710 research outputs found
Weak Lensing as a Calibrator of the Cluster Mass-Temperature Relation
The abundance of clusters at the present epoch and weak gravitational lensing
shear both constrain roughly the same combination of the power spectrum
normalization sigma_8 and matter energy density Omega_M. The cluster constraint
further depends on the normalization of the mass-temperature relation.
Therefore, combining the weak lensing and cluster abundance data can be used to
accurately calibrate the mass-temperature relation. We discuss this approach
and illustrate it using data from recent surveys.Comment: Matches the version in ApJL. Equation 4 corrected. Improvements in
the analysis move the cluster contours in Fig1 slightly upwards. No changes
in the conclusion
Advances in water mains network modelling for improved operations
Published© 2015 The Authors. Published by Elsevier Ltd. The traditional approach to water mains network model calibration is too coarse. System and data anomalies impact on the simulated pressures in the models. These include unknown status valves, incorrect pipe data including pipe roughness values and unknown leaks. A combination of smarter field testing and staged optimisation analyses provides a promising solution to solving this complex problem. An anonymous model has been used to demonstrate that inclusion in the field test of planned hydrant discharges and concurrent tactical valve operations will help detect the unknown status valves but also lead to more accurate pipe roughness values and leakage hotspots
Strong lensing constraints on the velocity dispersion and density profile of elliptical galaxies
We use the statistics of strong gravitational lensing from the CLASS survey
to impose constraints on the velocity dispersion and density profile of
elliptical galaxies. This approach differs from much recent work, where the
luminosity function, velocity dispersion and density profile were typically
{\it assumed} in order to constrain cosmological parameters. It is indeed
remarkable that observational cosmology has reached the point where we can
consider using cosmology to constrain astrophysics, rather than vice versa. We
use two different observables to obtain our constraints (total optical depth
and angular distributions of lensing events). In spite of the relatively poor
statistics and the uncertain identification of lenses in the survey, we obtain
interesting constraints on the velocity dispersion and density profiles of
elliptical galaxies. For example, assuming the SIS density profile and
marginalizing over other relevant parameters, we find 168 km/s < sigma_* < 200
km/s (68% CL), and 158 km/s < sigma_* < 220 km/s (95% CL). Furthermore, if we
instead assume a generalized NFW density profile and marginalize over other
parameters, the slope of the profile is constrained to be 1.50 < beta < 2.00
(95% CL). We also constrain the concentration parameter as a function of the
density profile slope in these models. These results are essentially
independent of the exact knowledge of cosmology. We briefly discuss the
possible impact on these constraints of allowing the galaxy luminosity function
to evolve with redshift, and also possible useful future directions for
exploration.Comment: Uses the final JVAS/CLASS sample, more careful choice of ellipticals,
added discussion of possible biases. Final results essentially unchanged.
Matches the MNRAS versio
Uticaj odgajivačkog područja i godine na osobine mlečnosti bikovskih majki simentalske rase
Cows which represent top of the genetic value of the population in regard to their traits are chosen for bull dams. Selection is based on origin, production performance (quantity of milk, milk fat and protein content), milking/dairy traits, reproductive indicators, exterior and linear type scores. This study included 292 cows of Simmental breed selected for bull dams on the territory of Republic of Serbia during one year. Selection of cows for herd of bull dams was done after finalized first and subsequent lactation. In this study, the effect of region and year of calving on milk traits is presented. Applying the method of least squares average value of milk production was obtained - 5.754,49 kg, milk fat content - 3,98% and quantity of milk fat - 230,24 kg. Regions had statistically highly significant effect (P (lt) 0,01) on all investigated milk traits. Year of calving showed no statistically significant effect on milk yield, yield of milk fat and content of milk fat (P>0,05).Za bikovske majke se odabiraju krave koje prema osobinama predstavljaju vrh genetske vrednosti populacije. Izbor se vrši na osnovu porekla, proizvodnih osobina (količina mleka, sadržaj mlečne masti i proteina), muznih osobina, reproduktivnih pokazatelja, eksterijera i linearnih ocena tipa. Ovim istraživanjem je obuhvaćeno 292 krave simentalske rase odabrane za bikovske majke na području Republike Srbije u toku godine. Odabiranje krava u zapat bikovskih majki izvršeno je posle završene prve, odnosno na osnovu sledećih laktacija. U radu je ispitan uticaj odgajivačkog područja i godine telenja na osobine mlečnosti. Koristeći metod najmanjih kvadrata dobijene su prosečne vrednosti proizvodnje mleka 5.754,49 kg, sadržaja mlečne masti 3,98% i količine mlečne masti 230,24 kg. Regioni su imali statistički visoko značajan uticaj (P (lt) 0,01) na sve ispitivane osobine mlečnosti. Na osobine prinosa mleka, mlečne masti i sadržaja mlečne masti, godina telenja nije ispoljila statistički značajan uticaj (P>0,05)
Nanostructured materials for optoelectronic applications
Study and optimization of new nanoscale materials useful for optoelectronic application have been considered. The search for the effective nanostructured materials has been revealed in two directions: to optimize the mechanical hardness of the inorganic systems and to increase the photorefractive parameters of the organics with nanoobjects. It has been testified that the surface mechanical properties of the inorganic materials via nanotubes treatment process can be drastically improved. For example, the surface mechanical hardness of the UV and IR range soft materials can be increased up to 3-10 times under the conditions of oriented nanotubes placement. It has been obtained that the nonlinear optical characteristics (nonlinear refraction n2 and cubic nonlinearity x(3)) of the organics thin films sensitized with fullerenes or nanotubes can be increased up to 3-4 orders of magnitude in comparison with the same parameters for bulk materials traditionally used for nonlinear optics.Selected papers presented at the Eleventh Annual Conference of the Materials Research Society of Serbia, YUCOMAT 200
