405 research outputs found
The Kinetics of the Formation of Aluminium Hydroxideby Seeding Sodium Aluminate Solutions with Hydrargillite Crystals IV. On the Ā»Contact-intercrystallizationĀ«
It is shown that agglomeration of fine particles takes place in this system by the contact of crystallites. This mechanism is very quick and does not involve any measurable separation of a new solid phase from the solution. The name Ā»contact-intercrystallizationĀ« is proposed. The most suitable way of evaluating the weight- size-distribution results is discussed. A method for distinguishing between various crystallization- mechanisms is proposed and some suggestions for practical application are given
Korelaciona analiza proizvodnih osobina domaÄe balkanske koze
The paper presents results of investigations of the domestic Balkan goat reared in the Sharplanina mountainous region pertaining to phenotypic correlations between the most important production traits (milk production traits for 578 goats), and growth traits of kids (for 710 kids in the suckling period). Research was done in herds of Balkan goats belonging to private farmers, during a two-year period. Simple correlation between mentioned traits were calculated using a PC and the LSMLMW program (Harvey, 1990). Data pertaining to correlation coefficients established between investigated milk production traits of the domestic Balkan goat, reflect existing correlations, which in most cases, were positive and statistically significant (P (lt) 0,01). Very strong correlations were established between the 1st and 2nd milk production control, as well as between the daily milk yield and the 2nd milk production control (0.796), as well as the total milk yield (0.870). Established coefficient were also statistically significant (P (lt) 0,01). Correlation between birth weight and the weight at specific ages (30, 60 and 90 days) were strong and very strong, while correlations between birth weight and average daily weight gain established by individual months (0.526, 0.553 and 0.384) varied between weak and strong, with an established weakening of correlations with advancing age.Kod domaÄih životinja postoje odreÄene meÄusobne veze i uslovljenosti u ispoljavanju pojedinih proizvodnih i drugih osobina. SuÅ”tina je u tome Å”to ispoljavanje jedne pojave, osnovne osobine, manje ili viÅ”e, uslovljava ispoljavanje druge pojave, odnosno osobine. ProuÄavanjem tih veza uoÄeno je da na njih mogu da utiÄu genetski i paragenetski Äinioci. U radu su prikazani rezultati ispitivanja fenotipskih korelacija izmeÄu osobina mleÄnosti (kod 578 koza) i porasta jaradi u dojnom periodu (kod 710 jaradi), domaÄe balkanske koze koja se odgaja na podruÄju planinskog masiva Å arplanine. Istraživanja su izvedena u stadima balkanskih koza privatnih odgajivaÄa, u toku dvogodiÅ”njeg perioda. Korelaciona zavisnost izmeÄu navedenih osobina uraÄena je primenom programa LSMLMW (Harvey, 1990). Podaci o utvrÄenim koeficijentima korelacije izmeÄu ispitivanih osobina mleÄnosti u domaÄe balkanske koze, odražavaju postojanje korelativne zavisnosti, pri Äemu su u veÄini sluÄajeva bili pozitivni i statistiÄki znaÄajni (P (lt) 0,01), osim za utvrÄene vrednosti ukupne koliÄine mleka sa prvom i drugom kontrolom, kao i dnevne mleÄnosti sa dužinom laktacije. TakoÄe, sve ustanovljene vrednosti za korelacije izmeÄu osobina porasta jaradi u dojnom periodu (mase jaradi po pojedinim periodima uzrasta, dnevnog prirasta) su pozitivne i statistiÄki vrlo znaÄajne (P (lt) 0,01)
Composite profile of the Fe K spectral line emitted from a binary system of supermassive black holes
We used a model of a relativistic accretion disk around a supermassive black
hole (SMBH), based on ray-tracing method in the Kerr metric, to study the
variations of the composite Fe K line emitted from two accretion disks
around SMBHs in a binary system. We assumed that the orbit of such a binary is
approximately Keplerian, and simulated the composite line shapes for different
orbital elements, accretion disk parameters and mass ratios of the components.
