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Упит dcterms_subject_txt:hammer with spikes

1033 items

  • Compaction of Municipal Solid Waste

    Jovana Janković Pantic, Dragoslav Rakić, Tina Đurić, Irena Basarić Ikodinović, Snežana Bogdanović (2022)
    Regardless of the numerous activities undertaken to reduce municipal solid waste, its annual volumes continue to grow. In Serbia, the most common and the only one form of waste disposal is at municipal landfills with daily compaction and soil covering. Municipal waste compacting is one of the basic components of the disposal process. Well compacted waste takes up less volume and allows much safer storage. In order to better predict the behavior of municipal waste at landfills, it is ...
    compaction, hammer with spikes, landfill, municipal solid waste, proctor compaction test

  • Geotechnical effects of municipal solid waste destruction with different compaction methods

    Jovana M Janković Pantić, Dragoslav R Rakić, Irena G Basarić Ikodinović, Tina D Đurić, Gordana Hadži-Niković (2022)
    Disposal of waste in municipal solid waste landfills is the only way of waste disposal in Serbia, with daily compaction and covering with soil material. Due to less space for the construction of new landfills, it is necessary to use their maximum capacity. Well-compacted municipal solid waste takes up less volume and enables safer storage, so it is useful to previously determine the compaction parameters in the laboratory: maximum dry unit weight (γdmax) and optimal water content (wopt). In ...
    komunalni otpad, zbijanje, Proktorov opit, malj sa šiljcima

  • Geotehnički efekti razaranja komunalnog otpada različitim postupcima zbijanja

    Jovana M. Janković Pantić (2022)
    Odlaganje otpada na komunalne deponije predstavlja osnovni način zbrinjavanja otpada u Srbiji. Kako bi se prostor za deponovanje materijala racionalno koristio potrebno ga je svakodnevno zbijati sa unapred definisanom količinom vode koja se dodaje. Dobro zbijeni komunalni otpad zauzima manju zapreminu i omogućuje sigurnije skladištenje, pa je korisno prethodno laboratorijski odrediti parametre zbijanja: maksimalnu suvu zapreminsku težinu (dmax) i optimalnu vlažnost (wopt). U Srbiji do sada nisu određivani parametri zbijanja, dok je u svetu primenjivana standardna metoda (Proktorov opit) ...
    komunalna deponija, zbijanje, Proktorov opit, malj sa šiljcima, koeficijent razaranja

  • Parametri zbijanja komunalnog otpada određeni različitim laboratorijskim metodama

    Jovana M Janković Pantić, Dragoslav R Rakić, Irena G Basarić Ikodinović, Tina D Đurić, Snežana Bogdanović (2021)
    Zbijanje komunalnog otpada predstavlja jednu od osnovnih faza korišćenja komunalne deponije. Zbog toga je kao i kod drugih nasutih građevina, veoma korisno odrediti parametre zbijanja: maksimalnu suvu zapreminsku težinu (dmax) i optimalnu vlažnost (wopt). Dobijeni rezultati mogu da posluže prilikom projektovanja kapaciteta deponije kao i prilikom definisanja obradivosti otpada. U dosadašnjoj praksi najčešći način određivanja parametra zbijanja je standardna metoda (Proktorov opit) koja se koristi u mehanici tla, uz eventualnu redukciju energije zbijanja. Međutim, različiti tretmani komunalnog otpada na ...
    deponija komunalnog otpada, zbijanje, Proktorov opit, malj sa šiljcima
    ... The samples werc tested т standard Proctor apparatus at (ће same compaction energy, but with two different hammers: standard flat hammer and hammer with spikes. In this way, it is possible to compare thc results obtained by different compaction procedures, and cffect of ће wastc composition on ...
    ... changing (ће. classic flat Proctor hammcr, by adding spikes, whose function is, im addition to compaction, destruction and shredding, ог municipal waste. The paper presents the behavior of municipal waste for two synthetic waste samples with different waste composition (Plandište landfill). The ...
    ... compaction conditions is determined. Кеу words: municipal waste landfill, compaction, Proctor compaction test, ћаттег with spikes 1. UVOD Odlaganje komunalnog otpada па deponije predstavlja jedan od vclikih izazova današnjicc sa ckološkog aspekta. Počevši od izbora lokacije, njenog životnog ...

