Search results for: recalcitrant organic compounds

Authors: Ghasem Khodahami, Vahid Rowshan, Mojtaba Pakparvar

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Stachys forms one of the largest genera in the flowering plant family Lamiaceae. The number of species in the genus is estimated from about 300 to about 450 and comprises some 34 species in Iran. This genus is one of the richest sources of diterpenes which are particularly interesting because of their ecological role as antifeedants against different species of insects and for their role as the medicinal properties of the plants. The ecological distribution of Stachys inflata was studied and the resulted eco-types were sampled from four regions ranging 230-340 mm of rainfall and 1690-2125 m a.s.l of height In Fars Province Southern Iran. The essential oils of air-dried samples were obtained by hydrodistillation and analyzed by gas chromatography and gas chromatography/mass spectrometry. The number of secondary metabolites varied from 25 to 50 depending to ecological conditions. The main compounds in these areas were: Germacrene D, Bicyclogermacrene, spathulenol, δ-cadinene. Statistical analysis of photochemical resulted in recognizing 3 distinct groups that show internal variety in these herbs.

Keywords: eco-type, phytochemistry, secondary metabolites, Stachys inflata

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Authors: Alaa A. Ghanem, S. E. M. Desouky

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Natural gas (NG) is considered one of the most essential global energy sources. NG fields are often far away from the market, and a long-distance transporting pipeline usually is required. Production of NG with high content of CO₂ leads to severe problems such as equipment corrosion along with the production line until refinery.in addition to a high level of toxicity and decreasing in calorific value of the NG. So it is recommended to remove or decrease the CO₂ percent to meet transport specifications. This can be reached using different removal techniques such as physical and chemical absorption, pressure swing adsorption, membrane separation, or low-temperature separation. Many solvents and chemicals are being used to capture carbon dioxide on a large scale; among them, Ionic liquids have great potential due to their tunable properties; low vapour pressure, low melting point, and sensible thermal stability. In this research, three modifiedimidazolium ionic liquids will be synthesized and characterized using different tools of analysis such as FT-IR, 1H NMR. Thermal stability and surface activity will be studied. The synthesized compounds will be evaluated as selective solvents for CO₂ removal from natural gas using PVT cell.

Keywords: natural gas, CO₂ capture, imidazolium ionic liquid, PVT cell

Procedia PDF Downloads 178

Authors: M. Grandcolas, N. Rival, H. Bu, S. Jahren, R. Schmid, H. Johnsen

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The concept of an autonomic self-healing material, where initiation of repair is integrated to the material, is now being considered for engineering applications and is a hot topic in the literature. Among several concepts/techniques, two are most interesting: i) Capsules: Integration of microcapsules in or at the surface of coatings or fibre-like structures has recently gained much attention. Upon damage-induced cracking, the microcapsules are broken by the propagating crack fronts resulting in a release of an active chemical (healing agent) by capillary action, subsequently repairing and avoiding further crack growth. ii) Self-healing polymers: Interestingly, the introduction of dynamic covalent bonds into polymer networks has also recently been used as a powerful approach towards the design of various intrinsically self-healing polymer systems. The idea behind this is to reconnect the chemical crosslinks which are broken when a material fractures, restoring the integrity of the material and thereby prolonging its lifetime. We propose here to integrate both self-healing concepts (capsules, self-healing polymers) in electrospun fibres and coatings. Different capsule preparation approaches have been investigated in SINTEF. The most advanced method to produce capsules is based on emulsification to create a water-in-oil emulsion before polymerisation. The healing agent is a polyurethane-based dispersion that was encapsulated in shell materials consisting of urea-benzaldehyde resins. Results showed the successful preparation of microcapsules and release of the agent when capsules break. Since capsules are produced in water-in-oil systems we mainly investigated organic solvent based coatings while a major challenge resides in the incorporation of capsules into water-based coatings. We also focused on developing more robust microcapsules to prevent premature rupture of the capsules. The capsules have been characterized in terms of size, and encapsulation and release might be visualized by incorporating fluorescent dyes and examine the capsules by microscopy techniques. Alternatively, electrospinning is an innovative technique that has attracted enormous attention due to unique properties of the produced nano-to-micro fibers, ease of fabrication and functionalization, and versatility in controlling parameters. Especially roll-to-roll electrospinning is a unique method which has been used in industry to produce nanofibers continuously. Electrospun nanofibers can usually reach a diameter down to 100 nm, depending on the polymer used, which is of interest for the concept with self-healing polymer systems. In this work, we proved the feasibility of fabrication of POSS-based (POSS: polyhedral oligomeric silsesquioxanes, tradename FunzioNano™) nanofibers via electrospinning. Two different formulations based on aqueous or organic solvents have shown nanofibres with a diameter between 200 – 450nm with low defects. The addition of FunzioNano™ in the polymer blend also showed enhanced properties in term of wettability, promising for e.g. membrane technology. The self-healing polymer systems developed are here POSS-based materials synthesized to develop dynamic soft brushes.

Keywords: capsules, coatings, electrospinning, fibers

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Authors: L. Giraudet, O. Simonetti, G. de Tournadre, N. Dumelié, B. Clarenc, F. Reisdorffer

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In this paper we intend to give a comprehensive view of the saturation misbehavior of thin film transistors (TFTs) based on disordered semiconductors, such as most organic TFTs, and its link to the field activation of the mobility. Experimental evidence of the field activation of the mobility is given for disordered semiconductor based TFTs, when reducing the gate length. Saturation misbehavior is observed simultaneously. Advanced transport models have been implemented in a quasi-2D numerical TFT simulation software. From the numerical simulations it is clearly established that field activation of the mobility alone cannot explain the saturation misbehavior. Evidence is given that high longitudinal field gradient at the drain end of the channel is responsible for an excess charge accumulation, preventing saturation. The two combined effects allow reproducing the experimental output characteristics of short channel TFTs, with S-shaped characteristics and saturation failure.

