86 research outputs found
Design of nanolayered and nanocomposite metal-nitride coatings
Razvijene su TiAlN/TiSiN i CrAlN/TiSiN nanoslojne prevlake u kojima je napravljen spoj nanoslojnog i nanokompozitnog dizajna. Akcenat je stavljen na proizvodnju prevlaka visoke tvrdoće i visoke otpornosti na lom. Proučavane su i jednoslojne TiAlN, nanokompozitne TiSiN i višeslojne TiAlN/TiSiN prevlake kako bi se utvrdilo kako dizajn utiče na osobine prevlaka. Sve prevlake pripremane su sa jednim, dva i tri stepena rotacije. Pokazano je da dizajn i vid rotacije značajno utiču na mikrostrukturu i teksturu prevlaka, a time na njihove mehaničke osobine, otpornost na lom, adheziju između prevlake i podloge, topografiju površine i tribološko ponašanje. Nanoslojne i nanokompozitne prevlake odlikuju se kompaktnom nanokristalnom mikrostrukturom, dok jednoslojne TiAlN prevlake imaju stubastu strukturu sa kristalnim zrnima veće veličine. Pri prelasku sa jednog na više stepeni rotacije mikrostruktura prevlaka postaje kompaktnija sa kristalnim zrnima manje veličine i manjom poroznošću. U skladu sa tim, najmanju hrapavost, najveću tvrdoću, najveću otpornost na lom i najveću otpornost na habanje imaju nanoslojne i nanokompozitne prevlake pripremane sa dva i tri stepena rotacije.With the aim to develop hard coatings characterized by both, high hardness and high resistance to cracking, synergy between nanolayered and nanocomposite design was made and nanolayered TiAlN/TiSiN and CrAlN/TiSiN coatings were produced. Monolayer TiAlN, nanocomposite TiSiN and multilayer TiAlN/TiSiN were also studied in order to find the relation between the coating design and their properties. All coatings were deposited with 1-fold, 2-fold and 3-fold rotation. It is shown that coating design and type of rotation have great influence on coating microstructure and texture, and in this way on their mechanical properties, resistance to cracking, adhesion between coating and substrate, surface topography and tribological behavior. Nanolayered and nanocomposite coatings are characterized by compact nanocrystalline microstructure, while monolayer TiAlN coatings have columnar structure with larger crystalline grains. By increasing the number of rotational degrees from 1-fold to 3-fold size of crystalline grains decreases and microstructure becomes more dense. Therefore, nanolayered and nanocomposite coatings deposited with 2-fold and 3-fold rotation are characterized by the highest hardness, highest resistance to cracking, highest wear resistance and the smoothest surface topography
Political activities of Milovan Đilas: (1944-1955)
Милован Ђилас (1911–1995) био је јеадан од четворице највиших партијских и
државних функционера послератне социјалистичке Југославије и касније једна од
најкрупнијих дисидентских фигура, не само у југословенском контексту, већ и у оквиру
Хладног рата. Предмет овога рада је део политичке биографије Милована Ђиласа, који
обухвата период од 1944. до 1954. године, односно од прве дипломатске (војне) мисије
у СССР-у до његовог пада са власти. Милован Ђилас је рођен у Подбишћу код
Мојковца 1911. године. Члан Комунистичке партије Југославије постаје 1932. Од краја
30-их део је самог врха партијског вођства (''велика четворка''), поред Јосипа Броза
Тита, Едварда Кардеља и Александра Ранковића. У рату и револуцији обављао је низ
војних и политичких дужности. У процесу револуционарног освајања власти Милован
Ђилас игра важну улогу, као и у процесу политичког обрачуна са остацима старог
система. У процесу изградње нове државе, Милован Ђилас је задужен првенствено за
област идеолошког и пропагандног рада, као и област културе и просвете. На
спољнополитичком пољу, Ђилас је играо важну улогу од самог почетка стварања нове
државе, од мисија у СССР-у до заступања Југославије у ОУН, преговора са Западом по
питању наоружања и контаката са западноевропском левицом. Од 1950. Ђилас
постепено гради свој идеолошки и политички концепт ''социјалистичке демократије'',
активно учествује у афирамацији демократизације и либерализације друштва, што је у
великој мери прихваћено као партијска ''линија'' на Шестом конгресу, 1952. После
Стаљинове смрти, марта 1953, Ђилас одбија да се повинује новом политичком ''курсу''
и наставља са критиком. Током друге половине 1953. и почетком 1954. објављује серију
чланака у листу Борба и Нова мисао, што га доводи у сукоб са остатком руководства,
пре свега са Титом. На Трећем (ванредном) пленуму, јануара 1954. Милован Ђилас је
оптужен за ''ревизионизам'' и смењен са свих партијских и државних функција и удаљен
са власти.
