6 research outputs found

    Distribution of chromium, nickel, copper and zinc in the Al Zintan area, northwestern Libya

    Get PDF
    Global population is growing rapidly. As a result, increasingly large areas are being settled and farmed. This devastates soils and causes pollution by heavy metals and other components. Heavy metals in the environment originate from both natural and anthropogenic sources. Natural sources generally include rock weathering and the propagation of heavy metals, such as Cr and Ni, from ultrabasic rocks. These are natural processes that generally do not threaten human health. Anthropogenic sources include industry and inappropriate disposal of waste in the environment. In such cases concentrations of heavy metals can be harmful to people and other living beings. Al Zintan is a city located in northwestern Libya, on a plateau mainly built up of Cretaceous sediments. Since the 1980’s, nomadic population has rapidly been settling this area. As a result, a former part of the desert was transformed and is used for farming. Soil sampling at Al Zintan was conducted in 2017, across a 2×2 km grid. A total of 143 samples were collected from depths of about 30 cm. The samples weighed 2 to 2.5 kg and generally comprised sand with a clay component. A Niton Xl3t goldd+ instrument was used for chemical analyses, based on which GIS heavy-metal distribution maps were generated. The distribution of Cr, Ni, Cu and Zn is discussed on the paper

    Efficiency evaluation of a bivalent vaccine in the prophylaxis of mastitis in cows

    Get PDF
    Mastitis in cows represents one of the most actual problems in intensive dairy production. The longtime different approaches to the treatment of mastitis have not offered a suitable solution, and the problem of mastitis is still present and acute. Prevention of pathogen penetration into the mammary gland, its colonization and multiplication impose a constant need for regular inspections of milk, as well as preventive and therapeutic measures to reduce the incidence of mastitis. Studies in the field of vaccination of ruminants against mastitis pathogens suggest a limited success in obtaining significant results in immunoprophylaxis. Considering the results of other researchers and our own research, and bearing in mind the problems mastitis caused by Staphylococcus aureus and Streptococcus agalactiae represent, the aim of this study was the preparation and testing of an indigenous vaccine prepared with two stable strains, SAU 7 (S. aureus) and SAG 3 (Str.agalactiae). The dose was 5 mL/cow and consisted of inactivated bacterial S. aureus SAU 7 cells in a concentration of 1x1010 cfu/mL and Str. agalactiae SAG 3 in a concentration of 4 x 109 cfu/mL. The number of somatic cells in the milk samples during the whole study period was higher in vaccinated cows in both groups compared with the control, but this difference was not statistically significant. The concentration of immunoglobulin IgG in the milk of vaccinated cows was significantly higher than the concentration of this class of proteins in the milk of unvaccinated cows. [Projekat Ministarstva nauke Republike Srbije, br. III 46002

    Plan integrisanog monitoringa kvaliteta zemljišta kao indikatora kvaliteta životne sredine u Novom Sadu

    Get PDF
    U radu je prikazan plan integisanog upravljanja životnom sredinom na primeru kontrole kvaliteta zemljišta u gradu Novom Sadu u Republici Srbiji. S obzirom da ima veoma povoljan geografski položaj, Novi Sad je grad gde se prepliću važni magistralni putevi, ima sve veći priliv stanovništva, kao i brzi razvoj industrije i poljoprivrede. Usled navedenih činjenica postoji i povećano zagađivanje vazduha, vode i zemljišta, kao i generisanje velike količine otpada. Pored parkova i devastiranih područja u okolini industrijskih zona, rasprostranjena poljoprivredna delatnost u prigradskim delovima, naročito je osetljiva na kvalitet zemljišta i obrnuto. U ovoj studiji analizirani su geografska pozicija i geomorfološke karakteristike područja grada, kao i vodeći ekološki problemi. Na osnovu datih činjenica predložen je integrisani monitoring jednog od indikatora kvaliteta životne sredine, kvalitet zemljišta. Predložena je mreža od ukupno 15 senzora za merenje pH vrednosti, vlage i temperature zemljišta na teritoriji grada. Podaci o kvalitetu zemljišta koji se na ovakav način dobijaju u realnom vremenu veoma značajni su za eliminisanje ili ublažavanje potencijalnih nepoželjnih posledica. Zahvaljujući brzom razvoju tehnologije primena senzorskih mreža sve više se koristi u modernim sistemima monitoringa i dostupna je za efikasno i ekonomski isplativo rešavanje problema zaštite životne sredine

