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Publikacije (48465)

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Ema Obralić, S. Ćatić, A. Odobašić, I. Šestan

: Construction materials in the form of any products are subject to unintentional or harmful changes, occurrences and processes that reduce their usability. The destruction of construction materials is aimed to be slowed down or prevented by measures and procedures of a special technological discipline - material protection, which is usually called surface protection, since harmful occurrences and processes mostly begin on the surface of the product. In addition to the many protective methods that are used, corrosion inhibitors have a special place due to their specificity and widespread use. Based on the performed tests and their analysis, it was determined that the inhibition efficiency obtained by electrochemical measurements is in good correlation with the results obtained by the FTIR method. Impedance measurements of steel St 37-4 Pectin C in the tested media show corrosion resistance. Pectin C in 3.5% HCl at a concentration of 2.0 g / l increases the value of the charge transfer resistance and the increases of the size of the absolute impedance in the Bode diagram, which further confirms the improved resistance to corrosion of steel.

A. Odobašić, Melisa Ahmetović, I. Šestan, Edmira Salihović, Amna Karić

Water quality is deteriorating over the years, and the main source of water pollution is industrial, agricultural and municipal wastewater. Heavy metals, organic compounds and microorganisms, present even in traces, can be very dangerous to human health, aquatic organisms and the environment. Therefore, in this study was investigate the possibility of modified and unmodified plum pits as biosorbents for Pb (II) ions removal from aqueous solution. Experimental data have shown that these bisorbents show a certain potential for application in the metal removal process. The feasibility was tested for an unmodified and modified biosorbent based on plum pits in the range of concentrations 150-200 mg/l (unmodified sample) and 100-200 mg/l (modified sample) at a contact time of 30 and 60 minutes . Adsorption parameters were determined using the Freundlich isotherm. The results showed that unmodified biosorbent based on plum pits with increasing concentration from 150 mg/L to 200 mg/L leads to a large increase in the percentage of removal of Pb (II) ions, with no significant effect on contact time. In contrast to the unmodified sample, the modified biosorbent based on plum pits % of removed Pb (II) ions significantly increases the contact time at the initial Pb (II) concentration of 100 mg/L, while at the initial concentration of 150 mg/L and longer mixing, the removal efficiency increases and amounts to 86.032 %. The calculated values of the parameters used in the Freundlich isotherm indicated the existence of high-energy sorption centers in the unmodified bisorbent based on plum pits, while the calculated values of the parameters used in the Freundlich isotherm for the modified biosorbent based on plum pits showed moderate mode adsorption.

In this study, metal complex of Copper(II) with a Schiff base derived from 2,2-dihydroxyindane-1,3-dione and 2-aminoethanoic acid were synthesized. The product are characterized by spectral methods. The antimicrobial activity was tested on reference bacterial strains and the antioxidant capacity was analyzed by using the DPPH and FRAP methods. The spectral data indicates that the Schiff base coordinates the Copper(II) as a tridentate ONO donor ligand. The compounds showed weaker antimicrobial activity on certain tested microorganisms. In vitro testing of antioxidant activity showed a significant reducing ability of the complex, as well as inhibitory activity against DPPH radicals.

In this study, the chemical profiles, antioxidant and antibacterial activity of Helivhrysum italicum essential oils from three plantation fields in Herzegovina were analysed. GC/MS analysis showed that all samples were rich in sesquiterpenes (45.19%-50.07%) and monoterpenes (21.15%-23.21%), followed by oxygenated monoterpenes (9.92%-14.03%). Diketones in the essential oil were detected in quantities ranging 5.72% to 6.67%. The main components in essential oils were γ-curcumene, α-pinene, β-selinene and neril-acetate. All tested essential oils exhibited relatively weak DPPH-scavenging capacity. The antimicrobial activity of the essential oil was assayed by using the disk diffusion method. E. coli was most resistant against all three tested H. italicum essential oils, while moderate inhibitory activity against S. aureus and C. albicans was detected. The L. monocytogenes was the most sensitive where all three tested samples showed inhibitory activity.

E. Begić, M. Causevic

Prevention of cardiovascular events and regression of atherosclerotic changes are the primary aims of preventive cardiovascular medicine. Arterial thrombosis is caused by endothelial dysfunction, which disrupts vascular haemostasis. Glucagon-like peptide 1 (GLP-1) receptor agonists have been initially used as glucose lowering agents, but over time have been used for other indications due to their cardiorenal benefit, as well as their benefit in the regression of atherosclerosis process. The aim of this paper is to present the benefits of GLP-1 receptor agonists in the prevention of atherosclerotic changes, in the preservation of brain vascular function, and to show the possible role in the treatment of neurodegenerative diseases.