The obtained results show that, if observed in the spectra of some SMBH
binaries during their different orbital phases, such composite Fe K
line profiles could be used to constrain the orbits and several properties of
such SMBH binaries.Comment: 8 pages, 4 figures, 2 tables. Accepted for publication in special
issue of Advances in Space Research on "Spectral Line Shapes in Astrophysics
and Related Phenomena
Uticaj zastupljenosti kadmijuma i arsena u obroku na proizvodne i reproduktivne osobine koza
Animals require microelements in small quantities, and they play a role in virtually all physiological and biochemical processes. The role of microelements is important role from bone structure to maintaining the structure of proteins and lipids. Microelements are provided to animals in food, by special supplementation (premixes), or in water. In addition to essential minerals, which are regularly used in goat nutrition, there are 10 other elements present in traces (mg/kg or ppm) which are also indispensable for the goat's organism, as follows: Fe, J, Cu, Zn, Mn, Co, Mo, Se, Cr, F. In addition to these, following elements have also been identified in goats' tissues: Al, B, Ge, Cd, As, Pb, Hg, Ru, and Nb, however their significance for the organism of goats has still not been established. Their lack in goat nutrition may to a large extent contribute to lower yields and bad health.Mikroelementi su životinjama potrebni u malim koliÄinama i uÄestvuju u skoro svim fizioloÅ”kim i biohemijskim procesima. PoÄev od strukture kostiju pa do održavanja strukture proteina i lipida, mikroelementi igraju važnu ulogu. ObezbeÄenje životinja sa mikroelementima obavlja se putem hrane, posebnim dodavanjem (putem predsmeÅ”a) ili putem vode. U intenzivnoj proizvodnji njihovo dodavanje je obavezno, jer se samo tako mogu obezbediti u dovoljnim koliÄinama za optimalno zdravstveno stanje i proizvodne rezultate. Osim esencijalnih minerala, koji se redovno koriste u ishrani koza, postoji joÅ” 10 elemenata prisutnih u tragovima (mg/kg ili ppm) koji su takoÄe, neophodni za organizam koza, a to su: Fe, J, Cu, Zn, Mn, Co, Mo, Se, Cr, F. Pored navedenih, u tkivima koza identifikovani su joÅ” i: Al, B, Ge, Cd, As, Pb, Hg, Ru, i Nb, za koje joÅ” nije utvrÄeno u kojoj su meri neophodni u organizmu koza. Njihov nedostatak u ishrani koza u velikoj meri može doprineti nižoj proizvodnji i loÅ”em zdravstvenom stanju
Observational Signature of Tidal Disruption of a Star by a Massive Black Hole
We have modeled the time-variable profiles of the Halpha emission line from
the non-axisymmetric disk and debris tail created in the tidal disruption of a
solar-type star by a million solar mass black hole. We find that the line
profiles at these very early stages of the evolution of the post-disruption
debris do not resemble the double peaked profiles expected from a rotating disk
since the debris has not yet settled into such a stable structure. The
predicted line profiles vary on fairly short time scales (of order hours to
days). As a result of the uneven distribution of the debris and the existence
of a ``tidal tail'' (the stream of returning debris), the line profiles depend
sensitively on the orientation of the tail relative to the line of sight. Given
the illuminating UV/X-ray light curve, we also model the Halpha light curve
from the debris.Comment: 2 pages, 1 figure, to appear in the proceedings of "The Interplay
among Black Holes, Stars and ISM in Galactic Nuclei", IAU 222, eds. Th.
Storchi Bergmann, L.C. Ho, and H.R. Schmit
Aligned Spins: Orbital Elements, Decaying Orbits, and Last Stable Circular Orbit to high post-Newtonian Orders
In this article the quasi-Keplerian parameterisation for the case that spins
and orbital angular momentum in a compact binary system are aligned or
anti-aligned with the orbital angular momentum vector is extended to 3PN
point-mass, next-to-next-to-leading order spin-orbit, next-to-next-to-leading
order spin(1)-spin(2), and next-to-leading order spin-squared dynamics in the
conservative regime. In a further step, we use the expressions for the
radiative multipole moments with spin to leading order linear and quadratic in
both spins to compute radiation losses of the orbital binding energy and
angular momentum. Orbital averaged expressions for the decay of energy and
eccentricity are provided. An expression for the last stable circular orbit is
given in terms of the angular velocity type variable .Comment: 30 pages, 2 figures, v2: update to match published versio
Uticaj kvasaca, probiotika i enzima u obrocima na proizvodnost visokomleÄnih krava u tranzicionom periodu
