidae)

In insects, cuticular hydrocarbon (CHC) profile is involved in many important biological functions and may vary in different conditions. Among fruit fly species, Drosophila subobscura is one of the most frequently used in genetic, ecological and evolutionary research, because of its rich chromosomal polymorphism, specific behavioral repertoires and habitat preferences. In this work, we identified and quantified cuticular chemoprofile of D. subobscura. Using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS), 25 chemical compounds were found in males and 23 compounds were found in females. Further, ANOVA confirmed significant sexual dimorphism in cuticular chemoprofile amounts. Knowledge of cuticular chemistry could contribute to further research in D. subobscura, starting from behavioral, up to ecological, since this species is recognized as an important model system for the study and monitoring of global climate changes

Irreversible UV-induced quercetin and rutin degradation in solution, studied by UV-spectrophotometry and HPLC chromatography

Irreversible degradation of quercetin and rutin, dissolved in methanol and water, induced by continuous UV-irradiation from two different sub-ranges (UV-B and UV-C) has been studied in this work. The degradation of both flavonoids is related to formation of UV-induced degradation products: both processes follow first-order kinetics. The degradation and products formation rate constants are both dependent on the involved UV-photons energy input in both solvents

UV-induced change in quercetin antioxidant activity toward benzophenone initiated lipid peroxidation

The aim of this work is to estimate the degradation and change in antioxidant activity of quercetin in the presence of two different mixtures of phospholipids in methanol solution, under continuous UV-irradiation from three different sub-ranges (UV-A, UV-B and UV-C), in the presence and in the absence of selected UV-absorbing photosensitizer, benzophenone. Quercetin is employed to control lipid peroxidation process generated by UV-irradiation, by absorbing part of the UV-incident light, or/and by scavenging the involved, created free radicals. The results show that quercetin undergoes to irreversible destruction, highly dependent on UV-photons energy input, more expressed in the presence than in the absence of benzophenone. In the same time quercetin expresses suppression effect on lipid peroxidation processes in UV-irradiated phospholipid mixtures in both cases - absence or presence of benzophenone (more or less effective, respectively). In UV-C-irradiated mixtures, benzophenone photosensitizing function is significantly reduced due to its strong absorption in the same UV-C spectral range, therefore affecting less antioxidant activity of the remained quercetin

ELECTROCHEMICAL BEHAVIOUR OF THE CATALYST WITH KAOLINITE-BENTONITE SUBSTRATE IN WATER UDC 66.097.3-039.7: 549.623.9 + 621.6.031

Abstract. Due to the fact that oxidation-reduction potential and rH2 value of every water are its crucial features, numereous efforts have been made to use electrochemical means for water preparation. In this paper, we report the results of electrochemical influence research of magnesium-aluminium silicate catalyst, in the form of ceramics made of kaolinite and bentonite clays, on the rH2, pH and EOR changes of the waters of particular characteristics in the wanted direction. Particularly, the possibility of changing "active water " characteristics was investigated. The composite made with microalloyed aluminium exhibits a very negative stationary potential and its interaction with water results in water reduction. Addition of some active components to the mixture of kaolin and bentonite can provide clay mixtures, which after sintering at high temperatures produce very porous ceramics with microcrystalline and amorphous regions of stoichiometric and nonstoichiometric new oxides and some metallized surface (in our case-mainly with magnesium surplus). Nonstoichiometric oxide mixtures and metallized amorphous ceramics regions show high electrochemical and chemical activities in contact with water. This leads to redox potential changes and appearance of Mg 2+ ions in the magnesium aluminium silicate–water system. Key words: "active water", composite, electrochemical characteristics, kaolinite- bentonite substrate, microalloyed aluminium, "passive water&quot