100 research outputs found

    Uticaj sezonskog faktora na varijabilnost hemijskog rastvaranja krečnjaka u Svrljiškoj kotlini

    Get PDF
    How big is the influence of climatic factor on the intensity of rocks dissolving (limestone) in Serbia? Previous investigations of rivers water chemistry changes have shown it insignificance. This investigation shows significant collective influence of climatic elements contained in "seasonal factor".Koliki je uticaj klimatskog faktora na intenzitet rastvaranja stena (krečnjaka) u Srbiji. Dosadašnjim istraživanjima promene hemizma vode rečnih tokova zaključeno je da je on minoran. Ovim istraživanjima uočen je značajan upliv zbirnog uticaja klimatskih elemenata sadržanih u "sezonskom faktoru"

    Intenzitet hemijske erozije u slivu Nišave

    Get PDF
    The Nišava catchment comprehends the area of 4068 km2. There are differences in erosion intensity due to different physical-geographical characteristics of that area. Mechanical water erosion in the Nišava catchment is 302,4 m3/km2/yr and chemical erosion is 67,2 t/km2/yr. Space differences are large (47,1-115.5 t/km2/yr) and are mostly determined by hydrological and lithological characteristics of that area.Sliv Nišave zahvata površinu od 4068 kt2. Shodno različitim fizičko-geografskim karakteristikama tog prostora, postoje i razlike u intenzitetu erozije. Mehanička vodna erozija u slivu Nišave iznosi 302,4 t3/kt2/god., a hemijska 67,2 1/kt2/god. Prostorne razlike su velike (47,1-115.5 1/kt2/god.) i u najvećoj meri su određene hidrološkim i petrološkim karakteristikama prostora

    Metodološki postupci istraživanja intenziteta hemijske erozije

    Get PDF
    Researching of intensity of chemical erosion nowadays includes different methods, which can be divided into three groups: laboratory experiments, terrain experiments and empirical methods. This work analyses some methods and results that are obtained by their use.U istraživanju intenziteta hemijske erozije danas su u opticaju različiti postupci, koji se mogu svrstati u tri grupe: laboratorijski eksperimenti, terenski eksperimenti i empirijske metode. U radu su analizirani pojedini postupci i prikazani rezultati koji su njihovim sprovođenjem dobijeni u Srbiji

    Ossifying Fibroma of the Orbit

    Get PDF
    Osificirajući fibrom glave i vrata rijedak je tumor koji najčešće zahvaća gornju i donju čeljust. Javlja se u trećem i četvrtom desetljeću života. Lezija je obično solitarna, dobro ograničena. Postupnim rastom stanjuje okolno zdravo koπtano tkivo. Radiološka slika ovisi o trajanju bolesti. U ranome stadiju prikazuje se kao oštro ograničeno prosvjetljenje s pojedinačnim nakupinama kalcifikata. U daljnjem tijeku, uz oštro ograničenu zonu prosvjetljenja na periferiji, središnje smještene nakupine kalcifikata postaju gušće. Histološku sliku karakterizira fibrozno tkivo isprepleteno koštanim trabekulama lamelarne kosti koje su obrubljene osteoblastima i mjestimice miksomatoznom stromom. Terapija je kirurška i sastoji se u potpunoj resekciji tumora, koja jedino može spriječiti pojavu lokalnoga recidiva. U radu smo prikazali rijedak slučaj osificirajućeg fibroma orbite koji je zahvatio zigomatičnu kost i proširio se preko velikoga krila sfenoida do optičkoga kanala. Specifičnost terapije u naše bolesnice jest u tome što je unatoč doticaja tumora s prednjom lubanjskom bazom nije upotrijebljen neurokirurški pristup.Ossifying fibroma of the head and neck is a rare tumour which most frequently involves the upper and lower jaw. It occurs during the third and fourth decade of life. The lesion is usually solitary and well circumscribed. It grows slowly, thinning the surrounding healthy bone tissue. Radiographic appearance depends on the duration of the disease. In the early stage it presents as a sharply circumscribed zone of translucency with single accumulations of calcification. During the further course, with the sharply circumscribed zone of translucency on the periphery, the centrally located accumulations of calcification become denser. The histological appearance is characterised by fibrous tissue, interwoven with bony trabeculae of lamellar bones, which are bordered with osteoblasts and scattered myxomatous stroma. Therapy is surgical and consists of total resection of the tumour, which is the only way to prevent the occurrence of a local recurrence. In this paper we present a rare case of ossifying fibroma of the orbit which involved the zygomatic bone and spread/extended via the large branch of the sphenoid up to the optic canal. The specificity of the therapy in our female patient was that in spite of contact of the tumour with the frontal base of the skull, a neurosurgical approach was not used

