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Упит dcterms_subject_txt:Boyd-Lawton limit formula

323 items

  • Classification of Terms on a Positive-Negative Feelings Polarity Scale Based on Emoticons

    Mihailo Škorić (2017)
    The goal of this paper is to draw attention to the possibility of using emoticon-riddled text on the web in language-neutral sentiment analysis. It introduces several innovations in the existing framework of research and tests their effectiveness. It also presents a software tool especially made for that purpose, explains how it builds a database with sentimental value of terms and offers the user manual. Finally, it presents a software tool that tests the new database and gives some examples ...
    data mining, information extraction, emotions, text on the web

  • Comparison of sequential and single extraction in order to estimate environmental impact of metals from fly ash

    Aleksandra Tasić, Ivana Sredović-Ignjatović, Ljubiša Ignjatović, Marija Ilić, Mališa Antić (2016)
    The aim of this paper is to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction pro¬cedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As and Be) in fly ash extracts were measured by inductively coupled plasma-atomic emission spectrometry. Single-agent extractions of metals were conducted at sonication times of 10, ...
    leteći pepeo uglja, ekstrakcija sa jednim agensom, sekvencijalna ekstrakcija, mikrotalasi, ultratalasi

  • Evaluation And Perspectives Of Underground Coal Mines In Serbia

    Vladimir Milisavljević, Milena Lekić, Ivica Ristović, Vojin Čokorilo, Aleksandar Cvjetić (2017)

  • Some examples of interactions between certain rare earth elements and soil

    Zlatko Nikolovski, Jelena Isailović, Dejan Jeremić, Sabina Kovač, Ilija Brčeski (2021)
    Freundlich adsorption isotherm, sequential extraction, metallic ions, ICP-OES

  • Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization

    Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić (2016)
    ... have elevated concentra- tions of Si, F, Li, B, As, etc. Gross alpha and beta activities were naturally low and in some cases below the detection limit (Table 1). REEY concentrations ranged from 43.68 to 2119.83 ng/L with a median value of 205.34 ng/L. Cluster C3 had significant MREE concentrations ...
    ... and Sr (16 mg/L). Elevated β-radioactivity was detected in samples with the highest salinity, while α-activity was low, even below the detection limit. Gross β-activity origi- 13 nated mainly from 40K (from <0.09 to 0.82±0.05 Bq/L), and 228Ra was found to be 0.65±0.03 Bq/L in one sample. Rare ...

  • Effects of external noise on threshold-induced correlations in ferromagnetic systems

    Dragutin Jovković, Sanja Janićević, Svetislav Mijatović, Lasse Laurson, Đorđe Spasojević (2021)
    Изингов модел, праг детекције, екстерни шум
    ... of relaxation can cause the extreme events such as avalanches that span almost the whole system leading to a phase transition in the thermodynamic limit [14]. Among these phenomena, magnetization and relaxation processes in ferromagnetic ma- terials play a distinguished role [15–23]. To model and explain ...
    ... signal V (t ) when driven by the increasing external magnetic field is equal to the number of spins flipped at the moment t . In what follows we will limit our analysis to the systems having the response signal V (t ) > 0 while the system is active and V (t ) = 0 otherwise. Unlike the signals generated ...
    ... adiabatic regime the interval of time between the end of previous and the beginning of next avalanche is technically infinite because this regime is the limit of the constant driving rate regime when the driving rate ω tends to zero. For this reason the external waiting in adiabatic regime doesn’t include ...

  • Remedijacija otpadnih voda Rudnika prirodnim zeolitom

    Igor Veličković (2024)
    U radu je razmatrano prečišćavanje otpadnih flotacijskih voda sa područja rudnika Rudnik prirodnim zeolitskim tufom sa planine Jastrebac. Prečišćavanje otpadnih flotacijskih voda sa područja rudnika Rudnik prirodnim zeoliskim tufom sa obronaka planine Jastrebac pokazala se veoma efikasnom. Naime, u tri otpadne flotacijske vode utvrđen je povišen sadržaj arsena, hroma, gvožđa, mangana, kao i nikla. Jednostavnim tretmanom zeolitskim tufom iz ovih voda uklonjeni su svi ovi elementi. Sadržaji gvožđe i mangana su sniženi od 95 do 99 %, dok su ...
    flotation waste water, zeolite tuff, purification
    ... površini zeolita uključuje procese izmene jona i hidrofobne interakcije ı ima drugačiji tok u zavisnosti od koncentracije surfaktanta u rastvoru (Xu & Boyd, 1995). Katjonski surfaktant HDTMA Jje prevelik da prodre u strukturu zeolita, pa se primećuje samo površinska interakcija (Li et al., 1999). Ako ...
    ... 131—150. Wang, S., Peng, Y. 2010. Natural zeolites as effective adsorbents in water and wastewater treatment. Chem. Engin.J. 156:11-24. Xu, S.; Boyd, S.A. Cationic Surfactant Adsorption by Swelling and Nonswelling Layer Silicates. Langmuir 1995, 11, 2508—2514. 34 O06pasau 1 H3JABA O AYTOPCTBY ...
    ... before the treatment, except for the content of arsenic, the other toxic elements were not present in concentrations above the maximum permissible limit value for water discharged into the environment. Arsenic contents before treatment were three to four times higher than the maximum allowed con ...