  • Mechanosynthesis and structural characterization of nanocrystalline Ce1–Y O2– (x=0.1–0.35) solid solutions

    Martin Fabián, Bratislav Antić, Vladimír Girman, Milica Vučinić-Vasić, Aleksandar Kremenović, Shigeru Suzuki, Horst Hahn, Vladimír Šepelák (2015)
    A series of nanostructuredfluorite-type Ce1–xYxO2–δ (0rxr0.35) solid solutions, prepared via highenergy milling of the CeO2/Y2O3mixtures, are investigated by XRD, HR-TEM, EDS and Raman spectroscopy. For thefirst time, complementary information on both the long-range and short-range structural features of mechanosynthesized Ce1–xYxO2–δ, obtained by Rietveld analysis of XRD data and Raman spectroscopy, is provided. The lattice parameters of the as-prepared solid solutions decrease with increasing yttrium content. Rietveld refinements of the XRD data reveal increase in microstrains in the host ceria ...
    Ceria, Yttrium, Solid solution, Mechanosynthesis, Oxygen vacancy, Nanocrystalline material

  • Witness of the history: A hundred years old the geological hammer of Jovan Zujovic

    Ljupko Rundić (2021)
    Током обележавања тридесет година постојања и рада Српског геолошког друштва 10. фебруара 1921. године, у знак великог поштовања према академику Јовану Жујовићу, председнику и оснивачу Српског геолошког друштва и српске геолошке школе, чланови СГД поклонили су му јединствени геолошки чекић са угравираном посветом и својим потписима. Током протеклих стотину година, многе генерације геолога проналазиле су инспирацију гледајући чекић и делећи ову причу с великим пијететом. Данас, када геолози посећују Спомен собу геологије (Рударско-геолошки факултет, ул. Каменичка бр. 6), где се пажљиво ...
    Геолошки чекић, Јован Жујовић, Српско геолошко друштво, 1921–2021

  • 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

  • Application of machine learning for diagnosing the operation of a deep well pump in oil production

    Maja Trikić (2024)
    This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.
    deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost
    ... learning can analyze these data to identify patterns and anomalies. For example, algorithms can detect unusual changes in vibrations or temperature spikes that indicate potential issues. 2. Anomaly detection Machine learning models can be trained on historical data of pump operations, including ...
    ... (in} 42 Figure 6.1. Examples of patterns for operating conditions on surface and downhole dynamometric cards: (a) normal operation; (b) fluid hammer; (c) moving valve leak; and (d) stationary valve leak 6.1 Sensor fault diagnostics Sensors are critical components of automated data acquisition ...
    ... training dataset Imbalanced With hyperparameter tuning WithTuning No hyperparameter tuning NoTuning Table 2. Resources and tags used for each experimentation 6.6.2 Results of Models Trained on Small Datasets Experiments were conducted with 24 models trained on datasets with 30, 90, and 180 samples ...

  • Influence of Initial Treatment on the Survival and Recurrence in Patients With Differentiated Thyroid Microcarcinoma

    Jasna Mihailović, Ljubomir Stefanović, Ranka Stanković (2013)
    ... and recurrence in patients with DTM. Methods: Between January 1979 and December 2006, 130 patients with DTM were retrospectively evaluated, with a median follow-up of 10 years. Total/near-total thyroidectomy was performed in 121 (93.1%) of 130 patients, followed with 131I ablation in 71 (54.6%) ...
    ... resection in patients with PTM.21 The British Thyroid Association is in agreement with previous guidelines suggesting that microcarcinomas of the thyroid gland can be adequately treated by lobectomy alone followed by L-thyroxine therapy.22 Ito et al18 conclude that hemithyroidectomy with elective lymph node ...
    ... recurrence and survival of patients with DTM. PATIENTS AND METHODS Patients A retrospective review of patients with DTM presenting at the Oncology Institute of Vojvodina from January 1979 to December 2006 was performed. During this period, a total of 1040 patients with DTC were treated. In this study ...

  • 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)
    ... times with distilled water and accordingly labelled as IH- 0.25 CEC saturated with HDTMA complex, 2H- 0.5 CEC saturated with HDTMA complex, 3H- 0.75 CEC saturated with HDTMA complex, 4H- 1 CEC saturated with HDTMA complex, 1P- 0.25 CEC saturated with PTMA complex, 2P- 0.5 CEC saturated with PTMA complex ...
    ... Kita-Ku, Tokyo, Japan), with a purity of 98%. A raw natural sample of bentonite 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 ...
    ... complex, 3P- 0.75 CEC saturated with PTMA complex, and 4P- I CEC saturated with PTMA complex. All samples are then treated with 1000 mg/L working solution of S-metolachlor 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 in ...