Keywords: mobility field activation, numerical simulation, OTFT, saturation failure

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Authors: Khalid S. Hashim, Andy Shaw, Rafid Alkhaddar

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Dissolved oxygen (DO) plays a key role in the electrocoagulation process (EC) as it oxidizes the heavy metals, ammonia, and cyanide into other forms that can be removed easily from water. Hence, many of the previous investigations used external aerators to provide the required DO inside EC reactors, especially when the water being treated had a low DO (such as leachate and high organic content waters), or when the DO depleted during the EC treatment. Although the external aeration process effectively enhances the DO concentration, it has a significant impact on energy consumption. Thus, the present project aims to fill a part of this gap in the literature by an innovative use of perforated flow columns in the design of an EC reactor (ECR1). In order to investigate the performance of ECR1, water samples with a controlled DO concentration were pumped at different flow rates (110, 220, and 440 ml/min) to the ECR1 for 10 min. The obtained results demonstrated that the ECR1 increased the DO concentration from 5.0 to 9.54, 10.53, and 11.0 mg/L, which is equivalent to 90.8%, 110.6%, and 120% at flow rates of 110, 220, and 440 mL/min respectively.

Keywords: flow column, electrocoagulation, dissolved oxygen, water treatment

Procedia PDF Downloads 345

Authors: S. Graeff-Hönninger, J. Pfenning, V. Gutsal, S. Wolf, S. Zikeli, W. Claupein

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Broccoli is considered as being a rich source of AOX like flavonoids, polyphenols, anthocyanins etc. and of major interest especially in the organic sector. However, AOX is environment dependent and often varies between cultivars. Aim of the study was to investigate the impact of cultivar and harvest date on AOX in broccoli. Activity of the AOX was determined using a Photochem®-Analyzer and a kit of reagent solutions for analysis. Results of the study showed that the lipid (ACL) and water-soluble antioxidant potential (AWC) of broccoli heads varied significantly between the four harvesting dates, but not among the different cultivars. The highest concentration of ACL was measured in broccoli heads harvested in September 2011, followed by heads harvested at the beginning of July in 2012. ACW was highest in heads harvested in October 2011. Lowest concentrations of ACW were measured in heads harvested in June 2012. Overall, the study indicated that the harvest date and thus growing conditions seem to be of high importance for final antioxidant capacity of broccoli.

Keywords: broccoli, open-pollinating, harvest date, epidemiological studies

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Authors: Edita Baltrėnaitė, Pranas Baltrėnas, Eglė MarčIulaitienė, Mantas PranskevičIus, Valeriia Chemerys

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The growing demand for organic products in the market promotes their use in various fields. One of such products is biochar. Among the innovative environmental applications, biochar has the potential as an adsorbent for retaining contaminants in environmental engineering and agrotechnical systems. Artificial modification of biochar can improve its adsorption capacity. However, indirect/natural change of biochar composition (e.g., contaminated biomass) based on syngenetic elements provides prospects for new applications of biochar as well as decreases the modification costs. Natural lignocellulosic and biochar composition variations would lead to a new field of application of biochar and reduce resources for biochar modifications. The aim of this study was to determine the influence of syngenetic elements of biochar’s feedstock on the physicochemical properties of lignocellulosic biochar. Syngenetic elements (e.g., Zn, Cu, Ni, Pb, Mg) and other intrinsic properties (e.g., lignin, COHN, moisture, ash) of indifferent types of lignocellulosic feedstock on the physicochemical characteristics of biochar are discussed.

Keywords: adsorption, lignocellulosic biochar, instrinsic properties, syngenetic elements

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Authors: Preeti Virkar, V. P. Uniyal, Vinod Kumar Bhatt

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With 50% decline in managed honey bee hives in the continents of Europe and America, farmers and landscape managers are turning to native wild bees for their essential ecosystem services of pollination. Wild bees population are too under danger due to the rapid land use changes from anthropogenic activities. With an escalating population reaching 9.0 billion by 2050, human-induced land use changes are predicted to further deteriorate the habitats of numerous species by the turn of this century. The status of bees are uncertain, especially in the tropical regions of the world, which also questions the crisis of global pollinator decline and their essential services to wild and managed flora. Our investigation collectively compares wild native bee diversity and their status in forests and agroecosystems in Doon Valley landscape, situated at the foothills of Himalayan ranges, Uttarakhand, India. We seek to ask whether (1) natural habitat are refuge to richer and rarer bees communities than the agroecosystems, (2) Are agroecosystems closer to natural habitats similar to them than agroecosystems farther away; hence support richer bee communities and hence, (3) Do polyculture farms support richer bee communities than monoculture. The data was collected using observation and pantrap sampling form February to May, 2012 to 2014. We recorded 43 species of bees in Doon Valley. They belonged to 5 families; Megachilidae, Apidae, Andrenidae, Halictidae and Collitidae. A multinomial model approach was used to classify the bees into 2 habitats, in which forests demonstrated to support greater number of specialist (26%, n= 11) species than agroecosystems (7%, n= 3). The valley had many species categorized as the rare (58%, n= 25) and very few generalists (9%, n=4). A linear regression model run on our data demonstrated higher bee diversity in agro-ecosystems in close proximity to forests (H’ for < 200 m = 1.60) compared to those further away (H’ for > 600 m = 0.56) (R2=0.782, SE=0.148, p value=0.004). Organic agriculture supported significantly greater species richness in comparison to conventional farms (Mann-Whitney U test, n1 = 33, n2 = 35; P = 0.001). Forests ecosystems are refuge to rare specialist groups and support bee communities in nearby agroecosystems. The findings of our investigation demonstrate the importance of natural habitats as a potential refuge for rare native wild bee pollinators. Polyculture in the valley behaves similar to natural habitats and supports diverse bee communities in comparison to conventional monocultures. Our study suggests that the farming communities adopt diverse organic agriculture systems to attract wild pollinators beneficial for better crop production. Forests are sanctuaries for bees to nest, forage, and breed. Therefore, our outcome also suggests landscape managers not only preserve protected areas but also enhance the floral diversity in semi-natural and urban areas.