Период политичке биографије Милована Ђиласа који је предмет истраживања у
великој мери је запостављен, како у науци тако и у публицистици. У њему се отвара
важно, можда и кључно питање како је Милован Ђилас радикално променио своје
становиште и од убеђеног стаљинисте постао отпадник комунистичког света. Поред
тога, назначени период крије у себи више питања, почев од начина политичког
обрачуна са старим системом, утицаја на идеолошко обликовање новог друштва,
сукоба са СССР-ом, критике совјетског система, афирмације југословенског искуства и
демократизације друштва, у чему је Ђилас имао запажену улогу. Такође, поставља се и
важно питање обрачуна унутар југословенског руководства. Резултати истраживања су
показали да се идеолошки и политички прелом Милована Ђиласа одиграо између 1949.
и 1953. године, од почетка критике совјетске политике и система до одлуке да се не
подлегне новом ''курсу'' помирења са СССР-ом. Дакле, један од најважнијих чинилаца
за Ђиласову промену и каснији сукоб са остатком руководства, био је утицај спољне
политике. Поред тога, за Ђиласову политичку судбину доста важну улогу је одиграо и
његов темперамент, личне особине, афинитети и порекло, као и велика разлика у свим
тим питањима са Јосипом Брозом Титом. Српска, као и светска историјска наука, осим
неколико радова, до сада се није темељно бавила Милованом Ђиласом, већ је његов лик
и дело углавном био препуштен другим научним дисциплинама, у којима има одређени
број врло озбиљних подухвата. Овај рад представља скроман покушај да се у светлу
научне историографије открије једно важно место у политичкој биографији Милована
Ђиласа, а то је време док је био на власти и његова политичка промена у том периоду.Milovan Đilas (1911–1995) was one of the top four party and state officials in the
postwar socialist Yugoslavia, and later on, one of the largest dissident figures, not only in the
context of Yugoslavia, but also within the Cold War. The subject of this paper is the part of
the political biography of Milovan Đilas, encompassing the period from 1944 to 1954, i.e.
from his first diplomatic (military) mission in the USSR until his fall from power. Milovan
Đilas was born in Podbišće near Mojkovac in 1911. He became a member of the Communist
Party of Yugoslavia in 1932. From the end of the 1930’s, he was a part of the very top of the
party leadership (“the great four”), besides Josip Broz Tito, Edvard Kardelj and Aleksandar
Ranković. During the war and revolution he performed a range of military and political
duties. Milovan Đilas had a very important role in the process of revolutionary conquest of
power, as well as in the process of political confrontations with the remnants of the old
system. In the process of building a new state, Milovan Đilas was primarily in charge of the
field of ideology and propaganda, as well as culture and education. In the field of foreign
affairs, Đilas had a very important role from the very beginning of a new state-building,
starting from the missions in the USSR to representing Yugoslavia in the OUN, negotiations
with the West on the issue of armament and contacts with the West European left. From 1950,
Milovan Đilas gradually built his own ideological and political concept of “social
democracy”, actively participating in the affirmation of society democratization and
liberalization, which was largely accepted as the party “line” at the Sixth Congress in 1952.
