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Упит dcterms_subject_txt:X-raydiffraction method

525 items

  • Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja

    Seyed Ali S. Razeghi (2022)
    Gubitak isplake predstavlja nekontrolisano isticanje bušaćeg fluida kroz formacije kao što su kaverne, pukotine, ili drugi slojevi. Tradicionalne metode procene gubitka isplake se zasnivaju na primeni seizmičkih podataka ili pronalasku „mesta“ gubitka isplake na osnovu raspoloživih podataka iz susednih bušotina. Međutim, ove metode procene nisu pouzdane.‘ U disertaciji je izvršena analiza i procena uticaja parametara bušenja, geoloških faktora, karakteristika formacije i fluida na gubitak isplake kao i na formiranje fraktura u formacijama. Uspostavljeni su modeli koji podrazumevaju proces obrade ...
    naftna bušotina, gubitak isplake, fuzzy logika, ANFIS model

  • Improvement of geodatabase queries within GeolISS

    Ranka Stanković (2008)
    ... which are represented in a GIS by digital data. There are two general approaches used for storing data in a GIS: the raster and the vector method. The first method represents geological features as images, whereas the latter uses geometrical shapes, namely different types of geometrical objects, for ...
    ... related attributes. Modern GIS technologies are based on digital information, with various methods used for creating digital data. The most common method of data creation is digitization, where a hard copy map or research plan is transferred to digital form by means of a computer-aided design program ...
    ... as well as header text (to be displayed in query construction), field type with coded values for string ‘C’, number ‘N,I’, date ‘D’, and domain ‘X’, with the domain name given separately. Ranka Stanković 69 Figure 3. The form for maintenance of query parameters Figure 4 depicts ...

  • Application of Expansive Mortars for the Formation of Artificial Screens During Blasting in Urban Areas

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Nikola Simić, Jelena Majstorović (2024)
    During construction of buildings in urban areas, sometimes there is a need to blast solid rock mass in the immediate vicinity of the surrounding buildings. In that case, the aim is not only to increase the efficiency of blasting, but also to reduce harmful effects of ground vibration induced by blasting. At the same time, it is very important to protect the buildings located in the safe zone from the blast site as well as remaining rock mass around ...
    expansive mortar, artificial screens, pressure, rock breaking, building foundation

  • Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering

    Josip Išek, Lazar Kaluđerović, Nikola Vuković, Maja Milošević, Ivana Vukašinović, Zorica Tomić (2020)
    γ-spectrometry, brushite, chukhrovite, phosphogypsum, radionuclides, recrystallization
    ... Studies im Chemical Process Technology, 1, 30-36. Hua S, Wang K. & Yao X. (2016) Developing high performance phosphogypsum- based cementitious materials for oil-well cementing through a step-by-step optimization method. Cement and Concrete Composites, 72, 299-308. IAEA (2013) Radiation Protection ...
    ... of the samples' containers, and the purified gypsum sample was measured once, after the con- tainer was sealed. By applying the y-spectrometry method, the activity concen- tration of _ŠU was determined from its decay products Th (63keV) and/or "Pa (1000 keV). The ecay products of ? Ra, _ Bi (609 ...
    ... similar result was obtained with calcium sulfate whiskers synthesized from flue gas desulfurization of gypsum using the atmospheric acidification method (Sun ef al., 2016). Whiteness index The WI of 52.5%, determined for raw phosphogypsum (PG1), is too low for potential use in some industries ...

  • Some models for determination of parameters of the soil oscillation law during blasting operations

    Suzana Lutovac, Dragan Medenica, Branko Gluščević, Rade Tokalić, Čedomir Beljić (2018)
    ... definite integral of the observed function. Surface S confined by continuous curve y = f (x), x-axis, and vertical lines x = a and x = b, if f (x) ě 0 for a ď x ď b (Figure 1), as the definite integral of the function f (x), obtains the following: S “ b ż a f pxq dx (17) Energies 2016, 9, 617 5 of 15 ...
    ... spaced, namely if: Ri`1 ´ Ri “ hi pi “ 1, 2, . . . , N ´ 1q (21) Energies 2016, 9, 617 5 of 15 a b X Figure 1. Surface S confined by continuous curve y = f(x), x-axis, and vertical lines x = a and x = b. When carrying out blasting operations, we register (measure) at suitable measuring points the values ...
    ...                                               ‐                       Figure 1. Surface S confined by continuous curve y = f (x), x-axis, and vertical lines x = a and x = b. When carrying out blasting operations, we register (measure) at suitable measuring points the values of oscillation velocities ...

