Natural and artificial (90Sr) radionuclides in some carbonated mineral waters used in Serbia

A radiological characterization of 7 different carbonated mineral water samples collected in the local supermarkets in the area of Belgrade (produced in Serbia) was carried out. Analysis included determination of gross alpha and gross beta activities. The obtained results showed that the natural activity concentrations of alpha and beta emitting radionuclides in carbonated mineral water samples were within World Health Organization recommended levels, except for the Heba Strong and Kiseljak samples where the beta activity exceeds 1 Bq/L. For these two water samples gamma spectrometry analysis was performed as well as determination of 90Sr by oxalic method. The instrumentation used to count the gross alpha and gross beta activities, as well as for 90Sr, was a/b low level proportional counter Thermo Eberline FHT 770 T. Gamma spectrometric measurements were performed using a HPGe Canberra detector with a counting efficiency of 20%. The annual effective dose equivalent due to ingestion of investigated waters was calculated for age group >17, and obtained values are lower than 0.1 mSv recommended reference level. Finally, a comparison of the investigated waters with worldwide data was made. [Projekat Ministarstva nauke Republike Srbije, br. III43009

Biogenic amines in protocerebral A2 neurosecretory neurons of Lymantria dispar L. (Lepidoptera:Lymantriidae): Response to trophic stress

The number, morphometric parameters and amount of aminergic neurosecretory product of protocerebral A2 neurosecretory neurons were investigated in the fifth instar of Lymantria dispar caterpillars, following a suitable or unsuitable trophic regime. Caterpillars originated from two populations (Quercus rubra or Robinia pseudoacacia forest) and were differently adapted to trophic stress, i.e. feeding on locust tree leaves - unsuitable host plant. The number of neurosecretory neurons was higher in the caterpillars originated from Robinia population than in Quercus population, regardless of feeding. A2 neurosecretory neurons, nuclei and their nucleoli were larger in caterpillars fed with unsuitable leaves in both populations. There was more aminergic product in the A2 neurosecretory neurons of the caterpillars fed with unsuitable leaves independently of population origin

Pyrolysis of medium-density fiberboard: optimized search for kinetics scheme and parameters via a genetic algorithm driven by Kissinger's method

The pyrolysis kinetics of charring materials plays an important role in understanding material combustions especially for construction materials with complex degradation chemistry. Thermogravimetric analysis (TGA) is frequently used to study the heterogeneous kinetics of solid fuels; however, there is no agreed method to determine the pyrolysis scheme and kinetic parameters for charring polymers with multiple components and competing reaction pathways. This study develops a new technique to estimate the possible numbers of species and sub-reactions in pyrolysis by analyzing the second derivatives of thermogravimetry (DDTG) curves. The pyrolysis of a medium-density fiberboard (MDF) in nitrogen is studied in detail, and the DDTG curves are used to locate the temperature of the peak mass-loss rate for each sub-reaction. Then, on the basis of the TG data under multiple heating rates, Kissinger’s method is used to quickly find the possible range of values of the kinetic parameters (<i>A</i> and <i>E</i>). These ranges are used to accelerate the optimization of the inverse problem using a genetic algorithm (GA) for the kinetic and stoichiometric parameters. The proposed method and kinetic scheme found are shown to match the experimental data and are able to predict accurately results at different heating rates better than Kissinger’s method. Moreover, the search method (K–K method) is highly efficient, faster than the regular GA search alone. Modeling results show that, as the TG data available increase, the interdependence among kinetic parameters becomes weak and the accuracy of the first-order model declines. Furthermore, conducting TG experiment under multiple heating rates is found to be crucial in obtaining good kinetic parameters

