1,170 research outputs found
An Algorithm for Generating New Mandelbrot and Julia Sets
The present paper is motivated from the paper of John R. Tippetts (Tippetts 1992) in which he gave an algorithm to generate an interesting Mandelbrot set. We not only generate Julia sets using Tippetts algorithm (Tippetts 1992), but also generate some new Julia and Mandelbrot sets by slightly modifying the Tippetts algorithm. This approach yields a new class of algorithms to produce new and alluring fractals with virtually infinite complexity. Keywords: Mandelbrot set, Julia set, recursion formula, algorith
Observations of Multiple Surges Associated with Magnetic Activities in AR10484 on 25 October 2003
We present a multiwavelength study of recurrent surges observed in H{\alpha},
UV (SOHO/EIT) and Radio (Learmonth, Australia) from the super-active region
NOAA 10484 on 25 October, 2003. Several bright structures visible in H{\alpha}
and UV corresponding to subflares are also observed at the base of each surge.
Type III bursts are triggered and RHESSI X-ray sources are evident with surge
activity. The major surge consists of the bunches of ejective paths forming a
fan-shape region with an angular size of (\approx 65\degree) during its maximum
phase. The ejection speed reaches upto \sim200 km/s. The SOHO/MDI magnetograms
reveal that a large dipole emerges east side of the active region on 18-20
October 2003, a few days before the surges. On October 25, 2003, the major
sunspots were surrounded by "moat regions" with moving magnetic features
(MMFs). Parasitic fragmented positive polarities were pushed by the ambient
dispersion motion of the MMFs and annihilated with negative polarities at the
borders of the moat region of the following spot to produce flares and surges.
A topology analysis of the global Sun using PFSS shows that the fan structures
visible in the EIT 171 A images follow magnetic field lines connecting the
present AR to a preceding AR in the South East. Radio observations of type III
bursts indicate that they are coincident with the surges, suggesting that
magnetic reconnection is the driver mechanism. The magnetic energy released by
reconnection is transformed into plasma heating and provides the kinetic energy
for the ejections. A lack of a radio signature in the high corona suggests that
the surges are confined to follow the closed field lines in the fans. We
conclude that these cool surges may have some local heating effects in the
closed loops, but probably play a minor role in global coronal heating and the
surge material does not escape to the solar wind.Comment: Accepted for the Publication in ApJ; 25 pages, 10 Figures, and 1
Tabl
Far-infrared observations of Circinus and NGC 4945 galaxies
Circinus and NGC 4945 are two galaxies luminous in the infrared and are characterized by compact non thermal radio nuclei, deep silicate absorption features and unusually strong water vapor maser luminosities. Moorwood and Glass (1984) have observed these galaxies extensively in the 1 to 20 micron range. In the far-infrared, observations up to 100 microns are available from the Infrared Astronomy Satellite (IRAS). In order to study the cool dust component of these galaxies, researchers observed them at 150 microns using the Tata Institute of Fundamental Research (TIFR) 100 cm balloon-borne telescope. Here, they report observations along with deconvolved maps at 50 and 100 microns obtained from the Chopped Photometric Channel (CPC) on board IRAS
Mass function and dynamical study of the open clusters Berkeley 24 and Czernik 27
We present a photometric study of the open clusters Berkeley 24 (Be
24) and Czernik 27 (Cz 27). The radii of the clusters are determined as
2\farcm7 and 2\farcm3 for Be 24 and Cz 27, respectively. We use the Gaia Data
Release 2 (GDR2) catalogue to estimate the mean proper motions for the
clusters. We found the mean proper motion of Be 24 as mas
yr and mas yr in right ascension and declination
for Be 24 and mas yr and mas yr for
Cz 27. We used probable cluster members selected from proper motion data for
the estimation of fundamental parameters. We infer reddenings =
mag and mag for the two clusters. Analysis of
extinction curves towards the two clusters show that both have normal
interstellar extinction laws in the optical as well as in the near-IR band.