After Stalin’s death in March 1953, Đilas refused to comply with the new political “trend”
and proceeded with criticizing. During the second half of 1953 and the beginning of 1954, he
published a series of articles in the newspapers “Borba” and “Nova misao”, which brought
him into conflict with the rest of the leadership, primarily with Tito. At the Third
(extraordinary) Plenum in January 1954, Đilas was accused of “revisionism” and was
dismissed from all party and state functions and deposed from power.
The period from the political biograhy of Milovan Đilas which is the subject of this
research is largely neglected both in science and popular literature. It opens an important,
maybe an essential issue of how Milovan Đilas radically changed his standpoint and, out of a
convinced Stalinist, became a dissident from the communist world. Besides, the alleged
period hides multiples questions, starting from the political confrontations with the old
system, influence on the ideological shaping of the new society, conflict with the USSR,
criticism of the soviet system, affirmation of the Yugoslav experience and society
democratization, in which Đilas had a remarkable role. There is also an important issue of the
confrontations within the Yugoslav authority. The research results have shown that Milovan
Đilas’ ideological and political split took place between 1949 and 1953, from the beginning of
his soviet politics criticism until the decision not to comply with the new “trend” of
reconciliation with the USSR. Therefore, one of the most important factors for Đilas’ change
and further conflict with the rest of the leadership was the foreign policy influence. Besides,
his temperament, personal characteristics, affinities and origin played a very important role
for Đilas’ political fate, as well as the great divergence with Josip Broz Tito in all matters.
Serbian, as well as the world historical science has not thoroughly dealt with Milovan Đilas so
far, but his character and work were left to other scientific disciplines, in which there are
fairly serious endeavours. This paper presents a modes attempt to reveal, in light of scientific
historiography, an important place in the political biography of Milovan Đilas, and that is the
time during his governance and his political change in that period
The effects of using soybean molasses in diets for dairy cows
Sojina melasa je hranivo koje se dobija kao sporedni proizvod pri proizvodnji
sojinog proteinskog koncentrata. U ograničenom broju ranijih istraživanja utvrđeno je
da korišćenje melase soje u obrocima za ishranu junadi u tovu, ima pozitivan efekat na
proizvodne performanse životinja. Osnovni cilj ovog istraživanja je ispitivanje
mogućnosti upotrebe sojine melase u kompletno mešanim obrocima za ishranu krava u
laktaciji. U radu su prikazani rezultati ispitivanja efekata korišćenja sojine melase u
ishrani krava u laktaciji na proizvodne rezultate, važnije pokazatelje metaboličkog
profila i parametre ruminalne sredine.
U jednofaktorijalnom ogledu sa dva tretmana, ispitivan je efekat korišćenja
melase soje, na proizvodne i fiziološke parametre krava u laktaciji. Istraživanje je
obuhvatilo 52 krave u laktaciji, od čega je 40 krava bilo crno-bele rase sa dominantnim
učešćem holštajn gena i 12 krava simentalske rase. Za potrebe ispitivanja krave su bile
podeljene u dve grupe - kontrolnu i oglednu. Na početku ogleda, grupe su bile
ujednačene po stadijumu laktacije i laktaciji po redu, po količini proizvedenog mleka i
telesnoj kondiciji. Istraživanje je trajalo 70 dana. U sastav kompletno mešanog obroka
(TMR, Total Mixed Ration) za ishranu krava u oglednoj grupi, uključena je sojina
melasa u količini od 1 kg/dan (na račun smanjene količine silaže vlažnog zrna
kukuruza), dok obrok koji su konzumirale krave iz kontrolne grupe nije sadržao melasu
soje. Osnovu kabastog dela obroka činili su silaža cele biljke kukuruza i seno lucerke.
