1,163 research outputs found
Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes
Axial emission profiles in a parallel plate dc micro discharge (feedgas:
argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time
resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A)
characteristics were recorded and Ar* metastable densities were measured by
tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in
the steady state regime are similar to corresponding profiles in standard size
discharges (d=1cm, p=1Torr). For some discharge conditions relaxation
oscillations are present when the micro discharge switches periodically between
low current Townsend-like mode and normal glow. At the same time the axial
emission profile shows transient behavior, starting with peak distribution at
the anode, which gradually moves towards the cathode during the normal glow.
The development of argon metastable densities highly correlates with the
oscillating discharge current. Gas temperatures in the low current
Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K)
were determined by the broadening of the recorded spectral profiles as a
function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno
Lawton, Michael T: Seven aneurysms: Tenets and techniques for clipping: Thieme 2011, ISBN 978-1-60406-054-6
In this paper, the removal of methylene blue (MB) from aqueous solution by biosorption onto apricot shellshas been investigated through batch experiments. Apricot shells were chosen as a locally available and abundant waste from fruit juice industry. Methylene blue is common pollutant of waste waters from textile industry. The influence of initial MB concentration on biosorption process has been studied. The experimental data have been analysed using Langmuir and Freundlichisotherm models. The Langmuir model better fits to experimental data, which explain monolayer adsorption. Maximum biosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shells with biosorption capacities of similar adsorbents previously investigated indicates that apricot shells could be a promising biosorbent for removal of MB from aqueous solution
Uticaj genetskih i faktora životne sredine na fenotipske karakteristike jagnjadi
The aim of this study was to determine the influence of environmental factors affecting body weight variability of lambs in two crossbreed groups: Pirot x WĆ¼rttemberg and Sjenica x WĆ¼rttemberg. Both populations were managed under the same farm conditions. The data were analyzed to determine the effect of age of the dam, weight of dam, birth type, sex, year and season, on the birth weight and weaning weight of crossbreed lambs. Statistical analysis was performed by GLM procedure using the SPSS statistical package program. The average birth weight of Pirot x WĆ¼rttemberg lambs was 3.56 kg while Sjenica x WĆ¼rttemberg lambs was slightly higher at 3.69 kg. The difference on birth weight between the two crosses was not statistically significant (P>0.05). The average weaning weight of Pirot x WĆ¼rttemberg lambs was 23.54 kg while Sjenica x WĆ¼rttemberg lambs had higher weight at 24.37 kg. The difference of 0.83 kg on weaning weight was statistically significant (P (lt) 0.05). Body weight, depending on the environmental factors, ranged from 3.17 to 3.96 kg at birth and from 22.12 to 24.18 kg at weaning in Pirot x WĆ¼rttemberg lambs. Body weight of Sjenica x WĆ¼rttemberg lambs ranged from 3.39 to 3.99 kg at birth and from 22.69 to 25.44 kg at weaning. Statistical analysis showed that the differences were statistically significant (P (lt) 0.05) and highly significant (P (lt) 0.01).Cilj ovog istraživanja je bio da se utvrdi uticaj faktora životne sredine na varijabilnost telesne težine jagnjadi u dve grupe meleza: pirotska x virtemberg I sjeniÄka x virtemberg. Obe populacije su držane pod istim uslovima na farmi. Podaci su analizirani da se utvrdi uticaj starosti majke, njene težine, tipa roÄenja, pola, godine i sezone, na težinu na roÄenju i odbijanju jagnjadi meleza. StatistiÄka analiza je izvedena pomoÄu GLM procedure, koristeÄi SPSS statistiÄki program paket. ProseÄna telesna masa meleza pirotska x virtemberg je 3,56 kg, dok sjeniÄka x virtemberg jagnjad bila neÅ”to veÄa - 3,69 kg. Razlika u težini na roÄenju izmeÄu dve grupe meleza nije bila statistiÄki znaÄajna (P>0,05). ProseÄna težina na odbijanju jagnjadi meleza pirotska x virtemberg je bila 23,54 kg, dok su jagnjad melezi sjeniÄka x virtemberg imala veÄu težinu - 24,37 kg. Razlika težine na zaluÄenju od 0,83 kg je statistiÄki znaÄajna (P (lt) 0,05). Telesna masa, u zavisnosti od faktora sredine, kretala se u rasponu od 3,17 do 3,96 kg na roÄenju i od 22,12 do 24,18 kg na odbijanju u jagnjadi pirotska x virtemberg. Telesna masa jagnjadi sjeniÄka x virtemberg kretala se u rasponu od 3,39 do 3,99 kg na roÄenju i od 22,69 do 25,44 kg na odbijanju. StatistiÄka analiza pokazala je da su razlike statistiÄki znaÄajne (P (lt) 0,05) i visoko znaÄajne (P (lt) 0,01)
