On the number of contacts of a floating polymer chain cross-linked with a surface adsorbed chain on fractal structures

We study the interaction problem of a linear polymer chain, floating in fractal containers that belong to the three-dimensional Sierpinski gasket (3D SG) family of fractals, with a surface-adsorbed linear polymer chain. Each member of the 3D SG fractal family has a fractal impenetrable 2D adsorbing surface, which appears to be 2D SG fractal. The two-polymer system is modelled by two mutually crossing self-avoiding walks. By applying the Monte Carlo Renormalization Group (MCRG) method, we calculate the critical exponents $\phi$, associated with the number of contacts of the 3D SG floating polymer chain, and the 2D SG adsorbed polymer chain, for a sequence of SG fractals with $2\le b\le 40$. Besides, we propose the codimension additivity (CA) argument formula for $\phi$, and compare its predictions with our reliable set of the MCRG data. We find that $\phi$ monotonically decreases with increasing $b$, that is, with increase of the container fractal dimension. Finally, we discuss the relations between different contact exponents, and analyze their possible behaviour in the fractal-to-Euclidean crossover region $b\to\infty$.Comment: 15 pages, 3 figure

Uticaj cijanobakterija (cyanophyta) na svojstva različitih tipova zemljišta Vojvodine

To examine the effect of cyanobacteria on the properties of different soil types of the Vojvodina Province soil samples were inoculated with a mixture of two cyanobacteria cultures. The experiment was conducted in greenhouse. It included two treatments, With and Without cyanobacteria. Each experiment unit (soil genetic horizon of layer) was replicated four times. It may be concluded on the basic of the obtained results that the cyanobacteria did not have a pronounced effect on the water-physical and basic chemical properties of the soils. Increases in the content of mineral nitrogen in all soil horizon and layers were observed. Soil inoculation with cyanobacteria decreased the level of electric conductivity in saturated water extract (Amo,p subhorizon in chernozem and Aoh,na/E horizon) and the content of Na in saturated water extract (Aoh,na/E horizon in solenetz).U cilju istraživanja uticaja cijanobakterija na promené svojstava različitih tipova zemljišta Vojvodine. Uzorci ispitivanih genetičkih horizonata i slojeva zemljišta su inokulisani inokulumom koji je predstavljao združenu kulturu cijanobakterija. Ogled je postavljen u stakleniku u dva tretmana (inokulisano cijanobakterijama i kontrola), u četiri ponavljanja. Na osnovu rezultata ogleda može se zaključiti da uticaj cijanobakterija na vodno fizička i većinu osnovnih hemijskih osobina zemljišta nije bio izražen. Zabeleženo je povećanje sadržaja mineralnog azota u svim genetičkim horizontima i slojevima ispitivanih zemljišta inokulisanog tretmana u odnosu na kontrolni. Inokulacija zemljišta cijanobakterijama je kod nekih genetičkih horizonata uticalo na statistički značajno smanjenje vrednosti električne provodljivosti u saturisanom vodnom ekstraktu (Amo,p podhorizonta černozema i Aoh,na/E horizonta solonjeca) i sadržaja Na+ jona vodnog ekstrakta (Aoh,na/E horizonta solonjeca)

Ellipsometric measurements of plastically deformed copper

Chemically pure copper (99.99) prepared in the sample of square cross-section (10 x 10 mm2) and length about 50 mm was extremely plastically deformed with the repeated application of equal channel angular pressing. Equal channel angular pressing was applied as an effective technique for producing bulk nanoscaled structures. It is well known that severe plastic deformation of metallic materials often leads to microstructure with ultrafine grains and cross-sections which remain about equal before and after deformation. Optical properties of the sample were studied using spectroscopic ellipsometry in UV-VIS range. The parameters of the sample like copper oxide and surface roughness overlayer were calculated using two-film model together with the Bruggeman effective medium approximation

