Metastability – Markovian approach

A complete system of events of nonlinear processes in complex dynamical systems describes the evolution of the distribution. Different stages of evolution of the distribution declared stable, metastable and unstable systems. Variance of probabilistic distribution plays a crucial role in determining the state of the system. It was found that the system is metastable, when it carried Markovian processes in continuous time. Metastability is the original metallurgical phenomenon and actively exists in the structure of the materials. In a metastable state, the structural distances in material are exponentially distributed

The determination of patulin in apple juice

Istraživana je mogućnost kvantitativnog određivanja patulina tu jabučinom soku. Postupak je uključivao ekstrakciju patulina iz soka s pomoću etil-acetata, pročišćavanje ekstrakata kromatografijom na stupcu silikagela te kvalitativno i kvantitativno određivanje s pomoću tankoslojne kromatografijc. Izlaganjem ploča za tankoslojnu kromatografiju koncentriranim parama amonijaka dobiveni su derivati s intenzivnijom fluorescencijom, što je olakšalo kvantitativno fluorodenzitometrijsko određivanje patulina. Granična koncentracija, što se s pomoću upotrijebljene metode mogla odrediti, bila je 200 ng čistog patulina i 100 µg patulina na litru soka. Djelotvomost postupka bila je od 78 do 110%, a prosječna vrijednost djelotvornosti bila je 98%.A quantitative method for the determination of patulin in apple juice was examined. The procedure involved patulin extraction from apple juice with ethyl acetate, clean-up with column chromatography and preparative thin-layer chromatography. Fluorescent derivatives, obtained by exposure of patulin on chromatographic plates to concentrated ammonia fumes, permitted a convenient quantitative fluorodensitometric assay of patulin by means of the fluorescence quenching method. The detection limits were 200 ng of pure patulin and 100 µg of patulin per litre of apple juice. The recoveries of added patulin ranged from 78 to 110.4 per cent, with a mean recovery of 97.8 per cent

Influence of the twilight period and different sampling methods on catch of Gobiids (Gobiidae) at four locations in the inshore parts of the Danube River

The aim of this work was to compare the efficiency of two different methods for fish sampling and to assess the influence of the twilight period on the catch of gobiids along the Danube River in Serbia. The samplings were performed by electrofishing and beach seining in inshore parts of the Danube River with water depth up to 120 cm at four locations: Novi Sad, Belgrade, Tekija, and Prahovo, in October 2012 and September 2013. At each location, the samplings were performed at 17:30, 18:30, 19:30 and 20:30. Totally, 539 gobiids were caught. The highest number of specimens (218) was registered at Tekija, while lower numbers were registered at Belgrade (192) and Prahovo (117), and only 12 specimens were caught at Novi Sad. The catch of the round goby Neogobius melanostomus and monkey goby Neogobius fluviatilis was more efficient by beach seining than by electrofishing, whereas the catch of the tubenose goby Proterorhinus semilunaris was more efficient by electrofishing. Both methods had similar efficiency in catching the bighead goby Ponticola kessleri and racer goby Babka gymnotrachelus. The species diversity and number of the caught specimens were the highest at 18:30. All five species were recorded at Belgrade, Tekija and Prahovo, while only the monkey goby and racer goby were caught at Novi Sad. The methods used in this study showed good efficiency in catching gobiids, especially at dusk. Even though these methods are difficult to apply in certain habitats, they could be highly relevant in the regular monitoring of gobiids along the inshore parts of rivers

Shift work and worker\u27s health complaints

Cilj istraživanja bio je usporediti zdravstvene probleme radnika koji rade u smjenama i radnika koji ne rade i nisu nikad radili u smjenama. Ispitano je 609 smjenskih radnika i 97 radnika koji ne rade u smjenama. Radnici su bili muškog spola, zaposleni u rafineriji. Zdravstveni problemi radnika ispitani su kao broj posjeta liječniku tijekom pet godina i kao subjektivne procjene vlastitog zdravstvenog stanja. Rezultati o posjetima liječniku pokazali su da su radnici koji ne rade u smjenama općenito više puta posjećivati liječnika nego smjenski radnici. Međutim, kada se broj posjeta liječniku zbog pojedinih skupina bolesti promatrao u odnosu na ukupni broj posjeta i osobito kada su se uzele u obzir subjektivne procjene zdravstvenog stanja, pokazalo se da su smjenski radnici izloženi povećanom riziku od nekih bolesti, u prvom redu bolesti probavnih organa.A comparative study of health complaints was performed in a large oil-refinery among a total of 609 shift workers and 97 non-shift workers. Health complaints were assessed on the basis of the workers\u27 medical records, where details of every visit to the physician over a period of five years were noted, and as subjective health complaints obtained by a questionnaire. In general, the non-shift workers visited the physician more often than the shift workers. However, when visits to the physician for special groups of diseases were considered taking into account the overall number of visits, and especially when the subjective health complaints were compared between the two groups of workers, the results indicated that the shift workers were at greater risk of some diseases, especially the digestive ones