Efekti dodavanja razliÄitih oblika selena u obroke za tovnu jagnjad
The study included lambs of Mis population, divided into two groups (experimental and control) .All the animals fed with identical portions of meals consisted of alfalfa hay and fully concentrate mixtures. Meals are only different in the fact that the experimental group received organic selenium and contained 2000 mg of selenium / kg preparations, while the control group received inorganic selenium in the form of sodium selenite (Na2SeO3). Each animal consumed the same amount of selenium than 0.3 mg / kg of dry matter in the organic or inorganic form, which added in the mineral-vitamin premix. Diet of lambs has been ad libitum. The body weight of lambs in both (control and experimental groups), were balanced at 60 days (19.60 kg : 19.65 kg) and 100 days (31.06 kg : 32.88 kg). The result on average daily gain of the control and experimental groups were almost similar and there were no statistically significant differences (P> 0.05) in the measured values from 28 to 60 days (259.0 : 255.0 g), from the 60-100 days (286.0 : 330.0g), and on average from 28 to 100 days (274.0 : 297.0. g). Both treatment have no significant effect on lambs' performance (body weight and growth). The study results showed that the diet of lambs experimental group, based meal supplement organic selenium resulted in significantly higher concentration of Se in MLD, kidneys, liver and spleen, compared with the control group, which are consumed inorganic form of selenium. The differences between the Se content in MLD the experimental and control groups were on significance level P (lt) 0.05, while the differences in the content of Se in kidney, liver and spleen, the aforementioned treatments were statistically highly significant (P (lt) 0.01). So fattening lambs are better utilizing organic source of selenium, which is associated with better absorption of this element.Selen (Se) je esencijalni mikroelement za ljude i životinje i predstavlja centralnu strukturnu komponentu niza specifiÄnih enzima a pre svega glutation peroksidaze. Uglavnom potiÄe iz biljaka, koje iz zemljiÅ”ta usvajaju selen u neorganskom obliku. Sadržaj Se u biljkama na naÅ”em podruÄju je nizak. Da bi se ublažile posledice nutritivnog deficita, neophodna je dopuna ovog elementa u obrocima za ishranu životinja. U tu svrhu se koriste organska i neorganska forma selena. Cilj ovog istraživanja je uporeÄivanje efekata razliÄitih formi selena na proizvodne performanse i retenciju selena u tkivima tovne jagnjadi. Istraživanjem je bilo obuhvaÄeno 30 jagnjadi Mis populacije, proseÄnog uzrasta oko 28 dana, podeljenih u dve grupe. Grla su hranjena identiÄnim obrocima koji su se sastojali od sena lucerke i potpune smeÅ”e koncentrata. Obroci su se razlikovali u tome Å”to je ogledna grupa dobijala organski selen koji je bio proizvod ameriÄke firme Alltech i sadržao je 2000 mg selena/kg preparata, dok je kontrolna grupa dobijala neorganski selen u obliku natrijumselenita (Na2SeO3). Svako grlo je konzumiralo identiÄnu koliÄinu selena od 0.3mg/kg suve materije u organskom odnosno neorganskom obliku koji su dodavani u mineralnovitaminsku predsmeÅ”u. Rezultati ogleda su pokazali da su telesne mase jagnjadi kontrolne i ogledne grupe bile ujednaÄene, kako 60. dana (19.60 kg; 19.65 kg), tako i 100. dana (31.06 kg; 32.88 kg). Dnevni prirasti jagnjadi kontrolne i ogledne grupe su takoÄe bili sliÄni i nije bilo statistiÄki znaÄajnih razlika (P>0.05) u vrednostima izmerenim od 28. do 60. dana (259.0 : 255.0g), od 60.-100. dana (286.0 : 330.0g), i proseÄno od 28. do 100. dana (274.0 :297.0. g). Izvori selena nisu znaÄajnije uticali na proseÄno konzumiranje suve materije (0.695 : 0.680 kg), ukupnih proteina (134.0:130.0 g), OHJ (0.844:0.818), kao ni na konverziju hranljivih materija: suva materija (2.345: 2.481 kg); ukupan protein (452 :476 g), OHJ (2.847: 2.987 kg), u periodu od 28-100. dana ogleda. Ishrana jagnjadi ogledne grupe, obrokom na bazi suplementa organskog selena je rezultirala znatno veÄim koncentracijama Se u MLD, bubrezima, jetri i slezini, u poreÄenju sa grlima kontrolne grupe, koja su konzumirala neorgansku formu selena.Ustanovljene razlike izmeÄu sadržaja Se u MLD jagnjadi ogledne i kontrolne grupe su na nivou znaÄajnosti P (lt) 0.05, dok su razlike u sadržaju Se u bubrezima, jetri i slezini, na navedenim tretmanima, bile statistiÄki veoma znaÄajne (P (lt) 0.01). Dakle, tovna janjad su bolje iskoristila organski izvor selena, Å”to se dovodi u vezu sa boljom apsorpcijom ovog element