  • Models of Determining the Parameters of Rock Mass Oscillation Equation with Experimental and Mass Blastings

    Suzana Lutovac, Branko Gluščević, Rade Tokalić, Jelena Majstorović, Čedomir Beljić (2018)
    ... so doing, the area bounded by x-axis, line segments x1M1 and xN MN and broken line, consisting of (N − 1) trapezoid [12,13], has the value: ST = 1 2 [ N−1 ∑ i=1 (yi + 3 + yi+1 + 3)·(xi+1 − xi)]. (29) Let’s mark the area bounded by line (27), lines x = x1, x = xN and x-axis with S. Its value is: S ...
    ... models, using the values obtained by experimental measurements. 3.3.1. Model 1—Determining the Parameters by Applying the Least Square Method The Least Square Method is mainly used to obtain the parameters K and n which represents a common model [9,10]. 3.3.2. Model 2—Determining the Parameters through ...
    ... change: logv = y; logK = b; −n = a; logR = x, (22) Equation (21) becomes a line equation: y = ax + b. (23) Minerals 2018, 8, 70 7 of 18 We will increase ordinate values y = logv by one positive number c, so that all points Mi(xi, yi + c) are above axis x = logR, i.e., so that yi + c = logvi + c ...

  • Моделирање утицаја одступања линије најмањех отпора од пројектоване на интензитет потреса од минирања

    Стефан Милановић (2024)
    Према дефиницији линија најмањег отпора представља најкраће растојање од центра минског пуњења до слободне површине. Oвим истраживањем представљен је утицај линије најмањег отпора, као и њеног одступања од пројектоване на интезитет потреса услед минирања. Проблем линије најмањег отпора је веома заступљен у пракси, где се занемарује изглед слободне површине, који може бити врло неправилан. Линију најмањег отпора је потребно мерити целом дужином минске бушотине према слободној површини, иако је у пракси случај да се мери најчешће као растојање од ...
    линија најмањег отпора, 3D модел, потреси услед минирања, минирање, слободна површина, метода раздвојених елемената

  • Design and drilling of wells in formations with high pressure

    Vojin Solomun (2024)
    Objectives of this Thesis are to: - Develop an awareness of the challenges presented from elevated temperatures and pressures in well construction. - Learn the key differences between ―normal‖ condition wells and HPHT wells. - Understand some of the indicators of thermal- and pressure-related problems. - Understand the responses which may be made to mitigate high pressure and high temperature ,,HPHT‘‘ challenges while drilling wells. HPHT wells are an unavoidable consequence of the ever expanding search for oil and gas resources around the world. As wells are ...
    HPHT, well, challenges, design, oil and gas
    ... axial load. The calculation method documented in API Bulletin 5C3 can be used to plot the curves of depth (axial load) vs annular 103 pressure (collapse load) for several pipe sizes, material specifications and pipe conditions. API allows the use of Drillpipe Grade E, X, G and S in a sour environment ...
    ... (NExT), 2016. Driller's Method, Wait & Weight Method, Volumetric The Driller's Method is the simpler well control procedure, although ıt takes longer, requiring two circulations (at least), which is a significant issue in expensive wells. The Wait and Weight method is viewed by many as “too complex” ...
    ... Picture 8.14 — BOP stack (NExT, 2016.) Well Control Program - Procedures such as shut-in method, flow checks, circulating rates, kill method to be utilized and alternatives to use if primary kill method does not work, must be established prior to drilling the well and defined in the WCPP. A ...