Kompletno mešani obroci za ishranu krava u oglednoj i kontrolnoj grupi su bili
izoenergetski i izoproteinski. Uzorci kompletno mešanog obroka su uzimani dva puta
nedeljno, za potrebe hemijske analize. Tokom eksperimentalnog perioda, proizvedena
količina mleka je registrovana svakodnevno, a sprovedene su i četiri kontrole mlečnosti,
u cilju utvrđivanja hemijskog sastava mleka. Uzorci krvi za biohemijska ispitivanja su
uzeti od svakog grla, punkcijom repne vene (v. coccigea), na početku i na kraju
eksperimentalnog perioda. Za determinisanje parametara ruminalne sredine, tečni
sadržaj rumena je uzet od 15 krava, iz svake grupe, korišćenjem buražne sonde, na kraju
ogleda...Soybean molasses is feed that is being obtained as a by-product of a production
of soybean protein concentrate. In a certain number of previous studies the use of
soybean molasses in rations for the nutrition of beef steers was proved to have a positive
effect on animal production performance. A main goal of this research is to study the
possibility of using the soybean molasses in total mixed rations (TMR) for the nutrition
of lactating dairy cows. The study presents results of the research the effects of using
soybean molasses in the nutrition of lactating dairy cows on their production results, on
important indicators of metabolic profile and parameters of ruminal content.
The trial was set as one-factorial experimental arrangement, where was
determined the effect of using the soybean molasses in ration, on the production and
physiological parameters of lactating cows. The research included 52 lactating cows, 40
Holstein and 12 Simmental cows. For the purpose of the investigation, the cows were
divided into two groups – control group and experimental one. The groups were
equalized regarding the stage of lactation and lactation in order, quantity of produced
milk and body condition score (BSC). The research lasted 70 for days. The TMR used
for the nutrition of cows in experimental group, was supplemented with soybean
molasses in the quantity of 1 kg/day (with the reduced quantity of high-moisture corn
grain silage), while the ration consumed by the cows in control group contained no
soybean molasses. The main forage feeds in TMRs were whole maize silage and alfalfa
hay. The total mixed rations used for cows in experimental and control group, were
approximately equal for energy and protein content. For the chemical analysis, the TMR
samples were collected twice weekly during trial period. During the experimental period
the milk yield was recorded daily, and also four sampling for milk composition analysis
were conducted. Blood samples for biochemical analysis were taken from each animal
by puncturing the caudal vein (v. coccigea), at the beginning and at the end of the
experimental period. For the purpose of determining the parameters of ruminal content a
samples was taken using the ruminal tube-like probe from 15 cows in each group, at the
end of the trial..
The Ethnic Discourse in the Serbian Opposition Press: Demokratija and Srpska reč, 1990–1991
Članak se bavi karakterom i zastupljenošću etničkoga diskursa u srbijanskim opozicijskim glasilima Demokratija i Srpska reč u periodu 1990./1991. Jedno od pitanja koje razmatra ovaj rad odnosi se na preispitivanje teze o nepostojanju relevantne političke alternative tzv. nacionalnom programu Slobodana Miloševića i njegove političke partije u Srbiji u predvečerje raspada Jugoslavije.A statistical analysis of the presence of ethnic discourse (ED) and its subcategory, discourse of ethnic intolerance (DEI), in the party organs Demokratija and Srpska reč shows the indisputably different political character and physiognomy of these two papers. Namely, the average presence of ED in the Srpska reč in the period from June 1990 to June 1991 was four times higher, and the prevalence of DEI ten times higher, than in the Demokratija. In addition to the varying prevalence and character of their ED content, these two organs were fundamentally different as regards the character of their remaining contents. In the Serbian Renewal Movement’s organ, the predominant part of the remaining discourse consisted of revisionist serials and essays dedicated to promoting the Chetnik Movement. These texts made up as much as half of the contents of individual issues of the monthly Srpska reč. Putting together all the pro-Chetnik contents and the ED contents of the Srpska reč, we can conclude that, on average, over 60 percent of each issue’s contents were exceptionally irrational, conservative, and nationalist.
On the other hand, after its first few issues, the Demokratija preserved an ethic of responsibility and a critical stance towards the social reality and political situation in the country. After these first few issues, the ethnic discourse in this organ was present only as a precedent and derailment, and was not a commonplace of political rhetoric, unlike in the case of the Srpska reč. The leadership of the Democratic Party certainly played a role in setting up these standards of civil discourse in this organ but, paradoxically, it often also took responsibility for sharpening the ‘national’ line of reasoning within the frame of (forced) political pragmatism. Đinđić’s or Mićunovićev’s ethnic discourse from August 1990 and May 1991 was not supported by a corresponding change in the physiognomy of the paper, which remained predominantly rational, critically oriented, civil, and socially responsible.
