Photolytic degradation of chlorpyrifos induced by an artificial light source

Chlorpyrifos dissolved in methanol was illuminated by the Xe polychromatic light source, which is commonly used as artificial solar radiation source. Photolytic degradation of the parent compound was followed by UV/Vis spectrophotometry and GC/MS technique. GC/MS measurementsindicated that very few pyridine containing intermediates are formed during the degradation process. After 2 hours of illumination almost no chlorpyrifos could be observed and significant mineralization (formation of carbon dioxide, water, alkyl phosphates and sulfates) was achieved.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effect of high levels of organic selenium on glutation-peroxidase (GSH-Px) activity in blood plasma of broilers

An experiment lasting 45 days was performed on 125 Hybro broilers divided into five groups. All compounds for broiler feed mixes used in the experiment contained 0.15 mg Se/kg, in the form of sodium selenite. The control group (K-group) of broilers was fed mixes without added organic selenium, and the experimental groups with mixes to which selenium, in the form of selenized-yeast, was added in quantities of 2, 5, 10, or 15 mg/kg. Selenized yeast (ICN - Gaienika) was obtained from beer yeast and contained 1.51, or 1.45 mg/g total, or organically bound selenium. At the beginning of the fattening period, GSH-Px plasma activity in broilers of the K-group ranged around 16.55 μkat/L, while GSH-Px plasma activity in broilers of experimental groups was statistically significantly higher, but without any major differences among the individual groups (on the average 25.53fjkat/L). In the blood plasma of K-group, GSH-Px activity dropped already in the second week of life and was maintained at a relatively constant level (about 10 μkat/L) until the end of the experiment. The same phenomenon was observed in the experimental groups, but the trend of declining GSH-Px activity in blood plasma was more expressed, and, contrary to the control group, was expressed also in the later phases of the experiment. In the 3rd week of the fattening period, GSH-Px plasma activity in broilers of the control and experimental groups was relatively equal, and then the plasma activity of GSH-Px in broilers of the experimental groups decreased, but there were no major differences among the individual groups

Analysis of the evaporative towers cooling system of a coal-fired power plant

The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system

Tumori ovarijuma u adolescentkinja i mladih žena

Phenomenon of heterogeneous ovary tumors is probably the result of activity of the whole series of various factors, which play significant role in genesis, development and classification of tumors, In the age of puberty and adolescence, as a transitional period from childhood to adulthood, it is not rarely seen that due to the influence of hormone regulation, social environment and psychophysical stability, the break of correlation of the mentioned factors can imperil reproductive health of young people. That is the moment when the illnesses of reproductive system become noteworthy for the first time. Thus the immense role of juvenile gynecology is to preserve reproductive health of adolescent girls by preventive health education. The most frequent illnesses of ovary are in tight connection with ovary tumor changes, which could have influence on the normal function of the ovary.Pojava raznovrsnih tumora ovarijalnog porekla, verovatno je posledica delovanja čitavog niza različitih faktora, koji imaju značajnu ulogu u pojavi, razvoju i klasifikaciji tumora. U pubertetu i adolescenciji, kao prelaznom periodu iz detinjstva u zrelo doba, pod uticajem hormonske regulacije, socijalne sredine i psihofizičke ravnoteže, najčešće može doći do prekida korelacije pomenutih faktora, a što može da ugrozi reproduktivno zdravije mladih. Bolesti reproduktivnog sistema tada prvi put postaju značajne. Zato je značaj i uloga juvenilne ginekologije da preventivno zdravstveno-vaspitnim radom i pravovremenim lečenjem sačuva reproduktivno zdravlje adolescentkinja, jer najčešća oboljenja ovarijuma su u tesnoj vezi sa tumoroznim promenama, koji mogu da utiču na normalnu funkciju ovarijuma

Desorption of metals from Cetraria islandica (L.) Ach. Lichen using solutions simulating acid rain

Desorption of metals K, Al, Ca, Mg, Fe, Ba, Zn, Mn, Cu and Sr from Cetraria islandica (L.) with solutions whose composition was similar to that of acid rain, was investigated. Desorption of metals from the lichen was performed by five successive desorption processes. Solution mixtures containing H2SO4, HNO3 and H2SO4-HNO3 were used for desorption. Each solution had three different pH values: 4.61, 5.15 and 5.75, so that the desorptions were performed with nine different solutions successively five times, always using the same solution volume. The investigated metals can be divided into two groups. One group was comprised of K, Ca and Mg, which were desorbed in each of the five desorption processes at all pH values used. The second group included Al, Fe, Zn, Ba, Mn and Sr; these were not desorbed in each individual desorption and not at all pH values, whereas Cu was not desorbed at all under any circumstances. Using the logarithmic dependence of the metal content as a function of the desorption number, it was found that potassium builds two types of links and is connected with weaker links in lichen. Potassium is completely desorbed, 80% in the first desorption, and then gradually in the following desorptions. Other metals are linked with one weaker link (desorption 1-38%) and with one very strong link (desorption below the metal detection limit). [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. ON 172019

