Претрага

Упит dcterms_creator_txt:Gérard M. Stampfli

977 items

  • 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
    ... Vwpa0o=20m · (6,37-4,7)m?=33,40m3 (7.3) Za eventualno armiranje koriste se obostrano nosive armaturne mreže o-8mm sa okcima dimenzija axa=150x150mm i oznakom Q-335, težine m=5,44kg/m?. Potrebna količina armature iznosi: m=20m · 6m2/m! · 5,44 kg/m?=652,8, usvaja se m=660kg. Potrebna količina ...
    ... iZnOSI; V=S-·v, m3/s (6.28) V=4.7·0.15=0.7 m3/s =42 m3/min gde jJe: V – količina vazduha, m*/s, m*/min, S – svetla površina pop. preseka prostorije (4.7+5.15 m?), m?, v — brzina vazdušne struje, m/s. 39 Otpor prostorija Dužina prostorija kroz koje se kreće vazdušna struja iznosi L=103m ...
    ... standardu SRPS B.ZO.203 na niski svod sa sledećim dimenzijama: svetla širina b=2,0 (2,2)m, visina h=2,5 m i dužina L=3,0 m. OK-5, koja je locirana naspram Komore za eksploziv (KE) i ima dimenzije b=3,1 m, h=2,5m i L=3m. Na slici br. 4.2. date su lokacije i položaj OK, a na slici br. 4.5. dimenzije ...

  • Multiple-Criteria Decision-Making in Mine Development Planning

    Sanja Bajić (2023)
    The Borska Reka ore deposit is an experimental location where developed methodologies have been applied. It is the largest ore body within the Bor mining complex, which has been the subject of numerous studies and analyses for more than three decades. The paper focuses on the application of FAHP and the VIKOR method to address ranking of alternatives and select the optimal mining method by means of fuzzy multicriteria optimization.

  • Услови заштите изворишта подземних вода “Јарош“ за водоснабдевање Сомбора

    Ивана Јовановић (2024)
    Територија града Сомбор се налази у периферном северозападном делу Војводине, односно Србије, у близини границе са Хрватском. Сам град Сомбор се налази југозападном делу територије и представља гравитациони центар тог подручја. Повољан географски положај условио је афирмацију Сомбора као градског насеља, са јаком пољопривредом, индустријом, занатством и прометом. "ВОДОКАНАЛ" из Сомбора је јавно комунално предузеће чија је основна делатност захват сирове подземне воде, њен третман, и дистрибуција ка потрошачима Сомбора и приградских насеља и насељених места: Лугова, Жарковца, Чонопље, ...
    заштита, извориште, водоснабдевање, Јарош, Сомбор
    ... ynacKa y d a6pnky Bo,ate. T i v j e s o v e Y T a p c k v ı M B O {m m m . ) Cnuka 11. Pezucnmposaue npoene Husoa noO3e.MHux 6o0a y nujesovempuMa Ha uU36OpuLua)ıV Japou." v mepuooy 01.12.2020. – 31.12.2021. zoo. 40 M Cywa MecevMax nanasaMs 'E 100 Hi r šeo FI 0 @9&&@@&“ OBE ...
    ... CMe?by]V. JaB-bajy ce y BHJIy TaHKOT 3acTOpa pa3nHuHTe neO:bHHe, oJ 0.5 m na no 12 m XOJIOIHIEH 4nyeujanna mepaca (6 – S m) y MoOpbonoIkKoM CMHC:Ty Je JeztHa 3apaBEbeHa IOBp ca XHTICOMeTDH|CKHM BHCHHaMa 0j1 86 no 89 m. Hsirpaljyje Jyro3ana;tHe nemoBe mojnpyuja HCTpaxKHBalba. Ca HcTouHe crpaHe ...
    ... BpenHocr Qakropa Ti 3a TJHHOBHTe HacHare y OKBHpYy aHanH3HpaHor nonpyuja ce Kkpehe o O m no 2.0 m QDaKkTOp Ti KOJH Ce OJIHOCH Ha eO:bBHHy IIeCKOBHTHX CeJHMeHaTa Y IIOBHaTH BOJIOHOCHOT XOpH3oHrTa ce Kpehe oji 0 m no 6,0 m. O akTop P: 3amrnrTHa yi1ora CTeHCKOrT IIOKpHBaua ce pauyHa 34 CBaKH CJIOJ IOCeOHO ...

