Primena GIS alata za pripremu ulaznih podataka za HBV-light hidrološki model

The role of hydrological models in water management is significant. One of their important applications is the development and management of water resources, including water quality and sediment transport. Semi-distributed hydrological models, such as HBV-light, provide the possibility of dividing the catchment into sub-catchments and zones according to height and type of land cover. GIS tools provide significant support to prepare input for these models. The paper presents the methodology for preparing input data, using the QGIS tool, for the HBV-light hydrological model, which is used for continuous hydrological simulations. This model transforms precipitation from the catchment into runoff. Three alternative methods are described and compared within the methodology, based on the example of the Veternica river catchment.Uloga hidroloških modela u vodoprivredi je značajna. Jedna od njihovih važnih primena je u razvoju i upravljanju vodnim resursima, uključujući i kvalitet vode i pronos nanosa. Semi-distribuirani hidrološki modeli, kao što je HBV-light, pružaju mogućnost podele sliva reka na podslivove i na zone prema visinama i prema vrsti zemljišnog prekrivača. Da bi se pripremili ulazni podaci za ove modele GIS alati pružaju značajnu podršku. U radu je prikazana metodologija pripreme ulaznih podataka, korišćenjem alata QGIS, za HBV-light hidrološki model, koji služi za kontinualne hidrološke simulacije. Ovaj model transformiše padavine sa sliva u oticaj. U okviru metodologije, na primeru sliva reke Veternice, opisane su i upoređene tri alternativne metode

Stereoselektivne sinteze α-hidroksi-β-aminokiselina iz prirodnih hiralnih prekursora

A method for the stereoselective homologation of -amino acids into syn-α-hydroxy-β-amino acids is described, based on the conversion of stereoisomeric cyanohydrins into trans-oxazolines. The synthetic potential of the method is illustrated in the enantioselective formal synthesis of Bestatin.Opisana je metoda za stereoselektivnu sintezu α-hidroksi-β-aminokiselina syn-konfiguracije, polazeći od α-aminokiselina, kao prirodnih hiralnih prekursora. Enantioselektivnost procesa zavisi od strukture polazne aminokiseline, kao i reakcionih uslova. Primena ove metode ilustrovana je u sintezi (2S,3R)-3-amino-2-hidroksi-4-fenilbutanske kiseline, konstituenta nekoliko važnih biološki aktivnih jedinjenja

Analiza sedam indirektnih metoda za proračun referentne evapotranspiracije u klimatskim uslovima Srbije