The analytical verification of facts in this paper certainly supports the thesis of Dubravka Stojanović from 1996 that there was no alternative to this programme in Serbia, at least not within the frame of these two most relevant opposition parties. Furthermore, this paper indicates that, in the summer and autumn of 1990 and in May 1991, the rhetoric of the party leaders of the Serbian Renewal Movement and Democratic Party attempted to be—and often was—more belligerent than Milošević’s. As regards almost all questions of the internal order of Yugoslavia, and especially regarding the status of the autonomy of Kosovo and the regulation of the position of Serbian people outside Serbia, the solutions advocated by the opposition were more radical than the ones advocated by Slobodan Milošević’s regime.
Az első világháború és a lakásbérleti piac, 1914-1938 : Kelet-közép- és délkelet-európai folyamatok tágabb európai kontextusban
The universal tenant-protection schemes and rent control system (RCS) were born out of the huge turmoil triggered by World War I. By the end of the war, the trend towards an ever more elaborated RCS was gaining firm ground; throughout 1920s it was the prevailing model of housing policy on the European continent. The four countries under study followed the above mentioned European trends of increasing state intervention in the housing market, and furthermore, their authorities, representing distinctive Southeast- and East-Central European patterns of administrative modus operandi, applied some of the most intensive forms of housing policies in Europe during the first postwar decade. In the first place, this refers to the practice of requisitioning housing units, which was maintained in these countries, even after it was abolished by the most interventionist Central European countries. According to the innovative 6-level developmental typology, this proved to be the highest level of state intervention in the housing market in interwar Europe (5 out of maximum 6), if the Bolshevik practices (6 out of 6) are to be excluded from the comparison. On the other hand, Southeast European countries managed to effectively return to prewar liberal practices, while this was not accomplished by the most liberal Western European countries. From this perspective, East-Central and Southeast European countries represent confronted patterns of the most liberal and the most interventionist housing policies in Europe in the period under review
Gender-related morphological characteristics in preschool children of Kolubara district
The aim of this study was to establish the gender-related differences among children 6-6.5 years of age in anthropometric characteristics so as to observe their development and make more appropriate selection for participation in guided and organised physical activities. A battery of 7 anthropometric measurements was used on the representative sample of 175 subjects of both genders from Valjevo (M=45 aged 6 and M=83 aged 6.5; F = 44 aged 6 and F=43 aged 6.5). The multivariate analysis of variance showed the existence of statistically significant differences (p=0.00) in the anthropometric space of the two ages analysed regarding the gender. Through the individual analysis, the differences at age 6 were found in the Upper arm skin fold variable (p=0.03) and the Back-skin fold (p=0.00), whereas with the 6.5-year-old subjects, the differences were found in the Body height variable (p=0.03), Upper arm skin fold (p=0.00) and Back skin fold (p=0.02), both in favour of the boys. It can be assumed that the differences are the result of the endogenous and exogenous factors upon the children’s organism in the period of childhood in a smaller urban community of the southwest Serbia
Application of artificial intelligence in factory maintenance
The work that will be presented in the rest of the document deals with the application of artificial intelligence AI, neural networks, machine learning on machine maintenance, which is a key resource for production in industry. It is a specific machine that must not have an interruption longer than 30 minutes during one shift. Due to the specific nature of the job of inserting fresh air into the blast furnace, the machine must work continuously during the entire furnace operation campaign. This campaign can last up to 12 months. By looking at the situation before the introduction of AI into the system, it was established that the stoppage is mainly caused by damage to the rolling bearings, which are the basis for starting the fan turbines. Further research led to the startling conclusion that bearings ran shorter when they were more lubricated than when they were not lubricated at all. Based on these observations, it was decided that it is necessary to create a program that will collect data on the sensors and based on this data, create an AI that will decide when and how much it is necessary to lubricate the bearings. The advantages of the system are related to the application of algorithms that significantly improve the efficiency of the software in the maintenance application, which significantly reduces the downtime of the machine, and increases its timeliness, availability and efficiency. The method of learning with incentives was applied. The program receives data from the sensors (pressure, temperature, vibrations and ultra sound), then performs an action on the machine via the actuator. The machine returns feedback via sensors to the program, which corrects the settings depending on the results (good or bad). The goal is for the program to learn during operation to have as high a percentage of good results as possible. Due to the complexity of the machine, there are limited limit values in the program, so that the program cannot cause damage to the machine during learning. The research results are presented using statistical methods in the paper.