  • Properties of fly ash and slag from the power plants

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    This paper describes the physical, chemical and mineral properties of ash and slag, which were taken from thermal power plants Nikola Tesla A, Nikola Tesla B, Kostolac A and Kostolac B. The knowledge of the mineralogical material composition is important because the type of minerals directly determines the properties of the fly ash and slag and their possible application. Laboratory tests showed that ash and slag samples consist of the following minerals: amorphous materials, quartz, feldspar, mullite, melilite, cristobalite, ...
    fly ash, slag, physical composition, chemical composition, mineral composition, X-ray diffraction method
    ... the amorphous material Q f M Ml An Cr He CaO Total mass (%) NT A – m 58 16 10 5 5 3 3 – – 100 NT A – j 66 17 9 3 2 2 – – – 99 NT B – m 50 17 12 6 4 7 4 – – 100 NT B – j 50 10 14 8 6 7 3 – 2 100 KO A – m 55 7 23 7 – – 4 4 – 100 KO A – j 55 10 12 3 2 10 1 7 – 100 KO B – m 55 19 13 5 – – 5 3 – 100 KO ...
    ... CaO(0.55) K2O(0.63) Al2O3(0.43) M(0.75) R(0.58) w(0.63) CaO(0.47) K2O(0.77) Al2O3(0.99) M(0.99) R(0.63) <63 M(0.60) AM(0.56) Q(0.59) M(1.00) AM(0.98) Q(0.41) LOI 1000 – loss on ignition 1000 °C; R – module R; AM – the amorphous material; Q – quartz; f – feldspar; M – mullite; Ml – melilite; Cr – c ...
    ... Range Mena Range NT A – m 0.43 0.30-0.57 40.67 16.0-68.0 2.11 2.05-2.15 11.88 NT A – j 0.29 0.22-0.38 22.67 16.0-30.0 2.09 2.08-2.10 12.76 NT B – m 0.26 0.08-0.71 44.67 35.0-51.0 2.13 2.08-2.20 11.53 NT B – j 0.20 0.15-0.28 51.33 46.0-57.0 2.10 2.05-2.16 13.15 KO A – m 0.17 0.10-0.23 17.33 15.0-19 ...

  • Модел померања терена услед утицаја рударских радова на основу радарских сателитских снимака

    Зоран Гојковић (2023)
    Површински коп, као систем који обезбеђује енергетску стабилност или снабдевање сировинама које су од изузетне важности за привредни напредак, својим функционисањем утиче на околна насељена места. Међу бројним аспектима овог утицаја, може се издвојити издвојити и анализирати утицај вертикалних и хоризонталних померања која се јављају на површи терена. Мониторинг вертикалних и хоризонталних померања површи терена околних насељених места треба да има што бољу временску резолуцију (временски период између праћења деформација) како би се вертикална и хоризонтална померања контролисала и ...
    Сентинел 1 интерферометрија, слегање, Перманентни скатерери, Костолац

  • Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers

    Milan Bogdanović, Snežana Bogdanović, Dragoslav Rakić, Irena Basarić Ikodinović (2024)
    This paper presents a dynamic California Bearing Ratio (CBRd) device that can be used on a prepared pavement foundation layer to obtain a certain parameter of the tested material in the laboratory and in situ in a direct and fast way. For the selected natural material (gravel), it is shown that the laboratory CBRd can be used to estimate the compaction and bearing capacity, because it correlates well with the parameters of the standard and modifed Proctor compaction tests. ...
    korelacija parametara, donji slojevi saobraćajnica, laboratorijska i terenska ispitivanja, dinamički kalifornijski indeks nosivosti CBRd
    ... density of the sample in Mg/m*. 30 a % - b 200 - ii D tl/(:· AŠ |=} 180 - 70 //E?] “ (-P-4"| AAJA N B D/_T'Jč, ___160 – A “A Ee . PrO M “ A Š Š D n f Č ĆA A -- o B 140 ; _ [- Ž . A a 50 M ~ : AAA AA n 070 - BI A AAAA %Ž mpon-- D A Z AA _ |j A 0 7 O A ŠA -& W m 1 l 100 _Z A a A |} ...
    ... Radical Statistician: A Beginners Guide to Unleashing the Power of Applied Statistics in the Real World, |im Higgins Publishing, USA (2005). o M T : M m n m p n n — 35 ...
    ... following material characteristics were determined by testing. The maximum dry bulk density was determined as follows: Pdmax (SP) = 1.97 Mg/m* and pqmax (MP) = 2.06 Mg/m* at the optimal water content w„„i (SP) = 9.5% and Wopt (MP) = 8.6%. The CBR,, SPLT, and LWD were used to estimate the compaction and ...