In order to calculate water deficit of agricultural crops, it is necessary to have an insight into the evapotranspiration process. As for evaluation of reference evapotranspiration, the Penman-Monteith (FAO56-PM) method, suggested by The International Commission on Irrigation and Drainage (ICID) and Food and Agriculture Organization of the United Nations (FAO), requires several climate parameters, which are often unavailable. Thus, in this paper, the methods for computing ETo, which use limited weather data, were tested and then compared to FAO56-PM. The selected methods were those most often used as the replacement for FAO56-PM: Hargreaves, adjusted Hargreaves, Copais, Turc, Priestley-Taylor, Makkink and Hamon. ETo was calculated at the daily and average monthly levels, for the 2010 2013 period, using data from the following meteorological stations: Niš, Belgrade, Novi Sad, Loznica, Valjevo, Zlatibor, Ćuprija and Kikinda. Special importance was given to the vegetation period during the dry season due to the application of irrigation. The comparison of methods was based on statistical analysis, using parameters: MXE, MAE, RMSD, ARMSD, WRMSD, b and R2. The highest rate of matching FAO-PM at the average monthly level, as well as during the 2012 growing season, was shown by Copais, Turc and Priestley-Taylor methods, thus these methods may be recommended as the replacement for FAO-PM under climate conditions of Serbia. In case only temperature data are available, the results of this research justify the use of the adjusted Hargreaves equation to calculate ETo for the vegetation period.Za izračunavanje potreba za vodom poljoprivrednih kultura neophodno je imati uvid u proces evapotranspiracije. Metoda Penman-Monteith (FAO56-PM), koja je od strane Međunarodne komisije za navodnjavanje i odvodnjavanje (engl. Internatioanl Commission on Irrigation and Drainage ICID) i Organizacije za hranu i poljoprivredu Ujedinjenih nacija (engl. Food and Agriculture Organisation FAO) predložena za proračun referentne evapotranspiracije (ETo), zahteva poznavanje više klimatskih parametara, koji često nisu dostupni. Zato su u ovom radu testirane metode za proračun ETo koje koriste manji broj podataka i upoređivane sa FAO56-PM. Izabrane su metode koje su najčešće korišćene kao zamena za FAO56-PM: Hargreaves, modifikovani Hargreaves, Copais, Turc, Priestley-Taylor, Makkink i Hamon. Proračun je rađen na dnevnom i prosečnom mesečnom nivou, za period 2010 2013. godine, na stanicama: Niš, Beograd, Novi Sad, Loznica, Valjevo, Zlatibor, Ćuprija i Kikinda. Poseban značaj dat je vegetacionom periodu tokom sušne godine, interesantnom sa aspekta primene navodnjavanja. Upoređivanje metoda rađeno je na osnovu statističke analize, pri čemu su korišćeni parametri: MXE, MAE, RMSD, ARMSD, WRMSD, b i R2. Najbolje slaganje sa metodom FAO-PM na prosečnom mesečnom nivou, kao i u letnjem periodu 2012. godine, pokazale su metode Copais, Turc i Priestley-Taylor, pa se one mogu preporučiti kao zamena za metodu FAO56-PM, u našim klimatskim uslovima. Ukoliko se raspolaže samo podacima o temperaturi vazduha, rezultati dobijeni u ovom istraživanju pokazuju opravdanost upotrebe modifikovane metode Hargreaves za proračun ETo u toku vegetacionog perioda

Zbijenost zemljišta različitih teksturnih klasa u zasadima malina ariljskog malinogorja

The principal aim of the present investigations was to establish the influence of threading by agricultural machines or people on the changes of penetration resistance (compaction) of the soils of various textural classes in Arilje raspberry growing area. The investigations included two most abundant soil types in the region, which differed significantly from the aspect of their textural composition: young non-carbonate sandy-loam alluvial soil (fluvisol) and silt-loam brown forest acid soil (dystric cambisol) on micashist. Measuring of penetration resistance in vertical direction, to the depth of 60 cm, between the rows of raspberry plants, at each 10 cm, was performed in the summer 2005 in two raspberry patches 10 years old. For the measurement of the penetration resistance a hand static penetrometer with cone of 30° and radius of 12.3 mm was applied. Repeated (10-20 times a year, according to the statement of the owner) passages of agricultural machines, frequently in very wet weather, as well as people passing (30-50 times a year) lead to a significant increase of penetration resistance (compaction) of the investigated soils in those areas, i.e. paths where machines and people moved. In these areas penetration resistance is 2 to 3 times higher than in surrounding untouched surfaces between the rows of raspberry plants. The values of penetration resistance (compaction) on the threaded paths vary between 1000 and 5000 kPa. The compaction increase made the penetration of raspberry roots into deeper soil layers very difficult.Cilj ovih istraživanja je bio utvrđivanje uticaja gaženja mehanizacijom i od strane ljudi, na izmene otpora penetracije (zbijenosti) zemljišta različitih teksturnih klasa u ariljskom malinogorju. Istraživanjima su obuhvaćena dva najzastupljenija tipa zemljišta u tom malinogorju koja se međusobno jako razlikuju po teksturi, i to: mlado beskarbonatno peskovito ilovasto aluvijalno zemljište (fluvisol) i praškasto ilovasto kiselo smeđe šumsko zemljište (distrični kambisol) na mikašistu. Merenje penetracionog otpora u vertikalnom pravcu, do 60 cm dubine, između redova malina na rastojanju od 10 cm obavljeno je u leto 2005. godine, i to u dva malinjaka starosti 10 godina. Za merenje penetracionog otpora korišćen je ručni statički penetrometar sa konusom od 30o i prečnikom 12.3 mm. Mnogobrojni (10-20 puta godišnje, po izjavi vlasnika malinjaka) prolazi poljoprivrednim mašinama često i po jako vlažnom zemljištu, kao i prolazi ljudi (30-50 godišnje) doveli su do znatnog povećanja otpora penetracije (zbijenosti) istraženih zemljišta na radnim stazama po kojima su se kretale mašine i ljudi. Na tim površinama penetracioni otpor je 2 do 4 puta veći nego na okolnim negaženim površinama između redova malina. Vrednosti otpora penetracije (zbijenosti) na radnim stazama variraju od 1000 do 5000 kPa. Povećanje zbijenosti jako je smanjilo prodiranje korena maline u dublje slojeve zemljišta, što je utvrđeno pri kopanju zemljišnih profila

