Development of the Simulation Model for Ready Mixed Concrete Supply Chain Cost Structure

Supply of Ready Mixed Concrete (RMC) is a common process of concrete works on any structure. There is often a need to supply one or more construction sites simultaneously from multiple concrete plants. This paper presents a new simulation model of RMC supply and delivery from three concrete plants to three construction sites. The model is dynamic, easily managed, and adjustable and it allows proper estimation of the cost and time required to solve the problem of RMC supply. Model verification was performed using a case study of concrete supply to construction sites in the city of Niš, Serbia. The case study is based on real parameters obtained from specific concrete plants and construction sites. The results of the simulation experiment with varying number of mixers indicate that there is a significant influence of vehicle number and volume on idling costs. Based on the model analysis in the case study, scenario 10 (minimum total idling cost is 14,09 €) is recommended as the optimal combination of truck mixers for the considered case study. The simulation results indicate that the selection of an adequate combination can significantly reduce the costs of idling, for both the mixer and the pump, which leads to minimal idling time and, consequently, to timely pouring of concrete without reducing its quality

Determination of cyclist competition speciality features for functional and morphological indicators

Uzorak ispitanika bio je sastavljen od drumskih biciklista koji su selektovani kao nacionalna klasa Rerpublike Srbije, i to od subuzoraka struktuiranih prema uzrasnim kategorijama, juniori, mlađi seniori „U23“ i seniori . Efektiv osnovnog uzorka bio je sastavljen od 76 ispitanika, prosečnog uzrasta 20.934±6.589 god, telesne visine 179.513±6.03 cm i telesne mase 68.661±6.03 kg. U svakoj od uzrasnih grupa bili su zastupljeni takmičari sledećih specijalnosti: sprinteri (N=20), vozači specijalisti u brdskim uslovima (N=35) i specijalisti u vožnji na pretežno ravnim terenima (N=21). U okviru testiranja rađen je sportskomedicinski pregled koji se sastajao od antropometrijskih i funkcionalnih testiranja. Iz tih testova izabrano je šest antropometrijskih mera, šest spirometrijskih varijabli dinamičkih plućnih kapaciteta i sedamnaest spiroergometrijskih varijabli dobijenih na dva nivoa opterećenja, maksimalnom i nivou ventilatornog anaerobnog praga. Svi rezultati prikupljeni u istraživanju obrađeni su analizama deskriptivne statističke analize, inferencijalne statističke analize i multivarijatne statističke analize. Primenjena metodologija bila je u funkciji ispitivanja zasnovanosti 5 hipoteza istraživanja. Dobijeni rezultati definisali su 7-dimenzionalnu strukturu latentnih dimenzija koji se mogu smatrati odgovornim za 74.81% ukupno registrovane varijanse analizirane kardiorespiratorne strukture biciklista. Diskriminacionom analizom utvrđeno je 11 varijable koje doprinose razdvajanju biciklista u različite takmičarske specijalnosti i to u dva kanonička korena. Dobijeni diskriminacioni model je, na osnovu rezultata koje su ispitanici prikazali u prediktivnim varijablama istraživanja, ispravno klasifikovao 91.428% biciklista specijalista za vožnju u pretežno ravnim terenima, zatim 85.714% vozača specijalista u brdskim uslovima i sve ispitanike sprintere (100%). U proseku je 92.105% ispitanika bilo ispravno klasifikovano, što govori o snazi dobijenog diskriminacionog modela. Ispitivanje kriterijuma za procenu pripadnosti biciklista određenoj takmičarskoj specijalnosti, na osnovu izabranih vrednosti antropometrijskih, kardiovaskularnih i respiratornih sposobnosti, kao i pokazatelja specifične radne sposobnosti, rezultiralo je sa predikcionim regresionim modelom visoke statističke značajnosti...The sample of respondents was composed of road cyclists who were selected as the national class of the Republic of Serbia, from subsample structured by age categories, juniors, young seniors "U23" and seniors. The primary sample effect was composed of 76 subjects, an average age of 20,934 ± 6,589 years, a body height of 179,513 ± 6.03 cm and a body weight of 68,661 ± 6.03 kg. In each of the age groups there were competitors of the following specialties: sprinter (N=20), specialists ride in mountain conditions (N=35) and specialists ride on predominantly flat terrain (N=21). As part of the testing, a medical and medical examination was made that consisted of anthropometric and functional testing. From these tests, six anthropometric measures, six spirometric dynamic pulmonary capacity variables and seventeen spiroergometric variables obtained at two levels of load were selected, the maximum and level of the ventilation anaerobic threshold. All results collected in the study were analyzed by descriptive statistical analysis, inferential statistical analysis and multivariate statistical analysis. The applied methodology was in function of testing the basis of the 5 hypotheses of the research. The obtained results defined the 7-dimensional structure of latent dimensions that can be considered responsible for 74.81% of the total registered variance of the analyzed cardiorespiratory structure of cyclists. The discriminatory analysis identified 11 variables that contribute to the separation of cyclists into different competitive specialties, in two canonical roots. Based on the results presented by the respondents in predictive variables, the obtained discriminatory model correctly classified 91.428% of bicycle specialists for ride in predominantly flat terrain, followed by 85.714% specialists in mountain conditions and all sprinter respondents (100%). On average, 92.105% of respondents were correctly classified, which speaks of the strength of the discriminatory model obtained. Examination of the criteria for assessing the belonging of cyclists to a specific competitor specialty, based on the selected values of anthropometric, cardiovascular and respiratory abilities, as well as indicators of specific working ability, resulted in a predictive regression model of high statistical significance..

