Search results for " sky"
showing 10 items of 52 documents
The substitution rate of HIV-1 subtypes: a genomic approach
2017
Abstract HIV-1M causes most infections in the AIDS pandemic. Its genetic diversity is defined by nine pure subtypes and more than sixty recombinant forms. We have performed a comparative analysis of the evolutionary rate of five pure subtypes (A1, B, C, D, and G) and two circulating recombinant forms (CRF01_AE and CRF02 AG) using data obtained from nearly complete genome coding sequences. Times to the most recent common ancestor (tMRCA) and substitution rates of these HIV genomes, and their genomic partitions, were estimated by Bayesian coalescent analyses. Genomic substitution rate estimates were compared between the HIV-1 datasets analyzed by means of randomization tests. Significant diff…
Testing standard and nonstandard neutrino physics with cosmological data
2012
Cosmological constraints on the sum of neutrino masses and on the effective number of neutrino species in standard and nonstandard scenarios are computed using the most recent available cosmological data. Our cosmological data sets include the measurement of the baryonic acoustic oscillation (BAO) feature in the data release 9 CMASS sample of the baryon oscillation spectroscopic survey. We study in detail the different degeneracies among the parameters, as well as the impact of the different data sets used in the analyses. When considering bounds on the sum of the three active neutrino masses, the information in the BAO signal from galaxy clustering measurements is approximately equally pow…
The Flux Density of Radiation Energy Originating from the Circumsolar Sky Measured at Groundbased Stations
1983
The aim of this project was the measurement of the radiant energy flux provided by the diffuse radiation of the ring shaped area of the sky around the unmasked sun disk. More than 200 measurements of the irradiance of this circumsolar cloudy or cloudfree sky up to an angular radius of 10° had been taken at Mainz (FRG), Deuselbach (FRG) and Adrano (Sicily). The measurements show that the irradiance of the circumsolar sky radiation may reach an amount of more then 30 % of the direct solar irradiance at the observation site. This means, optical systems combining the direct solar radiation and the circumsolar radiation may compensate — at least partly — the extinction losses of the direct solar…
An overview of and issues with sky radiometer technology and SKYNET
2020
This paper is an overview of the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, and data analyses from sky radiometer observations of aerosol, cloud, water vapor, and ozone. A formula was proposed for estimating the accuracy of the sky radiometer calibration constant F0 using the improved Langley (IL) method, which was found to be a good approximation to observed monthly mean uncertainty in F0, around 0.5 % to 2.4 % at the Tokyo and Rome sites and smaller values of around 0.3 % to 0.5 % at the mountain sites at Mt. Sarasw…
Solar angle and sky light effects on ground reflectance measurements in a citrus canopy
1993
Abstract Ground radiometry was used to gather spectral data from different targets of a citrus canopy, in order to analyze the effect of solar zenith angle and proportion of diffuse radiation on spectral reflectance. Results have shown that the variation in solar angle causes significant changes in nadirsensed reflectance from vegetation, which exhibits a marked diurnal pattern with a minimum slightly shifted from the solar noon. This fact is more noticeable in the near-infrared and middle-infrared regions of the spectrum. Furthermore, the visible part of the spectrum has resulted in being highly influenced by the diffuse radiation incident on the canopy, which has been quantified by two di…
Commensurability between Element Symmetry and the Number of Skyrmions Governing Skyrmion Diffusion in Confined Geometries
2020
Magnetic skyrmions are topological magnetic structures, which exhibit quasi-particle properties and can show enhanced stability against perturbation from thermal noise. Recently, thermal Brownian diffusion of these quasi-particles has been found in continuous films and applications in unconventional computing have received significant attention, which however require structured elements. Thus, as the next necessary step, we here study skyrmion diffusion in confined geometries and find it to be qualitatively different: The diffusion is governed by the interplay between the total number of skyrmions and the structure geometry. In particular, we ascertain the effect of circular and triangular …
Role of Sky-gardens in Improving Energy Performance of Tall Buildings
2018
Natural ventilation has been used as a passive strategy for many decades but only now its importance in tall buildings for addressing the issues of high energy usage and reducing carbon footprints is emerging. Sky-gardens can play an important role in successful implementation of natural ventilation through amplification of natural wind speeds. This study presents a state-of-the-art review on optimization of tall buildings energy performance through incorporation of sky-gardens. Pros and cons of use of natural ventilation for multi-story buildings are highlighted. Details of involved technical difficulties and barriers in the construction and operation process of sky-gardens are also given.…
The 2020 skyrmionics roadmap
2020
The notion of non-trivial topological winding in condensed matter systems represents a major area of present-day theoretical and experimental research. Magnetic materials offer a versatile platform that is particularly amenable for the exploration of topological spin solitons in real space such as skyrmions. First identified in non-centrosymmetric bulk materials, the rapidly growing zoology of materials systems hosting skyrmions and related topological spin solitons includes bulk compounds, surfaces, thin films, heterostructures, nano-wires and nano-dots. This underscores an exceptional potential for major breakthroughs ranging from fundamental questions to applications as driven by an inte…
A deep study of the high–energy transient sky
2021
This is an open access article. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds t…
Produktu izvietojums filmās: " Mierinājuma kvants", "Operācija Skyfall","Spektrs", "Greja piecdesmit nokrāsas", "Tumsa piecdesmit nokrāsās" un "Brīvī…
2018
Bakalaura darba tēma ir “Produktu izvietojums filmās: "Mierinājuma kvants", "Operācija Skyfall", "Spektrs", "Greja piecdesmit nokrāsas", "Tumsas piecdesmit nokrāsas" un "Brīvības piecdesmit nokrāsas”. Bakalaura darba mērķis ir izpētīt un uzskaitīt produktu izvietojumus Džeimsa Bonda un Piecdesmit nokrāsu filmu daļās, kā arī noskaidrot radīto produkta izvietojuma ietekmi uz skatītāju pēc pētāmo filmu noskatīšanās. Darba teorētiskajā daļā tiek aplūkota akadēmiskā literatūra par populāro kultūru un tās ietekmi uz kino, kā arī literatūra par produktu izvietošanu un tās galvenajām iezīmēm. Pētījumā iegūtie rezultāti liecina to, ka skatītāji apzinās un pamana zīmolu produktu izvietojumus, taču bi…