Specifically, the paper deals with the application of the Convolutional neural network CNN. The data measured on the sensors are sent to the database located on the server. The program groups this data and selects them based on the results - good and bad. The data is then used to train the network and create an optimal algorithm that, with its timely actions, should extend the service life of the rolling bearings on the machine, which is a key resource for the complete production of the factory. Based on the learning, the AI can generate reports based on which the procurement and replacement plan of critical components can be planned. By using the mentioned solution, the service life of the rolling bearings was increased by 20%, while the emergency outages of the plant were reduced to 0. The advantage of the used solution is reflected in high timeliness, availability, reliability, since there were no emergency outages since the implementation of the mentioned solution.Rad koji ce biti predstavljen u nastavku dokumenta bavi se prime-nom veštačke inteligencije AI, neuronskih mreža, mašinskog učenja na odrzavanju mašine koja je kjucni resurs za proizvodnju u industriji.Radi se o specificnoj masini koja u toku jedne smene ne sme imati prekid veci od 30min. Zbog specificnosti posla ubacivanje svezeg vazduha u visoku pec masina mora da radi kontinulno tokom cele kampanje rada peci. Ova kampanja moze da traje i do 12 meseci. Sagledavanjem stanja pre uvodjenja AI u sistem ustanovili smo da do zastoja uglavnom dolazi zbog ostecenja kotrljajucih lezajeva koje su osnov za pokretanje turbina ventilatora. Daljim istrazivanjima dosli smo do zapanjujucih zakljucaka da su lezajevi krace radili kada su bili vise podmazani nego kada uopste nije ni bilo podmazivanja. Na osnovu ovih zapazanja odlucili smo da je potrebno napraviti program koji ce vrsiti prikupljanje podataka na senzorima i na osnovu ovih podataka uraditi AI koja ce odlucivati kada i koliko je potrebno podmazati lezajeve. Prednosti sistema se odnose na primenu algoritama koji znatno poboljšavaju efikasnost softwera u aplikaciji održavanja čime se znatno smanjuje vreme otkaza mašine, a povećava njena ažurnost, dostupnost i efikasnost. Primenjena je metoda učenja uz podsticaje. Program prima podatke sa senzora (pritisak, temperatura, vibracije i ultra zvuk), zatim preko aktuatora vrši akciju na 97mašini. Mašina vraća povratnu informaciju preko senzora programu, koji koriguje podešavanja u zavisnosti od rezultata (dobri ili loši). Cilj je da program tokom rada nauči da ima što veći procenat dobrih rezultata.
Zbog složenosti mašine u programu su ograničene granične vrednosti tako da program ne može da prouzrokuje oštećenje mašine prilikom učenja. Rezultati istraživanja prikazani su statističkim metodama u radu.