A. Mesic, Marija Rogar, P. Hudler, N. Bilalović, Izet Eminovic, R. Komel

Glioblastoma multiforme (GBM) is the most frequent type of primary astrocytomas. We examined the association between single nucleotide polymorphisms (SNPs) in Aurora kinase A (AURKA), Aurora kinase B (AURKB), Aurora kinase C (AURKC) and Polo-like kinase 1 (PLK1) mitotic checkpoint genes and GBM risk by qPCR genotyping. In silico analysis was performed to evaluate effects of polymorphic biological sequences on protein binding motifs. Chi-square and Fisher statistics revealed a significant difference in genotypes frequencies between GBM patients and controls for AURKB rs2289590 variant (p = 0.038). Association with decreased GBM risk was demonstrated for AURKB rs2289590 AC genotype (OR = 0.54; 95% CI = 0.33–0.88; p = 0.015). Furthermore, AURKC rs11084490 CG genotype was associated with lower GBM risk (OR = 0.57; 95% CI = 0.34–0.95; p = 0.031). Bioinformatic analysis of rs2289590 polymorphic region identified additional binding site for the Yin-Yang 1 (YY1) transcription factor in the presence of C allele. Our results indicated that rs2289590 in AURKB and rs11084490 in AURKC were associated with a reduced GBM risk. The present study was performed on a less numerous but ethnically homogeneous population. Hence, future investigations in larger and multiethnic groups are needed to strengthen these results.

Vedad Burgic, Dino Kečo

Nowadays there are ham and spam messages that are sent to the users via SMS. The aim of this article is to show how machine learning and text processing technologies can be used in order to predict the trustworthiness of SMS messages. The data we are going to use is collected from Kaggle. This study is very important because it helps us to understand how machine learning and text processing can be used in order to predict message trustworthiness. At the time of writing this article, there was not an article explaining how this can be done using the Multinomial Naive Bayes algorithm. The methodology we used in this article consists of dataset collection, data cleaning, data analysis, text preparation, and training model. This will be seen in the methodology section in great detail. At the end of this article, we will show to u the accuracy that we have got when implementing a Multinomial Naive Bayes algorithm for the classification of SMS messages. This study was quite beneficial because anyone can see how Multinomial Naive Bayes algorithm usage can be beneficial in order to predict the trustworthiness of SMS messages.

A. Manjunath, Sabahudin Vrtagic, F. Doğan, M. Dordevic, M. Žarković, Jasmin Kevric, G. Dobrić

This research paper deals with the problem of Metal-Oxide Surge Arrester (MOSA) condition monitoring and a new methodology in surge arrester monitoring and diagnostics is presented. A machine learning algorithm (back propagation regression) is used to estimate the non-linearity coefficient of the surge arrester, based on operating voltage and leakage current of the arrester. Using a simulated system, this research investigates the possibility of application and efficiency of machine learning. It is shown that the applied learning algorithm results are competitive with the model results parameters calculated as R2 = 0.999 and mean absolute real error computed as 0.005 which has shown that the proposed model can be used for MOSA monitoring and diagnostic purposes.

Amir Fazlić, Zlata Ibrišimović, Z. Iličković, F. Andrejaš, S. Begić

: In this paper, the influence of MgO and CaO content on the quality of technical ceramics (which originally represents the Al 2 O 3 - SiO 2 - CaO - MgO system) has been investigated. Therefore, quality tests were performed on samples where the contents of CaO and MgO were taken as variable values. Based on the obtained test results and their analysis, certain characteristics of ceramics are defined with the different percentages of individual oxides content in 98.2 - 99% Al 2 O 3 .