Procena ekološkog rizika u funkciji zaštite životne sredine

This paper proposes an appropriate methodology for ecological risk assessment. The methodology has been applied in the region of Boka Kotorska Bay (Bay), Montenegro. The emphasis of the research is on the analysis of the impact of various stressors on the ecological components of Bay. The consequences of that impact can be seen in an increased level of eutrophication of water environment, mostly through the influence of nitrogen and its compounds. The actual research at/about the region of Boka Kotorska Bay was performed in the period of 2008. The study emphasized the importance of the acquisition, processing and analysis of various ecologically related data for more efficient monitoring and management of the environment. The suggested methodology of the ecological risk assessment is, therefore, a remarkable scientific and expert contribution in the area of environmental protection in our country and in general.U radu je predstavljena primena metodologije procene ekološkog rizika. Metodologija je primenjena na primeru Bokokotorskog zaliva (Zaliv). Istraživanjem je razmatrana procena uticaja većeg broja stresora na ekološke komponente Zaliva. Posledice ovih uticaja ispoljene su kroz povećan stepen eutrofikacije vodene sredine i dovode se u vezu sa koncentracijom azotnih jedinjenja (nitrata i nitrita) Konkretna merenja vršena su u 2008. godini. Istraživanjem je posebno ukazano na značaj razvoja sistema prikupljanja i obrade ekoloških i drugih informacija radi efikasnijeg upravljanja životnom sredinom datog prostora. Primenjena metodologija procene ekološkog rizika trebalo bi da u naučnom i stručnom pogledu predstavlja doprinos u oblasti zaštite životne sredine,kako kod nas, tako i u svetu

AGN and Star-Formation Properties of Inside-out Assembled Galaxy Candidates at z<0.1

We study a sample of 48127 galaxies selected from the SDSS MPA-JHU catalogue, with $\log M_{\star}/M_{\odot} = 10.73 - 11.03$ and $z<0.1$. Local galaxies in this stellar mass range have been shown to have systematically shorter assembly times within their inner regions ($<0.5~R_{50}$) when compared to that of the galaxy as a whole, contrary to lower or higher mass galaxies which show consistent assembly times at all radii. Hence, we refer to these galaxies as Inside-Out Assembled Galaxy (IOAG) candidates. We find that the majority of IOAG candidates with well-detected emission lines are classified as either AGN (40%) or composite (40%) in the BPT diagram. We also find that the majority of our sources are located below the main sequence of star formation, and within the green valley or red sequence. Most BPT-classified star-forming IOAG candidates have spiral morphologies and are in the main sequence, whereas Seyfert 2 and composites have mostly spiral morphologies but quiescent star formation rates (SFRs). We argue that a high fraction of IOAG candidates seem to be in the process of quenching, moving from the blue cloud to the red sequence. Those classified as AGN have systematically lower SFRs than star-forming galaxies suggesting that AGN activity may be related to this quenching. However, the spiral morphology of these galaxies remains in place, suggesting that the central star-formation is suppressed before the morphological transformation occurs.Comment: 11 pages, 9 figure, accepted for publication in MNRAS. A video description can be seen here https://youtu.be/oxfjbqMqeQ

Uporaba lokalnih sojeva bakterije Lactococcus lactis kao starter kultura u proizvodnji tradicionalnih crnogorskih sireva

The aim of this study is to characterise and examine the biochemical properties of 40 Lactococcus lactis strains isolated from indigenous Montenegrin dairy products in order to explore their potential to be used as starter cultures for producing typical Montenegrin cheese, such as ‘bijeli sir’, ‘masni sir’ and ‘njeguški sir’. Their safety regarding the production of biogenic amines, the presence of antimicrobial resistance and the antibacterial activity against relevant pathogens and spoilage microorganisms has also been tested. Based on the characterisation, all strains belong to L. lactis ssp. lactis. Out of these 40 strains, 23 displayed rapid acidification ability and proteolysis. However, none of the strains exhibited the ability of lipid degradation. Most of the strains were not associated with any health risk investigated. Summing up, a large percentage (27.5 %) of the tested strains showed good properties. These strains should be further examined for their possible application as specific starter cultures in the production of indigenous cheese in MontenegroSvrha je ovoga rada bila okarakterizirati i ispitati biokemijska svojstva 40 sojeva bakterije Lactococcus lactis, izoliranih iz autohtonih crnogorskih mliječnih proizvoda, te istražiti mogućnost njihove uporabe kao starter kultura u proizvodnji tipičnih crnogorskih sireva, kao što su bijeli sir, masni sir i njeguški sir. Također je ispitana sigurnost primjene tih sojeva, tj. sposobnost proizvodnje biogenih amina, antimikrobna rezistencija i sposobnost suzbijanja rasta važnih patogenih mikroorganizama i uzročnika kvarenja hrane. Karakterizacijom je utvrđeno da svih 40 sojeva pripadaju podvrsti L. lactis ssp. lactis. Njih 23 imala su sposobnost brzog zakiseljavanja i proteolize. Međutim, niti jedan soj nije pokazao sposobnost razgradnje lipida. Većina sojeva nije predstavljala nikakav rizik za zdravlje. Velik postotak sojeva (27,5 %) pokazao je dobra proizvodna svojstva, pa treba dodatno ispitati mogućnost njihove uporabe kao specifičnih starter kultura u proizvodnji autohtonih crnogorskih sireva