Uloga testova otpuštanja interferona gama u nadzoru nad tuberkulozom

Tuberculosis is still one of the major global public health threats. Countries with low incidence must focus on exhausting the reservoir of future cases by preventing reactivation. Therefore, it is important to identify and effectively treat those individuals who have latent tuberculosis infection and who may develop active disease. The tuberculin skin test has been the standard for detection of immune response against M. tuberculosis since the beginning of the 20th century. The new millennium has brought advancement in the diagnosis of latent tuberculosis infection. The name of the new blood test is interferon-gamma release assay (IGRA). Croatia is a middle-incidence country with a long decreasing trend and developed tuberculosis control. To reach low incidence and finally eliminate tuberculosis, its tuberculosis programme needs a more aggressive approach that would include intensive contact investigation and treatment of persons with latent tuberculosis infection. This article discusses the current uses of IGRA and its role in tuberculosis control.Tuberkuloza je i danas jedan od vodećih javnozdravstvenih problema. Zemlje s niskom incidencijom fokusiraju se na iscrpljivanje rezervoara budućih slučajeva sprječavanjem reaktivacije bolesti. To se odnosi na traženje i učinkovito liječenje infi ciranih osoba, primarno onih koje su u riziku od obolijevanja nakon infekcije. Tuberkulinski test je od početka 20. stoljeća bio standard u otkrivanju imunosnog odgovora na kontakt s Mycobacterium tuberculosis. Novo tisućljeće donijelo je određeni napredak u obliku novih testova za dijagnozu latentne tuberkulozne infekcije, krvne testove otpuštanja interferona gama. Hrvatska je zemlja srednje incidencije tuberkuloze s dugogodišnjim silaznim trendom i razvijenim protutuberkuloznim aktivnostima. U težnji prema niskoj incidenciji i u konačnici eliminaciji tuberkuloze potrebne su opsežnije aktivnosti unutar državnog programa nadzora nad tuberkulozom, uključujući intenzivnu obradu kontakata i probir na postojanje latentne tuberkulozne infekcije. Ovaj rad razmatra trenutačnu uporabu IGRE (engl. interferon - gamma release assay) i njezinu ulogu u nadzoru nad tuberkulozom

Risk assessment of the exposure to organohalogenated contaminants and heavy metals in food

Zadatak svih činilaca uključenih u proizvodnju hrane je da stvore uslove da hrana koja dolazi do potrošača bude bezbedna. Ocena bezbednosti hrane, između ostalog, podrazumeva i procenu rizika od supstanci prisutnih u hrani, naročito od onih koje nemaju gradivnu ili fiziološku vrednost. U realnim okolnostima ljudi su preko hrane istovremeno izloženi delovanju brojnih ksenobiotika, pa i teških metala i organohalogenih jedinjenja koji su odabrani za proučavanje u ovoj studiji. Pored procene rizika zasnovane na ispitivanju svakog pojedinačnog kontaminanta, cilj ove studije je bio i sprovođenje integrativne procene rizika poređenjem toksičnih efekata pojedinačnih kontaminanata i njihove smeše zbog istovremene izloženosti ovim toksičnim supstancama. Pretpostavka je da, iako ne postoji rizik pri izloženosti pojedinačnim toksičnim supstancama, integralni pristup proceni izloženosti može da ukaže na povećan rizik. Svi uzorci ispitanih namirnica su bili u skladu sa važećim propisom, sa izuzetkom jednog uzorka ribe (Hg) i 16 uzoraka kakaoa (Cd). Kadmijum je detektovan u najvećem broju vrsta namirnica kao i u najvećem broju ispitanih uzoraka; organohalogena jedinjenja su detektovana isključivo u namirnicama animalnog porekla – DDT u mleku, proizvodima od mleka i ribi, a ndl-PCB i PBDE isključivo u ribi. Najviše koncentracije kadmijuma dokazane su u lignjama i školjkama, žive u rečnim ribama, olova u čajevima i začinima, DDT u slatkovodnoj ribi a ndl-PCB i PBDE u morskoj ribi. Zbog značajnog udela u ishrani glavni izvor ekspozicije kadmijumu u sve tri posmatrane grupe bile su žitarice i povrće. Unos žive bio je dominantno preko ribe, a olova preko žitarica, voća i povrća. Determinističkom metodologijom dokazan je povećan rizik od unosa ispitanih kontaminanata u prosečnoj opštoj populaciji, populaciji na mediteranskoj dijeti i populaciji dece samo za ndl-PCB. Pored ndl-PCB, probabilističkom metodologijom je procenjen povećan rizik i od unosa Cd za prosečno izloženu populaciju sve tri ispitivane grupe...The principal goal of food-producing stakeholders is to provide safe food for the consumer. Food safety assessment consists of (among the other) risk assessment in respect to supstances that can be present in food, especially those of no nutritional or physiological significance. In real-life circumstances, humans are exposed to various xenobiotics, even heavy metals and organohalogenated compounds through food consumption, which are chosen for investigation in this study. Besides the risk assessment based on investigation of each contaminant individually, the aim of this study was to conduct integrative risk assessment by comparison of toxic effects between individual contaminants and their mixtures, due to the simultaneous exposure to these toxic substances. The hypothesis is, that even no increased risk exists through exposure to individual toxic substances, integrative approach to risk assessment may reveal increased risk. All samples of investigated foodstuffs were compliant with current legislative except one fish sample (Hg) and 16 cocoa powder samples (Cd). Cadmium was the most detected element in most types of foodstuffs and in largest number of tested samples as well; organohalogenated compounds were detected exclusively in animal-originated foodstuffs – DDT in milk, dairy products and fish, while ndl-PCBs and PBDE were detected in fish only. The highest concentrations of cadmium were found in squids and clams, mercury in freshwater fish, lead in teas and spices, DDT in freshwater fish, while the highest concentrations of ndl-PCBs and PBDE were found in marine fish. Due to the significant contribution to the total diet, the major exposition sources of cadmium in all three investigated groups were cereals and vegetables. Dominant intake of mercury is through fish, while intake of lead occurs through cereals, fruits and vegetables..