Keywords: native bees, pollinators, polyculture, agroecosystem, natural habitat, diversity, monoculture, specialists, generalists

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Authors: A. Eštoková, M. Kovalčíková, A. Luptáková, A. Sičáková, M. Ondová

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Concrete durability as an important engineering property of concrete, determining the service life of concrete structures very significantly, can be threatened and even lost due to the interactions of concrete with external environment. Bio-corrosion process caused by presence and activities of microorganisms producing sulphuric acid is a special type of sulphate deterioration of concrete materials. The effects of sulphur-oxidizing bacteria Acidithiobacillus thiooxidans on various concrete samples, based on silica fume and zeolite, were investigated in laboratory during 180 days. A laboratory study was conducted to compare the performance of concrete samples in terms of the concrete deterioration influenced by the leaching of calcium and silicon compounds from the cement matrix. The changes in the elemental concentrations of calcium and silicon in both solid samples and liquid leachates were measured by using X – ray fluorescence method. Experimental studies confirmed the silica fume based concrete samples were found out to have the best performance in terms of both silicon and calcium ions leaching.

Keywords: biocorrosion, concrete, leaching, bacteria

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Authors: Supriya Majumder, Pabitra Banik

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Fates of Arsenic (As) on the soil-plant environment belong to the critical emerging issue, which in turn to appraises the threatening implications of a human health risk — assessing the dynamics of As in soil solid components are likely to impose its potential availability towards plant uptake. In the present context, we introduced an improved Sequential Extraction Procedure (SEP) questioning to identify solid-phase speciation of As in paddy soil under variable soil environmental conditions during two consecutive seasons of rice cultivation practices. We coupled gradients of water management practices with the addition of fertilizer amendments to assess the changes in a partition of As through a field experimental study during monsoon and post-monsoon season using two rice cultivars. Water management regimes were varied based on the methods of cultivation of rice by Conventional (waterlogged) vis-a-vis System of Rice Intensification-SRI (saturated). Fertilizer amendment through the nutrient treatment of absolute control, NPK-RD, NPK-RD + Calcium silicate, NPK-RD + Ferrous sulfate, Farmyard manure (FYM), FYM + Calcium silicate, FYM + Ferrous sulfate, Vermicompost (VC), VC + Calcium silicate, VC + Ferrous sulfate were selected to construct the study. After harvest, soil samples were sequentially extracted to estimate partition of As among the different fractions such as: exchangeable (F1), specifically sorbed (F2), As bound to amorphous Fe oxides (F3), crystalline Fe oxides (F4), organic matter (F5) and residual phase (F6). Results showed that the major proportions of As were found in F3, F4 and F6, whereas F1 exhibited the lowest proportion of total soil As. Among the nutrient treatment mediated changes on As fractions, the application of organic manure and ferrous sulfate were significantly found to restrict the release of As from exchangeable phase. Meanwhile, conventional practice produced much higher release of As from F1 as compared to SRI, which may substantially increase the environmental risk. In contrast, SRI practice was found to retain a significantly higher proportion of As in F2, F3, and F4 phase resulting restricted mobilization of As. This was critically reflected towards rice grain As bioavailability where the reduction in grain As concentration of 33% and 55% in SRI concerning conventional treatment (p <0.05) during monsoon and post-monsoon season respectively. Also, prediction assay for rice grain As bioavailability based on the linear regression model was performed. Results demonstrated that rice grain As concentration was positively correlated with As concentration in F1 and negatively correlated with F2, F3, and F4 with a satisfactory level of variation being explained (p <0.001). Finally, we conclude that F1, F2, F3 and F4 are the major soil. As fractions critically may govern the potential availability of As in soil and suggest that rice cultivation with the SRI treatment is particularly at less risk of As availability in soil. Such exhaustive information may be useful for adopting certain management practices for rice grown in contaminated soil concerning to the environmental issues in particular.

Keywords: arsenic, fractionation, paddy soil, potential availability

Procedia PDF Downloads 127

Authors: S. Njoumi, L. Ben Haj Said, M. J. Amiot, S. Bellagha

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The main objective of this research was to establish the kinetics of variation of total polyphenol content (TPC) and total flavonoid content (TFC) in Tunisian Corchorus olitorius powder and in a traditional home cooked-meal (Molokheiya) when using stewing and stir-frying as cooking methods, but also to compare the effect of these two common cooking practices on water content, TPC, TFC and color. The L*, a* and b* coordinates values of the Molokheiya varied from 24.955±0.039 to 21.301±0.036, from -1.556±0.048 to 0.23±0.026 and from 5.675±0.052 to 6.313±0.103 when using stewing and from 21.328±0.025 to 20.56±0.021, from -1.093± 0.011to 0.121±0.007 and from 5.708±0.020 to 6.263±0.007 when using stir-frying, respectively. TPC and TFC increased during cooking. TPC of Molokheiya varied from 29.852±0.866 mg GAE/100 g to 220.416±0.519 mg GAE/100 g after 150 min of stewing and from 25.257±0.259 mg GAE/100 g to 208.897 ±0.173 mg GAE/100 g using stir-frying method during 150 min. TFC of Molokheiya varied from 48.229±1.47 mg QE/100 g to 843.802±1.841 mg QE/100 g when using stewing and from 37.031± 0.368 mg QE/100 g to 775.312±0.736 mg QE/100 g when using stir-frying. Kinetics followed similar curves in all cases but resulted in different final TPC and TFC. The shape of the kinetics curves suggests zero-order kinetics. The mathematical relations and the numerical approach used to model the kinetics of polyphenol and flavonoid contents in Molokheiya are described.

