969 research outputs found
Neutron Acceleration in Uniform Electromagnetic Fields
The question as to whether neutron acceleration can occur in uniform
electromagnetic fields is examined. Although such an effect has been predicted
using the canonical equations of motion some doubt has been raised recently as
to whether it is in principle observable for a spin 1/2 particle. To resolve
this issue a gedanken experiment is proposed and analyzed using a wave packet
construction for the neutron beam. By allowing arbitrary orientation for the
neutron spin as well as for the electric and magnetic fields a non vanishing
acceleration of the center of the neutron wave packet is found which confirms
the predictions of the canonical formalism.Comment: 11 page
Gravitational Phase Operator and Cosmic Strings
A quantum equivalence principle is formulated by means of a gravitational
phase operator which is an element of the Poincare group. This is applied to
the spinning cosmic string which suggests that it may (but not necessarily)
contain gravitational torsion. A new exact solution of the Einstein-
Cartan-Sciama-Kibble equations for the gravitational field with torsion is
obtained everywhere for a cosmic string with uniform energy density, spin
density and flux. A novel effect due to the quantized gravitational field of
the cosmic string on the wave function of a particle outside the string is used
to argue that spacetime points are not meaningful in quantum gravity.Comment: 22 pages, to be published Phys. Rev. D. Some minor changes have been
made and a reference has been added to the paper of D.V. Gal'tsov and P.S.
Letelier, Phys. Rev. D 47 (1993) 4273, which first contained the metric (2.2)
external to the cosmic string. The present paper extends this solution to a
regular solution inside the string as wel
Classical and Quantum Interaction of the Dipole
A unified and fully relativistic treatment of the interaction of the electric
and magnetic dipole moments of a particle with the electromagnetic field is
given. New forces on the particle due to the combined effect of electric and
magnetic dipoles are obtained. Four new experiments are proposed, three of
which would observe topological phase shifts.Comment: 10 pages, Latex/Revtex. Some minor errors have been correcte
FLY-CAPS- A Hybrid Firefly Feature Optimized Capsule Networks for Plant Disease Classification in Resource Constriant Internet of Things (IoT)
Recent advancements in artificial intelligence, automation, and the Internet of Things (IoT) enable farmers to better monitor and diagnose all agricultural procedures with super-intellectual accuracy. These technologies also contribute to boosting the productivity of agriculture, which increases the country’s economy. Though these technologies help farmers increase productivity, the detection of plant diseases still needs heightened scrutiny for prevention and cultivation. Plant disease categorization has expanded with the introduction of deep learning algorithms, but it still needs more innovation in terms of accuracy and computing burden. Thus, a novel deep learning model based on capsule networks with firefly optimization and potent multi-layered feedforward prediction networks is proposed in this research. The handcrafted features in this proposed system are optimized before being extracted using a capsule network, which reduces the complexity overhead and is suitable for IoT devices with limited resources. Finally fed to the feed forward layers for better classification. The extensive experimentation has been tested with the Plant Village databases, which contain more than 50,000 images of healthy and infected plants. Performance criteria including recall, specificity, recall, accuracy, and f1-score are used to assess the proposed algorithm's performance. Additionally, its efficiency and computational cost are contrasted with those of other recent models. The suggested model has greater performance (95%) with reduced computing overhead, according to experimental data, which is advantageous for the new prediction approach and the welfare of the farmer
PHYTOCHEMICAL AND PHARMACOLOGICAL EVALUATION OF ACALYPHA COMMUNIS MULL. ARG. FOR THEIR HEPATOPROTECTIVE ACTIVITY
Objective: Acalypha communis is a synonym of Ricinocarpus communis (Müll.Arg.) belonging to the family of Euphorbiaceae. A. communis possess awide variety of activities like antimicrobial. Hence, the present study was intended to evaluate ethanolic leaf extract of A. communis for hepatoprotectiveactivities.Methods: The hepatoprotective activity was studied by paracetamol (2 g/kg) and D-galactosamine (400 mg/kg) induced models. Acute toxicity studyand preliminary phytochemical screening were also studied to evaluate the toxicity.Results: No toxicity profile was observed in rats after oral administration of the ethanolic leaf extract at the dose of 5 g/kg body weight. Thedifferent dose of 200 mg/kg and 400 mg/kg administered with the extract of A. communis. There was significant (p<0.001) reduction in biochemicalparameters with respect to control. Phytochemical screening of the plant extract revealed the presence of tannins, alkaloids, flavonoids and saponins,and terpenoids.Conclusion: It can be concluded that the hepatoprotective activity elucidated by A. communis could be mainly due to the presences of high-value classof compound like the phenolic group as the major content in the plants.Keywords: Acalypha communis, Paracetamol, D-galactosamine, Biochemical parameters and histopathological studies
Galilean non-invariance of geometric phase
It is shown that geometric phase in non-relativistic quantum mechanics is not
Galilean invariant.Comment: LaTeX, 6 pages, no figure
Action principle formulation for motion of extended bodies in General Relativity
We present an action principle formulation for the study of motion of an
extended body in General Relativity in the limit of weak gravitational field.