    Visinsko zoniranje voda u slivu Rasine

    Get PDF
    The Rasina River Basin is located on the territory of Central Serbia. The aim of this paper is to determine the amount and spatial distribution of water resources, that is, to establish the participation of altitudinal zones in the formation of the total runoff in the Rasina River Basin area upstream from the 'Ćelije' reservoir. In terms of methodology, determination of water volume is based on four separated petrological-hydrological complexes. Average weighted specific runoff in a given territory is 9 l/s/km2. Metamorphites and magmatites are in the first place per participation in the total water runoff of 42.8 %. The second place belongs to sedimentary rocks that make 39.6 % of the total runoff . Unbound sediments participate in the total runoff value with 10.5 % and limestone with 7.1%.Sliv reke Rasine nalazi na teritoriji centralne Srbije. Cilj ovog rada je da se na prostoru sliva Rasine uzvodno od akumulacije 'Ćelije' utvrdi količina i prostorna distribucija vodnih kapaciteta, odnosno da se ustanovi učešće visinskih zona u formiranju ukupnog oticaja. U metodološkom smislu utvrđivanje vodnosti bazirano je preko četiri izdvojena petrološko-hidrološka kompleksa. Prosečni ponderisani specifični oticaj na datoj teritoriji iznosi 9 l/s/km2. Na prvom mestu po učešću u ukupnom oticanju voda 42,8 %, imaju metamorfiti i magmatiti. Drugo mesto pripada sedimentnim stenama koje sa 39,6 % čine deo ukupnog oticaja. Nevezani sedimenti učestvuju u ukupnoj vrednosti oticaja sa 10,5 %, a krečnjaci sa 7,1%

    Mineralizacija površinskih voda u slivu Visočice - prilog za predeono-ekološku analizu

    Get PDF
    The drainage basin is spatially and functionally clearly defined and relevant hydrologic, geomorphologic and ecologic landscape totality. Therefore, it mostly represents basic geo-spatial unit of generation, monitoring, and studying numerous physical-geographical and geo-ecologic occurrences and processes. One of the most important components of geo-space, on the level of basin, is manifested through the state and quality of surface waters. So, the acceptance of systematic approach in studying mineralization of the surface waters would contribute to the deeper understanding of the process in complex systematic surroundings which drainage basin represents. The Visočica Drainage Basin was chosen as proving ground of this kind of the research approach for several reasons. The highest specific runoff on the territory of Eastern Serbia, heterogeneous geologic structure of terrain, almost complete absence of the influence of the anthropogenic factor on the state of the environment, as well as the existence of water accumulation enabled perception of the values of dissolved mineral substances of surface waters as landscape-ecologic component of geo-space.Sliv je prostorno i funkcionalno, jasno definisana i relevantna hidrološka, geomorfološka i ekološka predeona celina. Zato on najčešće predstavlja osnovnu geoprostornu jedinicu generisanja, praćenja i proučavanja mnogobrojnih fizičko-geografskih i geo-ekoloških pojava i procesa. Jedna od najznačajnijih komponenti geoprostora na nivou sliva manifestuje se kroz stanje i kvalitet površinskih voda. S toga bi prihvatanje sistemskog pristupa u proučavanju mineralizacije površinskih voda potpomoglo dublje razumevanje procesa u složenom sistemskom okruženju kakav je sliv. Kao poligon takve vrste istraživačkog pristupa sliv Visočice odabran je iz nekoliko razloga. Najviši specifični oticaji na prostoru istočne Srbije, heterogen geološki sastav terena, skoro potpuno odsustvo uticaja antropogenog faktora na stanje životne sredine, kao i postojanje vodne akumulacije Zavoj omogućilo je sagledavanje vrednosti rastvorenih mineralnih materija površinskih voda kao predeono-ekološke komponente geoprostora

    Metodološka greška utvrđivanja koncentracije suspendovanog nanosa na našim rekama

    Get PDF
    Recent methodology of sampling and establishing silt deposit concentration in Serbian rivers is associated to numerous deficiencies. Daily concentrations of this type of river deposit on the most of the hydrological gauges were obtained on the base of only one measurement, which takes into consideration the matter of representative ness of those samples. Taking the samples of deposit in one point on the profile is little bit problematic because of dispersion of the obtained results. Very important matter is the question of choice of the sampling location. This analyses of data may lead to serious spots in calculating total carried deposit. From the above mentioned reasons, we decided to take precise measurements of silt deposit concentration as well as to establish methodological spots of measurements. The results of these measurements are analyzed and presented in this paper.Dosadašnja metodologija uzimanja uzoraka i utvrđivanja koncentracija suspendovanog nanosa na našim rekama karakteriše se brojnim nedostatcima. Dnevne koncentracije ovog tipa rečnog nanosa na najvećem broju hidroloških stanica dobijene su na osnovu samo jednog merenja čime se postavlja pitanje reprezentativnosti takvih uzoraka. Zahvatanje uzoraka nanosa u jednoj tački profila veoma je problematično zbog velikog stepena rasipanja dobijenih rezultata, a postavlja se i pitanje pravilnog izbora lokacija za obavljanje merenja. Ovakva vrsta podataka može dovesti do ozbiljnih pogrešaka u izračunavanju sumarnog pronosa nanosa. Iz navedenih razloga, pristupilo se ideji sprovođenja preciznijih merenja koncentracija suspendovanog nanosa i utvrđivanju metodološke greške postojećih merenja. Rezultati merenja analizirani su i prikazani u ovom radu