Effects of hemazin SC 500 (terbuthylazine) on antioxidative enzymes in human erythrocytes in vitro

The aim of this work was to investigate the effect of the commercial formulation hemazin SC 500, an herbicide containing terbuthylazine as the active compound, on the isoenzyme patterns and activities of Cu-Zn superoxide dismutase (SOD1) and catalase (CAT), as well as on the glutathione S-transferase (GST) activity, in human erythrocytes in vitro. The human erythrocytes were treated with hemazin SC 500 over a broad range of terbuthylazine concentrations (37 nmol L-1– –37 mol L-1) for 1 and 3 h at a temperature of 37°C. Native electrophoresis of the control and treated samples revealed two SOD1 and one CAT isoform. Treatment did not affect the SOD1 and CAT isoenzyme profile, but induced a change in their activities. Terbuthylazine at lower concentration induced a significant increase of the total SOD1 activity and decreased the GST activity in samples incubated for 1 and 3 h. On the other hand, the highest increase in the CAT activity was observed for the sample treated for 1 h with a higher concentration of terbuthylazine. Hemazin SC 500 containing terbuthylazine induces changes in the erythrocyte antioxidative system whereby the response of individual enzymatic antioxidants depends on the concentration of the pesticide and the incubation time

THE SCOPE AND STRUCTURE OF THE INCENTIVES IN AGRICULTURE AND RURAL DEVELOPMENT IN THE REPUBLIC OF SERBIA

The aim of the paper is to point out the scope and structure of the incentives from the agricultural budget of the Republic, as well as from the IPA Fund which are intended for the agricultural and rural development sector in Serbia. It is given a brief overview of the chronology of harmonization of national legislation in the field of agricultural production with European rules, the plan for realization of IPARD funds for the period 2014-2020, as well as a review of incentives from the agricultural budget for the period 2016-2019. For supporting the agriculture and rural development sector of Serbia within the IPARD measures, from the EU budget is intended EUR 175 mln., and from the national budget is intended EUR 55 mln. The largest amount of funds within the IPARD measures is planned for investments in the physical assets of agricultural holdings (43%). Something less contribution is scheduled for the investments in processing and marketing in agricultural holdings (37%). The left over measures include only 19% of the planned funds intended to support agricultural holdings within the IPARD assistance program. On the other hand, an analysis of the incentive structure from the Republic's agrarian budget indicates that the largest share has direct payments of over 50%, while the rural development measures are average financed with 12.3%

Speaking assesment in Serbian as a foreign language Оценка устной речи в сербском языке как иностранном