Konkretno rad se bavi primenom neuronske mreze Convolutional neural network CNN. Podatke izmerenih na senzorima salju se u bazu podatka koja se nalazi na serveru. Program grupise ove podatke i selektuje ih na osnovu rezultata dobri I losi. Podaci se zatim koriste da se izvrsi ucenje mreze i napravi optimalan algoritam koji ce svojim pravovremenim akcijama treba da produzi radni vek kotrljajucih lezajeva na masini koja predstavlja kljucni resurs za kompletnu proizvodnju fabrike. Na osnovu ucenja AI moze da vrsi generisanje izvestaja na osnovu kojih se moze planirati nabavka I plan zamene kriticnih komponenata. Upotrebom pomenutog resenja radni vek kotrljajucih lezajeva je povecan za 20%, dok su havarijski ispadi postrojenja svedeni na 0. Prednost upotrebljenog resenja ogleda se u velikoj azurnosti, dostupnosti pouzadnosti posto nije bilo havarijskih ispada od implementacije pomenutog resenja
The assessment of genetic potential in performance tested gilts by means of selection indexes method
The objective of this research paper was to make an assessment of breeding value of performance tested gilts of Swedish Landrace and F-1 crossbreds of Swedish Landrace and Great Yorkshire by the method of selection index. The traits on whose basis the breeding value was estimated were: daily liveweight gain, average backfat thickness measured at two sites and carcass meat percentage. These traits were corrected for body mass of 100kg by the method of base indexes and the following average values were determined: corrected daily liveweight gain (KZDP) 408.93g/day, corrected average backfat thickness measured at two sites (KSL) 9.77mm and corrected carcass meat percentage (KPM) 61.08%. Studying the effect of genotype, year and birth season of gilts a statistically significant variation (P>0.05) of these traits provoked by the mentioned factors was not determined while the gilts sire statistically highly significantly (P lt 0.001) influenced all studied traits. Heritability coefficients were: h(2)= 0.255 for KZDP, h(2)= 0.356 for KSL and h(2)= 0.349 for KPM. The four selection index equations were constructed among which as the most optimal was chosen the one which includes all three traits (KZDP, KSL and KPM) and whose coefficient of the correlation of selection index and aggregate genotype was r(IAG) = 0.594
Evaluacija faktora značajnih za nivo učešća na tržištu organizacija koje posluju u republici srbiji
nem
POLLUTION INDICES OF TRACE ELEMENTS IN SOILS OF PČINJA AND JABLANICA DISTRICTS
Soil samples collected from two districts of southern Serbia, Pčinja and Jablanica, were
analyzed in order to determine the content of eleven heavy metals and metalloids (As, B,
Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Zn). The concentration of the elements was measured by
atomic absorption spectrometry in 152 samples collected from agricultural land. The main
goal was to assess the environmental and health risk of eleven heavy metals and metalloids
tested in the soil. To determine the degree of soil contamination, measured concentrations
were compared with limits and remediation values given in the Serbian Rulebook. It was
determined that the average content of tested elements in mg/kg was: As (12.76), B
(113.73), Cd (1.10), Cr (58.01), Cu (29.62), Hg (0.33), Mn (1067.89), Mo (0.21), Ni
(34.85), Pb (233.38), Zn (64.49). The average content of all examined trace elements in
soil did not exceed the remediation values. However, the average content of Cd, Hg, Pb
exceeded the limit values. Five pollution indices were used to assess environmental risk:
enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF),
pollution load index (PLI), and potential environmental risk index (RI). Based on EF and
Igeo, it was concluded that the biggest problem was As, Hg and Pb. More than half of the
samples are moderately contaminated with Pb, over 30% of samples are heavily
contaminated with Hg, while some samples were highly polluted with As. Contamination
factor, as well as PLI and RI, showed moderate contamination of the soil with Hg and Cd.
The health risk assessment was estimated by hazard index (HI) and the carcinogenic risk
index (CR), which determine the non-carcinogenic and carcinogenic effects that heavy
metals can cause in the human body, throught ingestion, inhalation and dermal contact
with contaminated soil. This study showed that there was no non-carcinogenic risk as
adults-hazard index (HI) calculated for each sample was less than one. On the other hand,
there was a higher risk for children's health since over 85% of soil samples had HI values
greater than one. Combine carcinogenic risk of all elements was estimated with lifetime
carcinogenic risk (LCR). There is no risk of developing cancer in both groups because
more than 90% of the samples had acceptable carcinogenic risk values between 1,0*10-6
i 1,0*10-4, while a small number had concern LCR values grater than 1,0*10-4
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