Keywords: Corchorus olitorius, Molokheiya, phenolic compounds, kinetic

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Authors: Serier Bouchenak NORA, Bouguerni ABDELMADJID

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Algeria is a Mediterranean country which provides an ideal habitat for a wide range of species of medicinal plants. The objective of this current work is to extract the gel contained in the leaves of Aloe vera in order to formulate an oral gel as a prebiotic and see its effects on probiotics (lactic and pseudo lactic bacteria and bifido bacterium). Aloe vera polysaccharid extract is a matrix mainly composed of non-digestible oligosaccharids or slow-fermentation polysaccharids, as this produces a lower pH. The behavior of Aloe vera during in vitro fermentation of the colon was similar to that of lactulose, indicating the possibility of using Aloe vera and its polysaccharids extracts as a prebiotic. The microbiological control of the two kinds of bacteria (bifidobacteria and staphylococci) has demonstrated the gel capacity to stimulate them by these bioactive compounds. The generation time of Bifidobacteria in fermented milk with added prebiotic Aloe vera gel is 80.408 min with a µ growth rate equal to 0.012 min -1. The doubling time is 61.459 min with a growth rate µ equal to 0.016 min -1 for the Streptococcus sp. species.

Keywords: aloe vera, probiotics, prebiotics, growth rate, bifidobacteria

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Authors: V. Hakimzadeh, M. Noori, M. maleki

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The aim of this study was to determine the composition and antimicrobial effect of Mentha piperita essential oil in "in-vitro" condition. The chemical composition of the essential oil obtained by hydro-distillation was examined by GC/MS and the antimicrobial effect was studied on the growth of seven microbial species including Bacillus cereus, Pseudomonas aeruginosa and Proteus vulgaris using micro-dilution method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Chemical composition analysis identified a total of 28 compounds in which the main components were menthol (32%), mentone (13.4), menthyl acetate (12%), 1,8-cineole (8.2%) and neomenthol (4%) representing 69.6 % of the total oil. Other separated components accounted for less than 30.4% of the oil. Results of antimicrobial analysis showed that the MIC values for Bacillus cereus, Pseudomonas aeruginosa and Proteus vulgaris was respectively 50, 200 and 100 µg/ml and the MBC was determined at 200, 400 and 200 µg/ml respectively. The results of the present study indicated that Mentha piperita essential oil had significant antimicrobial activity.

Keywords: antimicrobial activity, essential oil composition, Mentha piperita

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Authors: W. Mazari, K. Boucherit, Z. Boucherit-Otmani, M. N. Rahmoun, M. Benabdallah

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The hospital or any other establishment of care can be considered as an ecosystem where the patient comes into contact with a frightening microbial universe and a risk to contract infection that is referred to as nosocomial or health care-associated. In these last years, the incidence of these infections has risen sharply. Several microorganisms are the cause of these nosocomial infections and the emergence of resistance of the microbial strains against antibiotics creates a danger to public health. The search for new antimicrobial agents to overcome this problem has produced interesting compounds through chemical synthesis, which plays a very important role in the research and discovery of new drugs. It is in this framework that our study was conducted at our laboratory and it involves evaluating the antibacterial activity of thirteen 2-pyridone derivatives synthesized by two methods, the diffusion disc method and the dilution method against eight Gram negative bacterial strains. The results seem interesting especially for two products that have shown the best activities against Escherichia coli ATCC 25922 and Enterobacter cloacae ATCC 13047 with CMI of 512µg/ml.

Keywords: heterocyclic derivatives, chemical synthesis, antimicrobial activity, biotechnology

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Authors: Apurva Singh, Naseem Ahmed

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Dual functional manganese complex compelling with 2-hydrazineylpyridine moiety as ligand relevant to the activity of galactose oxidase enzyme is synthesized. Single crystal XRD and EPR studies showed both Manganese-centers are in +2 oxidation states with μ-Chlorido-bridged between them. The catalysts have maintained stability even at 300°C temperature, as demonstrated through TGA analysis. PXRD and XPS studies were used to further characterize the catalyst structure. The catalyst (Mn-C₁) is highly efficient in the selective dehydrogenative oxidation of alcohols in the presence of oxidant 30 % aq. H₂O₂ through a radical pathway. Likewise, the catalysts (Mn-C₁ and Mn-C₄) were efficiently used in the synthesis of β-hydroxy carbonyl compounds (aldol products) and chalcones up to 90% and 95% yield, respectively, at different temperatures via C-H bond activation. Both benzylic and aliphatic substrates are explored, having functional group tolerance.

Keywords: manganese-based 2-hydrazineylpyridine complex, β-hydroxy carbonyl product, free-radical reaction, dehydrogenative oxidation, Lewis acidity

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Authors: Zhichao Li

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This project has treated the waste-water that contains the nitrogen heterocyclic aromatic hydrocarbons, by using the phenol-induced microbial communities. The treatment of nitrogen heterocyclic aromatic hydrocarbons is a difficult problem for coking waste-water treatment. Pyridine, quinoline and indole are three kinds of most common nitrogen heterocyclic compounds in the f, and treating these refractory organics biologically has always been a research focus. The phenol-degrading bacteria can be used in the enhanced biological treatment effectively, and has a good treatment effect. Therefore, using the phenol-induced microbial communities to treat the coking waste-water can remove multiple pollutants concurrently, and improve the treating efficiency of coking waste-water. Experiments have proved that the phenol-induced microbial communities can degrade the nitrogen heterocyclic ring aromatic hydrocarbon efficiently.