Предмет овог истраживања представља процена усмене продукције у српском као страном језику. Као један од најважнијих разлога за одабир управо овакве теме истраживања издвајамо то што се у савременој глотодидактици као примарни циљ учења страних језика, а самим тим и српског као страног језика, поставља способност усменог изражавања, одн. употреба језика у реалним комуникативним ситуацијама. Циљ овог истраживања јесте утврђивање недвосмислених упутстава и прецизних критеријума за процењивање усмене продукције у српском као страном језику. Аналитичко-дескриптивни метод чини окосницу методологије истраживања у овом раду. Након уводних разматрања, која се тичу кратког историјата учења и наставе страних језика, али са фокусом на српски као страни језик, компетенцијског приступа настави и учењу страних језика и месту које тестирање заузима у настави страних језика, детаљно истражујемо процену усменог изражавања у српском као страном језику. У централни део истраживања уврстили смо представљање великог броја релевантних студија на српском, енглеском, словеначком, хрватском и руском језику, у којима је описана процена усменог изражавања за сваки од наведених језика, а који су нам послужили као теоријски оквир за формирање критеријума и дескриптора за процену говорења на српском као страном језику за све нивое знања (А1−Ц2). Неколико поглавља посветили смо и креирању испитних материјала (тематске области, питања и пропратне илустрације за усмене провере знања), као и прецизне скале за евалуацију усмене продукције у српском као страном језику. Сви предлози критеријума, скала и целокупан предложени материјал за процену говорења, верификовани су током испитних активности Центра за српски као страни језик на Филолошком факултету Универзитета у Београду између 2019. и 2022. године.The subject of this research is the speaking assessment of Serbian as a foreign language. As one of the most important reasons for choosing this research topic, we single out the fact that in modern glottodidactics, the primary goal of learning foreign languages, and therefore Serbian as a foreign language, is the ability to express oneself orally, i.e., language use in real communicative situations. The purpose of this research is to determine explicit instructions and precise criteria for evaluating speaking production in Serbian as a foreign language. The analytical-descriptive method forms the mainstream of the research methodology in this paper. After the introductory considerations, which concern a short history of learning and teaching foreign languages, but with the focus on Serbian as a foreign language, the competence approach to teaching and learning foreign languages and the role of testing in foreign language teaching, we explore in detail the assessment of speaking production in Serbian as a foreign language. In the central part of the research, we included the presentation of a large number of relevant studies in Serbian, English, Slovenian, Croatian and Russian languages, which described the assessment of speaking production for each of the mentioned languages, and which served us as a theoretical framework for the formation of criteria and descriptors for assessment of speaking in Serbian as a foreign language for all levels of knowledge (A1−C2). We devoted several chapters to the creation of test materials (thematic areas, questions and accompanying illustrations for speaking tests), as well as precise scales for the evaluation of speaking production in Serbian as a foreign language. All proposed criteria, the evaluation scale, and the entire proposed material for the assessment of speaking were verified during the examination activities of the Center for Serbian as a Foreign Language at the Faculty of Philology at the University of Belgrade between 2019 and 2022

Accreditation of Laboratories, Standards and Supported Legislation in European Union

Mandat M/451 EN europskim organizacijama CEN-u, CENELEC-u i ETSI-ju u okviru kojeg bi se uredilo područje akreditacije laboratorija dodijeljen je od strane Europske unije krajem 2007. godine. Europske normizacijske organizacije CEN, CENELEC i ETSI su taj mandat prihvatile i u radu su opisani daljnji postupci tih organizacija na izradi normi u okviru dodijeljenog mandata kao i novi zakonski propisi Europske unije koji reguliraju to područje. U radu su prikazane i najnovije izmjene popisa normi koje ulaze u mandate M/451 EN koje se očekuju krajem 2011. godine.Mandate M/451 EN was assigned to the European organizations CEN, CENELEC and ETSI , under which the field of laboratory accreditation would be regulated, was assigned by the European Union at the and of year 2007. European organizations CEN, CENELEC and ETSI have accepted the mandate and this paper describes their work on the development of standards under the assigned mandate and the legal regulations governing the area. The most recent amendments to the list of standards covered by the M/451 EN mandate expected to be made by the end of year 2011 are presented as well

Morphometry of the Pelvic Ring in Definition of Biomechanical Factors Influencing the Type of Pelvic Fracture

The aim of the study was to supplement data on pelvic morphology and structural geometry. Using these data, a mathematical and biomechanical model was constructed. The research was divided into two parts. The first part comprised radiogrammetric analysis of pelvic morphology and geometry based on 60 AP x-rays of male and female pelvises. The spatial definition of the pelvis was given by three transverse and one sagittal diameter. Transverse diameters were measured at the level of iliac wings, at the narrowest supraacetabular portion and on the line passing through the center of both femoral heads. The fourth diameter was the height of the pelvis. Geometric properties and structure of pelvic bones and position of muscles in relation to bone elements of the pelvis were analyzed in the second part. Knowing geometric dimensions of the pelvis and the body weight, it is possible to calculate the magnitude of gravitational forces acting upon certain pelvic portions. This biomechanical model serves for simulation of operative methods of fixation and allows search for the optimal solution, which is stable enough to withstand all the forces acting upon fragments of a fractured pelvic ring