  • Flyrock induced by blasting in surface mining

    Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac (2022)
    Miniranje predstavlja i dalje najefikasniji i najjeftiniji način eksploatacije velikih količina čvrstih mineralnih sirovina na površinskim kopovima. Energija eksplozije se koristi za fragmentaciju čvrste stenske mase do zahtevane granulacije. Pored pozitivnih efekata miniranja, postoje i određeni neželjeni efekti svakog procesa miniranja koji se mogu javiti, a to su: potresi tla, razletanje komada stene, vazdušni udari, otrovni i zagušljivi gasovi i prašina. Razletanje komada stene je nekontrolisano izbacivanje fragmenata odminirane stenske mase i predstavlja jedan od glavnih izvora materijalne štete ...
    razletanje, bušenje, miniranje, površinska eksploatacija, bezbednost, nesreća

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Proučavanje razvića Bihaćkog i Cazinskog basena primenom gravimetrijskih podataka

    Snežana M. ignjatović, Ivana M. Vasiljević, Nevena R. Andrić-Tomašević, Ana S. Mladenović (2024)
    Bihaćki i Cazinski baseni su neogeni baseni, koji pripadaju spoljašnjim Dinaridima i formirani su tokom kasne faze razvoja Dinarida. Ovi baseni su od posebnog interesa zbog svoje geološke prošlosti i potencijalnih strukturnih karakteristika. U istraživanju, primenjeni su gravimetrijski podaci u clju boljeg razumevanja evolucije ovih basena. Primenom različitih postupaka matematičkih transformacija na gravimetrijskim podacima može se ustanoviti gravitacioni uticaj neogenih basena male gustine i mogu se detektovati strukture, koje su potencijalno vezane za njihovo formiranje. U ovom istraživanju, analiza ...
    matematičke transformacije podataka, kontakti, neogeni baseni

  • Geotehnički uslovi izgradnje tunela „Debelo brdo“ na autoputu E-80 Niš - Pločnik

    Dragoslav Rakić, Radojica Lapčević, Irena Basarić Ikodinović, Dragan Lukić (2022)
    Tunel „Debelo brdo“ nazvan je po najizraženijem relјefnom obliku na ovoj drugoj deonici autoputa E-80 Niš – Pločnik. Osnovnu geološku građu na lokaciji tunela čini Mio-Plioceni kompleks heterogenog litološkog sastava. Izgradnja tunela je predviđena delom u otvorenom iskopu dužine 240 m, a delom sa podzemnim iskopom dužine 190 m. U zoni tunela, padina je okarakterisana kao uslovno stabilna, pa bi neadekvatna zasecanja mogla da izazovu klizanja terena. Iz tih razloga, u okviru rada posebno su prikazani geotehnički uslovi izgradnje ...
    Tunel „Debelo brdo“, Geotehnički parametri, Privremene kosine, Šipovi, Podgrada.
    ... neposredno ispod nje. i zdvojenim im zonama, prognoznim nivoom podzemne vode em m om iskopa, prikazani su na Slici 4. Slika 4. 3. - Tabela 1. I D I m , a maksimalna 36.5 m) laboratorijska Opiti standardne penetracije 8 SPT opita Dilatometarski opit ...
    ... basaric@rgf.bg.ac.rs 4 Univerzitet u Novom Sadu , , drlukic.lukic@gmail.com Rezime: autoputa E-80 Osnovnu g -Plioceni . Izgradnja tunela je predvi m m. U zoni tunela, padina je okarakterisana kao uslovno stabilna, pa bi neadekvatna zasecanja mogla da izazovu klizanja terena. Iz tih razloga, u okviru ...
    ... complex of heterogeneous lithological composition. The construction of the tunnel is partly planned in an open excavation 240 m long, and partly with an underground excavation 190 m long. In the tunnel zone, the slope is characterized as conditionally stable, so inadequate cuts could cause sliding of the ...