Sadržaj različitih oblika gvožđa i aluminijuma u zemljištu tipa solođ

The objective of the study treated in this paper has been to confirm the presence of eluvial-illuvial processes on the basis of the distribution of different forms of iron and aluminum along the soil profiles classified as the solod soil in the soil map of the Vojvodina Province R=1:50 000. A detailed study of the different forms of Fe and Al has clearly differentiated the total contents of Fe and Al in the eluvial and illuvial horizons in all soil profiles (i.e. lower contents of these two elements in the Aoh, Eg and Aoh/Eg horizons compared with the illuvial Btg and Btg, na horizons). The contents of available forms of Fe and Al in surface horizons were high and toxic in all soil profiles studied. Such contents are characteristic for acid and poorly aerated soils which have low values of oxidoreducing potential and they indicate that degradation processes are present in these soils.Cilj istraživanja prikazanih u ovom radu je da se na osnovu distribucije različitih oblika gvožđa i aluminijuma po dubini profila zemljišta, na lokalitetima koja su na pedološkoj karti Vojvodine R= 1:50 000, označena kao solođi, potvrdi pretpostavka o postojanju eluvijalno-iluvijalnih procesa kod ovog tipa zemljišta. Utvrđena je jasna diferencijacija ukupnog sadržaja Fe i Al između eluvijalnih i iluvijalnih horizonata kod svih ispitivanih profila (tj. manji sadržaj ovih elemenata u Aoh, Eg i Aoh/Eg horizontima u odnosu na iluvijalne Btg i Btg, na horizonte), dok je sadržaj pristupačnih oblika Fe i Al u površinskim horizontima visok i toksičan. Ovakav sadržaj ispitivanih elemenata, karakterističan je za kisela i slabo aerisana zemljišta sa niskim vrednostima oksidoredukcionog potencijala i ukazuje na degradacione procese u ispitivanim zemljištima

Zemljišta Srbije i prisutni degradacioni procesi

In view of the topicality of the subject of soil protection from degradation, the paper discusses some basic considerations concerning soil genesis, pedogenetic processes, and soil degradation caused by human activity in Serbia. It can be said that at present the main processes connected with soil loss and soil degradation in Serbia are as follows: 1) change in the intended use of the soil (soil loss and damage due to industrial, mining, and power-producing activities) 2) loss of soil organic matter, 3) acidification and salinization of soil, 4) different forms of soil contaminations (as a result of the excessive use of agrochemicals, heavy metals, industrial pollution, etc.), 5) aeolian and water erosion, and 6) compaction and other types of physical degradation of agricultural soil. The most important aspects of soil protection from degradation are preventive measures, the identification of potential dangers, and the finding of ways to overcome them. Only usage of systematic monitoring of soil quality and other tools provide proper results in the protection of the soil from degradation.Imajući u vidu aktuelnost problematike zaštite zemljišta od degradacije, u ovom radu su prikazana osnovna razmatranja vezana za postanak zemljišta, pedogenetske procese, kao i procese degradacije zemljišta u Srbiji izazvane aktivnošću čoveka. Danas bi se moglo reći da su glavni procesi vezani za gubitak i degradaciju zemljišta na teritoriji Srbije sledeći: 1) promena namene korišćenja zemljišta (gubitak i oštećenja zemljišta usled industrijskih, rudarskih i energetskih aktivnosti), 2) smanjenje sadržaja organske materije zemljišta, 3) zakišeljavanje i zaslanjivanje zemljišta, 4) različiti oblici zagađivanja (kontaminacije) zemljišta (prekomerna primena agrohemikalija, teški metali, industrijska zagađenja i sl.), 5) eolska i vodna erozija, i 6) sabijanje i drugo fizičko propadanje zemljišta. U zaštiti zemljišta od degradacije najznačajnije su preventivne mere, uočavanje opasnosti i iznalaženje odgovarajućih rešenja za njihovo prevazilaženje. U tom cilju, predlaže se sistematska kontrola, tj. monitoring kvaliteta zemljišta

Soil quality for sustainable production of sunflower and soybean

The production plots of three large sunflower and soybean growers in the Vojvodina Province (AIC "Bečej" in Bečej, "Agrodunav" in Karavukovo and "Graničar" in Adaševci) were analyzed in 2002 and 2003, as a part of the project titled "Soil characterization and land management for production of highvalue food from sunflower and soybean". Soil samples taken from profiles (24) and topsoil (55) were analyzed for more than 30 parameters, i.e. physical properties, main chemical properties, total contents of microelements and heavy metals, contents of polycyclic aromatic hydrocarbons (PAHs) and the activity concentration of radionuclides