  • Tehno – ekonomska ocena ležišta bakra i zlata u istočnoj Srbiji

    Strahinja Sarajlić (2024)
    U svrhu postizanja optimalnih rezultata pri eksploataciji ovog ležišta bakra i zlata, koje se nalazi u istočnom delu Srbije, biće primenjena metoda podetažnog zarušavanja rude i okolnih stena.Tehno-ekonomska ocena opravdanosti eksploatacije rude bakra iz ovog ležišta, urađena je na bazi projektovanih parametara datih u tehničkom projektu. Urađena je analiza i ocenjena je rentabilnost ovog projekta na bazi predviđenog veka eksploatacije od 19 godina.Procenjeno je da je investicioni projekat u celini rentabilan i ekonomski potpuno opravdan. opravdan.
    tehno – ekonomska ocena, investicioni projekat, otvaranje rudnika, metoda otkopavanja, ekonomska ocena, kapitalna investicija
    ... svih potencijalno iskoristivih metala izraženu u bakru. Za masivno-sulfidnu mineralizaciju ležišta, ekvivalentni bakar se računa prema sledećoj formuli: Cuekv = Cu + (0,6667 x Au) pri čemu je sadržaj bakra izražen u procentima, a sadržaj zlata u gramima po toni (g/t). 3. Geološko – ekonomski ...
    ... čemu će se koristiti ekvivalentni, odnosno uslovni bakar (Cuekv) kao osnov za proračun. Za računanje minimalnog ekonomskog sadržaja koristiće se formula Jankovića i Milovanovića za slučaj da je finalni proizvod koncentrat: ___(Tgi+Te+T)'kyb'Sk Smin = — kk % pri čemu je: Smin - minimalni ekonomski ...
    ... komponenti, umanjen za troškove dobijanja tih komponenti, predstavlja vrednost rude. Janković i Milovanović su u svojoj knjizi iz 1985. godine dali formulu po kojoj je moguće izračunati vrednost 1 tone rude: Sy-kop:k \= Ta —g ——,USD/t pri čemu je: Tek= 1.072,33 USD/t - prodajna cena 1t koncentrata; ...

  • Proračun kapaciteta bagera u selektivnom radu na Pk ,,Drmno

    Dušan Stanisavljević (2024)
    U ovom Završnom radu obrađena je problematika proračuna kapaciteta bagera u površinskoj eksploataciji ležišta mineralnih sirovina. Dat je prikaz opštih karakteristika i načina rada rotornih bagera, kao i proracun kapaciteta bagera u selektivnom radu na PK ,,Drmno,,. Urađena je analiza dobijenih rezultata I izveden krajinji zaključak iz istih.
    površinski kop, kapacitet, rotorni bager, analiza
    ... prema učešću tih stena u masivu ili etaži po formuli: Qt= pl1*Qti + p2*Qt2 + pn*Qtn ; gde je: P - učešće pojedinih vrsta stene (pl +p2+...+pn=1 ) 25 – Teoretski kapacitet rotornog bagera može se računati ı preko zapremina rezova po formuli: Qt= 60*c*v*h, (rm3/h) gde Je: c - debljina ...
    ... (Verladegerat mit Raupenfahrewerk), samohodni utovarni uređaj na gusenicama. Svaki tip bagera proizveden u nemačkim firmama KRUPP i OK predstavljen je formulom: SchRs-800x15/1,5 gde je: – Sch -– rotorni bager, – R - gusenični uređaj za krertanje, – s - obrtna platforma, – 800 - zapremina vedrice, ...
    ... parametre za stabilnost kosina) ı tehnologije rada, odnosno predstavlja njegov maksimalno mogući kapacitet u određenom otkopu ı steni , a računa se po formuli: k < ; ch i pj Qtž*ka ,(cm3/h),gdeje: kp - koeficijent punjenja kašike kr - koeficijent rastresitosti stene ko – koeficijent otkopa ( pro ...