Sustainable Tourism as a Part of Comprehensive Environmental Monitoring. A Study of Serbia
The sustainable tourism comprises the freedom of tourist travelling, satisfying the economic, social and aesthetic needs, with the preservation of the characteristics of the natural and social environment and the cultural and historical heritage. It should optimize the usage of environmental resources that make the key element of tourism development, maintaining the essential ecologic processes and helping in heritage preservation, and providing the sustainable long-term business.As the consequences of the anthropogenic activities are obvious in the deterioration of the environment quality, the analysis of the status and influence on the environment and humans, as well as on the flora and fauna, must be under constant monitoring. The aim is to detect the corresponding influences and changes and to establish their cause. The paper approaches the structure, the processes and the application of the comprehensive monitoring of the environment with the aim of creating a database for the development of sustainable tourism in Serbia. The risk of the anthropogenic pollution of the environment, as a result of tourist activities, and monitoring of these activities in order to create a database for a planned and coordinated activity of tourism development will be considered in detail
Linearna povezanost osobina porasta jagnjadi Ŕarplaninske rase u ekstenzivnim uslovima gajenja
The fastest phase of growth, observed in young animals, is often assumed to be linear, and linear regressions or ratios between BW gain and time are used to model growth. However, growth curves, due to their flexibility, are likely to be more suitable to describe even early growth. The research was performed in the region of Sharplanina Mountain in the population of the local Å arplanina breed of sheep. The following traits of lambs were considered: BWB, BW30, BW60 and BW90. Statistical analysis was conducted using the Pearson's correlation and multivariate linear regression model. This involved computing all possible and the best subset regression equation. Each equation was then assessed by its coefficient of determination (R2) and the constant based on the number of variable that used for the prediction. Results showed that weight of lambs from birth to weaning increased by about six times. Specifically lambs achieved an average total gain of 17.66 kg, or 196 g per day. There were a very significant correlation (P (lt) 0.01) between BWB and BW30, BW60 and BW90. Likewise, shown a very significant correlation (P (lt) 0.01) between BW30-BW60, BW30- BW90 and BW60-BW90. Also shown the coefficient of multiple determinations (R-squared R2) was 0.507 which means that 50.7% of the variance BW90, determined variance of the predictor variables represented in the model. Adjusted coefficient of multiple determination (adjusted R2) is 0.506 which means that 50.6% of the variance BW90, determined variance of the predictor variables that are in the model. Any increase in weight of lambs during the observed period of age is associated with an increase of dependent variable BW90. In particular, any increase in BW30 to 1 kg, is associated with an increase in BW90 to 1.928 kg.Istraživanje je sprovedeno u regionu Å ar planine u populaciji lokalne Å”arplaninske rase ovaca. SledeÄe osobine jagnjad su posmatrane: masa pri roÄenju, sa 30,60 i 90 dana uzrasta (BWB, BW30, BW60 i BW90). StatistiÄka analiza je sprovedena primenom SPSS paketa. IzraÄunate su Pearson korelacije i multivarijantna linearna regresija. To je znaÄilo raÄunanje svih moguÄih i najboljih podskupova jednaÄina regresije. Svaka jednaÄina je ocenjena kao i njen koeficijent determinacije (R2). Rezultati su pokazali da je masa jagnjadi od roÄenja do odbijanja poveÄana za oko Å”est puta. Konkretno jagnjad su ostvarila proseÄan ukupan prirast od 17,66 kg, ili 196 g dnevno. UtvrÄena je vrlo znaÄajna korelacija (P (lt) 0,01) izmeÄu BWB i BW30, BW60 i BW90. Isto tako, pokazala se veoma znaÄajna korelacija (P (lt) 0,01) izmeÄu BW30-BW60, BW30-BW90 i BW60-BW90. TakoÄe, dobijeni koeficijent viÅ”estruke determinacije (R-skuared R2) znaÄi da je 50,7% varijanse BW90, determinisano varijansom prediktorskih varijabli predstavljenih u modelu. Korigovani koeficijent viÅ”estruke determinacije (R2 prilagoÄeni) je 0.506, Å”to znaÄi da je 50,6% varijanse BW90, uslovljeno varijansama prediktorskih varijabli koje su u modelu. Svako poveÄanje mase jagnjadi u toku posmatranog perioda života je povezano sa poveÄanjem zavisno promenljive BW90. PraktiÄno, svako poveÄanje BW30 za 1 kg, je povezano sa poveÄanjem BW90 za 1.928 kg