Karakterizacija Morus vrsta u odnosu na mikro, makro i toksične elemente
This study examines the mineral composition of the extracts of the fruits, leaves and roots of white mulberry (Morus alba L.) and black mulberry (Morus nigra L.) grown in Serbia. All extract samples of white and black mulberry were analyzed for the content of micro (B, Co, Cr, Cu, Fe, Li, Mn, Ni, Se, Sr, Zn), macro (Ca, Mg, Na), and toxic metals (Al, As, Cd, Hg, Pb) by inductively coupled plasma optical emission spectrometry (ICP-OES). The study revealed that parts of the plant had statistically significant impact on the levels of the examined elements among the two Morus species. All extracts contained high amounts of Ca, Mg, Na, B, Cu, Fe, Mn and Zn. The studies showed that in the most of extracts dominant macro element was Mg (591- 1942 μg/g of dry extract), while dominant microelements were Zn, B, Cu in all extracts, except for the black mulberry leaves, whose extract was most abundant in Fe (143 μg/g of dry extract). The highest content of micro and macro elements was detected in the extract of black mulberry leaves. This work contributes to the knowledge of the nutritional properties of Morus species. The obtained results may be useful in the evaluation of new dietary and food products.Ispitivanje je bazirano na određivanju mineralnog sastava ekstrakata Morus alba L. (beli dud) i Morus nigra L . (crni dud) uključujući plod, list i koren sa teritorije Srbije. U svim analiziranim ekstraktima određen je sadržaj mikro (B, Co, Cr, Cu, Fe, Li, Mn, Ni, Se, Sr, Zn), makro (Ca, Mg, Na) i toksičnih elemenata (Al, As, Cd, Hg, Pb) primenom optičke emisione spektroskopije sa induktivno kuplovanom plazmom (ICP-OES). Ispitivanje je pokazalo da postoji statistički značajna korelacija između delova biljke Morus vrste i sadržaja ispitivanih elemenata. U svim ekstraktima je dokazan visok sadržaj elemenata: Ca, Mg, Na, B, Cu, Fe, Mn i Zn, respektivno. Dominantan makro element u većem broju ekstrakata je Mg (591 - 1942 μg/g suvog ekstrakta). Što se tiče mikroelemenata, u svim ispitivanim ekstraktima u većem sadržaju su zastupljeni Zn, B i Cu. U uzorku M. nigra posebno se izdvaja Fe po svom sadržaju (143 μg/g suvog ekstrakta) u odnosu na ostale prisutne elemente. Od svih ispitivanih uzoraka najviši sadržaj mikro i makro elemenata je detektovan u ekstraktima lista M. Nigra. Ovaj rad doprinosi poznavanju nutritivnih svojstava Morus vrsta. Dobijeni rezultati mogu biti korisni u kreiranju novih dijetetskih i prehrambenih proizvoda
Measurement of 60CO gamma radiation induced attenuation in multimode step-index POF at 530 nm
As optical fibres are used ever more extensively in space applications, nuclear industry, medicine and high-energy physics experiments, it has become essential to investigate the influence of ionizing radiation on their characteristics. In this work, the radiation-induced attenuation at 530 nm is investigated experimentally in step-index multimode polymethyl-methacrylate plastic optical fibres exposed to low dose-rate gamma radiation. Cumulative doses ranged from 50 Gy to 500 Gy. The radiation induced attenuation has been empirically found to obey the power law RIA= aDb, where D is the total radiation dose and a and b are the constants determined by fitting
A web-based platform for water efficient households
16th Water Distribution System Analysis Conference, WDSA2014 — Urban Water Hydroinformatics and Strategic PlanningThe advent of ICT services on water sector offers new perspective towards sustainable water management. This paper presents an innovative web-based platform, targeting primarily the household end-users. The platform enables consumers to monitor and control, on real-time basis, the water and energy consumption of their household providing valuable information and feedback. At the same time, the platform further supports end-users to modify and improve their consumption profile via an interactive educational process that comprises a variety of on-line tools and applications. This paper discusses the rationale, structure and technologies upon which the platform has been developed and presents an early prototype of the various tools, applications and facilities.European Union Seventh Framework Programme (FP7/2007-2013), through the iWIDGET Project (2012-2015
Efficiency of different methods and forms of microelements application in function of n fertilizer in apple trees
In order to achieve a high yield and quality of apple fruit, more effective ways of fertilization are required in the modern, high density apple orchards. The objective of this research was to determine the efficiency (partial nutrient balance, PNB) of different methods (foliar and fertrigation) and forms (chelates and salts) of microelements application in relation to the levels of N fertilization in apple orchard cultivar (‘Golden Delicious’). The combined effects of these fertilizers on the number of apple fruits per tree and on the yield per tree were also studied. Foliar application of Mn, Zn and Fe had significantly higher partial nutrient balance values compared to the soil application in both years of the experiment. However, most of the PNB values were below 10% indicating relatively low efficiency of the applied fertilizers with microelements
Free energy of alternating two-component polymer brushes on cylindrical templates
We use computer simulations to investigate the stability of a two-component
polymer brush de-mixing on a curved template into phases of different
morphological properties. It has been previously shown via molecular dynamics
simulations that immiscible chains having different length and anchored to a
cylindrical template will phase separate into striped phases of different
widths oriented perpendicularly to the cylindrical axis. We calculate free
energy differences for a variety of stripe widths, and extract simple
relationships between the sizes of the two polymers, N_1 and N_2, and the free
energy dependence on the stripe width. We explain these relationships using
simple physical arguments based upon previous theoretical work on the free
energy of polymer brushes.Comment: 5 pages, 5 figures, accepted for publication in the Journal of
Chemical Physic
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