2,355 research outputs found
Mapping of noise pollution by different interpolation methods in recovery section of Ghandi telecommunication Cables Company
Background: Noise pollution and workers\u27 noise exposure are common in industrial factories in Iran. In order to reduce this noise pollution, evaluation and investigation of noise emission are both necessary. In this study, different noise mapping methodsare used for determining the distribution of noise.
Materials and Methods: In the present study, for preparing a noise map in a hall of an industrial factory, sampling was carried out in 6×6 m grid. After data normalization the variogram was developed. For interpolation of mentioned parameter, kriging and Inverse Distance Weighting methods were used. The best model for interpolation was selected by cross validation and error evaluation methods, such as Route Mean Square Error(RMSE).
Results: The results showed that kriging method is better than other methods for prediction of noise property. The noise map was prepared, using the best interpolation method in Geographical Information System environment.
Conclusion: Workers in this industrial hall were exposed to noise which is mainly induced by noisy machines. Noise maps which were produced in this study showed the distribution of noise and, also revealed that workers suffer from serious noise pollution
Long-range interactions between an atom in its ground S state and an open-shell linear molecule
Theory of long-range interactions between an atom in its ground S state and a
linear molecule in a degenerate state with a non-zero projection of the
electronic orbital angular momentum is presented. It is shown how the
long-range coefficients can be related to the first and second-order molecular
properties. The expressions for the long-range coefficients are written in
terms of all components of the static and dynamic multipole polarizability
tensor, including the nonadiagonal terms connecting states with the opposite
projection of the electronic orbital angular momentum. It is also shown that
for the interactions of molecules in excited states that are connected to the
ground state by multipolar transition moments additional terms in the
long-range induction energy appear. All these theoretical developments are
illustrated with the numerical results for systems of interest for the
sympathetic cooling experiments: interactions of the ground state Rb(S)
atom with CO(), OH(), NH(), and CH() and of the
ground state Li(S) atom with CH().Comment: 30 pages, 3 figure
Dirac particle in a spherical scalar potential well
In this paper we investigate a solution of the Dirac equation for a
spin- particle in a scalar potential well with full spherical
symmetry. The energy eigenvalues for the quark particle in states
(with ) and states (with ) are calculated. We
also study the continuous Dirac wave function for a quark in such a potential,
which is not necessarily infinite. Our results, at infinite limit, are in good
agreement with the MIT bag model. We make some remarks about the sharpness
value of the wave function on the wall. This model, for finite values of
potential, also could serve as an effective model for the nucleus where
is the effective single particle potential.Comment: 9 pages, 8 figures, revtex4, version to appear in PR
Overlapping Resonances Interference-induced Transparency: The Photoexcitation Spectrum of Pyrazine
The phenomenon of "overlapping resonances interference-induced transparency"
(ORIT) is introduced and studied in detail for the
photoexcitation of cold pyrazine (CHN). In ORIT a molecule becomes
transparent at specific wavelengths due to interferences between envelopes of
spectral lines displaying overlapping resonances. An example is the
internal conversion in pyrazine where destructive
interference between overlapping resonances causes the light
absorption to disappear at certain wavelengths. ORIT may be of practical
importance in multi-component mixtures where it would allow for the selective
excitation of some molecules in preference to others. Interference induced
cross section enhancement is also shown.Comment: 13 pages, 7 figure
Antioxidant and antihemolytic activities of methanol extract of Hyssopus angustifolius
This study was designed to evaluate antioxidant and antihemolytic activities of Hyssopus angustifolius flower, stem and leaf methanol extracts by employing various in vitro assays. The leaf extract showed the best activity in DPPH (63.2 ± 2.3 μg mL-1) and H2O2  (55.6 ± 2.6 μg mL-1) models compared to the other extracts. However, flower extract exhibited the highest Fe2+ chelating activity (131.4 ± 4.4 μg mL-1). The extracts exhibited good antioxidant activity in linoleic acid peroxidation and reducing power assays, but were not comparable to vitamin C. The stem (23.58 ± 0.7 μg mL-1) and leaf (26.21 ± 1 μg mL-1) extracts showed highest level of antihemolytic activity than the flower extract
How to Measure the Quantum State of Collective Atomic Spin Excitation
The spin state of an atomic ensemble can be viewed as two bosonic modes,
i.e., a quantum signal mode and a -numbered ``local oscillator'' mode when
large numbers of spin-1/2 atoms are spin-polarized along a certain axis and
collectively manipulated within the vicinity of the axis. We present a concrete
procedure which determines the spin-excitation-number distribution, i.e., the
diagonal elements of the density matrix in the Dicke basis for the collective
spin state. By seeing the collective spin state as a statistical mixture of the
inherently-entangled Dicke states, the physical picture of its multi-particle
entanglement is made clear.Comment: 6 pages, to appear in Phys. Rev.
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