National and University Library of the Republic of Srpska: DOI Srspka / DOI Српска
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Assessing the possibility of solidification and stabilization of pyrite cinder by using quicklime and fly ash
Full text linkThe aim of this study was to determine the possibility of using two low-cost binders,quicklime and fly ash for the solidification/stabilization (S/S) of pyrite cinder.Pyrite cinder, used in this study, represents a remnant from sulfuric acid productionin fertilizer factory IHP “Prahovo” A.D. (Serbia), and has a very high toxicmetal content. High contents and leachability of copper, lead and zinc make thiswaste material hazardous, representing an extraordinary risk to the environment.In order to determine the leaching behavior of the S/S mixtures, four single-stepleaching tests were performed, each one having a different sort of leaching fluid(deionized water, inorganic and organic acidic solutions). X-ray diffraction (XRD),scanning electron microscope (SEM) and energy dispersive X-ray analyzer (EDS)were implemented to elucidate the mechanisms responsible for immobilization ofCu, Pb and Zn. Overall, the test results indicated that S/S treatment using bothquicklime and fly ash was effective in immobilizing these metals, especially whenthere is a higher share of binder present. Treated waste can be safe for disposal andeven considered for “controlled utilization”. Furthermore, the use of fly ash for S/Streatment of pyrite cinder solves the disposal problems of two waste types, as it alsorepresents a secondary industrial product
Determination of arsenic content in tea samples available on Republic of Srpska market by atomic absorption spectrophotometry
Full text linkIntroduction. Arsenic exists in various forms in nature and living organisms.Toxic elements, including arsenic, which are present in some plants,can severely damage haemopoietic, immune, nervous and reproductivesystems. For this reason, a content of heavy metals is one of the criteria forthe assessment of the safe use of plant material in the production of traditionalmedicines and herbal infusions. This instigates the need for constantand organized safety control of plants that are used as raw materialsin pharmaceutical industry.The aim of this study is to determine the arsenic content in selected teaswhich are available on the market of the Republic of Srpska.Methods. The 10 g samples of 13 herbal and 3 fruit teas were mineralizedby dry ashing and arsenic contents were determined by the atomicabsorption spectrophotometer Agilent Technologies Series 200 with anair-acetylene burner and D2 background correction.Results. Mean arsenic concentrations in the herbal tea samples rangedfrom 0.009 to 0.145 mg/kg. The lowest arsenic concentration in a singlesample of 0.007 mg/kg was found in Chamomile tea and Uva ursi collectedas a wild plant at elevation above 1200 m. The highest arsenic concentrationwas found in the sample of Sambucus nigra tea (0.145 mg/kg). Infruit teas, the arsenic concentration ranged from 0.014 mg/kg (Cranberry)to 0.027 mg/kg (Fruit mix).Conclusion. Arsenic content in all analyzed tea samples is below the valuestipulated by the national legislation
FACTORS OF JOB SATISFACTION AND THEIR EFFECTS ON EMPLOYEES’ BEHAVIOR IN A MANUFACTURING COMPANY IN THE REPUBLIC OF MACEDONIA
Full text linkThis paper elaborates the issue about job satisfaction, observing it through the prism of the factors that lead towards its achievement, but also observing whether its absence has an impact on the employees’ behavior in the organization, employees’ productivity, absenteeism, fluctuation, as well as customers’ behavior, satisfaction and loyalty. Based on a sample of 100 employees with different gender, educational and age structure from one of the leading manufacturing companies in the Republic of Macedonia, this research revealed which factors cause job satisfaction of the employees in the Republic of Macedonia, whether the demographic characteristics influence the differences in the ranking of these factors, as well as which conditions and processes at the workplace, the absence of job satisfaction affects significantly. We can conclude that employee job satisfaction in the country is largely determined by the factors that enable the realization of self-esteem and self-realization needs, according to the Maslow's hierarchy of needs, while the wages and the financial rewards and benefits are not ranked as the most significant factors observed at the level of all respondents. Analyzing them individually, according to gender, as well as by the level of education, which often arises as a reason for the difference in the choice of the respondents, the findings show that the financial motivators have key influence on the job satisfaction of the male employees, as well as of those with completed secondary education
СТИДЉИВОСТ ДЈЕЦЕ И УКЉУЧЕНОСТ У НАСТАВУ
No full textЉуди су социјалана бића, те већину својих потреба и активности остварују путем интеракције са другим људима. Стидљивост је тиме универзално искуство сваког појединца. Појам стидљивост је у широкој употреби у свакодневном говору, али није у потпуности схваћен и објашњен. Укљученост ученика у наставу испитали смо кроз компетенције (емоционалне, социјалне, когнитивне) ученика и њихове ставове о стидљивости. Кључно питање у овом истраживању било је да ли различит ниво стидљивости детерминише (емоционалну, социјалну и когнитивну) укљученост ученика у наставу
Software for Measuring Acoustic Parameters in Open-plan Offices