The main goal of this paper was to investigate the influence of some additives included into high yielding dairy cows rations to overcome the problems in early lactation. These substances directly affect the productive performances of dairy cows as well as udder health. The commercial name of investigated preparation is 'YEASTURE' and it is composed of live yeast cultures selected from three strains Saccharomyces cerevisisiae in combination with probiotic bacteria and enzymes (Lactobacillus casei, Streptococcus faecium, Aspergillus oryzae, Lactobacillus acidophilus, 1,3-b and 1,6 D-Glucan, hemicellulase, Protease, Cellulase, Alpha amylase) which have the ability to modify the fermentation in rumen stimulating the development of ruminal bacteria and increasing the fibre digestion. Effects of this preparation have been investigated on 60 Holstein-Friesian cows divided into two groups. The diets were identical, and trial group received also 10 g of preparation Yeasture daily. Application of Yeasture started 15 days prior to calving and lasted until 60th day of lactation As a research result improved in vitro disappearance of diet dry matter from roughage (alfalfa hay, maize silage and ensiled sugar beet pulp) was established. Preparation Yeasture influenced quantity and composition of the milk. The difference between trial and control group was 2.57 kg 4%FCM or 8.70% (P (lt) 0.01) and 7.16% milk fat (P (lt) 0.05).Trial group supplemented with Yeasture showed lower somatic cells count by 7.3 percent points what indicated better health of cow's udder. Based on the presented results it can be concluded that inclusion of preparation Yeasture into diets for dairy cows in transition period can be recommended.Period zasuÅ”enja i rana laktacija karakteriÅ”u se brojnim problemima koji mogu da se uspeÅ”no premoste ukljuÄivanjem dodataka u hranu kao Å”to su probiotici, kvasci, enzimi i dr. U radu su ispitani efekti preparata yeasture koji predstavlja kompoziciju ovih dodataka a koji je ukljuÄen u obroke krava dve nedelje pre i osam nedelja posle telenja u koliÄini od 10 g po grlu dnevno. UkljuÄivanje pomenutih dodataka uticalo je na poboljÅ”anje svarljivosti suve materije kabastih hraniva (sena lucerke, silaže cele biljke kukuruza i siliranog rezanca Å”eÄerne repe) Å”to je konaÄno znaÄajno uticalo na poboljÅ”anje proizvodnih performansi odnosno poveÄanje koliÄine mleka za 10.86%. Jednovremeno pomenuti dodaci povoljno su uticali na popravljanje zdravstvenog stanja vimena krava Å”to se odrazilo na smanjenje broja somatskih Äelija za 7.3 procentnih poena. Najvažniji parametri krvi pre i posle eksperimenta kretali su se u fizioloÅ”ki optimalnim granicama. Navedeni argumenti su dovoljan razlog da se ukljuÄivanje pomenutih supstansi u obroke visokomleÄnih krava u periodu zasuÅ”enja i rane laktacije preporuÄi u proizvodnji mleka
Motion and gravitational wave forms of eccentric compact binaries with orbital-angular-momentum-aligned spins under next-to-leading order in spin-orbit and leading order in spin(1)-spin(2) and spin-squared couplings
A quasi-Keplerian parameterisation for the solutions of second post-Newtonian
(PN) accurate equations of motion for spinning compact binaries is obtained
including leading order spin-spin and next-to-leading order spin-orbit
interactions. Rotational deformation of the compact objects is incorporated.
For arbitrary mass ratios the spin orientations are taken to be parallel or
anti-parallel to the orbital angular momentum vector. The emitted gravitational
wave forms are given in analytic form up to 2PN point particle, 1.5PN spin
orbit and 1PN spin-spin contributions, where the spins are counted of 0PN
order.Comment: 26 pages, 1 figure, published in CQG. Current version: we removed a
remark and clarified the derivation of the orbital element \e_ph
Properties of Accretion Flows Around Coalescing Supermassive Black Holes
What are the properties of accretion flows in the vicinity of coalescing
supermassive black holes (SBHs)? The answer to this question has direct
implications for the feasibility of coincident detections of electromagnetic
(EM) and gravitational wave (GW) signals from coalescences. Such detections are
considered to be the next observational grand challenge that will enable
testing general relativity in the strong, nonlinear regime and improve our
understanding of evolution and growth of these massive compact objects. In this
paper we review the properties of the environment of coalescing binaries in the
context of the circumbinary disk and hot, radiatively inefficient accretion
flow models and use them to mark the extent of the parameter space spanned by
this problem. We report the results from an ongoing, general relativistic,
hydrodynamical study of the inspiral and merger of black holes, motivated by
the latter scenario. We find that correlated EM+GW oscillations can arise
during the inspiral phase followed by the gradual rise and subsequent drop-off
in the light curve at the time of coalescence. While there are indications that
the latter EM signature is a more robust one, a detection of either signal
coincidentally with GWs would be a convincing evidence for an impending SBH
binary coalescence. The observability of an EM counterpart in the hot accretion
flow scenario depends on the details of a model. In the case of the most
massive binaries observable by the Laser Interferometer Space Antenna, upper
limits on luminosity imply that they may be identified by EM searches out to
z~0.1-1. However, given the radiatively inefficient nature of the gas flow, we
speculate that a majority of massive binaries may appear as low luminosity AGN
in the local universe.Comment: Revised version accepted to Class. Quantum Grav. for proceedings of
8th LISA Symposium. 15 pages, 3 figures, includes changes suggested in
referee report
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