Ages of asteroid families estimated using the YORP-eye method

In the present paper we complete the analysis discussed in a previous work, using an improved algorithm and an extended database of families. We confirm that the analysis connected to the search for the YORP-eye can lead to an estimate of the age

Ligninolytic potential and medicinal properties of extracrs of Trametes fr. species.

Rod Trametes Fr. obuhvata vrste širokog rasprostranjena sa dobro razvijenim ligninolitičkim enzimskim sistemom i značajnim kapacitetom u sintezi raznovrsnih biološki aktivnih jedinjenja, zbog čega sve više nalaze primenu u mnogobrojnim biotehnološkim procesima. Ciljevi ovog istraživanja bili su optimizacija uslova kultivacije za produkciju ligninolitičkih enzima i degradaciju odabranog biljnog otpada sa T. gibbosa, praćenje varijabilnosti u kapacitetu lignocelulolize unutar roda Trametes kao i određivanje antifungalnog, antioksidativnog, genoprotektivnog, citotoksičnog i anti-neurodegenerativnog efekta ekstrakata plodonosnih tela i micelije. Pšenična slama je bila bolji izvor ugljenika nego piljevina bukve za produkciju Mn-oksidujućih peroksidaza i lakaza T. gibbosa koji je maksimalni stepen delignifikacije (48,3%) postigao nakon 19 dana čvrste fermentacije u prisustvu 10,0 mM azota u formi (NH4)2SO4 i 10% pšeničnih mekinja kao dodatnog izvora azota. Prisustvo Fe2+ i Zn2+ u koncentraciji od 0,5 mM, kao i 0,1 mM p-anizidina i 0,5% veratril alkohola je značajno stimulisalo ligninolizu. Značajna inter- i intra-specijska varijabilnost u sintezi proučavanih enzima, degradaciji polimera biljnog ćelijskog zida kao i u selektivnosti delignifikacije je takođe uočena između 6 vrsta i 11 sojeva. T. hirsuta BEOFB 30 je bio najefikasniji i najselektivniji razlagač lignina (56,0% razloženog lignina prema 17,4% hidrolizovane celuloze), posebno u prisustvu p-anizidina koji je stimulisao produkciju Mn-oksidujućih peroksidaza. Dvofaktorskom analizom varijanse je pokazano da su soj, prisustvo indukujućih supstanci kao i njihova interakcija faktori koji značajno utiču na stepen ligninolize. Etanolni ekstrakti bazidiokarpa i micelije T. gibbosa, T. hirsuta i T. versicolor, su imali slab antifungalni potencijal koji se ogledao u slaboj inhibiciji rasta testiranih humanih patogena a jedino je micelijski ekstrakt T. hirsuta pokazao fungicidno dejstvo na Aspergillus glaucus (MFC = 32,0 mg/mL). Ekstrakt plodonosnih tela T. versicolor je pokazao najveći kapacitet neutralizacije DPPH i ABTS radikala (dobijene EC50 vrednosti su 15,22 odnosno 8,46 mg/mL), a glavni nosioci ove aktivnosti su bili fenoli čija je koncentracija bila u pozitivnoj korelaciji sa antioksidativnim kapacitetom...The genus Trametes Fr. encompasses widely distributed species with strongly developed ligninolytic enzyme system and significant capacity to synthesize diverse biologically active compounds, because of which are increasingly used in numerous biotechnological processes. The aims of this research were the optimization of cultivation conditions for ligninolytic enzyme production and degradation of selected plant residues with T. gibbosa, assessment of the variability in capacity of lignocellulolysis within the genus Trametes and determination of antifungal, antioxidative, genoprotective, cytotoxic and antineurodegenerative effects of basidiocarp and mycelial extracts. In comparison with beach sawdust wheat straw was better carbon source for production of Mn-oxidizing peroxidases and laccase by T. gibbosa which maximum rate of delignification (48.3%) was achieved after 19 day of solid-state fermentation in the presence of 10.0 mM of nitrogen in the form of (NH4)2SO4 and with 10% of wheat bran as additional nitrogen source. Supplementation of wheat straw with Fe2+ and Zn2+ in concentration of 0.5 mM, p-anisidine in concentration of 0.5% and veratryl alcohol in solutions’ concentration of 0.5% significantly stimulated lygninolysis. Significant inter- and intraspecific variability in synthesis of studied enzymes, degradation of plant cell wall polymers and selectivity in delignification was noticed among 6 species and 11 strains. T. hirsuta BEOFB 30 was the most efficient and the most selective lignin degrader (56.0% of degraded lignin vs. 17.4% of hydrolysed cellulose), particularly in the presence of p-anisidine which stimulated Mn-oxidizing peroxidises production. Results of two-way analysis of variance showed that strain, presence of inducers and their interaction represent factors which significantly affect rate of lygninolysis. Ethanolic extracts of basidiocarps and mycelia of T. gibbosa, T. hirsuta and T. versicolor showed weak antifungal potential which reflected in low growth inhibition of tested human pathogens and only mycelial extract of T. hirsuta BEOFB 30 showed fungicidal effect on Aspergillus glaucus (MFC = 32.0 mg/mL). Basidiocarp extract of T. versicolor showed the highest capacity in neutralization of DPPH and ABTS radicals (obtained EC50 values were 15.22 and 8.46 mg/mL, respectively), and the main carriers of this activity were phenolic compounds, which concentration was positively correlated with antioxidative capacity..