  • The Reciprocal Algebraic Integers Having Small House

    Dragan Stankov (2021)
    Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomials

  • Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu

    Marija D. Prekajski (2014-04-04)
    Nanoprahovi kristalnih faza iz serije čvrstih rastvora u pseudo-binarnom sistemuCeO2-Bi2O3 sintetisani su primenom jednostavne i ekonomične samopropagirajućemetode na sobnoj temperaturi korišćenjem nitrata metala i natrijum-hidroksida kaopolaznih supstanci. Osim krajnjih članova niza, CeO2 i niskotemperaturne polimorfnemodifikacije α-Bi2O3, sintetisani su i čvrsti rastvori nominalnog sastava Ce1-xBixO2-δ,gde je x = 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9. Rezultati proučavanja metodomrendgenske difraktometrije na polikristalnom materijalu i ramanske spektroskopskeanalize pokazali su da su sintetisani prahovi sa nižim sadržajem bizmuta (x = 0,1 ...
    nanostrukturni materijali, čvrsti rastvori, CeO2, Bi2O3, rendgenskadifraktometrija praha, Ritveldova metoda, mikrostrukrurna analiza

  • Kristalne strukture Cs2HoSi4O10F i Cs2TmSi4O10F

    Predrag Dabić, Sabina Kovač, Aleksandar Kremenović (2021)
    ... The compounds were synthesized by the method of crystal growth from a high-temperature solution (Tmax = 1373 K) using REE2O3 (REE = Ho, Tm), SiO2 and CsF as starting materials. The crystal structures of both compounds were determined by single-crystal X-ray diffraction analysis. They represent ...

  • Postojeće stanje i budući trendovi u preventivnoj zaštiti podzemnih voda Srbije

    Vladimir Živanović (2022)
    Podzemne vode predstavljaju osnovni, a u mnogim zemljama i jedini resurs za javno vodosnabdevanje stanovništva tako da zaštita podzemnih voda predstavlja bitan preduslov za njihovo dugotrajno i održivo korišćenje. Kako u svetu, tako i u Srbiji, zaštita podzemnih voda se najvećim delom svodi na primenu preventivnih mera zaštite. Kod planiranja zaštite većih prostora sve više se koriste metode za ocenu ranjivosti podzemnih voda. Njihova primena je posebno naglašena u karstnim područjima zato što se tu izdvajaju delovi terena sa ...
    Zaštita podzemnih voda, karte ranjivosti podzemnih voda, karta hazarda, karte rizika od kontaminacije, monitoring podzemnih voda, Srbija

  • Review: Methodological approaches and research techniques for addressing construction and remediation problems in karst reservoirs

    Saša Milanović, Ljiljana Vasić (2021)
    Earth and Planetary Sciences (miscellaneous), Water Science and Technology

  • Аnaliza mogućnosti povećanja nagiba završne kosine površinskog kopa “Podbraćan”

    Vladimir Čebašek, Veljko Rupar (2018)
    Eksploatacijom boksita iz ležišta "Podbraćan" formiran je površinski kop sa maksimalnom visinom zavšne kosine od 280 m. Redovnom kontrolom stabilnosti trenutnog stanja kosina površinskog kopa utvrđeno je da faktor sigurnosti iznosi Fs = 1.71 – 1.85, a što je ukazalo da postoji mogućnost povećanja nagiba kosine. U radu je prikazan postupak analize mogućnosti povećanja nagiba završne kosine površinskog kopa "Podbraćan".
    stabilnost kosina, povećanje nagiba kosina, metoda konačnih elemenata

  • FTIR spectroscopic study оf S-мetolachlor сorption оn inorganic and organically modified montmorillonite from Bogovina

    Lazar Kaluđerović, Zorica Tomić, Jelena Bogosavljević, Ljubomir Životić, Maja Milošević (2021)
    ... was collected from the Bogovina locality (Serbia). Clay fraction, with montmorillonite as the dominant mineral, was separated using the decantation method. Clay fraction (< 2 mm) was then treated with 30% hydrogen peroxide in order to remove organic matter from the sample. 330 SERBIAN SOCIETY OF ...
    ... and marked as NaM-SM, 1H-SM, 2H-SM, 3H-SM, 4H-SM, IP-SM, 2P-SM, 3P-SM, and 4P- SM. FTIR spectroscopy All samples were investigated using FTIR method (Fourier-transform infrared spectroscopy). All results were obtained in Laboratory for infrared spectroscopy at the Faculty of Science, University ...
    ... Figure 3. Suggested interactions betveen PTMA*cations and phenolin interlayerspace of montmorillonite (Majdan et al., 2009) CONCLUSION FTIR method was very useful in the process of examination of interactions between Na- montmorillonite and organic complexes such as HDTMA bromide and PTMA chloride ...

