5,122 research outputs found
A near infrared photometric plane for ellipticals and bulges of spirals
We report the existence of a single plane in the space of global photometric
parameters describing elliptical galaxies and the bulges of early type spiral
galaxies. The three parameters which define the plane are obtained by fitting
the Sersic form to the brightness distribution obtained from near-infrared K
band images. We find, from the range covered by their shape parameters, that
the elliptical galaxies form a more homogeneous population than the bulges.
Known correlations like the Kormendy relation are projections of the
photometric plane. The existence of the plane has interesting implications for
bulge formation models.Comment: 12 pages, LaTeX including 5 figures. To appear in the Astrophysical
Journal Letter
Exchange energy and generalized polarization in the presence of spin-orbit coupling in two dimensions
We discuss a general form of the exchange energy for a homogeneous system of
interacting electrons in two spatial dimensions which is particularly suited in
the presence of a generic spin-orbit interaction. The theory is best formulated
in terms of a generalized fractional electronic polarization. Remarkably we
find that a net generalized polarization does not necessarily translate into an
increase in the magnitude of the exchange energy, a fact that in turn favors
unpolarized states. Our results account qualitatively for the findings of
recent experimental investigations
Perancangan Media Pembelajaran Interaktif Pada Mata Pelajaran Motor Listrik
Pendidik merupakan pemeran utama dalam pembelajaran haruslah profesional dalam bidangnya agar dapat menjalankan tugas dan fungsinya sebagai pendidik sekaligus pengajar yang berkompeten. Untuk itu, Pendidik harus terampil mengajar, dan mampu mengatasi berbagai kendala yang ditemui dalam pembelajaran. Perancangan media pembelajaran interaktif dapat meningkatkan potensi keterampilan peserta didik dibidangnya, diperlukan pembelajaran yang inovatifif dan kreatif, salah satu pembelajaran yang inovatif adalah pembelajaran berbasis media interaktif.Dengan kata lain diharapkan kiranya dosen mampu meningkatkan keterampilan dan kreativitas peserta didik,
Studying the Effect of Adding Aleppo Pylon to the Properties of Insulating and Accumulation of Polyvinyl Chloride Films
This research presents a study of the effect of adding natural and modified Aleppo Pylon (Syrian clay) in different proportions to the properties of polymeric films prepared from poly vinyl chlorid (PVC) polymer and dried at three different drying degrees (60oC, 100oC, 150oC). The clay surface was changed from hydrophilic to hydrophobic by treating the surface with quaternary alkyl ammonium salts. Both types of Aleppo Pylone were added to the polymer by weight (0%, 2.5%, 5%, 7.5%, 10%), and the polymeric films were prepared by way of mixing well of PVC polymer and clay. The mixing technique used hexanol as a solvent. The clay was mixed with the polymer at 150 Co temperature using a magnetic stirrer. The effect of adding natural and modified Aleppo Pylon to the properties of water absorption ratio, moisture content, migration of components in moderate, acidic and alkaline aqueous solutions, thermal stability and air permeability of polymeric films prepared from PVC polymer and clay with different drying degrees was studied and compared with them, in order to reach an improved PVC that can be used in the field of packaging
Impact of biochar and arbuscular mycorrhizal inoculation on root colonization and selected soil chemical properties in south western Nigeria
The use of biochar and arbuscular mycorrhizal fungi (AMF) provide many opportunities for soil improvement, it is, therefore, important to understand their impact on soil and plant development so as to optimally exploit their potentials. Screenhouse experiment was conducted to evaluate the impact of biochar application and arbuscular mycorrhizal (AM) inoculation on root colonization and selected soil chemical properties. The experiment was laid out in a 2×5×2 factorial, fitted into a completely randomized design with three replications. The factors included tomato genotypes (Ex-Lafia and Ex-Lokoja), biochar application rates (0, 5, 10, 15, and 20 t ha-1) and AMF (with and without AMF). Data were subjected to analysis of variance and significant means were separated using Duncan’s Multiple Range Test (p<0.05). The results showed that AM inoculation significantly (p<0.05) increased root colonization (51.33%) when compared with non mycorrhizal plants (10.17%). However, no significant differences were observed in soil pH, organic carbon and available P between mycorrhizal and non mycorrhizal plants. On the other hand, amendment with the 20t ha-1 of biochar recorded significantly (p<0.05) higher values of AM root colonization (46.25%), soil pH (7.05) and available P (13.93 mg kg-1) when compared to other biochar rates though comparable with 15 t ha-1 in soil pH (7.05) and available P (12.26 mg kg-1). It is therefore concluded that AM inoculation in biochar-amended soil improved root colonization while biochar application enhances root colonization, soil pH and available P.Keywords: Biochar, AM inoculation, soil chemical properties
Correlations among global photometric properties of disk galaxies
Using a two-dimensional galaxy image decomposition technique, we extract
global bulge and disk parameters for a complete sample of early type disk
galaxies in the near infrared K band. We find significant correlation of the
bulge parameter n with the central bulge surface brightness and with
effective radius r_e. Using bivar iate analysis techniques, we find that , and are distributed in a plane with small scatter. We
do not find a strong correlation of n with bulge-to-disk luminosity ratio,
contrary to earlier reports. r_e and the disk scale length r_d are well
correlated for these early type disk galaxies, but with large scatter. We
examine the implications of our results to various bulge formation scenarios in
disk galaxies.Comment: 14 pages, LaTeX including 14 figures. To appear in the Astrophysical
Journa
Comment on "Gravitationally Induced Neutrino-Oscillation Phases"
We critically examine the recent claim (gr-qc/9603008) of a ``new effect'' of
gravitationally induced quantum mechanical phases in neutrino oscillations. A
straightforward exercise in the Schwarzschild coordinates appropriate to a
spherically symmetric non-rotating star shows that, although there is a general
relativistic effect of the star's gravity on neutrino oscillations, it is not
of the form claimed, and is too small to be measured.Comment: Plain LaTeX, 7 pages, no figure
Perancangan Sekolah Alam Bahari Bandar Bakau di Dumai
Green school is an informal school wich focus on character education for children about the preservation of the nature coast. For that the green school of bahari bandar bakau became a place in accordance with the curriculum of basic education to optimize green school of bandar bakau informal standards become formal. In the design this green school of bahari bandar bakau will be done with the contextual approach coastal architecture within the Dumai coastal areas, also uses the concept of archipelago built space values so that the green school can remember and demonstrated the importance values of the archipelago built space. Some indicators which become the state of the art is sustainablility, harmony of nature, the climate response, collective consciousness, intelligence and knowledge of the culture as a basic for generating design of green school in accordance with national curriculum standards and contextual with the maritime environment
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