  • Zaštita od miniranja

    Suzana Lutovac, Miloš Gligorić (2024)
    Miniranje

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... was analysed by energy-dispersive X-ray spectrometry (EDS, X-Max, Oxford Instruments PLC, Abingdon, UK), using internal standards with detection limit ~0.1 wt.%. Simultaneously, the homogeneity and possible zoning were analysed by backscattered electron (BSE) micrographs (Figure 1c,d). 2.2. X-ray ...
    ... with a large surface-to-volume ratio [28]. Assuming, the spherical shape of the particles and the observed speed of oxide formation, the detection limit of ~1% by volume criterion for a 5 nm thick surface oxide layer formed upon ~10 min air exposure is already achieved for 1.5 am grains. As the standard ...

  • Integrative GHG Assessment in Oil and Gas Industry

    Aleksandar Mirković, Marija Živković, Stevan Đenadić, Darja Lubarda, Chinedu Anyanwa (2023)
    Reducing greenhouse gas emissions is one of the main targets of national strategies in European countries. As a main contributor to emissions, the energy sector is recognized as the most promising to apply measures and actions aimed to decrease GHG emissions. The Oil and Gas industry as a significant contributor to global greenhouse gas emissions is facing a growing need for estimating, mitigating, and reducing the impact of their operations on the atmosphere to stay competitive in a newly ...
    energetska tranzicija, gasovi staklene baste, industrija, nafta i gas
    ... Paris Agreement in 2015, signatory countries achicved international consensus to limit increases in the global average temperature to well below 2%C compared to pre-industrial levels, and to make efforts to limit the temperature increase to 1.55C compared to pre-industrial levels [6]. The task set ...

  • Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series

    Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić (2021)
    Underground mining engineers and planners in our country are faced with extremely difficult working conditions and a continuous shortage of money. Production disruptions are frequent and can sometimes last more than a week. During this time, gate road support is additionally exposed to rock stress and the result is its progressive deformation and the loss of functionality of gate roads. In such an environment, it is necessary to develop a low-cost methodology to maintain a gate road support system. ...
    deformacije podgrade, lasersko skeniranje, višekanalna singularna spektralna analiza, prognoza, klasterisanje fuzzy vremenskih serija

  • Optimizacija dužine strele rotornih bagera u funkciji stabilnosti kosina i efektivnosti rada na površinskim kopovima lignita Srbije

    Branko M. Petrović (2016-07-12)
    Rotorni bageri su mašine koje se u današnje vreme najviše primenjuju uprocesu masovne eksploatacije uglja zahvaljujući, pre svega, nizu tehničkoeksploatacionihprednosti u odnosu na druge vrste bagera. Raznovrsnirudarsko-tehnički zahtevi otkopavanja doprineli su razvoju nekoliko tipova ovihmašina, tako da svaki od njih ima svoje prednosti i nedostatke u odnosu nadrugi tip.Predmet istraživanja u disertaciji odnosi se na izbor optimalnekonstrukcije strele bagera i njene usaglašenosti sa uslovima radne sredine kojiće vladati na površinskim kopovima lignita Srbije, imajući u vidu složene usloveeksploatacije (velika ...
    površinski kop, parametri bloka, kapacitet, rotorni bager, strelabagera, geomehanika, stabilnost kosina, ekonomija

  • Agates of the Lece Volcanic Complex (Serbia): Mineralogical and Geochemical Characteristics

    Zoran Miladinović, Vladimir Simić, Nenad Nikolić, Nataša Jović Orsini, Milena Rosić (2024)
    Agate veins and nodules occur in the Lece Volcanic Complex (Oligocene-Miocene) situated in the south of Serbia and occupying an area of 700 km2. This volcanic complex is composed predominantly of andesites, with sporadic occurrences of andesite-basalts, dacites and latites, and features agate formations that have been very little investigated. This study focuses on five selected agate occurrences within the Lece Volcanic Complex, employing optical microscopy, scanning electron microscopy (SEM), X-ray powder diffraction analysis, inductively coupled plasma mass spectrometry ...
    Lecki vulkanski kompleks, andeyit, kalcedon, kvarc, opal-CT, mikrostruktura, organska materija