Keywords: phenol, nitrogen heterocyclic aromatic hydrocarbons, phenol-degrading bacteria, microbial communities, biological treatment technology

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Authors: Anna Kolanowska, Anna Kuziel, Sławomir Boncel

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Carbon nanotubes (CNTs) represent a combination of lightness and nanoscopic size with high tensile strength, excellent thermal and electrical conductivity. By now, CNTs have been used as a support in heterogeneous catalysis (CuCl anchored to pre-functionalized CNTs) in the Ullmann-type coupling with aryl halides toward formation of C-N and C-O bonds. The results indicated that the stability of the catalyst was much improved and the elaborated catalytic system was efficient and recyclable. However, CNTs have not been considered as the substrate itself in the Ullmann-type reactions. But if successful, this functionalization would open new areas of CNT chemistry leading to enhanced in-solvent/matrix nanotube individualization. The copper-catalyzed Ullmann-type reaction is an attractive method for the formation of carbon-heteroatom and carbon-carbon bonds in organic synthesis. This condensation reaction is usually conducted at temperature as high as 200 oC, often in the presence of stoichiometric amounts of copper reagent and with activated aryl halides. However, a small amount of organic additive (e.g. diamines, amino acids, diols, 1,10-phenanthroline) can be applied in order to increase the solubility and stability of copper catalyst, and at the same time to allow performing the reaction under mild conditions. The copper (pre-)catalyst is prepared by in situ mixing of copper salt and the appropriate chelator. Our research is focused on the application of Ullmann-type reaction for the covalent functionalization of CNTs. Firstly, CNTs were chlorinated by using iodine trichloride (ICl3) in carbon tetrachloride (CCl4). This method involves formation of several chemical species (ICl, Cl2 and I2Cl6), but the most reactive is the dimer. The fact (that the dimer is the main individual in CCl4) is the reason for high reactivity and possibly high functionalization levels of CNTs. This method, indeed, yielded a notable amount of chlorine onto the MWCNT surface. The next step was the reaction of CNT-Cl with three substrates: aniline, iodobenzene and phenol for the formation C-N, C-C and C-O bonds, respectively, in the presence of 1,10-phenanthroline and cesium carbonate (Cs2CO3) as a base. As the CNT substrates, two multi-wall CNT (MWCNT) types were used: commercially available Nanocyl NC7000™ (9.6 nm diameter, 1.5 µm length, 90% purity) and thicker MWCNTs (in-house) synthesized in our laboratory using catalytic chemical vapour deposition (c-CVD). In-house CNTs had diameter ranging between 60-70 nm and length up to 300 µm. Since classical Ullmann reaction was found as suffering from poor yields, we have investigated the effect of various solvents (toluene, acetonitrile, dimethyl sulfoxide and N,N-dimethylformamide) on the coupling of substrates. Owing to the fact that the aryl halides show the reactivity order of I>Br>Cl>F, we have also investigated the effect of iodine presence on CNT surface on reaction yield. In this case, in first step we have used iodine monochloride instead of iodine trichloride. Finally, we have used the optimized reaction conditions with p-bromophenol and 1,2,4-trihydroxybenzene for the control of CNT dispersion.

Keywords: carbon nanotubes, coupling reaction, functionalization, Ullmann reaction

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Authors: Ganesh V., Asit Kumar Khanra

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An in-situ powder metallurgy technique was employed to create Ni-Al3Ni/Al3Ni2 core-shell-shaped aluminum-based intermetallic reinforced composites. The impact of Ni addition on the phase composition, microstructure, and mechanical characteristics of the Al-4Cu-xNi (x = 0, 2, 4, 6, 8, 10 wt.%) in relation to various sintering temperatures was investigated. Microstructure evolution was extensively examined using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscopy (TEM) techniques. Initially, under sintering conditions, the formation of "Single Core-Shell" structures was observed, consisting of Ni as the core with Al3Ni2 intermetallic, whereas samples sintered at 620°C exhibited both "Single Core-Shell" and "Double Core-Shell" structures containing Al3Ni2 and Al3Ni intermetallics formed between the Al matrix and Ni reinforcements. The composite achieved a high compressive yield strength of 198.13 MPa and ultimate strength of 410.68 MPa, with 24% total elongation for the sample containing 10 wt.% Ni. Additionally, there was a substantial increase in hardness, reaching 124.21 HV, which is 2.4 times higher than that of the base aluminum. Nanoindentation studies showed hardness values of 1.54, 4.65, 21.01, 13.16, 5.52, 6.27, and 8.39GPa corresponding to α-Al matrix, Ni, Al3Ni2, Ni and Al3Ni2 interface, Al3Ni, and their respective interfaces. Even at 200°C, it retained 54% of its room temperature strength (90.51 MPa). To investigate the deformation behavior of the composite material, experiments were conducted at deformation temperatures ranging from 300°C to 500°C, with strain rates varying from 0.0001s-1 to 0.1s-1. A sine-hyperbolic constitutive equation was developed to characterize the flow stress of the composite, which exhibited a significantly higher hot deformation activation energy of 231.44 kJ/mol compared to the self-diffusion of pure aluminum. The formation of Al2Cu intermetallics at grain boundaries and Al3Ni2/Al3Ni within the matrix hindered dislocation movement, leading to an increase in activation energy, which might have an adverse effect on high-temperature applications. Two models, the Strain-compensated Arrhenius model and the Artificial Neural Network (ANN) model, were developed to predict the composite's flow behavior. The ANN model outperformed the Strain-compensated Arrhenius model with a lower average absolute relative error of 2.266%, a smaller root means square error of 1.2488 MPa, and a higher correlation coefficient of 0.9997. Processing maps revealed that the optimal hot working conditions for the composite were in the temperature range of 420-500°C and strain rates between 0.0001s-1 and 0.001s-1. The changes in the composite microstructure were successfully correlated with the theory of processing maps, considering temperature and strain rate conditions. The uneven distribution in the shape and size of Core-shell/Al3Ni intermetallic compounds influenced the flow stress curves, leading to Dynamic Recrystallization (DRX), followed by partial Dynamic Recovery (DRV), and ultimately strain hardening. This composite material shows promise for applications in the automobile and aerospace industries.