Development of maintenance model choice method in function of increased aircraft fleet availability

Predmet istraživanja doktorske disertacije jeste izbor modela neperfektnog održavanja koji je moguće primeniti na održavanje flote vazduhoplova u okviru trenutne organizacije održavanja a na osnovu parametara koji se prate u toku eksploatacije. Pregled ponuđenih modela održavanja i klasifikacija prema politikama održavanja poslužio je za izbor modela koji za ulazne parametre raspoloživosti uzima norme koje se prate pri održavanju flote vazduhoplova. Na osnovu predloženog logičkog dijagrama odlučivanja problem je rešen odabirom konkretnog modela neperfektnog održavanja. Primenom izabrane metode neperfektnog održavanja na numeričkom modelu dobijene su vrednosti za intervale između preventivnih održavanja kao i maksimalni broj uzastopnih korektivnih popravki za svaki od podsistema. Primena preporučenih normi na numeričkom modelu dala je razliku u trenutnoj i ostvarenoj raspoloživosti za svaki od podsistema. Razvijen je simulacioni model procesa eksploatacije flote aviona G-4 za karakterističan zadatak u školskoj nameni. Postavka rasporeda entiteta i logika rada simulacije u najvećoj mogućoj meri slede zadatu organizaciju izvršenja zadataka i održavanja flote vazduhoplova. Scenariji u simulaciji eksploatacije flote vazduhoplova formirani su oko primenjenog koncepta održavanja. Referentni scenario predstavlja aktuelni koncept održavanja prema dostignutim resursima. Eksperimentalni scenario predstavlja upotrebu koncepta baziranog na primeni izabrane metode neperfektnog održavanja. Varijacijom normi održavanja u aktuelnom konceptu registrovane su promene statističkih pokazatelja Dostignute raspoloživosti i Dnevne ispravnosti. Koncept neperfektnog održavanja u eksperimentalnom scenariju uz ograničenja broja uzastopnih popravki potvrdio je razlike u promeni vrednosti statističkih parametara u odnosu na referentni scenario.The subject of doctoral dissertation research is the choice of a of imperfect maintenance model that can be applied to maintaining the aircraft fleet within the current maintenance organization based on parameters that are being monitored during exploitation. An overview of the offered maintenance models and classifications according to maintenance policies was used to select models that for the input parameters of availability take the norms that accompany the maintenance of the aircraft fleet. Based on the proposed logical decision diagram, the problem is solved by selecting a concrete model of imperfect maintenance. Using the chosen method of imperfect maintenance on the numerical model, the values for the intervals between preventive maintenance and the maximum number of consecutive corrective corrections for each of the subsystems were obtained. The application of the recommended norms on the numerical model gave a difference in the current and realized availability for each of the subsystems. A simulation model of the G-4 fleet exploitation process for a characteristic task in the training purpose was developed. The layout of the entities and the simulation work logic are as closely as possible to the assigned organization of tasks and maintenance of the fleet of aircraft. Scenarios in the simulations of the exploitation of the fleet of aircraft were formed around the applied maintenance concept. The reference scenario represents the current maintenance concept (hard time). The experimental scenario represents the use of a concept based on the application of the chosen method of imperfect maintenance. By varying the different parameters in the current concept, changes have been registered through the indicators of Availability and Daily correctness. The concept of imperfect maintenance in the experimental scenario with the limit of the number of consecutive corrections confirmed the differences in the movement of the values of the statistical parameters relative to the reference one

