Detection of multi-muonic events in underground laboratory and energy dependant solar modulation of muonic component of the cosmic rays flux.

Веза између космичких зрака и активности Сунца је истраживана коришћењем различитих техника које укључују и детекторске системе које се налазе на површини Земље, попут неутронских монитора и мионских детектора. Употребом ових детектора регистроване су промене флукса космичког зрачења услед периодичне и апериодичне активности Сунца. Ова активност се преноси кроз хелиосферу и утиче на космичке зраке које долазе изван нашег система. Овај утицај (соларна модулација) је све мањи са порастом енергије честица од којих се космичко зрачење састоји. Тиме се, посматрајући флукс космичког зрачења, може установити активност наше звезде која утиче на нашу планету и цивилизацију. Поред тога, познајући промене флукса изазване соларном модулацијом, могуће је и посматрати промене и самог флукса примарног космичког зрачења који нам говори о галактичком окружењу у коме се Сунчев систем налази...The relation between solar activity and cosmic-rays has been studied with various techniques including detectors at the surface of the Earth such as neutron monitors and muon detectors. Variation of flux observed with these particle detectors can be periodic and aperiodic due to Solar and heliospheric activity. The influence of the Sun on cosmic-rays (solar modulation) is smaller with higher energy of the primary particles of the cosmic-rays. Thus, by monitoring cosmic rays flux, it is posible to asset the acitivity of our star which influense Earth enviroment and our civilisation. Also, it it possible to monitor chenge of cosmic-rays’ flux coused by something other then solar activity which gives us information of our galactic environement..

The role and importance of logistics in diversifying the risk of import dependence of the Republic of Serbia on oil and petroleum products

After the outbreak of the conflict in Ukraine in early 2022, a series of events followed that influenced the change of the international order and the entire geopolitical scene. There has been an economic regrouping and redefinition of interstate relations, and in some countries there has been a deterioration or breakin of relations, and in others there has been a deepening and strengthening of cooperation. Bearing in mind that some are leaders in the export of oil and petroleum products, and some are the biggest importers of the same, the international market of these energy products has changed. This is also indicated by the prices of oil and petroleum products on the international market, as a clear indicator of the changed conditions on the supply and demand side. Securitization of the supply of oil and petroleum products, as well as the prevention of negative-inflationary consequences of price shocks of these energies to internal economic flows implies a strategic approach in supply chain management and logistics. Successfully coping with such challenges implies a multifaceted and synchronized approach by the state or competent entities. First of all, states or entities representing them may sign long-term arrangements on the supply of oil and petroleum products, which cannot be considered an absolute solution in the long term, given the general geopolitical circumstances, but also the practice in bilateral cooperation. Then, states can start the production of oil and petroleum products from conventional-commercial sources, if there are financial and objective-technical conditions for this. The third, and no less important approach, is to create conditions for the exploitation of renewable energy sources, which can help users meet their energy needs. This would reduce the demand for other energy sources, so if the country is imported dependent on fossil fuels, the need for imports would also reduce the import dependence of the country. All three approaches are in the function of diversifying the risk of fuel imports, and if this sphere is not given attention, all economic flows of any oil and petroleum products importing country can be drastically disrupted. There are many examples of mistakes made in the procurement strategy of oil and petroleum products, i.e. gas in the foreground. This paper covers the most interesting examples from practice in order to project the risks and damages that imported countries dependent on oil and petroleum products have faced due to the latest developments in Ukraine. In this paper, the authors also point out the economic aspects that reflect possible directions of diversification of risks from the import of oil and petroleum products, as well as the connection of diversification of import risk with supply and logistics in the Republic of Serbia

Exploring the Interrelationship between Scientific Knowledge and Economic Growth in Serbia: Empirical Insights

The primary objective of this study is to examine the nature of the relationship between the production of scientific knowledge and economic growth in Serbia during the period 1996-2022. For this purpose, the Vector Autoregression approach, along with the impulse response function and forecast error variance decomposition, was employed. Results suggest an impact of economic growth on the production of scientific knowledge, while no impact in the opposite direction is detected. The Serbian government should persist in investing in science and work closely with the scientific community to overcome barriers to scientific knowledge's full contribution to economic prosperity

Influence of Sintering Atmosphere on the Crystal Structure, Microstructure, Dielectric and Optical Properties of BaTi1-xSnxO3 (x = 0, 0.05 and 0.1) Ceramics