  • Projection of SO2 emissions in coal power plants in Serbia

    Aleksandar Madžarević, Predrag Jovančić, Stevan Đenadić, Filip Miletić, Miodrag Ristović, Miroslav Crnogorac (2023)
    The production of electricity in the countries of South-Eastern Europe (SEE) was mainly related to the use of coal, predominantly lignite. The total installed capacity of thermal power plants using coal in these seven countries is 17.813 MW, distributed in 31 thermoblocks. The mentioned plants are the dominant pollutant emitters in all observed countries. Data on the largest emitters in the countries of the European Union and a comparison with SEE countries were collected. The calculation of emissions of ...
    енергeтика, емисије, СО2, угаљ, електране
    ... amount of SO» produced in the amount of 86424 t, an average of 16759 t of SO» should go into the atmosphere. This value represents the permissible limit. 4. CONCLUSION Air pollution from coal-fired thermal power plants knows no national borders. Through the paper, it was pointed out that the area ...

  • Smanjenje sleganja plitkih temelja primenom mikrošipova

    Slobodan Ćorić, Dragoslav Rakić (2021)
    Mikrošipovi su šipovi malog prečnika koji se grade tako što se u tlu specijalni postupkom formira bušotina koja se zatim armira i injektira. Njihov prečnik je najčešće 150 – 300 mm, a dužina može da bude i više desetina metara. Mikrošipovi mogu da se grade u svim vrstama tla i mogu da budu vertikalni i kosi. Oni se, stoga, koriste kao zamena za konvencionalne šipove i ankere. Primena mikrošipova u fundiranju predstavlja jedan savremeni način izgradnje i sanacije temelja/objekata. ...
    mikrošipovi, sleganje plitkih temelja i mikrošipova, krutost tla i mikrošipova

  • Comparative analysis of karst water quality parameters of the Banja spring near Valjevo (Republic of Serbia)

    Jovana Lončar, Jovana Mladenović, Vesna Ristić Vakanjac, Veljko Marinović, Branislav Petrović, Petar Vojnović, Radisav Golubović (2024)
    The monitoring of karst spring release regimes is becoming more and more relevant due to the fact that karst waters are of exceptional quality and most often it is only necessary to chlorinate these waters in order to use them for water supply. In addition to monitoring the discharge regime, it is certainly necessary to establish monitoring of quality parameters that are generally observed sporadically (seasonally or monthly). An example of a well-designed monitoring of quantitative and qualitative parameters ...
    pH, Ec, mutnoća, isticanje, karstno vrelo

  • Tehnologija izrade jamskog magacina eksploziva i eksplozivnih sredstava

    Sara Nikolić (2024)
    Završni rad sa temom „Tehnologija izrade jamskog magacina eksploziva i eksplozivnih sredstava” sastoji je iz opšteg dela i specijalnog dela. U opštem delu prikazani su : geologija ležišta, određivanje kapaciteta magacina eksplozivnih sredstava, lokacija i opis magacina. U specijalnom – drugom delu ovog završnog rada prikazani su: potrebni proračuni, tehnologija izrade magacina, predmer i predračun radova, normativi materijala, energije i radne snage, organizacija i dinamika izvodjenja radova. Prilikom izrade završnog rada, uz primenu svih propisa vezanih za ovu oblast, korišćene su ...
    magacin, eksploziv, sredstva za iniciranje, hodnik, komor
    ... sredstva usvojeno je i iznosi d=8,Om, što je u granicama koje su propisane (dmm=6,0m). Međutim, dimenzije celine se mogu tačno izračunati pomoću formula kako je to dobijeno proračunom u sledećem poglavlju. U sledećem tekstu date su vrednosti dužina i azimuta koje zaklapaju pojedine ose prostorija ...
    ... tri kriterijuma dati veću vrednost. Debljina pregrade koja ne omogućava prenošenje detonacije između dve susedne komore MES proračunava se po formuli: Ba-Kı ·'K»· Ž/č, (m) (5.1) Ba=1,25 · 0,005 · V5000=1,25 · 0,095 · 17,1=2,03m, gde jJe: Ba- debljina pregrade između komora, Ki=1+1,25 - ...
    ... v — brzina (m/s), · A - amplituda , · v - frekvencija (Hz), · X - talasna dužina (m). Seizmički sigurno rastojanje proračunava se na osnovu formule: R=1,2 · K· 3/Q, (m) (5.2) R=1,2 · 3 · V5000=3,60 · 17,1=61,56m, gde jJe: R=61,56 m, - seiznmički sigurno rastojanje, Q=5.000 kg, - količina ...

  • Threshold-induced correlations in the Random Field Ising Model

    Sanja Janićević, Dragutin Jovković, Lasse Laurson, Đorđe Spasojević (2018)
    Multidisciplinary