Main and additional sleep characteristics of rotating shift workers

U radu su ispitane različite karakteristike spavanja rotirajućih smjenskih radnika (n=604) i radnika kontrolne skupine (n=113). Utvrđeno je da smjenski radnici imaju općenito lošiju kvalitetu spavanja te da nakon rada u jutarnjoj smjeni spavaju kraće, a u slobodne dane duže nego radnici kontrolne skupine. U skupini smjenskih radnika različite mogućnosti spavanja s obzirom na smjenu i slobodne dane značajno su utjecale na trajanje glavne epizode spavanja i učestalost dodatnog spavanja. Ova skupina kompenzirala je kratko trajanje spavanja nakon rada u jutarnjoj i noćnoj smjeni dužim spavanjem nakon rada u poslijepodnevnoj smjeni i u slobodne dane. Usto su kratko spavanje nakon rada u noćnoj smjeni kompenzirali još jednim dodatnim spavanjem, dok dodatno spavanje nakon jutarnje smjene nije imalo funkciju nadoknade kratkog spavanja. U kontrolnoj skupini radnika različite mogućnosti spavanja s obzirom na radne i slobodne dane također su utjecale na trajanje glavne epizode spavanja. Radnici ove skupine kompenzirali su kratko trajanje spavanja u radne dane samo dužim spavanjem u slobodne dane. Povezanost kvalitete spavanja i trajanja glavnog spavanja razlikovala se s obzirom na smjene i slobodne dane. Kvaliteta i učestalost dodatnog spavanja bili su povezani samo kod radnika kontrolne skupine.Various sleep characteristics were examined among rotating shift workers (n = 603) and control workers (n = 113). The results showed the shift workers to have poorer sleep quality than the control group. In addition their main sleep episode was shorter on morning shift and longer on days off in comparison to controls. Shift workers\u27 main sleep length and frequency of napping were affected by the situation in which they were taken (morning, afternoon, night shift or days off). In the group of shift workers the short main sleep episode on morning and night shifts was compensated by longer sleep on afternoon shift and days off. The short night shift sleep was additionally compensated by napping. However, naps taken on the meening shift did not prove to be compensatory. The length of the main sleep episode was affected by the situation in which sleep was taken also in the control group of workers. In this group only the longer main sleep episode on days off appeared to have a compensatory function for the short main sleep on working days. The relationship between sleep quality and main sleep duration was determined by the situation in which sleep was taken, while the relationship between sleep quality and napping was established only for the control group of workers

Origin of Middle-Infrared Peaks in Cerium Compounds

We have demonstrated that the middle-infrared (mid-IR) peaks in the optical conductivity spectra of Ce$X_3$ ($X$ = Pd, Sn, In) can be explained by first-principle band structure calculation with the spin-orbit interaction. The mid-IR peak shapes in these materials are not identical to one another: CePd$_3$, CeSn$_3$, and CeIn$_3$ have a triple-peak structure, double-peak structure and broad single-peak structure, respectively. These peaks can be theoretically explained by the optical transition from the occupied state to the spin-orbit splitted Ce $4f$ state. This result indicates that the mid-IR peaks originate from the simple band picture with the Ce $4f$ state near the Fermi level, not from the conventional cf hybridization gap based on the periodic Anderson model.Comment: 5 pages, 6 figures. To be published in J. Phys. Soc. Jpn. 78(1) (2009

Influence of the twilight period and different sampling methods on catch of Gobiids (Gobiidae) at four locations in the inshore parts of the Danube River

The aim of this work was to compare the efficiency of two different methods for fish sampling and to assess the influence of the twilight period on the catch of gobiids along the Danube River in Serbia. The samplings were performed by electrofishing and beach seining in inshore parts of the Danube River with water depth up to 120 cm at four locations: Novi Sad, Belgrade, Tekija, and Prahovo, in October 2012 and September 2013. At each location, the samplings were performed at 17:30, 18:30, 19:30 and 20:30. Totally, 539 gobiids were caught. The highest number of specimens (218) was registered at Tekija, while lower numbers were registered at Belgrade (192) and Prahovo (117), and only 12 specimens were caught at Novi Sad. The catch of the round goby Neogobius melanostomus and monkey goby Neogobius fluviatilis was more efficient by beach seining than by electrofishing, whereas the catch of the tubenose goby Proterorhinus semilunaris was more efficient by electrofishing. Both methods had similar efficiency in catching the bighead goby Ponticola kessleri and racer goby Babka gymnotrachelus. The species diversity and number of the caught specimens were the highest at 18:30. All five species were recorded at Belgrade, Tekija and Prahovo, while only the monkey goby and racer goby were caught at Novi Sad. The methods used in this study showed good efficiency in catching gobiids, especially at dusk. Even though these methods are difficult to apply in certain habitats, they could be highly relevant in the regular monitoring of gobiids along the inshore parts of rivers