Povezanost izmeÄu mase tela pri roÄenju i karakteristika porasta jagnjadi
Research was carried out in population of R2 generation Pirot pramenka x Pirot improved sheep during period of three years. Lambs were divided into three groups: I from 2.5 kg to 3.5 kg; II from 3.6 kg to 4.5 kg; III from 4.6 kg to 5.5 kg. Weight of lambs was controlled at birth, with 30, 60 and 90 days of age. Average body weight at birth of the tested lambs was 3.35 kg in the first group, 4.30 kg in the second group and 5.06 kg in the third group. At 30 days of age, the body weight of the lambs was 10.19 kg in the first group, 11.39 kg in the second and 12.49 kg in the third group. All these differences in body weight of lambs at birth were statistically highly significant (PĀ¬ 0.01). With 60 days of age, average body weight was 16.48 kg in the first group, 19.01 kg in the second and 20.49 kg in the third group. Differences between groups of lambs at this age were statistically very significant (PĀ¬0.01).On the end of experiment at 90 days of lambs age, we have found the following values of the body weight of lambs: 26.35 kg in the first group, when the second 30.49 kg and 28.93 kg in the third group. Differences between groups of lambs at this age were statistically very significant (PĀ¬0.01). At the age of 90 days maximum weight of the body was in the second group of lambs, or a group which body weight at birth occupied the mean of the population. Correlations between body weights of lambs vary from weak to midsized values. The highest values of correlation coefficients were found between body weight at birth and weight of lambs at 30 days of age.Istraživanja su sprovedena u populaciji R2 generacije Pirotska pramenka x Pirotska oplemenjena ovca tokom perioda od tri godine. Jagnjad su bila podeljeni u tri grupe: I od 2,5 kg do 3,5 kg; II od 3,6 kg do 4,5 kg; III od 4,6 kg do 5,5 kg. Masa jagnjadi je kontrolisana na roÄenju, sa 30, 60 i 90 dana starosti. ProseÄna telesna težina na roÄenju testiranih jagnjadi bila je 3,35 kg u prvoj grupi, 4,30 kg u drugoj grupi i 5,06 kg u treÄoj grupi . Sa 30 dana starosti ,telesna masa jagnjadi bila je 10,19 kg u prvoj grupi, 11,39 kg udrugoj i 12,49 kg u treÄoj grupi. Sve ove razlike u telesnoj masi jagnjadi na roÄenju su visoko statistiÄki znaÄajne (PĀ¬0,01). Sa 60 dana starosti, proseÄna telesna masa je bila 16,48 kg u prvoj grupi, 19,01 kg udrugoj i 20,49 kg u treÄoj grupi. Razlike izmeÄu grupa jagnjadi u ovom uzrastu su statistiÄki vrlo znaÄajne (PĀ¬0,01). Na kraju eksperimenta sa 90 dana starosti, pronaÅ”li smo sledeÄe vrednosti telesne mase jagnjadi: 26.35 kg u prvoj grupi, 30,49 kg u drugoj grupi i 28,93 kg u treÄoj grupi. Razlike izmeÄu grupa jagnjadi u ovom uzrastu su statistiÄki vrlo znaÄajne (PĀ¬0,01). U uzrastu od 90 dana maksimalna masa tela je registrovana u drugoj grupi jagnjadi, ili grupi Äija telesna masa na roÄenju zauzima srednju vrednost populacije. Korelacija izmeÄu telesne mase jagnjadi variraju od slabe do srednje vrednosti. NajveÄe vrednosti koeficijenata korelacije su pronaÄene izmeÄu telesne mase na roÄenju i mase jagnjadi sa 30 dana starosti
Models of spin-orbit coupled oligomers
We address the stability and dynamics of eigenmodes in linearly-shaped
strings (dimers, trimers, tetramers, and pentamers) built of droplets of a
binary Bose-Einstein condensate (BEC). The binary BEC is composed of atoms in
two pseudo-spin states with attractive interactions, dressed by properly
arranged laser fields, which induce the (pseudo-) spin-orbit (SO) coupling. We
demonstrate that the SO-coupling terms help to create eigenmodes of particular
types in the strings. Dimer, trimer, and pentamer eigenmodes of the linear
system, which correspond to the zero eigenvalue (EV, alias chemical potential)
extend into the nonlinear ones, keeping an exact analytical form, while
tetramers do not admit such a continuation, because the respective spectrum
does not contain a zero EV. Stability areas of these modes shrink with the
increasing nonlinearity. Besides these modes, other types of nonlinear states,
which are produced by the continuation of their linear counterparts
corresponding to some nonzero EVs, are found in a numerical form (including
ones for the tetramer system). They are stable in nearly entire existence
regions in trimer and pentamer systems, but only in a very small area for the
tetramers. Similar results are also obtained, but not displayed in detail, for
hexa- and septamers.Comment: Chaos, in pres
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