Keywords: core-shell structure, hot deformation, intermetallic compounds, powder metallurgy

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Authors: Hui-Hsin Huang, Yi-Feng Lin, Che-Chia Hu

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To date, photocatalytic wastewater treatment using solar energy has attracted considerable attention. In this study, strontium titanates with various morphologies, i.e., nanofibers and cubic-like particles, were prepared as photocatalysts using the electrospinning (ES), solid-state (SS), and sol-gel (SG) methods. X-ray diffraction (XRD) analysis showed that ES and SS can be assigned to pure phase SrTiO3, while SG was referred to Sr2TiO4. These samples displayed optical absorption edges at 385-395 nm, indicating they can be activated in UV light irradiation. Scanning electron microscope (SEM) analyses revealed that ES SrTiO3 has a uniform fibrous structure with length and diameter of several microns and 100-200 nm, respectively. After loading of nanoparticulate Ag as a co-catalyst onto the surface of strontium titanates, ES sample exhibited highest photocatalytic activity to degrade methylene orange dye solution in comparison to that of SS and SG ones. These results indicate that Ag-loaded ES SrTiO3, which has a desirable SrTiO3 phase and a facile electron transfer along the preferential direction in fibrous structure, can be a promising photocatalyst.

Keywords: photocatalytic degradation, strontium titanate, electrospinning, co-catalyst

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Authors: Athena Nguyen, Rojin Belganeh

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Detecting and identifying differences in like polymer materials are key factors in failure and deformulation analysis, and reverse engineering. Pyrolysis-GC/MS is an easy solid sample introduction technique which expands the application areas of gas chromatography and mass spectrometry. The Micro furnace pyrolyzer is directly interfaced with the GC injector preventing any potential of cold spot, carryover, and cross contamination. In this presentation, the analysis of the differences in three polystyrene samples is demonstrated. Although the three samples look very similar by Evolve gas analysis (EGA) and Flash pyrolysis, there are indications of small levels of other materials. By performing Thermal desorption-GC/MS, the additive compounds between samples show the differences. EGA, flash pyrolysis, and thermal desorption analysis are the different modes of operations of the micro-furnace pyrolyzer enabling users to perform multiple analytical techniques.

Keywords: Gas chromatography/Mass spectrometry, pyrolysis, pyrolyzer, thermal desorption-GC/MS

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Authors: Li Lu

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This work studies the processing of an all-solid-state sodium-ion battery (ASSB), utilizing sodium vanadium phosphate (NVP) as both the cathode and anode. The solid electrolyte is composed of a polymer matrix combined with nanoscale sodium zirconium phosphosilicate, Na₃Zr₂Si₂PO1₁₂ (NZSP) framework. To effectively enhance the desolvation of sodium salt, NaTFSI in the composite electrolyte, ferroelectric nano-ceramic particles are added to the electrolyte, achieving a high ionic conductivity in the range of 10⁻⁴ to 10⁻³ S/cm at room temperature. The full battery demonstrates impressive cycling performance, maintaining stability over 1000 charge/discharge cycles with minimal degradation. Atomic force microscopy (AFM) is employed to indirectly observe the ion transportation mechanisms within the battery, providing insights into the dynamics of sodium ion (Na⁺) movement. This study highlights the potential of polymer-NZSP composite electrolytes in enhancing the performance and longevity of ASSBs for next-generation energy storage applications.

Keywords: solid-state electrolyte, solid-state battery, composite electrolyte, impedance

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Authors: S. N. Harun, H. Ahmad

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A series of ruthenium(II) complexes, including two novel compounds [Ru(dppz)2(L)]2+ where dppz = dipyrido-[3,2-a:2’,3’-c]phenazine, and L = 2-phenylimidazo[4,5-f][1,10]phenanthroline (PIP) or 2-(4-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline (p-HPIP) have been synthesized and characterized. The previously reported complexes [Ru(bpy)2L]2+ and [Ru(phen)2L]2+ were also prepared. All complexes were characterized by elemental analysis, 1H-NMR spectroscopy, ESI-Mass spectroscopy and FT-IR spectroscopy. The photophysical properties were analyzed by UV-Visible spectroscopy and fluorescence spectroscopy. [Ru(dppz)2(PIP)]2+ and [Ru(dppz)2(p-HPIP)]2+ displayed ‘molecular light-switch’ effect as they have high emission in acetonitrile but no emission in water. The cytotoxicity of all complexes against cancer cell lines Hela and MCF-7 were investigated through standard MTT assay. [Ru(dppz)2(PIP)]2+ showed moderate toxicity on both MCF-7 and Hela with IC50 of 37.64 µM and 28.02 µM, respectively. Interestingly, [Ru(dppz)2(p-HPIP)]2+ exhibited remarkable cytotoxicity results with IC50 of 13.52 µM on Hela and 11.63 µM on MCF-7 cell lines which are comparable to the infamous anti-cancer drug, cisplatin. The cytotoxicity of this complex series increased as the ligands size extended in order of [Ru(bpy)2(L)]2+ < [Ru(phen)2(L)]2+ < [Ru(dppz)2(L)]2+.

Keywords: ruthenium, cytotoxicity, molecular light-switch, anticancer

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Authors: S. Krimat, T. Dob, L. Lamari, H. Metidji

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The aim of this study is to evaluate the antioxidant and antimicrobial activity of hydromethanolic extract of selected Algerian medicinal flora. The antioxidant activity of extract was evaluated in terms of radical scavenging potential (DPPH) and β-carotene bleaching assay. Total phenolic contents and flavonoid contents were also measured. Antimicrobial activity of these plants was tested against five microorganisms Pseu-domonas aeruginosa Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Candida albicans. The results showed that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay (IC50 = 4.60 μg/ml), while Populus trimula had the highest antioxidant activity in β-carotene/linolaic acid assay. The most interesting antimicrobial activity was obtained from Sysimbrium officinalis, Rhamnus alaternus, Origanum glandulosum, Cupressus sempervirens, Pinus halipensis and Centaurea calcitrapa. The results indicate that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.