  • Tectonic evolution of the Circum-Moesian orocline of the Carpatho-Balkanides: Paleomagnetic constraints

    Emő Márton, Vesna Cvetkov, Miodrag Banješević, Gábor Imre, Aleksandar Pačevski (2024)
    Apuseni-Banat-Timok-Srednogorie belt, danubicum, paleomagnetism, oroclinal bending

  • 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

  • Interaction of sodium dodecylsulfate (SDS) with homoionic montmorillonites: adsorption isotherms and metal-ion release

    M. Ilic, J. Gonzalez, A. Pohlmeier, H. D. Narres, M. J. Schwuger (1996)
    The interaction of dodecylsulfate anions (DS−) with homoionic Ca-, Mg-, Ni-, Cu-, Cd-, Pb- and Fe-montmorillonites were investigated. Mg- and Cd-montmorillonite do not adsorb DS−, and an anion exchange at the edges of the clay mineral does not take place. Three different adsorption processes are identified on the other montmorillonites: i) Fe-montmorillonite is covered with amorphous iron hydroxide, and DS−-anions are bound at positively charged sites. ii) On Ca- and Pb-montmorillonite DS− is precipitated as Me(DS)2. iii) On Ni- ...
    Натријум додецилсулфат, адсорпциона преципитација, монтморилонит

  • On the compatibility of lexical resources for NooJ

    Ranka Stanković, Miloš Utvić, Duško Vitas, Cvetana Krstev, Ivan Obradović (2012)
    Lexical resources for many languages are provided for the NooJ linguistic development environment. Meta-data descriptions of morphosyntactic and semantic properties of these languages and their resources are a mandatory part of each language module. In this paper we analyze how well the meta-data actually describe resources for a chosen subset of languages and to what extent are they compatible across languages to support multilingual processing. We show that there is place for improvement in both directions.
    ... Gender Fr S+p m+f En Hu PL Pl S+p mo+mr+mz+f+n Hr S+p m+f+n Bg S+p m+f+n Sr S+p+w m+f+n Table 2. Analysis of *.def metadata: ADJECTIVES Nb Gender Pers Tense/ Mood Fr S+p m+f 1+2+3 INF+G+PP+PR+IP+S+C+I+PS+SI+F En S+p 1+2+3 G+INF+PP+PR+PT Hu E+t 1+2+3 K+M+F+P Pl S+p mo+mr+ ...
    ... IA+VHIN+VHINN+Os+sA g+HAT+UN Pl M+f+s+p+Bi+Ce+Do+In+Lo+Mi+Wo+F+G+H+J+K+P+Q+S+T+U+Z Hr INF+INFk+PR+PRk+PRd+IMP+AO+AO2+PDR+PDT+IMT+GPS+GP P+s+p+1+2+3+m+f+n+np+cp+sp Bg s+p+0+d+h+l+o+v+c+f+m+n+y+z+i+a+t+1+2+3+b+w+x+A+B+C+K+ P+F+M+N+R+E+D+I+Y+Z+X+W+Q Sr m+f+n+1+2+3+4+5+6+7+s+p+w+v+q+g+i+a+ ...
    ... other properties, and their value domains. Nb Gen Specific Fr s+p m+f N_Struct=AAN+AN+E01+NA+NAA+NAN+NCN+ND N+NN+NPN+NPNPN+NPV+NX+NX4+PN+VN+VV+ VX+XA+XN+XV+XX N_Sem=Anl+Hum+HumColl+Conc+Alim+Anim+Abst+ Pol+PR En s+p m+f +n N_Struct=2XN+NCN+NPN+NsN+NX+PMCO+XN N_Distribution=Abst+Anl ...