An open architecture control system for multi‐axis wood CNC machining center

Abstract: This paper presents an open architecture control system for multi‐axis wood computer numerical control (CNC) milling machining centre, based on LinuxCNC. The wood CNC machining system is supported by an equivalent virtual machine in a CAD/CAM environment, as well as in the control system. Simulation within virtual environment is essential for multi‐axis machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before it’s sent to the actual machine, while the virtual machine in the control system represents the final verification of the program, as well as the process monitoring system. Configuration of the control system and implementation of virtual machines will be shown, along with the conducted machining experiments that ensued after the successful simulation on developed virtual machines

Double Tooth

The form of primary and permanent teeth can differ morphologically from that which is considered normal, completely or in some parts. The changes in tooth form can be hereditary or caused by some disease or trauma. Fusion is a union of one or more teeth during development. Gemination means that two separate morphological units were created by division of the tooth germ. The intention of this study was to state the prevalence of double teeth (fusion and gemination) among the persons tested, as to gender, distribution in the maxilla or mandible, and whether the anomaly occurred bilaterally or unilaterally. The results of this investigation have shown that in a total of examined 3,517 plaster models, a prevalence of double teeth was 0.2%. 57.2% of them were fusioned and 42.9% geminated

Copper-induced changes of lipid peroxidation and hemato-biochemical parameters in rat blood: Protective role of flavonoids

The effects of subchronic exposure to copper (Cu) on lipid peroxidation, hemato-biochemical parameters, and the possible protective role of flavonoids Quercetin and (-)-Epicatechin were studied. Male Wistar albino rats were treated with Cu (560 mg/L, p.o. as CuCl2·2H2O for 5 weeks) and Quercetin and (-)-Epicatechin (40 mg/kg BW each, i.p., every third day during the last 3 weeks) alone or in combination. Cu increased the concentration of lipid peroxides, decreased the number of erythrocytes, hemoglobin and hematocrit values and increased the activities of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase. Coadministration of Quercetin and (-)-Epicatechin with Cu lowered the process of lipid peroxidation and restored examined hemato-biochemical parameters to control values. Our results indicate that Cu induced oxidative damage in erythrocytes, which led to anemia, while Quercetin and (-)-Epicatechin showed a protective effect on the hemato-biochemical processes in the blood of rats

Doses in the Vicinity of Mobile X-ray Equipment in a Children’s Intensive Care Unit

Most of the patients in the intensive care unit for children are newborns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment including mobile shields is routinely used for diagnosis of the respiratory tract, heart and endovascular cateterisation. The aim of this work was to determine the radiation exposure to the children in the vicinity of the exposed patient in the same or next room. Three measurement runs were carried out with thermoluminescence dosimetry system. The results show that the homogeneity of the irradiation field is adequate, the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is very low, practically in the range of the lowest detectable dose. The entrance dose on the breast of the patient was found to be 0.07 mSv. Therefore, there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment

Doses in the Vicinity of Mobile X-ray Equipment in a Children’s Intensive Care Unit

Most of the patients in the intensive care unit for children are newborns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment including mobile shields is routinely used for diagnosis of the respiratory tract, heart and endovascular cateterisation. The aim of this work was to determine the radiation exposure to the children in the vicinity of the exposed patient in the same or next room. Three measurement runs were carried out with thermoluminescence dosimetry system. The results show that the homogeneity of the irradiation field is adequate, the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is very low, practically in the range of the lowest detectable dose. The entrance dose on the breast of the patient was found to be 0.07 mSv. Therefore, there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment

Seasonal variations of microbiological parameters of water quality of the Velika Morava river Serbia

In this study, we investigated the level of sanitary pollution and organic contamination of the Velika Morava River, the largest river in central Serbia. Samples of water for microbiological analysis were collected at 5 sites, monthly, from April 2010 to February 2011. Sanitary analysis, i.e. enumeration of total and fecal coliforms and intestinal enterococci, indicated moderate to critical fecal contamination, while organic load assessment (oligotroph to heterotroph ratio, index of phosphatase activity) revealed the category of moderately polluted water. We also investigated seasonal variations of these groups of bacteria and the factors that could contribute to these differences. Our results showed that the micro- biological quality of the water in the Velika Morava River during different seasons is affected by numerous factors such as unequal loading of wastewaters, solar irradiation, and relations of flow/dilution and rainfall/runoff. [Acknowledgments. This study was financially supported by the Ministry of Education and Science of the Republic of Serbia: projects No 173025, No 177045 and No 043002.