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  • MDPI  (56,387)
  • 2015-2019  (56,387)
  • 1950-1954
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  • 1
    Publication Date: 2019
    Description: The aim of the work was to determine the influence of salicylic acid (SA) oxidation products on the effectiveness of their further removal in the membrane filtration process. Two commercial polyamide-based polymer membranes, HL (GE Osmonics) and TS80 (TriSepTM), were used and characterized by SEM microscopic analysis, contact angles, and free surface energy. The products of salicylic acid oxidation, 2,3- and 2,5-dihydroxybenzoic acid and catechol, were determined and their impact on the removal of unreacted salicylic acid in the nanofiltration process was investigated. It was also checked to what extent and why they were retained or not by the membranes. The results of the research have shown that the main product of salicylic acid oxidation, 2,3-dihydroxybenzoic acid, has a negative impact on the retention of salicylic acid in the nanofiltration stage, while the other product, catechol, improves SA retention. The determined values of contact angles correlate well with solubility (S) of the tested compounds, which increases in the following order SSA 〈 S2,3-DHBA 〈 SCAT, while the contact angle of the membrane decreases. Nevertheless, it has been shown that some oxidation products can penetrate the environment due to poorer membrane separation properties of these products.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 2
    Publication Date: 2019
    Description: Recently, there has been an increased interest in exploring periodic structures having higher symmetry properties, primarily based on metallic realization. The design of dielectric glide-symmetric structures has many challenges, and this paper presents a systematic analysis approach based on Floquet mode decomposition and mode matching technique. The presented procedure connects the analysis of standard periodic structures and glide-symmetric realizations, thus giving insight into the wave propagation and interaction characteristics. The obtained results were verified in comparison with results from known references and using a commercial solver, proving that the proposed analysis technique is inherently accurate, and the degree of accuracy depends only on the number of modes used. The proposed analysis approach represents the first step in the design process of dielectric periodic structures with glide symmetry.
    Electronic ISSN: 2073-8994
    Topics: Mathematics
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  • 3
    Publication Date: 2019
    Description: Background: The aim of this study was to examine the effect of dietary education on glycemic control in patients with any type of diabetes at four-week and two-year follow-ups. Methods: A two-year prospective study was conducted in three phases: before, four weeks after, and two years after an educational program. The participants were patients diagnosed with diabetes who were receiving insulin or oral hypoglycemics and who attended the Diabetes Clinic of the General County Hospital Našice, Croatia to receive their treatment. The questionnaire and educational program were created for the purpose of this study. Measurements were made (fasting blood glucose, glycated hemoglobin, body mass index, blood pressure, knowledge test) at baseline, four weeks and two years after education. Results: A total of 109 participants took part in the study, of which 56 (51.4%) were on insulin therapy and 53 (48.6%) were on oral therapy, after two years, 78 (72%) subjects were followed up with. There was no control group. At the two-year follow-up, participants with insulin therapy had significantly higher glycated hemoglobin (Mann–Whitney U test, p = 0.035). Significant differences were observed in fasted blood glucose (Friedman’s test, p = 0.001), diastolic pressure (Friedman’s test, P = 0.018), and glycated hemoglobin (Wilcoxon test, p 〈 0.001) between Phase 1 and Phase 3. Conclusions: Education has a positive effect on adherence to recommended diet and glycemia regulation in diabetes patients after four-week follow-ups. However, after two years, participants showed a decrease in adherence to recommended diet and increased glycemia.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 4
    Publication Date: 2019
    Description: Interesting aesthetic properties of tropical woods, like surface texture and colour, are rarely impaired due to weathering, rotting and other degradation processes. This study analyses the colour of 21 tropical woods before and after six weeks of intentional attack by the brown-rot fungus Coniophora puteana. The CIEL*a*b* colour system was applied for measuring the lightness, redness and yellowness, and from these parameters the hue tone angle and colour saturation were calculated. Lighter tropical woods tended to appear a less red and a more yellow, and had a greater hue tone angle. However, for the original woods was not found dependence between the lightness and colour saturation. Tropical woods at attack by C. puteana lost a weight from 0.08% to 6.48%. The lightest and moderately light species—like okoumé, iroko, ovengol and sapelli—significantly darkened, while the darkest species—wengé and ipé—significantly lightened. The majority of tropical woods obtained a brighter shade of yellow, typically wengé, okoumé and blue gum, while some of them also a brighter shade of green, typically sapelli, padouk and macaranduba. C. puteana specifically affected the hue tone angle and colour saturation of tested tropical woods, but without an apparent changing the tendency of these colour parameters to lightness. The total colour difference of tested tropical woods significantly increased in connection with changes of their lightness (ΔE*ab = 5.92 − 0.50·ΔL*; R2 = 0.37), but it was not influenced by the red and yellow tint changes, and weight losses.