Due to specific dielectric and ferroelectric properties, functional ceramics based on barium titanate (BaTiO3) have found application in semiconductor industries. Appropriate electrical properties of barium titanate-based materials, such as magnitude of relative dielectric permittivity and the Curie temperature, can be achieved by varying sintering conditions (which influenced ceramics’ microstructure) and/or by doping with various cations. In this study, we investigated the influence of sintering atmosphere (air and argon) on the crystal structure, microstructure, dielectric and optical properties of barium titanate-stannate (BTS; BaTi1-xSnxO3) ceramics. The BTS powders (with x = 0, 0.05 and 0.1; denoted BT, BTS5 and BTS 10, respectively) were synthesized by the solid-state reaction technique. The powders were subsequently uniaxially pressed (P = 240 MPa) into cylindrical compacts (ø 6 mm and h ≈ 2 mm) and sintered in SETSYS TMA (Setaram Instrumentation, Caluire, France). Sintering experiments were performed at a heating rate of 10 °/min up 1420 °C and with a dwell time of 2 hours; to determine the influence of sintering atmosphere, two sets of experiments were performed: (1) in air, and (2) in Ar. During sintering, the shrinkage was recorded in the axial (h) direction. The crystal structure of the BTS ceramics was studied at room temperature by X-ray diffractometry and Raman spectroscopy. The microstructure and chemical (Ti/Sn) composition were examined by SEM–EDS methods. The electrical measurements were made in air, at 1 kHz using a Wayne Kerr Universal Bridge B224; the measurements were done in cooling, from 160 to 20 °C. For optical characterization UV-Vis diffusive reflectance and photoluminescence spectroscopy were employed. A profound effect of an argon atmosphere on the examined properties of the sintered BTS ceramics has been found; the mostly important is an increase of the magnitude of relative dielectric permittivity

REVERSE ENGINEERING OF THE MITKOVIC TYPE INTERNAL FIXATOR FOR LATERAL TIBIAL PLATEAU

In orthopaedic surgery it is very important to use proper fixation techniques in the treatment of various medical conditions, i.e. bone fractures or other traumas. If an internal fixation method, such as plating, is required, it is possible to use Dynamic Compression Plates (DCP) or Locking Compression Plates (LCP) and their variants. For DCP implants it is important to match the patient's bone shape with the most possible accuracy, so that the most frequent implant bending is applied in the surgery. For LCP implants it is not so important to match the patient’s bone shape, but additional locking screw holes are required. To improve the geometrical accuracy and anatomical correctness of the shape of DCP and to improve the LCP geometric definition, new geometrical modelling methods for the Mitkovic type internal fixator for Lateral Tibia Plateau are developed and presented in this research. The presented results are quite promising; it can be concluded that these methods can be applied to the creation of geometrical models of internal fixator customized for the given patient or optimized for a group of patients with required geometrical accuracy and morphological correctness

The New Setup in the Belgrade Low-Level and Cosmic-Ray Laboratory

The Belgrade underground laboratory consists of two interconnected spaces, a ground level laboratory and a shallow underground one, at 25 m.w.e.. The laboratory hosts a low-background gamma spectroscopy system and cosmic-ray muon detectors. With recently adopted digital data acquisition system it is possible to study simultaneously independent operation of two detector systems, as well as processes induced by cosmic-ray muons in germanium spectrometers. Characteristics and potentials of present experimental setup, together with some preliminary results for the flux of fast neutrons and stopped muons are reported.Comment: 12 pages, 16 figure

Monte Carlo simulation of HPGe detector background coming from radionuclides, cosmic and skyshine radiation

U Niskofonskoj laboratoriji za Nuklearnu fiziku, više godina se izučavaju osobine fona HPGe detektora. Izučavanje fona važno je za eksperimente sa malim brojem interesantnih dogadjaja ili retkih procesa u podzemnim laboratorijama. Izučavanja fona u Niskofonskoj laboratoriji započeta su izučavanjem fona zračenja od radionuklida, kao i fona od kosmičkog zračenja, koincidentnim tehnikama. Nedavno je izučavan i fon od skyshine zračenja. U ovom radu je predstavljena Monte Karlo simulacija fona HPGe detektora koji dolazi od pomenuta tri izvora zračenja. Rezultati simulacija kosmičkog zračenja odlično se slažu sa eksperimentalnim rezultatima, dok se za druge komponente mogu poboljšati. Postoji prednost simulacija koje daju razloženi fon na tri komponente, koja omogućava da se rezultati simulacija tri komponente fona za jednu laboratoriju mogu simulirati za druge podzemne ili nadzemne laboratorije menjanjem parametara u simulacionim programima. Fon se može simulirati za laboratorije koje mogu biti na različitoj geografskoj širini, nadmorskoj visini, sa različitim sastavom radionuklida u zemljištu i geometrijom laboratorije u kojoj se vrše merenja. Predstavljeni su nedostaci simulacija i da se rezultati mogu poboljšati radeći na detaljima u nekoliko faza simulacije.In the Low Background Laboratory for Nuclear Physics background radiation of the HPGe detector was researched. This research is important for experiments with small number of interesting events or rare processes studied in underground laboratories. The background radiation research started with research of background from radionuclides and Cosmic rays using coincidence techniques. Recently, the skyshine radiation was researched. In this paper the Monte Carlo simulation of HPGe background is presented. Results for cosmic ray simulations agree very good with the experimental results, and for others can be improved. The simulation for other ground and underground laboratories can be done, by changing longitude, latitude and elevation, composition of radionuclides in soil. The possible improvements of the simulations are discussed.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Monte Carlo simulation of HPGe detector background coming from radionuclides, cosmic and skyshine radiation