Full text linkThis paper presents a development of software for the measurement and estimation of the quality of acoustic design in open-plan offices. The measurement method is defined by a standard and measurements should be performed in a large number of different spatial positions in order to measure and determine the acoustic quality of the surroundings of as many workstations as possible. The presented software significantly simplifies the process of analyzing open-plan offices by processing the signal at the time of measurement. Furthermore, it allows for the storing of measured signals and parameter values, which can be of importance for further analysis or repeated calculations. The presented procedure leads to the reduction of the necessary hardware elements for completing the analysis. All that is needed for measurement are a sound source, a microphone, a sound card and a computer. As a result, the user obtains a detailed report of the characteristics of the analyzed office space and a descriptive mark which depends on the values of the calculated parameters
Cybersecurity of Railway Command and Control Systems
Full text linkWith the large-scale migration to computer-based and network technology, the threat of unauthorized remote access to railway command and control systems does not appear to be something extraordinary.But external effects shall be considered alongside with internal factorsof signalling software and hardware such errors and undocumented features. Risk mitigation in terms of cybersecurity of signalling installations can onlybe achieved as a combination of means designed within some holistic approach integrating both safety and IT security aspects
An exploration of the effects of low-pressure plasma discharge on the physicochemical properties of chia (Salvia hispanica L.) flour
Full text linkThis work explores the preliminary feasibility of employing the low-pressure coldplasma technology for the modification of the properties of chia flour. Chia flour wasexposed to low pressure plasma in air for 5 min, 10 min, and 15 min, at two differentpower levels (40 W and 60 W). The oils extracted from untreated and treated chiaflour were exhaustively characterized for fatty acid composition, nutritional value,and rancidity indices using thermal calorimetric methods (DSC/TGA). The resultsindicated a significant change in the colour of flour with an increase in lightness.Infrared and ultraviolet spectroscopy indicated changes in the tocopherol groups ofthe oil extracted from plasma treated chia flour. However, the oil extracted fromplasma treated chia flour revealed a loss of conjugated dienes and formation oftrans-fatty acids as seen in conventional hydrogenation of edible oils. DSC and TGAresults revealed better oxidative stability of low-pressure plasma treated oils thancontrol, which was linked to a relative increase of MUFA in the former
UTICAJ INDIVIDUALIZOVANE NASTAVE NA KREATIVNO ČITANJE
No full textTradicionalnoj nastavi se zamjerada sputava i nedovoljno stimulišeaktivnost učenika, te da im ne omogućavaispoljavanje kreativnosti priusvajanju nastavnih sadržaja. U radusu prikazani rezultati eksperimentalnogistraživanja uticaja modelaindividualizovane razredne nastaveknjiževnosti na kretaivno čitanjeučenika. U šest odjeljеnja petograzreda osnovne škole realizovan jeeksperiment sa paralelnim grupama.U eksperimentalnoj grupi primjenjenisu modeli indidividualizovanenasteve: 1. primjenom nastavnihlistića, 2. nastava različitihnivoa složenosti, 3. interaktivna nastavarazličitih nivoa složenosti. Ukontrolnoj grupi primjenjivana jeuobičajena, tradicionalna pretežnofrontalna natava. Rezultati jednogodišnjegeksperimentalnog istraživanjapokazuju da su eksperimentalnegrupe sa kojima je realizovana individualizovanarazredna nastav književnostiprimjenom nastavnih listića,nastavа različitih nivoa složenosti iinteraktivnа nastave različitih nivoasloženosti bile u prosjeku statističkiznačajno uspješnije u kreativnom čitanjuu odnosu na kontrolne grupesa kojima je realizovana uobičajena,tradicionalna nastava
Participating in Kinesiology Activities in Primaryeducation Students’ Free Time
Full text linkThe objective of the research was to investigate to what extent students of first and second grades of primary school participate in physical activities in their free time. We are living in the age of sedentary lifestyle, which is becoming a problem of public health. 189 respondents took part in this research of which 93 girls and 96 boys aged 7 to 9. To assess the level of students’ activity in their free time, a poll was used consisting of eight questions from the questionnaire “Fels physical activity questionnaire for children” (FPAQ). Based on queries from the questionnaire, indices were calculated from the area of sports (IS), free time (ISV; household chores (IKP) and total physical activity result (UTA). To assess body composition, anthropometric measures of height, mass, BMI and percentage of fat in the body were used. To assess those, we used the device for measuring physical composition– Omron BF500 Body Composition Monitor. Results indicate that 59.26% do not meet daily recommendations for participating in physical activities. As regards the difference in students’ age, it is notable that second grade students are somewhat more physically active. Observing average results, it is clear that students were most physically active in their free time. The lowest values were recorded in the area of sports at school, (1.15), yet lower values were also obtained from sports club activities (2.06). It is evident that students of that age are minimally active during their PE classes and this is a segment where the number of physically active students can be increased. Increasing physical activity at school shall encourage students to participate in physical activity outside educational institutions
Mission critical ICT
Full text linkIn this paper, three technologies intended to be implemented in Private Mobile Radio systems are analyzed and compared: TETRA (Terrestrial Trunked Radio), LTE (Long Term Evolution) and DMR (Digital Mobile Radio). Characteristics of these networks are collected and compared in one SWOT table. Based on this analysis, appropriate recommendations are made, which should be taken into account when choosing a specific solution for specific uses in Critical Communications systems