This gives the classical equations of motion for multipole moments of arbitrary
order coupling to the gravitational field. In particular, a new force due to
the octupole moment is obtained. The action also yields the gravitationally
induced phase shifts in quantum interference experiments due to the coupling of
all multipole moments.Comment: Revised version derives Octupole moment force. Some clarifications
and a reference added. To appear in Phys. Rev.
Local contribution of a quantum condensate to the vacuum energy density
We evaluate the local contribution g_[mu nu]L of coherent matter with
lagrangian density L to the vacuum energy density. Focusing on the case of
superconductors obeying the Ginzburg-Landau equation, we express the
relativistic invariant density L in terms of low-energy quantities containing
the pairs density. We discuss under which physical conditions the sign of the
local contribution of the collective wave function to the vacuum energy density
is positive or negative. Effects of this kind can play an important role in
bringing about local changes in the amplitude of gravitational vacuum
fluctuations - a phenomenon reminiscent of the Casimir effect in QED.Comment: LaTeX, 8 pages. Final journal versio
Fatty acid signatures of the Indian mackerel Rastrelliger kanagurta (Cuvier)from the Arabian Sea along the Indian coast
The fatty acid profile of the Indian mackerel Rastrelliger kanagurta from the Arabian Sea was studied
in relation to its maturation and spawning cycle. Among fatty acids, polyunsaturated fatty acids (PUFA)
component was the highest (46.9%) followed by saturated fatty acids (SFA) and monounsaturated fatty
acids (MUFA) at 41.8% and 11% respectively. No differences were observed between the period of
low spawning activity in January and peak spawning activity in May. However significant (p<0.05)
differences were observed with regard to sex where females had higher levels of SFA and MUFA while
males had higher levels of PUFA. With regard to maturity stages, only females showed significant
differences (p<0.05) in MUFA content with higher level in mature stages compared to immature stages.
Docosahexaenoic acid (DHA) was the single largest component of PUFA. The absence of marked
temperature differences in the Arabian Sea probably precludes seasonal effects on the levels of SFA,
MUFA and PUFA in the Indian mackerel while variations of individual FA within these groups indicate
lipid dynamics in relation to reproduction and feeding
Global Topology and Local Violation of Discrete Symmetries
Cosmological models that are locally consistent with general relativity and
the standard model in which an object transported around the universe undergoes
P, C and CP transformations, are constructed. This leads to generalization of
the gauge fields that describe electro-weak and strong interactions by
enlarging the gauge groups to include anti-unitary transformations. Gedanken
experiments show that if all interactions obey Einstein causality then P, C and
CP cannot be violated in these models. But another model, which would violate
charge superselection rule even for an isolated system, is allowed. It is
suggested that the fundamental physical laws must have these discrete
symmetries which are broken spontaneously, or they must be non causal.Comment: 12 pages, 1 figure, latex, Revtex. Charge conjugation which is
physically implemented in a cosmology with the appropriate topology is
described in more detail. Some minor errors are corrected. Shortened to meet
the page limit of Physical Review Letters to which this paper was submitte
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