  • The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje

    Boban Pavlović, Milica Pešić-Georgiadis (2019)
    In order to determine the solar energy potential for a specified location, it is crucial to consider the latitude, altitude, slope, terrain morphology, atmospheric conditions, etc. Such a complex calculation and mapping of solar energy can be done using the ArcGIS geoprocessing tool, named Area Solar Radiation (ASR). By using the ASR tool, supported with the adequate input data, it is possible to calculate the maximum solar radiation energy (irradiation) for a defined area and for a specified time ...
    Obnovljivi izvori energije, potencijal solarne energije, GIS, mapiranje solarnog potencijala
    ... Conference on Energy and Climate Change, 9-11 October 2019, Athens - Greece Share in Total Primary Energy Production from Renewables m Biomass m Hydropower m Wind power m Biogas, Solar, Geothermal energy Figure 1: Total production of primary energy from RES in Serbia per energy source (Republic of ...
    ... solar radiation energy for a flat surface during winter ranges between 1.1 kWh / m in Northern Serbia and 1.7 kWh / m? in Southern Serbia, and in the summer between 5.4 kWh / m? in Northern Serbia and 6.9 kWh / m? in Southern Serbia (University of Belgrade, 2004). It should be noted that the data ...
    ... 29 kWh / m?in January and near 175 kWh / mžin July. By dividing the mean value of the monthly insolation with the number of days in months, the average daily solar radiation energy is calculated. The average daily solar radiation energy is 0.94 kWh / m? for January and 5.65 kWh / m?for July ...

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • Results of comprehensive monitoring activities on Umka landslide, Belgrade, Serbia

    Biljana Abolmasov, Uroš Đurić (2021)
    klizišta, monitoring
    ... (Ćorić et al. 2016; Abolmasov et al. 2012). This landslide is fan-shaped, with the length along the slope of 900 m, 1650 m wide in the toe, reaching maximum depth of sliding surface at 26 m, and average slope gradient of 9 . Previous geotechnical research has shown that Umka landslide can be described ...
    ... techniques. Results Displacement rates from GNSS indicate that object point Umka GNSS has moved 0.30 m towards the North and 0.50 m towards the West, while the vertical displacement was approximately -0.15 m for the 2014-2018 time span. Similar range of GNSS displacement rates were found in previously published ...
    ... confirm that the Umka is a slow to very slow moving landslide. REFERENCES Abolmasov B., Milenković S., Jelisavac B., Vujanić V., Pejić M. and Pejović M., 2012, Using GNSS sensors in real time monitoring of slow moving landslides-a case study. Proceedings of the 11th International and 2nd American ...

  • Differently shaped nanocrystalline (Fe, Y)3O4 and its adsorption efficiency toward inorganic arsenic species

    Biljana P Dojčinović, Boštjan Jančar, Lotfi Bessais, Aleksandar Kremenović, Nataša P Jović-Jovičić, Predrag T Banković, Dalibor M Stanković, Miloš Ognjanović, Bratislav V Antić (2019)
    Herein we report effects of partial substitution of Fe3+ by Y3+ in magnetite (Fe3O4) on morphology and inorganic arsenic species adsorption efficiency of the Fe3−xYxO4 nanoparticles formed. The series of Fe3−xYxO4 (x=0.00, 0.042 and 0.084, labeled as Y00, Y05 and Y10, respectively) was synthesized using co-precipitation followed by microwave-hydrothermal treatment (MW) at 200°C. With increase of yttrium content(xvalue), both the morphological inhomogeneity of the samples and the fraction of spinel nanorods as compared to spinel pseudospherical particles increased. By ...
    microstructure, microwave-hydrothermal synthesis, adsorption, magnetic nanoparticles, arsenic

  • Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites

    Marija Šuljagić, Aleksandar Kremenović, Ivan Petronijević, Adis Džunuzović, Miljana Mirković, Vladimir Pavlović, Ljubica Anđelković (2023)
    To investigate the effect of synthesis procedure and sintering temperature on the functional properties of perovskite/spinel ceramics, BaTiO3/CoFe2O4 composites were prepared by thermal decomposition, coprecipitation, and microemulsion method, and sintered at 1150°C and 1300°C. The phase composition and morphology of as-prepared powders as well as sintered ceramics were thoroughly examined by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). The dielectric and ferroelectric measurements were performed in detail. Generally, the ...
    Perovskite/spinel ceramics, Multiferroic, Sintering, Influence of synthesis method

  • Geochemical evaluation of dolostone deposits in Montenegro: Implications for potential industrial applications

    Darko Bozovic, Vladimir Simic, Dragan Radulovic, Slobodan Radusinovic, Vesna Matovic, Anja Terzic (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    примарне сировине, минералогија, физичко-механичка својства, технолошка својства, наука о материјалима