U Niskofonskoj laboratoriji za Nuklearnu fiziku, više godina se izučavaju osobine fona HPGe detektora. Izučavanje fona važno je za eksperimente sa malim brojem interesantnih dogadjaja ili retkih procesa u podzemnim laboratorijama. Izučavanja fona u Niskofonskoj laboratoriji započeta su izučavanjem fona zračenja od radionuklida, kao i fona od kosmičkog zračenja, koincidentnim tehnikama. Nedavno je izučavan i fon od skyshine zračenja. U ovom radu je predstavljena Monte Karlo simulacija fona HPGe detektora koji dolazi od pomenuta tri izvora zračenja. Rezultati simulacija kosmičkog zračenja odlično se slažu sa eksperimentalnim rezultatima, dok se za druge komponente mogu poboljšati. Postoji prednost simulacija koje daju razloženi fon na tri komponente, koja omogućava da se rezultati simulacija tri komponente fona za jednu laboratoriju mogu simulirati za druge podzemne ili nadzemne laboratorije menjanjem parametara u simulacionim programima. Fon se može simulirati za laboratorije koje mogu biti na različitoj geografskoj širini, nadmorskoj visini, sa različitim sastavom radionuklida u zemljištu i geometrijom laboratorije u kojoj se vrše merenja. Predstavljeni su nedostaci simulacija i da se rezultati mogu poboljšati radeći na detaljima u nekoliko faza simulacije.In the Low Background Laboratory for Nuclear Physics background radiation of the HPGe detector was researched. This research is important for experiments with small number of interesting events or rare processes studied in underground laboratories. The background radiation research started with research of background from radionuclides and Cosmic rays using coincidence techniques. Recently, the skyshine radiation was researched. In this paper the Monte Carlo simulation of HPGe background is presented. Results for cosmic ray simulations agree very good with the experimental results, and for others can be improved. The simulation for other ground and underground laboratories can be done, by changing longitude, latitude and elevation, composition of radionuclides in soil. The possible improvements of the simulations are discussed.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Origin and Spatial Distribution of Heavy Metals in Mountain Beech Forests Soils Across Europe

The objectives of this research were to investigate the concentration; characterize the distribution; and determine the sources of heavy metals in European mountain beech forest soils. Total of 37 soil samples were collected from 11 countries (Bosnia and Herzegovina, Bulgaria, Czech Republic, Germany, Italy, Poland, Romania, Serbia, Slovakia, Slovenia and Spain). Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, Zn, and Hg were in ranges of 0.98-22.98 mg kg-1, 0.99-6.03 mg kg-1, 2.51-26.01 mg kg-1, 4.22-83.42 mg kg-1, 11.25-39.77 mg kg-1, 4.79-56.34 mg kg-1, 1.38-91.76 mg kg-1, 32.50-252.20 mg kg-1, 0.20-5.07 mg kg-1, respectively. Hotspots of heavy metals were observed in luvisol and rendzina soils developed on carbonate bedrock. Multivariate analyses discriminated between component 1 with a large positive associations of As, Cd, Cr, Zn, Hg, Pb, CaCO3, Corganic, pH, EC, Mg, and Ca and component 2 with a large positive associations of Co, Cr, Cu, Ni, clay, Al, and Fe. Positive matrix factorization Factor 1 was defined by As, Pb, and Zn, Cu and Hg provided similar contributions for Factors 1 and 2. Cd, Co, Cr, and Ni provided the highest percentage contributions for Factor 2. Pollution index, Enrichment factor of Cr, Hg, As, Pb, Ni, Cd, Cu, Zn, and Co ranges: 0.05–1.17, 4.48–246.63, 0.01–3.21, 0.06–2.97, 0.18–3.40, 4.30–81.62, 0.56–3.20, 0.52–3.83 and 0.21–3.81, respectively

Belgrade’s Urban Green Areas Current Soil State and Its Way to Sustainability

Urban forests are important part of cities’ green infrastructure, especially in cities with great anthropogenic pressure as Belgrade is. Urban green areas enable people to connect with nature and contribute to livability in cities, but some studies reported soil pollution particularly with heavy metals. Due to that, soil samples from Avala Mt,. and Byford’s and Zvezdara Forests were collected from 15 sites and three depths (0-10 cm, 10-20 cm and 20-40 cm), making a total of 45 analyzed samples. Among all analysis, content of microelements was measured for the purposes of this research. No significant changes were observed comparing sites or depths and among all measured elements Zn was the most and Hg the least abundant. Analysis of microelements in soil showed that sustainable soil quality Ni levels are exceeded in all samples, while Cr, Cd and Co levels only in some. All of these results can be explained by forests’ age, geological origin and anthropogenic origin and influence. Even though due to Serbian Soil Quality Regulation no remediation is required for now, in the light of predicted climate change, regular monitoring and assessment should be done to display soil quality and to maintain or improve urban forests sustainability