Keywords: Algerian medicinal plants, antimicrobial activity, antioxidant activity, disc diffusion method

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Authors: Hakim Aguedal, Abdelkader Iddou, Abdalla Aziz, Abdelhadi Bentouami, Ferhat Bensalah, Salah Bensadek

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The major environmental risk of soil pollution is the contamination of groundwater by infiltration of organic and inorganic pollutants that can cause a serious pollution. To prevent the migration of this pollution through this structure, many studies propose the installation of layers, which play a role of a barrier that inhibiting the contamination of groundwater by limiting or slowing the flow of rainwater carrying pollution through the layers of soil. However, it is practically impossible to build a barrier layer that let through only water, but it is possible to design a structure with low permeability, which reduces the infiltration of dangerous pollutant. In an environmental context of groundwater protection, the main objective of this study was to investigate the environmental and appropriate suitability method to preserve groundwater, by establishment of a permeable reactive barrier (PRB) intermediate in soil. Followed the influence of several parameters allow us to find the most effective materials and the most appropriate way to incorporate this barrier in the soil.

Keywords: Ground water, protection, permeable reactive Barrier, soil pollution.

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Authors: R. S. Fisca, Y. R. Elox, L. Umi, U. Z. Luttfia, Kun Harismah

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Petai (Parkia speciosa) is a plant indigenous to Southeast Asia. It is consumed either raw or cooked. It has been used in folk medicine to treat diabetes, hypertension, and kidney problems. It contains minerals and vitamins. Petai contains a lot of chemical compounds that are beneficial for health, including antioxidants, Vitamin B6 0,9mg, energy 142 g. cal, 10.4 g protein. 2 g fat, 22 g carbohydrates, 95 mg calcium, phosphorus 115 mg, 1 mg iron, 200 IU of vitamin A, vitamin B1 0.17 mg, 36 mg of vitamin C that can resolve various health problems. These chips are the result of innovation from petai packaged in such a way becomes a tasty snack chips and can be enjoyed by many people to relax and also nutritious for health. In the manufacture of petai chips require several steps of them start by boiling, flating, drying and the last frying. In introducing the products widely we sell petai chips with several methods. Some of these methods include direct sales, delivery order, online/social media, and open some booth at a few places and the car free day in Solo every sunday. Opportunity in selling petai chips is very wide because there is no competitors with similar business. With the innovation of petai chips become healthy snacks can be introduced to the public and can even be exported out of the country as one of the extraordinary snacks from Indonesia.

Keywords: antioxidants, chips, healty, petai

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Authors: Nisha Sharma, Mili Kaur, Ashutosh Halder, Seema Kaushal, Manoj Kumar, Manish Jain

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Purpose: To investigate microRNAs (miRNA) as an epigenomic etiological factor in idiopathic non-obstructive azoospermia (NOA). In order to achieve the same, an association was seen between occupational exposure to radiation, thermal, and chemical factors and idiopathic cases of non-obstructive azoospermia, and later, testicular differential miRNA expression profiling was done in exposure group NOA cases. Method: It is a prospective study in which 200 apparent idiopathic male factor infertility cases, who have been advised to undergo testicular fine needle aspiration (FNA) evaluation, are recruited. A detailed occupational history was taken to understand the possible type of exposure due to the nature and duration of work. A total of 26 patients were excluded upon XY-FISH and Yq microdeletion tests due to the presence of genetic causes of infertility, 6 hypospermatogeneis (HS), six Sertoli cell-only syndrome (SCOS), and six normospermatogeneis patients testicular FNA samples were used for RNA isolation followed by small RNA sequencing and nCounter miRNA expression analysis. Differential miRNA expression profile of HS and SCOS patients was done. A web-based tool, miRNet, was used to predict the interacting compounds or chemicals using the shortlisted miRNAs with high fold change. The major limitation encountered in this study was the insufficient quantity of testicular FNA sample used for total RNA isolation, which resulted in a low yield and RNA integrity number (RIN) value. Therefore, the number of RNA samples admissible for differential miRNA expression analysis was very small in comparison to the total number of patients recruited. Results: Differential expression analysis revealed 69 down-regulated and 40 up-regulated miRNAs in HS and 66 down-regulated and 33 up-regulated miRNAs in SCOS in comparison to normospermatogenesis controls. The miRNA interaction analysis using the miRNet tool showed that the differential expression profiles of HS and SCOS patients were associated with arsenic trioxide, bisphenol-A, calcium sulphate, lithium, and cadmium. These compounds are reproductive toxins and might be responsible for miRNA-mediated epigenetic deregulation leading to NOA. The association between occupational risk factor exposure and the non-exposure group of NOA patients was not statistically significant, with ꭓ2 (3, N= 178) = 6.70, p= 0.082. The association between individual exposure groups (radiation, thermal, and chemical) and various sub-types of NOA is also not significant, with ꭓ2 (9, N= 178) = 15.06, p= 0.089. Functional analysis of HS and SCOS patients' miRNA profiles revealed some important miR-family members in terms of male fertility. The miR-181 family plays a role in the differentiation of spermatogonia and spermatocytes, as well as the transcriptional regulation of haploid germ cells. The miR-34 family is expressed in spermatocytes and round spermatids and is involved in the regulation of SSCs differentiation. Conclusion: The reproductive toxins might adopt the miRNA-mediated mechanism of disease development in idiopathic cases of NOA. Chemical compound induced; miRNA-mediated epigenetic deregulation can give a future perspective on the etiopathogenesis of the disease.

Keywords: microRNA, non-obstructive azoospermia (NOA), occupational exposure, hypospermatogenesis (HS), Sertoli cell only syndrome (SCOS)

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Authors: Mehmet Durnali

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The main purpose of this study is to find out, analyze and discuss basic principles of education and training in the constitutions, including the latest amendment, of France, Indonesia, Japan, South Africa, the United States of America, and Turkey. This research specifically aims at establishing a framework in order to compare educational values such as right of education, responsibilities of states and those of people, and other issues pertaining to education in the Constitution of Turkey to others. Additionally, it emphasizes the meaning of education in constitution, the reasons for references to education in constitutions and why it is important for people, states or nations and state organs. Qualitative analysis technique is performed to accomplish the aim of this study. Maximum variation sampling is used. The main data source of the analysis is official organic laws of those countries. The data is examined by using descriptive and content analysis method.