From the ultraviolet excess measurement, we derive metallicities of [Fe/H]=
dex and dex for the clusters Be 24 and Cz 27,
respectively. The distances, as determined from main sequence fitting, are
kpc and kpc. The comparison of observed CMDs with
isochrones, leads to an age of Gyr and Gyr for
Be 24 and Cz 27, respectively.
In addition to this, we have also studied the mass function and dynamical
state of these two clusters for the first time using probable cluster members.
The mass function is derived after including the corrections for data
incompleteness and field star contamination. Our analysis shows that both
clusters are now dynamically relaxedComment: 16 pages including 8 tables. 22 figures. Accepted by MNRA
Quaternion Analysis for Generalized Electromagnetic Fields of Dyons in Isotropic Medium
Quaternion analysis of time dependent Maxwell's equations in presence of
electric and magnetic charges has been developed and the solutions for the
classical problem of moving charges (electric and magnetic) are obtained in
unique, simple and consistent manner
Efficient absolute aspect determination of a balloon borne far infrared telescope using a solid state optical photometer
The observational and operational efficiency of the TIFR 1 meter balloon
borne far infrared telescope has been improved by incorporating a multielement
solid state optical photometer (SSOP) at the Cassegrain focus of the telescope.
The SSOP is based on a 1-D linear photo diode array (PDA). The online and
offline processing schemes of the PDA signals which have been developed, lead
to improvement in the determination of absolute telescope aspect (
0\farcm8), which is very crucial for carrying out the observations as well as
offline analysis. The SSOP and its performance during a recent balloon flight
are presented here.Comment: To appear in the February 2000 issue of the PAS
Sequence of complementary deoxyribonucleic acid encoding bonnet monkey (Macaca radiata) zona pellucida glycoprotein-ZP1 and its high-level expression in Escherichia coli
Zona pellucida (ZP) glycoproteins have been proposed as candidate antigens for immunocontraception. Studies on this potential use can be facilitated by the availability of recombinant proteins. A cDNA lambda gt11 library was constructed using poly(A)+ mRNA isolated from bonnet monkey (Macaca radiata) ovaries and was screened for bonnet monkey ZP1 using a 404-basepair (bp) human ZP1 fragment (nucleotides 818-1221) as probe. Bonnet monkey ZP1 cDNA comprises 1617 nucleotides and encodes a polypeptide of 539 amino acid residues that share 92.0% identity with human ZP1. The major difference between bonnet monkey ZP1 and human ZP1 is the deletion of a 28-amino acid domain (amino acid residues 100-127 corresponding to human ZP1). An internal fragment (1317 bp) of bonnet monkey ZP1, excluding the N-terminus signal sequence and the C-terminus transmembrane-like domain, was amplified by polymerase chain reaction. The amplified Sac I and Kpn I restricted fragment was cloned in a frame downstream of the T5 promoter under the lac operator control for expression in the pQE-30 vector. Recombinant ZP1 (r-ZP1) was expressed as a polyhistidine fusion protein in Escherichia coli strains SG13009[pREP4] and ompT and Ion protease-deficient BL21 (plysS). SDS-PAGE analysis and immunoblotting with a murine monoclonal antibody, MA-410 (raised against porcine ZP3alpha--a homologue of bonnet monkey ZP1--and cross-reactive with bonnet monkey zona pellucida), revealed major bands of 51 and 40 kDa besides truncated fragments. Optimum expression of r-ZP1 was observed at 0.5 mM isopropyl beta-D-thiogalactopyranoside (IPTG). Immunization of male rabbits with r-ZP1 purified on nickel-nitrilotriacetic acid (NTA) resin under denaturing conditions and of female rabbits with r-ZP1 conjugated with diphtheria toxoid-generated antibodies reactive with r-ZP1 in ELISA. Moreover, immune sera, when tested by indirect immunofluorescence on bonnet monkey ovarian sections, showed positive fluorescence with zona pellucida. The information on the sequence of bonnet monkey ZP1 and the availability of the recombinant protein will help toward better understanding and evaluation of the contraceptive potential of homologous immunization in a nonhuman primate model
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