Supplementary data for article:Trmčić, M.; Matović, R. V.; Tovilović, G.; Ristic, B. Z.; Trajković, V. S.; Ferjančić, Z.; Saičić, R. A Novel C,D-Spirolactone Analogue of Paclitaxel: Autophagy Instead of Apoptosis as a Previously Unknown Mechanism of Cytotoxic Action for Taxoids. Organic and Biomolecular Chemistry 2012, 10 (25), 4933–4942. https://doi.org/10.1039/c2ob25514f

Supplementary material for: [https://doi.org/10.1039/c2ob25514f]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1304

Profitability of organic farming of spelt in the climate conditions of Serbia

This research focuses on assessing the general profitability of organically produced spelt. Spelt is an ancient grain that has experienced a resurgence in Serbia in the late seventies of the previous century, due to its exceptional nutritional value and high compatibility with organic farming. Field experiments were conducted in northern Serbia over four years, applying further financial analysis. The main goal of the research is to identify and quantify the costs, benefits, and general profitability of organic production of spelt in the climatic conditions of Serbia. Results indicate that organically produced spelt is economically profitable, primarily due to its significantly higher market price compared to conventionally produced spelt. Given climate change concerns, promoting the cultivation of climateresilient crops, like spelt, becomes crucial. Organic spelt cultivation could play a significant role in adapting crops to climate change, emphasizing the need for activities that mitigate negative environmental impacts

Profitability assessment of potato production applying different irrigation methods

The present research was conducted during the dry and warm growing seasons of 2011, 2012 and 2013 at Guča, which is a well-known potato-growing region of Serbia. Potato was grown under both rainfed conditions and with irrigation, applying two methods: sprinkler and subsurface drip irrigation. The objective of the research was to conduct a comparative analysis and assess the profitability of potato production under rainfed conditions and with irrigation by these two methods. The main outcome of the research showed that higher yields and more profitable production are achievable with irrigation, compared to rainfed conditions. Subsurface drip irrigation was found to be more profitable than sprinkler irrigation. The results provided insight into the structure and distribution of income and expenses, the income and expense growth trend, the percentage profit growth in the case of sprinkler and subsurface drip irrigation, as well as potential income losses at the national level if the irrigation methods considered are not used. A detailed analysis of the production costs provided insight into the feasibility of optimizing potato-growing approaches for all three types of production. The higher profitability of irrigated potato production opens the question of the need to increase irrigation coverage in Serbia