  • Речници у дигиталном добу - информатичка подршка за српски језик

    Биљана Рујевић (2022)
    Морфолошки речници српског језика представљају електронски језички ресурс који има значајну историју развоја и коришћења за потребе обраде природних језика. С обзиром на то да су чувани у облику датотека чији је број нарастао па је самим тим управљање речницима постало отежано јавила се потреба за смештањем информација из речника у облик лексикографске базе. Како би се омогућио симултани рад на развоју речника за више корисника јавила се потреба за веб-апликацијом заснованој на лексикографској бази. Како би се размотриле ...
    електронски речници, лексикографска база података, лексички ресурси, српски језик

  • Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material

    Borislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić (2022)
    Pyrophyllite, with the chemical formula Al2Si4O10(OH)2, is a naturally occurring and abundant van der Waals mineral belonging to the group of phyllosilicates. It is very soft, layered crystal used for sculpting and an excellent electrical and thermal insulator aimed for the operation at high pressure and temperature. Here, for the first time, two-dimensional (2D) pyrophyllite obtained by both mechanical and liquid phase exfoliation is presented and investigated at the nanoscale. The layered structure provides low friction coefficient of around ...
    Atomic force microscopy, Insulating properties, Nanofriction and wear, Natural two dimensional materials, Phyllosilicates, Pyrophyllite

  • Hydrochemical features and their controlling factors in the Kucaj-Beljanica Massif, Serbia

    Fen Huang, Ljiljana Vasic, Xia Wu, Jianhua Cao, Saša Milanovic (2019)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change

  • Mesozoic carbonate rocks in Serbia used as dimension stone

    Vesna Matović, Tijana Vojnović Ćalić (2016)
    The building industry in Serbia uses, to a great extent, imported natural stone for architectural purposes. The significance of local deposits, particularly limestones, is not adequately perceived despite the country’s abundance of these valuable resources. Therefore, this study focuses on Serbia’s Mesozoic carbonate rocks, specifically on the deposits of four selected quarries: Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, ...
    Ukrasni kamen, Mezozoik, Krečnjak, Srbija, Petrografija, Fizičko-mehanička svojstva
    ... N 0 0 0OS9% 9L-LL 9 I _ [A\ || _ [31] 61 _ 0 0 6 SILL I g l x x x _ 6 0 I _ 0 0 6 PULL bPt9l _ bij iis _ 890 _ _ Ob9% tULL HRAl _ LL 9I _ x _ _ 069% cI-LL [ . 101 |4] OI 00 670 I 0 0 099% T-LL 9 I _ 001 ...
    ... 0 x 09970 C I - D 4 ! 91 091 iil 00 0 0 LO O I 0 6 9 | 1I-Di 97c s 4l is \J tPcO x x 069C O I - D c O LI 011 | 0 00 910 LI O c ' 089% 67Di ba:00 6 1 861 1Ic 00 0 0 0 O I 069% D [ 61 t0C LO 00 910 x O c ...
    ... density was determined according to the standard method SRPS B.B8.032 (1980) (corresponding to Euro- pean Committee for Standardization EN 1936:2006). On the same, but powdery samples, the real densities were determined using a pycnometer method. Considering the values of real and bulk density ...

  • 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
    ... composition of the arsenopyrite crystal was analysed inside the TEM chamber by energy-dispersive X-ray spectroscopy (EDS). The quantification was assessed by the Cliff-Lorimer ratio thin section method (four iterations), with the Si-K line as the ratio standard element and line [20]. The calculated ...
    ... length (L) was calibrated by MAG*ICAL traceable TEM calibration standard to enhance the method”s precision. Quantitative analysis of electron diffraction was calculated according, to Bragg's law nA = 2d x sin0, using, an approximation for small angles 20 = ~A/d = R/L, with the final reduction ...
    ... 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 Powder Diffraction ...