E. Silva, Wenderson Holanda de Oliveira, C. Costa, G. C. Ferreira, Paulo Cesar Flores Júnior

Introdução: A implantação de viveiros que foquem na produção de mudas de espécies nativas de todos os estágios de sucessão ecológica e que primem pela qualidade é um norteador do processo produtivo. Considerando que os viveiros florestais podem representar importantes alternativas de geração de emprego e renda nas comunidades rurais e a elevada demanda por profissionais capacitados para contribuir com a sustentabilidade econômica, social e ambiental. Objetivo: Mostrar que através da produção de mudas florestais nativas aliadas a fixação de aprendizagem e trabalho prático, contribui para a formação de estudantes da Engenharia Florestal, ou seja, recursos humanos capacitados a trabalharem os aspectos técnicos, operacionais e de gestão nos viveiros florestais. Material e Métodos: O viveiro didático Vila da Folha localiza-se no município de Belém, PA, dentro dos limites da Universidade Federal Rural da Amazônia (UFRA) e faz parte do Programa de Educação Tutorial em Eng. Florestal. Nesta unidade didática, os discentes são responsáveis pela coleta de sementes, recebimento dos lotes de sementes, preparo de substratos, semeadura e manejo da produção de mudas nativas. Resultados: A atividade iniciou-se com um curso sobre preparo de substrato oferecido pelo Instituto de Desenvolvimento Florestal e da Biodiversidade do Estado do Pará (IDEFLOR-Bio). Sementes foram obtidas por meio de coletas realizadas no Bosque Rodrigues Alves e nas dependências da UFRA. No viveiro foram produzidas um total de 3.896 mudas. As mudas produzidas foram das espécies: ipê amarelo rugoso (278 mudas), ipê amarelo cerrado (171 mudas), ipê branco (702 mudas), ipê rosa (1.260 mudas), açaí (1.182 mudas), pau-preto (250 mudas) e andiroba (53 mudas). Conclusão: Por meio da prática de produção de mudas florestais nativas os discentes do curso de Engenharia Florestal estão sendo capacitados a trabalharem os aspectos técnicos, operacionais e de gestão nos viveiros. Assim, a atividade prática de viveiro florestal auxilia na capacitação e formação de recursos humanos para atuação neste tipo empreendimento.

Kristina Božinović, N. Strbac, A. Mitovski, M. Sokić, D. Minić, B. Marković, J. Stojanović

The roasting of sulfide ores and concentrates is one of the most important steps in pyrometallurgical metal production from primary raw materials, due to the necessity of excess sulfur removal, present in the virgin material. Pentlandite is one of the main sources for nickel pyrometallurgical production. The knowledge of its reaction mechanism, products distribution during oxidation and reaction kinetics is important for optimizing the production process. Raw pentlandite-bearing ore from the Levack mine (Ontario, Canada) was subjected to oxidative roasting in the air atmosphere. A chemical analysis of the initial sample was conducted according to EDXRF (Energy-Dispersive X-ray Fluorescence) and AAS (Atomic Adsorption Spectrometry) results. The characterization of the initial sample and oxidation products was conducted by an XRD (X-ray Diffraction) and SEM/EDS (Scanning Electron Microscopy with Energy Dispersive Spectrometry) analysis. Thermodynamic calculations, a phase analysis and construction of Kellogg diagrams for Ni-S-O and Fe-S-O systems at 298 K, 773 K, 923 K and 1073 K were used for proposing the theoretical reaction mechanism. A thermal analysis (TG/DTA—Thermogravimetric and Differential Thermal Analyses) was conducted in temperature range 298–1273 K, under a heating rate of 15° min−1. A kinetic analysis was conducted according to the non-isothermal method of Daniels and Borchardt, under a heating rate of 15° min−1. Calculated activation energies of 113 kJ mol−1, 146 kJ mol−1 and 356 kJ mol−1 for three oxidation stages imply that in every examined stage of the oxidation process, temperature is a dominant factor determining the reaction rate.

As the number of older adults in low- and middle- income (LMIC) countries is expected to grow substantially over the next several decades, it is important to develop programs for the prevention of major depression in later life. These programs should be flexible enough to be adjusted to the needs of poorly resourced LMICs. The current report provides an overview of a “depression in later life” (DIL) study in Goa, India, as a promising and effective mental health prevention program, with the potential for implementation in other LMICs. DIL study uses unspecialized physicians and lay health counselors (LHCs) to deliver both scalable psychological intervention and low-intensity intervention, consistent with Institute of Medicine’s (IOM, 1994) indicated prevention approach. DIL intervention led to reduced incidence of Major Depressive Disorder in DIL-randomized participants and as such it is important in meeting the 2016-2030 United Nations Sustainable Development Goal of “Ensuring healthy lives and promoting the well-being for all at all ages."

S. Ambroziak, Kenan Turbic, L. Correia

This paper presents the initial results of wideband channel measurements for polarised off-body communications at 5.8 GHz in an indoor environment. Channel Impulse Response measurements were performed simultaneously for two orthogonal polarisations of a wearable antenna (several placements) and repeated for vertical and horizontal orientations of the off-body one. Four types of scenarios were considered in order to investigate the influence of user dynamics, presence of people in the environment, and body-shadowing effects from the user or other persons obstructing Line-of-Sight in between transmitter and receiver. Initial results are presented.

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