Geološka osnova zemljišnog pokrivača Vojvodine

Zemljišta Vojvodine nastala su pretežno na sedimentnim stenama. Samo zemljišta na Fruškoj Gori i Vršačkim planinama imaju za geološku podlogu uglavnom metamorfne a delom i magmatske stene. Reljef Vojvodine je formiran dejstvom endogenih i egzogenih sila. Posredstvom endogenih sila formirani su morfostrukturni oblici u reljefu, odnosno stvorene su osnovne konture današnjeg reljefa. Završni oblici reljefa Vojvodine su rezultat periodičnog navejavanja lesa, erozionog rada atmosferilija i reka kao i akumulacije fluvijalnog materijala na rečnim terasama. U reljefu Vojvodine razlikuju se sledeće geomorfološke celine: niskoplaninski oblici (Fruška Gora i Vršačke planine), lesne zaravni (platoi), peščane zaravni (Subotičko-Horgoška i Deliblatska peščara), lesne terase, aluvijalne terase i aluvijalne ravni. Kao rezultat određene konstelacije pedogenetskih faktora i različitog intenziteta njihovog delovanja javlja se raznoliki zemljišni pokrivač Vojvodine: na aluvijalnim nanosima na rečnim terasama, razvijaju se fluvisoli, semiglejna zemljišta, ritske crnice, močvarnoglejna i halomorfna zemljišta; na lesnim platoima černozemi; na lesnim terasama černozemno oglejena zemljišta i slatine; na eolskom pesku arenosoli, rendzine i černozemi; na Fruškoj Gori i Vršačkim planinama s heterogenim supstratom razvijaju se rendzine, rankeri, eutrična i distrična smeđa, lesivirana i koluvijalna zemljišta

Optical properties of plastically deformed copper

Pure copper (99.99), prepared in the sample of square cross-section (10 x 10 mm2) and length about 50 mm, was extremely plastically deformed with the repeated application of Equal Channel Angular Pressing (ECAP). ECAP was applied as an effective technique for producing bulk nano-scaled structures. Optical properties of the sample were investigated using Raman spectroscopy. Two types of lines: narrow (with width of 7 cm¡1) and wide ( 40 cm¡1) are registered. Existence of two types of lines indicates that in the specimen exists nano-sized crystal structures of both Cu and CuO related with three dimensional amorphous boundary spaces, which indicates that plastic deformation of the sample did not lead to total amorphisation of the specimen

Kvalitet vode za navodnjavanje i saliniteta zemljišta u intenzivnoj povrtarskoj proizvodnji

The study encompassed an area of about 1,200 ha of agricultural soil used by four major vegetable producers in the province of Vojvodina. Irrigation water quality in most of the samples was indicative of increased mineralization, but no threat of alkalization was detected. The levels of trace elements and heavy metals in the water were below the MTC (maximum tolerable concentration). In most of the soil samples, the levels of total water soluble salts and electrical conductivity in a saturated soil extract ranged from 0.03 to 0.10 % and from 0.1 to 1,5 dS/m, respectively. This would rule out the possibility of salinization of the irrigated areas studied, but the inadequate quality of the water being applied requires that the salinity status of the irrigation systems be monitored constantly.U radu su prikazani rezultati istraživanja kvaliteta vode koja se koristi za navodnjavanje, kao i rezultati ispitivanja saliniteta zemljišta koje se navodnjava. Istraživanjem je obuhvaćena površina od oko 1.200 ha poljoprivrednog zemljišta kod četiri velika proizvođača povrća u Vojvodini. Kvalitet vode koja se koristi za navodnjavanje kod većine ispitivanih uzoraka ukazuje na njihovu povećanu mineralizaciju ali ne i na opasnost od alkalizacije. Sadržaj mikroelemenata i teških metala u vodama je uglavnom ispod MDK, osim u tri uzorka u kojima se uočava blago povećan sadržaj nikla iznad MDK. Sadržaj ukupnih vodorastvorljivih soli, kao i električni konduktivitet u saturisanom zemljišnom ekstraktu, kod većine ispitivanih uzoraka zemljišta kretao se u intervalu od 0,03% do 0,12%, tj. od 0,1 do 1,5 dS/m, te se ne može govoriti o procesu zaslanjivanja navodnjavanih površina, ali neodgovarajući kvalitet primenjivane vode zahteva stalno praćenje stanja saliniteta zemljišta u sistemima za navodnjavanje

Analiza uticaja sabijanja zemljišta na prinos pšenice i kukuruza na uvratinama

The results of research of analysis of influence of soil compaction on maize and wheat yield on headland and in inside of a field were shown in this paper. The larger maize yield in inside of a field was established by 42,81 % in regard to yield on headland. The larger wheat yield in inside of a field was established by 51,35 % in regard to yield on headland too. Afterwards the chemical structure of soil on headland and in inside of a field were given.U radu su prikazani rezultati analize uticaja sabijanja zemljišta na uvratinama i unutrašnjem delu parcele na prinos kukuruza i pšenice. Utvrđen je veći prinos kukuruza u unutrašnjem delu parcele za 42,81% u odnosu na prinos na uvratini. Takođe utvrđen je veći prinos pšenice u unutrašnjem delu parcele za 51,35% u odnosu na prinos na uvratini. Zatim dat je hemijski sastav zemljišta na uvratini i unutrašnjem delu parcele