    Promene temperature vazduha u svetu i Srbiji i Severno atlantska oscilacija (NAO)

    Get PDF
    In this paper connection between temperature changes and North Atlantic oscillation (NAO) has been investigated in the period from 1979 until 2006. Satellite temperature data from UAHMSU were investigated in relation to North Atlantic Oscillation index on the Earth, in Europe and in Serbia. Statistically insignificant correlation coefficient has been obtained for the area of Serbia. The analysis of periodicity of 2.8±0.5 year is in accordance with that one obtained by Landschieidt (2001). However, in order to give final conclusion regarding to climate change more parameters should be analyzed.U radu je istraživana veza između temperature vazduha i Severno atlantske oscilacije (NAO) u svetu , u periodu od 1979. do 2006. godine. Ispitivana je veza između satelitskih podataka temperature vazduha UAHMSU i NAO indeksa na prostoru Srbije (17.5-22.5°E i 42.5-47.5°N ), u Evropi (10-45°E i 35-70°N) i svetu po pojasevima od po 10° geografske širine. Uočen je statistički nesignifikantan koeficijent korelacije za prostor Srbije. Analiza elementarne periodičnosti je pokazala da u posmatranom periodu prosečna dužina osnovne periode za MSU od približno 2.8±0.5 godina, odgovara periodičnosti varijanse NAO, koju je dao Landschieidt (2001). Ipak, u isticanju mogućih uzroka savremenih kolebanja klime trebalo bi istovremeno analizirati više parametara cirkulacije atmosfere

    Ugroženost akumulacije 'Zavoj' erozivnim procesima - metodološki, saznajni i zaštitni aspekt

    Get PDF
    In this paper land erosion has been investigated from its temporal and spatial variability point of view. The aim of the application of contemporary soft wares and satellite observations was to create an adequate data base which allows faster and more adequate possibility for monitoring the intensity of erosive processes, as well as meaningful decision for application of different ways of anti erosive techniques of the most dangerous areas. Geomorphologic mapping of erosive processes using plane and satellite images has allowed rational planning of field observations and, at the other side very detailed establishing of the intensity of previous erosion. A new approach applied in this paper during data processing of all relevant parameters influencing erosion is based on using of software Geomedia 5.2 (Intergraph).Rad tretira proces erozije zemljišta sa stanovišta njegove prostorno-vremenske varijabilnosti. Primena savremenih programskih paketa i satelitskih osmatranja ima za cilj formiranje adekvatne baze podataka, koja omogućava bržu i adekvatniju mogućnost praćenja stanja i intenziteta erozivnih procesa, a samim tim i svrsishodniju odluku o primeni različitih vidova anterozivnih mera zaštite najugroženijih prostora. Geomorfološko kartiranje erozivnih procesa putem avionskih i satelitskih snimaka omogućilo je, s jedne strane, racionalno planiranje terenskih opseravcija, a sa druge strane veoma detaljno utvrđivanje intenziteta erozije u prošlosti. Novi pristup primenjen u ovom radu prilikom obrade svih relevantnih parametara koji utiču na proces erozije, zasniva se na korišćenju programskog paketa Geomedia 5.2 (Intergraf)

    Promene temperature vazduha na osnovu satelitskih osmatranja u Srbiji i svetu

    Get PDF
    In this paper the air temperature changes have been investigated on the base of satellite measurement, in the period from 1979 until 2006. The analysis has shown that there is no temperature amplification with altitude. Data for Serbia have shown negative trend of temperature in the last 20 years of the investigated period. Although it is not statistically significant, the sign is not in accordance with the increasing CO2 concentration. This may mean that the sign of satellite temperature doesn't support hypothesis about domination of anthropogenic greenhouse effects. .U radu je analizirana promena temperature vazduha u Srbiji i svetu, na osnovu podataka satelitskih osmatranja, u periodu od 1979. do 2006. godine. Analiza trenda je pokazala da nema amplifikacije trenda porasta temperature sa visinom. Analiza za Srbiju pokazala je u poslednjih 20 godina u posmatranom periodu od 1987. do 2006. godine negativan, trend temperature vazduha. Iako statistički nesignifikantan, znak trenda nije saglasan sa rastućom koncentracijom antropogenog SO2. To bi značilo da znak promena satelitskih temperatura vazduha u posmatranom periodu nije u skladu sa očekivanim, u uslovima dominacije antropogenog efekta staklene bašte
    corecore