1,340 research outputs found
Unified Angular Momentum of Dyons
Unified quaternionic angular momentum for the fields of dyons and
gravito-dyons has been developed and the commutation relations for dynamical
variables are obtained in compact and consistent manner. Demonstrating the
quaternion forms of unified fields of dyons (electromagnetic fields) and
gravito-dyons (gravito-Heavisidian fields of linear gravity), corresponding
quantum equations are reformulated in compact, simpler and manifestly covariant
way
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
Histomorphological analysis and clinical correlation of neoplastic and non neoplastic skin lesions: a study in a tertiary care centre of Western Uttar Pradesh, India
Background: Clinical examination may suffice in making diagnosis of most dermatologic disorders but histopathological examination is often required to confirm the diagnosis and further categorize the lesions. Authors carried out this study to analyse the demographic and histomorphological characteristics of skin lesions, to determine the frequency of various dermatological disorders in the region and to evaluate the agreement between clinical and histopathological diagnosis.Methods: Punch biopsies of skin lesions received in histopathology section, were included in the study. Cases over a period of six months were analysed. Clinical details were recorded and histopathological analysis done. Special stains were applied wherever required.Results: Of the 120 cases studied, maximum cases fell in the category of 31-40 years, with male predominance. Authors observed wide variety of non-neoplastic and neoplastic lesions. Infectious diseases were the most common of all pathologies. Leprosy was the most common histopathological diagnosis. Complete clinicopathologic correlation was seen in 51.67% of cases while partial correlation was noted in 23.33% making a total of 75%. 25% histopathological diagnosis were inconsistent with the clinical diagnosis.Conclusions: Histopathology is a gold standard investigation and plays a very important role in confirmation of clinical diagnosis of various skin lesions. Punch biopsy is a relatively easy outpatient procedure to perform
Modelling and Simulation of Tactical Team Behaviour
Realistic military simulations are needed for analysis, planning, and training. Intelligentagent technology is a valuable software concept with the potential of being widely used inmilitary simulation applications. They provide a powerful abstraction mechanism required fordesigning simulations of complex and dynamic battlefields. Their ability to model the tacticaldecision-making behaviour of simulated battlefield entities gives them an edge over othertechniques. During battlefield simulation, these entities generally represent individualisticbehaviour, taking operational order from higher control and executing relevant plans. However,since a complex battlefield scenario typically involves thousands of entities, their coordinatedteam behaviour should also be considered to make the simulation more realistic. This paperdemonstrates the use of intelligent agent-based team behaviour modelling concepts in simulatingthe armoured tanks in a tactical masking scenario
Generalized Gravi-Electromagnetism
A self consistant and manifestly covariant theory for the dynamics of four
charges (masses) (namely electric, magnetic, gravitational, Heavisidian) has
been developed in simple, compact and consistent manner. Starting with an
invariant Lagrangian density and its quaternionic representation, we have
obtained the consistent field equation for the dynamics of four charges. It has
been shown that the present reformulation reproduces the dynamics of individual
charges (masses) in the absence of other charge (masses) as well as the
generalized theory of dyons (gravito - dyons) in the absence gravito - dyons
(dyons). key words: dyons, gravito - dyons, quaternion PACS NO: 14.80H
Quaternion Gravi-Electromagnetism
Defining the generalized charge, potential, current and generalized fields as
complex quantities where real and imaginary parts represent gravitation and
electromagnetism respectively, corresponding field equation, equation of motion
and other quantum equations are derived in manifestly covariant manner. It has
been shown that the field equations are invariant under Lorentz as well as
duality transformations. It has been shown that the quaternionic formulation
presented here remains invariant under quaternion transformations.Comment: Key Words: Quaternion, dyons, gravito-dyons, gravi-electromagnetism.
PACS No.: 04.90. +e ; 14.80. H
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