  • Surface functional groups and degree of carbonization of selected chars from different processes and feedstock

    Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)
    The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...
    Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS
    ... were measured with a Jenway 4330 (Jenway, Gransmore Green, Essex, England) with automatic temperature compensation for 25 "C. Removal of acid soluble ash components. The chars were shaken for 24 h with 0.05 M HClin order to remove ash components [57]. Then they were washed twice with 1 M CaCl, ...
    ... of material. Ag/AgCI electrodes filled with 4 mM NaC!I were used for potential measurement. 2% (w/w with respect to the mass of sand) of charcoal was added to air-dry sand and the materials were mixed by stirring with a spatula. The mixture was wetted with electrolyte solu- tion and stirred again ...
    ... here preferably with the wavenumbers of the untreated samples, with few exceptions. Broad bands from OH stretching vibrations of phenolic and carboxylic groups are present in accor- dance with spectra of biochar made by fast pyrolysis from different types of wood [17,21,56] with transmission minima ...

  • Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete

    Milan Kragović, Nenad Ristić , Jelena Gulicovski, Andrijana Nedeljković, Snežana Pašalić, Ivica Ristović, Marija Stojmenović (2021)
    sagorevanje lignita, otpadna šljaka, zamena cementa, proizvodnja maltera i betona, fizičko-mehanička i fizičko-hemijska karakterizacija
    ... by mixing the slag with silica fumess in minimal amounts (slag/silica fumes = 88%/12%). The maximal possible cement replacement was 20% with 17.8% of slag and 2.2% of silica fumes. The leaching tests were also performed in accordance with the standard EN 12457-2 on the mortar with 20% of cement replacement ...
    ... vessel with a capacity of 8 dm3 and a special lid with a pump and manometer. The density of hardened concrete (water-saturated) was determined according to standard EN 12390-7 on the samples shaped like cubes with a side length of 150 mm. Flexural strength was determined in accordance with standard ...
    ... The leaching was carried out on crushed hardened mortar with water by mixing the mixture for 24 h, with the liquid/solid ratio of 10 dm3/kg. The results showed the negligible release of heavy metals whose values were much lower in comparison with values prescribed by the “Rulebook on permitted quantities ...

  • Geotechnical zoning of the terrain along the first section of E-80 highway in Serbia – SEETO route 7

    Dragoslav Rakić, Zoran Berisavljević, Irena Basarić, Snežana Bogdanović, Jovana Janković (2019)
    Part of E-80 highway that passes through Serbia (from the city of Nis to the administrative border Merdare) is 77 km long. The highway is divided into two sections: the first from Nis to Plocnik (39.4 km long) and the second from Plocnik to the administrative border with Kosovo. The route is designed through a typical plain and hilly terrain in which different geological units are dominant: crystalline schists, neogene sediments of foothills and quaternary sediments in the valley ...
    ... A-terrains with minimal limitations, B-terrains with minor limitations and C-terrains with larger limitations (Figure 7). A - terrains with minimal limitations are favourable and stable in natural conditions. These terrains include crystalline schist complex, clastic carbonate sediments with e ...
    ... complex and clastic carbonate rocks with eluvial-deluvial weathering zone of thickness over 2 m on slopes with inclination >100, lake sediments with eluvium and deluvium >2 m on slopes with inclination > 50 and alluvial and spacious or smaller torrential areas with occasional active influence of ...
    ... ridge and slopes with inclination up to 100. Also, lake sediments are included with eluvial and deluvial structures, river-terraced plateaus and spacious torrential areas, distant from the influence of river and stream flow. B - terrains with minor limitations are terrains with conditionally ...

  • Hydrothermal Synthesized and Alkaline Activated Carbons Prepared from Glucose and Fructose—Detailed Characterization and Testing in Heavy Metals and Methylene Blue Removal

    Sanja Krstić, Milan Kragović, Maja Pagnacco, Vladimir Dodevski, Branka Kaluđerović, Miloš Momčilović, Ivica Ristović, Marija Stojmenović (2018)
    glukoza, fruktoza, аktivni ugalj, hidrotermalni tretman, aktivacija hidroksida, teški metali, metilen plavo
    ... showed that the carbon content was much higher after activation with KOH and NaOH. • Samples activated with KOH and NaOH pose much better textural properties in comparison with samples activated with LiOH. • After treating of carbon samples with KOH, the changing and destroying of their spherical shapes ...
    ... content of organic carbon was much higher after activation with NaOH and KOH in comparison with samples obtained by activation with LiOH. That may be explained as a consequence of the formation of crystal layers after activation which are reach with carbonates and oxides, whereby this phenomenon is the most ...
    ... highest affinity for lead cations, followed with cadmium, while for the removal of Zn2+ affinity was the weakest. Also, as expected, the samples activated with KOH showed better removal of all three heavy metal cations in comparison with those activated with LiOH and NaOH. Minerals 2018, 8, 246 11 ...