    Electronic ISSN: 1999-4907
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 5
    Publication Date: 2019
    Description: Nigeria is one of the most dynamic economies in Africa. Strong GDP and population growth coupled with urbanization trends place tremendous pressures on natural resources and the food systems that are dependent on them. Understanding the impact of these “mega trends” is important to identify key leverage points for navigating towards improved nutrition and food security in Nigeria. This paper contributes to the Foresight Project of the Food Systems for Healthier Diets which aims to analyse how the food system in Nigeria is expected to transform in the next decades, and to identify the leverage points for making sure that the transformation contributes to balanced consumer diets. For the food systems foresight, a well-established global economy-wide model, MAGNET, is applied that enables to capture the interlinkages among different food industry players in one consistent framework. By linking MAGNET to the GENUS nutritional database, it is further possible to relate the developments occurring on a macro-level with detailed macro and micronutrient consumption. Model projections suggest that a process of intensification of agriculture in combination with land substitution appears critical for the evolution of food and nutrition security, and for shifts towards healthy diets for the population. Intensification results in greater diversity of the production systems, which in turn cascades into positive effects on the diversity in the food supply and better food security outcomes.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 6
    Publication Date: 2019
    Description: The way in which European genetic variants of Anaplasma phagocytophilum circulate in their natural foci and which variants cause disease in humans or livestock remains thus far unclear. Red deer and roe deer are suggested to be reservoirs for some European A. phagocytophilum strains, and Ixodes ricinus is their principal vector. Based on groEL gene sequences, five A. phagocytophilum ecotypes have been identified. Ecotype I is associated with the broadest host range, including strains that cause disease in domestic animals and humans. Ecotype II is associated with roe deer and does not include zoonotic strains. In the present study, questing I. ricinus were collected in urban, pasture, and natural habitats in the Czech Republic, Germany, and Slovakia. A fragment of the msp2 gene of A. phagocytophilum was amplified by real-time PCR in DNA isolated from ticks. Positive samples were further analyzed by nested PCRs targeting fragments of the 16S rRNA and groEL genes, followed by sequencing. Samples were stratified according to the presence/absence of roe deer at the sampling sites. Geographic origin, habitat, and tick stage were also considered. The probability that A. phagocytophilum is a particular ecotype was estimated by a generalized linear model. Anaplasma phagocytophilum was identified by genetic typing in 274 I. ricinus ticks. The majority belonged to ecotype I (63.9%), 28.5% were ecotype II, and both ecotypes were identified in 7.7% of ticks. Ecotype II was more frequently identified in ticks originating from a site with presence of roe deer, whereas ecotype I was more frequent in adult ticks than in nymphs. Models taking into account the country-specific, site-specific, and habitat-specific aspects did not improve the goodness of the fit. Thus, roe deer presence in a certain site and the tick developmental stage are suggested to be the two factors consistently influencing the occurrence of a particular A. phagocytophilum ecotype in a positive I. ricinus tick.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 7
    Publication Date: 2018
    Description: Careful conceptualization and differentiation of both spirituality and religiosity is a necessary precondition for understanding the potential role they play in health, whether physical or mental. The aim of this study was to explore the associations of spirituality with self-rated health, health complaints, and life satisfaction of adolescents with the moderating role of religiosity. Data from the Health Behaviour in School-aged Children study conducted in 2014 in Slovakia were used. The final sample consisted of 658 adolescents (mean age = 15.37; 50.6% boys). Data regarding spirituality, religiosity, self-rated health, health complaints, and life satisfaction were obtained. Binary logistic models revealed spirituality to be associated with self-rated health, health complaints, and life satisfaction. A moderating role of religiosity was not confirmed. The presented findings indicate the need to distinguish between the concepts of religiosity and spirituality in connection with subjective health and life satisfaction.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 8
    Publication Date: 2019
    Description: This work analyses a two-terminal algorithm designed to locate unsymmetrical faults on 110 kV power transmission lines. The algorithm processes synchronized voltage and current data obtained from both ends of the protected transmission line and calculates the distance of the fault. It is based on decomposing the equivalent circuit into the positive-, negative- and zero-sequence components and finding the point where the output voltages of the right and the left side of the transmission line are equal. Compared to the conventional distance relay locator, the accuracy of this method is higher and less influenced by the fault resistance, the parallel-operated line effect and line asymmetry, as discussed in this work. It is, however, very sensitive to the synchronization accuracy. The mathematical model of the power system was created in the PSCAD (Power Systems Computer Aided Design) environment and the computational algorithm was implemented in Mathematica software.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 9
    Publication Date: 2019
    Description: Through analyzing the concentrations of selected heavy metals (Ba, Mn, Pb, Sr, Zn) in the bones and teeth of wild living and ecologically equivalent ruminants from the Tian-Shan (Capra sibirica and Ovis ammon polii) and the West Carpathians (Rupicapra rupicapra tatrica) we compared the environmental pollution levels of these two mountain ranges. The samples were analyzed by X-ray fluorescence. Significantly higher contents of Zn and Mn as well as a higher frequency of measurable occurrences of Mn, Ba, and Pb in samples from the West Carpathians confirmed the results of our previous study, that the West Carpathians are relatively more polluted by heavy metals than the Tian-Shan Mountains. The most probably contamination sources are mining and smelting as well as traffic emissions, which can reach remote mountain ranges through long distance atmospheric transport.
    Electronic ISSN: 2073-4433
    Topics: Geosciences
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  • 10
    Publication Date: 2019
    Description: A simple, novel approach is proposed for the preparation of plasma-exfoliated graphene (PEGN) by reducing graphene oxide (GO) through a dielectric-barrier discharge (DBD) plasma treatment in a H2 atmosphere. The surface chemistry, microstructures, and crystallinity of the prepared samples were characterized via X-ray photoelectron spectroscopy, transmission electron microscopy, and Raman spectrometry to determine the formation mechanism of the PEGN. The results demonstrated that the prepared PEGN had only a few layers in its structure and that most of the functional groups containing oxygen on the GO surface were removed. The PEGN exhibited a considerably higher capacity, better cycling stability, and favorable electron transfer rate for use as a cathode material for lithium-ion batteries. This proposed approach is fast, convenient, and inexpensive, constituting a novel means of producing graphene.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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