Keywords: education in the constitution, education law, legal principles of education, right to education

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Authors: Tsegay Kahsay Gebrekidan, Gebremariam Gebrezgabher Gebremedhin, Abraha Kahsay Weldemariam, Meaza Kidane Teferi

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Municipal solid waste management (MSWM) in Ethiopia is a complex issue with institutional, social, political, environmental, and economic dimensions, impacting sustainable development. Effective MSWM planning necessitates understanding the generation rate and composition of waste. This systematic review synthesizes qualitative and quantitative data from various sources to aggregate current knowledge, identify gaps, and provide a comprehensive understanding of municipal solid waste management in Ethiopia. The findings reveal that the generation rate of municipal solid waste in Ethiopia is 0.38 kg/ca/day, with the waste composition being predominantly food waste, followed by ash, dust, and sand, and yard waste. Over 85% of this MSW is either reusable or recyclable, with a significant portion being organic matter (73.13% biodegradable) and 11.78% recyclable materials. Physicochemical analyses reveal that Ethiopian MSW is suitable for composting and biogas production, offering opportunities to reduce environmental pollution, and GHGs, support urban agriculture, and create job opportunities. However; challenges persist, including a lack of political will, weak municipal planning, limited community awareness, and inadequate waste management infrastructure, and only 31.8% of MSW is collected legally, leading to inefficient and harmful disposal practices. To improve MSWM, Ethiopia should focus on public awareness; increased funding, infrastructure investment, private sector partnerships, and implementing the 4 R principles (reduce, reuse, and recycle). An integrated approach involving government, industry, and civil society is essential. Further research on the physicochemical properties and strategic uses of MSW is needed to enhance management practices. Implications: The comprehensive study of municipal solid waste management (MSWM) in Ethiopia reveals the intricate interplay of institutional, social, political, environmental, and economic factors that influence the nation’s sustainable development. The findings underscore the urgent need for tailored, integrated waste management strategies that are informed by a thorough understanding of MSW generation rates, composition, and current management practices. Ethiopia’s lower per capita MSW generation compared to developed countries and the predominantly organic composition of its waste present significant opportunities for sustainable waste management practices such as composting and recycling. These practices can not only minimize the environmental impact but also support urban greening, agriculture, and renewable energy production. The high organic content, suitable physicochemical properties of MSW for composting, and potential for biogas and briquette production highlight pathways for creating employment, reducing waste, and enhancing soil fertility. Despite these opportunities, Ethiopia faces substantial challenges due to inadequate political will, weak municipal planning, limited community awareness, insufficient waste management infrastructure, and poor policy implementation. The high rate of illegal waste disposal further exacerbates environmental and health issues, emphasizing the need for a more effective and integrated MSWM approach. To address these challenges and harness the potential of MSW, Ethiopia must prioritize increasing public awareness; investing in infrastructure, fostering private sector partnerships, and implementing the principles of reduce, reuse, and recycle (3 R). Developing strategies that involve all stakeholders and turning waste into valuable resources is crucial. Government, industry, and civil society must collaborate to implement integrated MSWM systems that focus on waste reduction at the source, alternative material use, and advanced recycling technologies. Further research at both federal and regional levels is essential to optimize the physicochemical analysis and strategic use of MSW. Prompt action is required to transform waste management into a pillar of sustainable urban development, ultimately improving environmental quality and human health in Ethiopia.

Keywords: biodegradable, healthy environment, integrated solid waste management, municipal

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Authors: Pervin Basaran Akocak

Abstract:

Food antimicrobials are compounds that are incorporated into food matrixes in order to cause death or delay the growth of spoilage or pathogenic microorganisms. As a result, microbiological deterioration is prevented throughout storage and food distribution. In this study, the effect of natural antimycotic natamycin (C33H47NO13, with a molecular mass of 665.725), a GRAS (Generally Recognized As Safe) commercial compound produced by different strains of Streptomyces sp., was tested against various fermented food contamination fungi and yeast species. At the concentration of 100 µg/ml, natamycin exhibited stronger antifungal activity against fungi than yeast species tested. The exposure time of natamycin for complete inhibition of the species tested were found to be between 100-180 min at 300-750 µg/ml concentration. SEM observations of fungal species demonstrated that natamycin distorted and damaged the conidia and hyphae by inhibiting spore germination and mycelial growth. Natamycin can be considered as a potential candidate in hurdle food treatments for preventing fungal and yeast invasion and resulting deterioration of fermented products.

Keywords: natamycin, antifungal, fermented food, food spoilage fungi

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Authors: Tomasz Borowski, Dawid Sołoducha, Rafał Rakoczy, Marian Kordas

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The growing interest in magnetic fields applications is visible due to the increased number of articles on this topic published in the last few years. In this study, the influence of various magnetic fields (MF) on the mass transfer process was examined. To carry out the prototype set-up equipped with an MF generator that is able to generate a pulsed magnetic field (PMF), oscillating magnetic field (OMF), rotating magnetic field (RMF) and static magnetic field (SMF) was used. To demonstrate the effect of MF’s on mass transfer, the calcium carbonate precipitation process was selected. To the vessel with attached conductometric probes and placed inside the generator, specific doses of calcium chloride and sodium carbonate were added. Electrical conductivity changes of the mixture inside the vessel were measured over time until equilibrium was established. Measurements were conducted for various MF strengths and concentrations of added chemical compounds. Obtained results were analyzed, which allowed to creation of mathematical correlation models showing the influence of MF’s on the studied process.

Keywords: mass transfer, oscillating magnetic field, rotating magnetic field, static magnetic field

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