771 research outputs found
Two -unit equations with many solutions
We show that there exist arbitrarily large sets of prime numbers such
that the equation has more than
solutions in coprime integers , , all of whose prime factors lie in
the set . We also show that there exist sets for which the equation
has more than solutions with all prime factors
of and lying in .Comment: 6 page
Electrostatic Structures in Space Plasmas: Stability of Two-dimensional Magnetic Bernstein-Greene-Kruskal Modes
Electrostatic structures have been observed in many regions of space plasmas,
including the solar wind, the magnetosphere, the auroral acceleration region,
and in association with shocks, turbulence, and magnetic reconnection. Due to
potentially large amplitude of electric fields within these structures, their
effects on particle heating, scattering, or acceleration can be important. One
possible theoretical description of some of these structures is the concept of
Bernstein-Greene-Kruskal (BGK) modes, which are exact nonlinear solutions of
the Vlasov-Poisson system of equations in collisionless kinetic theory. BGK
modes have been studied extensively for many decades, predominately in one
dimension (1D), although there have been observations showing that some of
these structures have clear 3D features. While there have been approximate
solutions of higher dimensional BGK modes, an exact 3D BGK mode solution in a
finite magnetic field has not been found yet. Recently we have constructed
exact solutions of 2D BGK modes in a magnetized plasma with finite magnetic
field strength in order to gain insights of the ultimate 3D theory [Ng,
Bhattacharjee, and Skiff, Phys. Plasmas 13, 055903 (2006)]. Based on the
analytic form of these solutions, as well as Particle-in-Cell (PIC)
simulations, we will present numerical studies of their stability for different
levels of background magnetic field strength.Comment: Submitted to AIP Journal Proceedings for "Tenth Annual International
Astrophysics Conference
Light-heavy ion measurements in CR-39 located on the Earth side of LDEF
The azimuthal angle distribution and the charge and energy spectra of selected light-heavy (5 less than or equal to Z less than or equal to 8) stopping particles were measured in a single layer of CR-39 plastic nuclear track detector (PNTD) from the stack of the A0015 experiment located on the Earth-end of the LDEF satellite. The directional incidence of the trapped protons is studied by comparing the azimuthal angle distribution of selected recoils, obtained in the LDEF detectors, to that obtained through calibrations of PNTD's with exposures performed with 200 MeV proton beams from different directions
IMPACT OF MICRO PLASTICS EXPOSURE ON VITELLOGENESIS AND SEX HORMONES OF FEMALE MOLE CRAB EMERITA ASIATICA
The marine ecosystem now considered as the major concern due to the contamination of micro plastics that affects the marine organisms by accidental ingestion and causes physiological, morphological and genetic profiles. The organisms also effect on endocrine system that leads to reproductive damage, hence the present investigation was focused on the effect of micro plastics exposure on reproductive system of female crab Emerita asiatica. After 24 and 48 days of the experimental periods, the female crabs then estimated for the hormonal changes in the ovaries of mussels by estimating vitellogenin, 17β-estradiol, and testosterone and some biochemical parameters such as protein and glycogen content to observe for toxic stress. The results showed that significant decrease in the vitellogenin and 17β-estradiol besides elevated level of testosterone was observed in the animals exposed for 28 days with 1000 particles mL-1. In addition to that, level of protein and glycogen level was significantly debited in the hemolymph due to toxic stress. Hence, the present study found that exposure of micro plastics would reduce the reproductive hormones of female crab and affect their reproductive system. Overall, the present study provides the importance of usage and discarding the plastics in the environment. The micro plastic contamination in the environment not only affect the aquatic crustacean’s species, which can ultimately be affecting the Human beings through the collapsing of food chain
Some recent observations on small-scale fishery In the vicinity of Madras
Madras zone is one of the important fishing centres on the east coast of India. To understand the fish landings from different gears in Madras, three landing centres, viz., Kasimedu, Triplicane and Nochikuppam were selected. Kasimedu is about 8 km north of Triplicane and Nochikuppam is about 2 km south of Triplicane. The major catch components from the demersal trawls of this area arc silver bellies, threadfin breams, sciaenids, lizardfish, prawns, squids and cuttlefish. These groups are landed in a meagre quantity by the traditional gears, thus maintaining compatability between mechanised and non-mechanised gears in the exploitation of fishery resources off Madras
A Web-based approach to automated inspection and quality control of manufactured parts
This paper presents an approach for the automated inspection and quality control of manufactured parts from a remote site. A web-based control system was developed to establish communication among the various components of the experimental manufacturing cell, consisting of an IBM 7535 robot, a measuring station and a part feed station. The various cell components are interfaced with the computer through digital and analog interface modules from National Instruments and is controlled using a graphical programming language called LabVIEW. A dedicated web page was developed for the cell that allows remote users to perform online quality tests. Details pertaining to the cell and the control architecture developed to automate the quality control task are presented in this paper. The feasibility of providing non-site based hands-on engineering and technology education is also explored through this project
Arsenic-induced oxidative stress in fresh water catfish Tilapia mossambica
An experiment was conducted to investigate bioaccumulation potential of arsenic and changes in oxidative stress indices in liver tissue from arsenic exposed fish Tilapia mossambica were used for the present investigation. The Tilapia mossambica were exposed to two non lethal doses of arsenic for 10 days, which induced tissue lipid peroxidation, increased the ratio of oxidized to reduced glutathione and produced excess H2O2 within 1–2 days of exposure. Furthermore, arsenic treatment increased the activity of antioxidant enzymes such as superoxide dismutase (SOD), and catalase but decreased glutathione reductase (GR) activity within a day of exposure, indicating the generation of oxidative stress in fish at an early stage. It is therefore concluded that peroxisomal H2O2 metabolizing enzymes are potential targets of arsenic toxicity in Tilapia mossambica
The Dominance of Power and Mythological Representations in Girish Karnad’s The Fire and the Rain
This Research paper Focuses on Dominance of power and mythological creatures in the The play The Fire and the Rain, Which occurs in a small region of India long ago that has experienced a lack of rain for ten years. The king proposed to propitiate the Gods through fire sacrifice. So that God would be pleased and send rain to the parched land. In this fire sacrifice Paravasu the son of a learned Brahmin Raibhya, was appointed as the Chief Priest. And the play deals with this appointment and the disappointments of certain other characters. One disappointment definitely with reference to the father going by ancient Indian tradition, a lot of emphasis was put on age seniority i.e. age has always been respected. Older people have always been considered wiser because of their wider experience. Going by this tradition the learned Raibhya should have been appointed as the chief Priest but for practical reasons longevity of life span, the King chose to appoint Paravasu, the elder son as the Chief Priest. This appointment had disappointed and agonized the senior. The high priest of the temple, Paravasu is eager to perform a ceremony to bring rain. the play The Fire and The Rain opens with the representative of an actor`s group expressing their desire to give a dramatic performance as a means of entertainment for the Gods. After much discussion the group is given permission to perform at the fire sacrifice
- …