118 research outputs found
Focusing by Plano-Concave lens using Negative Refraction
We demonstrate focusing of a plane microwave by a plano-concave lens
fabricated from a photonic crystal (PhC) having negative refractive index and
left-handed electromagnetic properties. An inverse experiment, in which a plane
wave is produced from a source placed at the focal point of the lens is also
reported. A frequency dependent negative refractive index, is obtained for the
lens from the experimental data which matches well with that determined from
band structure calculations
Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals
We demonstrate negative refraction of microwaves in metallic photonic
crystals. The spectral response of the photonic crystal, which manifests both
positive and negative refraction, is in complete agreement with band-structure
calculations and numerical simulations. The negative refraction observed
corresponds to left-handed electromagnetism and arises due to the dispersion
characteristics of waves in a periodic medium. This mechanism for negative
refraction is different from that in metamaterials.Comment: 13 pages, 4 figure
A Crystallized Treatise on Determinants of Motivational Environment in Oil and Natural Gas Corporation Limited (ONGC)
Technologies have become stakes and those companies who can turn strategy into action at jet speed can bring seamless changes in the organization. In this context motivation has become an important HR intervention in making human resources effective. Companies realized the importance of the motivation as the contribution of employees directly relates their vision and mission statements. Demotivated workforce can cause havoc in failing to meet the organizational objectives. It has the role to develop and intensify the desire of every member of the organization to work effectively and efficiently in their roles. After employees are hired and trained, it is important to motivate them to get the desired efforts from them, to achieve organizational objectives. Owing to the stiff competition among the Multi Nationals in retaining them has become challenge, this paper focus on motivating the workforce by introducing various HR Interventions to motivate and retain for the benefit of the organizational objectives. For this cause a range of motivational factors were considered for a critical assessment on motivational environment in ONGC. Keywords: Motivation, technology, environment, organizational objectives, workforce DOI: 10.7176/EJBM/13-11-03 Publication date:June 30th 202
FUZZY LOGIC CONTROL OF A LABORATORY MAGNETIC LEVITATION SYSTEM
ABSTRACT This paper deals with the Fuzz
Non-linear microwave impedance of short and long Josephson Junctions
The non-linear dependence on applied field () or current () of the microwave (ac) impedance of both
short and long Josephson junctions is calculated under a variety of excitation
conditions. The dependence on the junction width is studied, for both field
symmetric (current anti-symmetric) and field anti-symmetric (current symmetric)
excitation configurations.The resistance shows step-like features every time a
fluxon (soliton) enters the junction, with a corresponding phase slip seen in
the reactance. For finite widths the interference of fluxons leads to some
interesting effects which are described. Many of these calculated results are
observed in microwave impedance measurements on intrinsic and fabricated
Josephson junctions in the high temperature superconductors, and new effects
are suggested. When a field () or current () is applied,
interesting phase locking effects are observed in the ac impedance
. In particular an almost periodic dependence on the dc bias is
seen similar to that observed in microwave experiments at very low dc field
bias. These results are generic to all systems with a potential
in the overdamped limit and subjected to an ac drive.Comment: 7 pages, 11 figure
Onset of dielectric modes at 110K and 60K due to local lattice distortions in non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals
We report the observation of two dielectric transitions at 110K and 60K in
the microwave response of non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals.
The transitions are characterized by a change in polarizability and presence of
loss peaks, associated with overdamped dielectric modes. An explanation is
presented in terms of changes in polarizability of the apical O atoms in the
Ba-O layer, affected by lattice softening at 110K, due to change in buckling of
the Cu-O layer. The onset of another mode at 60K strongly suggests an
additional local lattice change at this temperature. Thus microwave dielectric
measurements are sensitive indicators of lattice softening which may be
relevant to superconductivity.Comment: 5 pages, 3 ps format figure
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