Procjena zdravstvenoga rizika nakon istovremenog izlaganja olovu, kadmiju i živi iz poljoprivrednoga tla s područja Tuzlanskoga kantona (Bosna i Hercegovina)

The aim of this study was to assess the risk of human exposure to lead (Pb), cadmium (Cd), and mercury (Hg) through agricultural soil by considering both uncertainty and variability in key exposure parameters. For this reason we collected soil samples from 29 locations in the Tuzla Canton (Bosnia and Herzegovina) and measured their metal levels with inductively coupled plasma atomic emission or absorption spectrometry (ICP-AES and ICP-AAS, respectively). The levels of Pb ranged from 13.33 to 1692.33 mg/kg, of Cd from 0.05 to 3.67 mg/kg, and of Hg from 0.02 to 2.73 mg/kg. To estimate cancer and non-cancer risks we used deterministic and semi-probabilistic methods. Lead was found to involve higher health risk than the other two heavy metals. Its hazard index (HI) decreased between population groups (children>women>men) and exposure routes (ingestion>skin contact>inhalation). Our Monte Carlo simulations indicated that Pb HIs for both adult populations had a 0.6 % probability to exceed the threshold value of 1, while in children this probability was 14.2 %. Cd and Hg showed no probability to exceed the threshold in any scenario. Our simulation results raise concern about possible adverse health effects of heavy metals from soil, especially in children. It is very important to continue monitoring environmental pollution and assess human health risk, not only with respect to soil, but also with other important environmental compartments, such as air and water.Cilj ovog istraživanja bio je procijeniti izloženost ljudi olovu (Pb), kadmiju (Cd) i živi (Hg) iz poljoprivrednog tla, uzimajući u obzir pridružene nesigurnosti i varijabilnosti u ključnim parametrima izloženosti. Primjenom metoda induktivno spregnute plazme i atomske emisijske ili apsorpcijske spektrometrije (ICP-AES i AAS) određena je koncentracija metala u uzorcima poljoprivrednoga tla prikupljenog s 29 lokacija u Tuzlanskom kantonu (Bosna i Hercegovina). Koncentracije Pb kretale su se u rasponu od 13,33 do 1692,33 mg/kg, Cd od 0,05 do 3,67 mg/kg i Hg od 0,02 do 2,73 mg/kg. Za procjenu kancerogenog i nekancerogenog rizika koristili smo se determinističkim i semiprobabilističkim pristupom u procjeni rizika. Utvrđeno je da Pb doprinosi povećanom zdravstvenom riziku više nego druga dva teška metala. Indeks opasnosti (eng. hazard index ‒ HI) smanjivao se među populacijskim skupinama (djeca > žene > muškarci) i putevima izloženosti (ingestija > dermalni kontakt > inhalacija). Naše Monte Carlo simulacije pokazale su da HI za Pb uključujuči obje populacije odraslih imaju 0,6 % vjerojatnosti da će prijeći vrijednost praga od 1, dok je u djece ta vjerojatnost bila 14,2 %. Vjerojatnost da će premašiti prag u bilo kom scenariju nisu pokazali Cd i Hg. Rezultati naših simulacija izazivaju zabrinutost zbog mogućih štetnih učinaka teških metala iz tla, posebice u djece. Vrlo je važno nastaviti pratiti onečišćenje okoliša i procijeniti rizik za zdravlje ljudi, ne samo putem tla, već i putem drugih značajnih dijelova okoliša, poput zraka i vode

Effects of Air Polution on Growth in Schoolchildren

The growth is considered a very sensitive indicator of the impact of environment of the health status of children. The aim of the study was to investigate whether air pollution is related to children’s growth. The subjects were 1059 pupils, aged 7–11 years, living for more than ten years in the same home in the city of Ni{ (Serbia). Exposed group of children (N=545) were attending the school located in a city area with a high level of air pollution, while the children (N=514), in the comparison group, designed as non-exposed group, were attending the school in the area with a lower level of air pollution. The air concentrations of black smoke, nitrogen dioxide, sulfur dioxide and lead in sediment matter were determined in ten-year period. Air pollution is associated with children’s height and weight, specially before the age of 9 years. There was a significant difference in the prevalence of thinness in children exposed to higher concentrations of air pollutants (p=0.038). It might be possible that air pollution negatively contributed to the growth rate in urban children