scholarly journals A dynamical evolution of GRB-afterglows in a new generic model

2022 ◽  
Author(s):  
Esma Zouaoui ◽  
Noureddine Mebarki ◽  
Achour Benslama
Keyword(s):  
General Expression ◽  
Dynamical Evolution ◽  
Radiation Energy ◽  
Generic Model ◽  
New Model

In this paper, a new model using a general expression of the radiation energy and explaining the dynamics of the afterglows is proposed. It is shown that this model is suitable for the ultra-relativistic and non-relativistic phases as well as the study of radiative and adiabatic fireballs.

CAVITY QUANTUM ELECTRODYNAMICS OF COMPETING ONE AND TWO PHOTON PROCESSES

1996 ◽  
Vol 10 (09) ◽  
pp. 385-391
Author(s):  
AMITABH JOSHI
Keyword(s):  
Electromagnetic Field ◽  
Quantum Electrodynamics ◽  
Dynamical Evolution ◽  
Single Mode ◽  
Cavity Quantum Electrodynamics ◽  
Rabi Splitting ◽  
New Model ◽  
Two Photon ◽  
Photon Transition ◽  
Vacuum Rabi Splitting

We consider a new model of cavity quantum electrodynamics consisting of the interaction of a single mode of electromagnetic field with two non-identical two-level atoms undergoing one and two photon transition respectively in an ideal cavity. The exact analytic results for the vacuum Rabi splitting and the dynamical evolution of the model are given.

Développement complet de la polarisabilité des molécules tétraédriques XY4

1991 ◽  
Vol 69 (1) ◽  
pp. 26-35 ◽  
Author(s):  
A. Boutahar ◽  
M. Loete
Keyword(s):  
General Expression ◽  
Coupling Scheme ◽  
Order Of Approximation ◽  
Raman Intensity ◽  
Matrix Elements ◽  
New Model ◽  
Vibration Rotation ◽  
Tetrahedral Molecules ◽  
Group Polarizability

A new model of polarizability is presented consistent with the Hamiltonian of tetrahedral molecules XY4. Using a coupling scheme in the Td group, polarizability operators are obtained up to any order of approximation for all vibration–rotation bands of any symmetry. This model leads to an unique formula for matrix elements of these operators. We also give the general expression for the Raman intensity of a transition.

scholarly journals Agroclimatic Impact on Gastrointestinal Infection: A Mathematical Model

2020 ◽  
Author(s):  
Goutam Ghosh ◽  
Subhasish Bandyopadhyay ◽  
Amit Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
Dynamical Evolution ◽  
Extended Period ◽  
Gastrointestinal Parasites ◽  
Generic Model ◽  
Successful Implementation ◽  
Gastrointestinal Infection ◽  
Key Factors ◽  
High Infection ◽  
Cattle Health

Identifying the correct dosage and time are key factors to successful implementation of anthelmintic. Comparing differential evolution of infection between anthelmintic treated animals against untreated ones, we present a mathematical model that first calibrates data collected and analyzed over an extended period of 10 years (2011-2019), and then predicts the dynamical evolution of gastrointestinal parasites in livestock, focusing specifically on Stronglye \& Coccidia oocysts, the two prime negative contributors to cattle health, measured using the standard Eggs-Per-Gram (EPG) index. The model incorporates information about all three critical regimes of infection - low infection regime ($< 50$ EPG), medium infection regime ($50-100$ EPG) and high infection regime ($>100$ EPG), including fatally large doses of infection ($> 500$), and probabilistically estimates the variation in animal weight due to infection propagation. A key success of our model is its ability to accurately predict the appropriate anthelmintic treatment times for cattle from a numerical solution of the model presented. The generic model can be applied to other agroclimatic conditions and can serve as a major diagnostic tool for anthelmintic strategizing.

Statistical results on discovered near-Earth asteroids

1999 ◽  
Vol 173 ◽  
pp. 81-86
Author(s):  
S. Berinde
Keyword(s):  
Dynamical Evolution ◽  
Minor Planet ◽  
Orbital Elements ◽  
The Earth ◽  
Near Earth Asteroids ◽  
Statistical Results

AbstractThe first part of this paper gives a recent overview (until July 1st, 1998) of the Near-Earth Asteroids (NEAs) database stored at Minor Planet Center. Some statistical interpretations point out strong observational biases in the population of discovered NEAs, due to the preferential discoveries, depending on the objects’ distances and sizes. It is known that many newly discovered NEAs have no accurately determinated orbits because of the lack of observations. Consequently, it is hard to speak about future encounters and collisions with the Earth in terms of mutual distances between bodies. Because the dynamical evolution of asteroids’ orbits is less sensitive to the improvement of their orbital elements, we introduced a new subclass of NEAs named Earth-encounter asteroids in order to describe more reliably the potentially dangerous bodies as impactors with the Earth. So, we pay attention at those asteroids having an encounter between their orbits and that of the Earth within 100 years, trying to classify these encounters.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

Evolution of collisional systems

1984 ◽  
Vol 75 ◽  
pp. 361-362
Author(s):  
André Brahic
Keyword(s):  
Gravitational Field ◽  
Dynamical Evolution ◽  
Oblate Planet

AbstractThe dynamical evolution of planetary discs in the gravitational field of an oblate planet and a satellite is numerically simulated.

The Jovian ring

1984 ◽  
Vol 75 ◽  
pp. 203-209
Author(s):  
Joseph A. Burns
Keyword(s):  
Equatorial Plane ◽  
Charged Particles ◽  
Dynamical Evolution ◽  
Main Band ◽  
Small Grains ◽  
Three Components

ABSTRACTLying in Jupiter's equatorial plane is a diaphanous ring having little substructure within its three components (main band, faint disk, and halo). Micron-sized grains account for much of the visible ring, but particles of centimeter sizes and larger must also be present to absorb charged particles. Since dynamical evolution times and survival life times are quite short (≲102-3yr) for small grains, the Jovian ring is being continually replenished; probably most of the visible ring is generated by micrometeoroids colliding into unseen parent bodies that reside in the main band.

The Hitachi Model HS-8 Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 238-239
Author(s):  
H. Akabori ◽  
K. Nishiwaki ◽  
K. Yoneta
Keyword(s):  
Electron Microscope ◽  
New Model ◽  
Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

516: A Simplified Method to Estimate the Absolute Renal Uptake of 99MTC-DMSA: Evaluation with a New Model using the Radioactivity of Nephrectomy Specimens as Reference

2005 ◽  
Vol 173 (4S) ◽  
pp. 140-141
Author(s):  
Mariana Lima ◽  
Celso D. Ramos ◽  
Sérgio Q. Brunetto ◽  
Marcelo Lopes de Lima ◽  
Carla R.M. Sansana ◽  
...  
Keyword(s):  
New Model ◽  
Renal Uptake ◽  
Simplified Method ◽  
The Absolute
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