    Symulacja wpływu wód kopalniach do wyrobiska. Studium przypadku: kopalnia węgla Štavalj (południowo-zachodnia Serbia)

    No full text
    The inflow of mine water to mining operations is often caused by random events such as precipitation. Consequently, the mine water inflow regime can be defined as a function of random events applying the theory of random processes. Regression models of the multiple linear correlation type have been used to simulate the inflow of mine water into mining operations, produce short-range predictions and facilitate rapid response inside the mine. The significance of such models lies in the ability to simulate and predict the consequences (mine water inflow), caused by events of a random nature (meteorological parameters: precipitation and air temperature). The presented prognostic models have been calibrated for mine water inflow to the Štavalj Coal Mine in southwestern Serbia. Mathematical dependencies were defined based on daily mine water inflow rates recorded during the period from 2003 to 2011, which can be used to generate short-range (1-7 day) predictions of mean daily mine water inflow rates to the Štavalj Coal Mine. A strong correlation (coefficient of correlation r = 0.93, Sig. = 0.00) was derived for the one-day forecast. The coefficients of correlation for predictions of mean daily mine water inflow rates related to time periods of two, three...seven days gradually declined to 0.63 (7-day mean daily inflow rate).Przedostawanie się wody do wyrobisk górniczych spowodowane jest czynnikami losowymi, na przykład opadami. Dlatego też dopływ wód kopalniach zdefiniować można jako funkcję czynników losowych, z zastosowaniem teorii procesów losowych. Symulacje dopływu wód kopalniach do wyrobiska prowadzono z wykorzystaniem modelu regresji typu wielokrotnych korelacji liniowych, na tej podstawie opracowano prognozy krótkoterminowe, tym samym umożliwiając podjecie szybkich działań w kopalni. Znaczenie modeli takich polega na ich przydatności do symulacji i przewidywania skutków dopływu wód kopalnianych, spowodowanego czynnikami losowymi (parametry meteorologiczne: opady i temperatura powietrza). Zaproponowany model skalibrowany został na przykładzie badanego dopływu wód kopalnianych do kopalni Stavalj w południowo-zachodniej Serbii. Matematyczne zależności zdefiniowano w oparciu o dobowe natężenia przepływu wód kopalniach zarejestrowane w okresie od 2003 do 2011 roku, które wykorzystać można do opracowania krótkoterminowych prognoz (obejmujących 1-7 dni) średniego natężenia przepływu wody do kopalni węgla Stavalj. Stwierdzono wysoki poziom korelacji dla prognozy jednodniowej (współczynnik korelacji r = 0.93). Wartości współczynnika korelacji otrzymywane dla kolejnych dni stopniowo malały, do 0.63 dla prognozy siedmiodniowej

    Proteingehalt im Samenplasma von Zuchtebern auf den Betrieben für intensive Schweineproduktion in Serbien

    No full text
    The aim of this study was to investigate: (a) seminal plasma protein content in the Land-race (n = 38), Large White (n = 44) and Duroc (n = 24) boars breed, as well as boars distribution according to protein content in seminal plasma, and (b) the sperm motility in the semen samples, forming from the ejaculates with high or low protein content, stored in vitro on 17°C for 3 days. Not significant (p > 0.05) differences was found in seminal plasma protein content between three boar breeds. Only 31% of the 106 investigated boars had > 3.6% protein in seminal plasma. Progressive motility was significantly higher (p lt 0.01) in the ejaculates with high, compared to the ejaculates with low protein content (82% vs. 76%). After 3 days of storage, in thel:4 dilution proportion, the average progressive motility was significantly (p lt 0.01) decreased in relation to this value in native semen from the boars with high (82% to 64%), as well from the boars with low protein content in seminal plasma (76% to 48%). However, the average diluted semen progressive motility was significantly greater (p lt 0.01) in the boars with high (64%), compared to the boars with low protein content in seminal plasma (48%). The number of good diluted semen samples (>65% progressive motility), was also significantly (p lt 0.01) greater in the boars with high (41%), compared to the boars with low protein content in seminal plasma (12%)
    corecore