Metal-Glass Composite Material

The aim of the paper is to create a metal-glass composite material as well as to examine the possibility of using this composite material for industrial application. Powder of commercial austenitic stainless steel (SURFIT TM 316L) of the diameter from 45 to 65 µm was used in this the experiment. The steel powder of the spherical shape is obtained by atomization od gas. The source of glass was basalt rock from the locality "Vrelo" Kopaonik, Republic of Serbia, due to relative low melting point and low viscosity. Composite materials were manufactured by mechanical mixing steel powders with fresh crushed basal rock in diameter below 45 µm. Mixture of basalt content of 10, 30 and 50 wt.% were prepared. Green compacts were obtained by pressing under pressure of 150 MPa using a steel mold. Thermal treatment is done at 1250 ⁰C for 30, 45 and 60 minutes in a vacuum furnace. Starting powder as well as sintered composites were characterized by X-ray diffraction method (XRD). Morphology of powders and microstructural development were followed by scanning electron microscope (SEM). Mechanical properties were investigated by Vickers hardness

The Process of Making Flooring Elements for Interior and Exterior Paving and a Flooring Element

Postupak izrade elemenata podnih obloga za unutrašnje i spoljašnje popločavanje i element podne obloge, pripada oblasti hemije, obrade materijala i građevinarstva, u širem smislu, a odnosi se na završne radove i oblikovane keramičke proizvode karakteristične po svom sastavu i svojstvima u užem smislu. Uz pravilnu tehnološku proceduru, koju čine: mlevenje, mešanje, presovanje i sinterovanje materijala, nastaje element (5) željenih mehaničkih svojstava, koj može biti u obliku cigle ili ploče različitih geometrijskih oblika u osnovi. Za izradu elemenata (5) koristi se mleveni bazaltni prah (2.2) u koji se kao vezivno sredstvo dodaje paraplast, čijim mešanjem se dobije smeša (S). Radi poboljšanja mehaničkih svojstava elemenata (5), u smešu (S) se dodaju čelična vlakna (2.1) kako bi se formirala mešavina (M). Element (5) se sastoji od jezgra (J), koje je izrađeno od mešavine smeše (S) i čeličnih vlakana (2.1) i omotača (4) koji je izrađen od smeše (S) koju čini bazaltni prah (2.2) i paraplast. Element (5) se potom može brusiti i polirati u cilju dobijanja željenih tolerancija i kvaliteta površine za finalnu industrijsku primenu.Registarski broj: 63186Broj i datum rešenja o priznanju prava: 2022/4928, 17.05.2022.Podaci o nosiocu prava: INSTITUT ZA NUKLEARNE NAUKE „VINČA“ – INSTITUT OD NACIONALNOG ZNAČAJA ZA REPUBLIKU SRBIJU, UNIVERZITETA U BEOGRADU (CENTAR ZA SINTEZU, PROCESIRANJE I KARAKTERIZACIJU MATERIJALA ZA PRIMENU U EKSTREMNIM USLOVIMA-CEXTREME LAB), Mike Petrovića Alasa 12-14, 11351 Beograd-Vinča, RSPriznati datum podnošenja prijave: 07.05.202

High-density ceramics obtained by andesite basalt sintering

In the present study, andesite basalt originated from the deposit site “Donje Jarinje”, Serbia, was examined as a potential raw material for high-density ceramics production. The production of high-density ceramics included dry milling, homogenization, cold isostatic pressing and sintering in the air. To determine the optimal processing parameters the sintering was conducted at 1040, 1050, 1060, 1070 and 1080°C, and afterwards the sintering duration was varied from 30 to 240min at the optimal sintering temperature of 1060°C. Characterization of the starting and sintered materials included the estimation of particle size distribution, density, hardness and fracture toughness complemented with X-ray diffraction, optical light microscopy, scanning electron microscopy and energy dispersive spectroscopy analysis. Phase transformations did not occur during processing in the investigated temperature range from 1040 to 1080°C. The obtained research results showed that 99.5% of relative density and the highest hardness and fracture toughness values of 6.7GPa and 2.2MPa•m1/2, respectively, were achieved for the andesite basalt sintered at 1060°C for 60min in the air. The results of the present study confirmed that the sintered andesite basalt can be used as a high-density ceramic material for various industrial applications