  • 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)

  • Substitution reactions of some novel sterically hindered monofunctional Pd(II) complexes

    Aleksandar Mijatović, Jovana Bogojeski, Biljana Petrović, Živadin D. Bugarčić (2011)
    Reakcije supstitucije monofunkcionalnih kompleksa [(TLtBu)PdCl]+ i [Pd(tpdm)Cl]+, gde je TLtBu = 2,6-bis[(1,3-di-terc-butilimidazolin-2-imino)metil]piridin i tpdm = terpiridindimetan, sa nukleofilima kao što su: tiourea, I−, Br−, NO2−, piridin i dimetil-sulfoksid (DMSO) proučavani su u 0,1 M vodenom rastvoru NaClO4 u prisustvu 10 mM NaCl. Reakcije su sprovedene na tri različite temperature (288, 298 i 308 K) korišćenjem tehnike zaustavljenog protoka na različitim temperaturama. Reakcije supstitucije su praćene pod uslovima pseudo prvog reda sa velikim viškom nukleofila. Dobijeni rezultati pokazuju da kompleks ...
    Materials Chemistry, Inorganic Chemistry, Physical and Theoretical Chemistry
    ... w technique. The substitutions were followed under the pseudo-first-order conditions with a large excess of nucleophiles. Obtained results show that the complex with tpdm ligand reacts faster than the complexes with TLtBu ligand due to the bulk- iness of the inert tridentate ligands. Also, the presence ...
    ... activity [19] while complexes with amino alcohols, such as L-pro- linol, L-valinol, L-isoleucinol show certain antitumor activity [20]. As a part of our interest in the synthesis, structure and reactivity of coordination complexes of Pd(II) with chelating ligands [1–6,21,22] and with the aim to contribute towards ...
    ... technique. The substitutions were followed under the pseudo-first-order conditions with a large excess of nucleophiles. Obtained results at show that the complex with tpdm ligand reacts faster than the complexes with TL" ligand due to the bulk- Substitution iness of the inert tridentate ligands. Also ...

  • Hydrochemical changes and groundwater grouping data by multivariate statistical methods within one karst system: recharge–discharge zone (Eastern Serbia case study)

    Ljiljana Vasić, Dragana Živojinović, Vladana Rajaković-Ognjanović (2020)
    Geochemistry and Petrology

  • A tool for identifying the criticality in the disordered systems with metastable dynamics

    Svetislav Mijatović, Dragutin Jovković, Sanja Janićević, Stefan Graovac, Đorđe Spasojević (2021)
    Физика кондензоване материје

  • Stratigraphy and Microfauna (Radiolarians and Foraminifera) of the Upper Cretaceous (Upper Santonian–Lower Campanian) Carbonate Deposits in the Area of Struganik Village, Western Serbia)

    Liubov Bragina, Nikita Bragin, Luidmila Kopaevich, Nevenka Đerić, Nataša Gerzina Spajić (2020)
    Santonian, Campanian, radiolarians, planktonic foraminifera, biostratigraphy, limestones, Struganik, Serbia

  • ‘Blue-’ and ‘Brown-speckled’ pottery from Qalhât, the Sultanate of Oman (13–16th centuries): Comparison with traditional Omani 19–20 century productions

    Liliana Gianni, Hélène Renel, Aleksandar Kremenović, Philippe Colomban (2020)
    Representative ‘Blue speckled’ (13–16th centuries) and ‘Brown speckled’ (13–21st century) wares recovered from the excavations in Qalhât or collected around Bahlâ city (Sultanate of Oman) were characterized by XRPD, SEM-EDS, Raman/optical microspectroscopy, and thermal expansion. Minerals present in the body (quartz, augite and albite as major phases, calcite, dolomite, rutile, anatase, phosphate, hematite and magnetite as minor phases) were identified by XRPD and/or Raman spectroscopy. SEM-EDXS microanalysis was performed on the glazes in order to compare their composition, especially ...
    Firing, Glaze, Traditional ceramics, Provenance studies, Augite