Etymology in journal "Naš jezik" ; Этимология в журнале "Наш језик"

Предмет дисертације су етимолошки подаци који се налазе у чланцима објављеним у лингвистичком часопису „Наш језик“ у временском распону од 1932/1933. до 2013. године. Међу његовим корицама су се, у складу с програмом часописа, нашли радови посвећени изучавању и нормирању српског (раније српско-хрватског) књижевног језика, решавању питања језичке културе, неговању те културе и усмеравању правца њеног даљег развитка. Иако је у „Нашем језику“ објављен мањи број етимолошких студија, часопис се показао као богат извор етимолошких података, а под тим подразумевамо сваку информацију која се тиче порекла, развоја и/или историје одређене речи, израза или синтаксичке конструкције...The subject of this dissertation is the etymological information found in the papers published in the linguistic journal Naš jezik from 1932/1933 to 2013. In accordance with the journal program, the papers published in these volumes are dealing with topics such as study and standardization of the Serbian (formerly Serbo-Croatian) literary language; they are also addressing various language culture issues, fostering language culture as well as steering the direction of its further development. Even though only a smaller number of etymological studies have been published in the journal Naš jezik, it has proven to be a rich source of etymological information, and by that, we mean any information concerning origin, development, and/or history of a specific word, phrase or syntactic construction..

Digital Manufacturing in SMEs based on the context of the Industry 4.0 framework-one approach

Serbia is rapidly working on the development and implementation of digital manufacturing models in SMEs, through the national Industry 4.0 Platform. The aim is to create a pilot intelligent workshop which would be used to develop and showcase examples of best practice for digital manufacturing. Currently, most SMEs use CAD, CAM, ERP models, which form the basis for the development of the concept of digital manufacturing through cloud computing, BDA, IIoT and smart supply-chains, as elements of Industry 4.0. This paper gives a practical example of an SME with all the above-mentioned elements of digital manufacturing

Digital Manufacturing in SMEs based on the context of the Industry 4.0 framework-one approach

Serbia is rapidly working on the development and implementation of digital manufacturing models in SMEs, through the national Industry 4.0 Platform. The aim is to create a pilot intelligent workshop which would be used to develop and showcase examples of best practice for digital manufacturing. Currently, most SMEs use CAD, CAM, ERP models, which form the basis for the development of the concept of digital manufacturing through cloud computing, BDA, IIoT and smart supply-chains, as elements of Industry 4.0. This paper gives a practical example of an SME with all the above-mentioned elements of digital manufacturing

Novel methods for axial fan impeller geometry analysis and experimental investigations of the generated swirl turbulent flow

Geometry analysis of the axial fan impeller, experimentally obtained operating characteristics and experimental investigations of the turbulent swirl flow generated behind the impeller are presented in this paper. Formerly designed and manufactured, axial fan impeller blade geometry (originally designed by Prof Dr-Ing. Z. Protic(dagger)) has been digitized using a three-dimensional scanner. In parallel, the same impeller has been modeled by beta version software for modeling axial turbomachines, based on modified classical calculation. These results were compared. Afterwards, the axial fan operating characteristics were measured on the standardized test rig in the Laboratory for Hydraulic Machinery and Energy Systems, Faculty of Mechanical Engineering, University of Belgrade. Optimum blade impeller position was determined on the basis of these results. Afterwards, impeller with angle 22 without outlet vanes, was positioned in a circular pipe. Rotational speed has been varied in the range from 500 till 2500 rpm. Reynolds numbers generated in this way, calculated for axial velocity component, was in the range from 0.68.10(5) till 2.5.10(5). Laser Doppler anemometry measurements and stereo particle image velocimetry measurements of the three-dimensional velocity field in the swirl turbulent fluid flow behind the axial fan have been performed for each regime. Obtained results point out extraordinary complexity of the structure of generated three-dimensional turbulent velocity fields