836 research outputs found
Design and Analysis of Tripple Band Koch Fractal Yagi Uda Antenna
The proposed antenna is Koch fractal printed Yagi-Uda antenna fed by SMA connector. The radiation characteristics of the antenna are simulated by CST Microwave Studio and analysed with the help of simulated results. The antenna's currents distribution becomes more uniform after being fractal, which is conducive to increase the antenna’s radiation directivity. The proposed Koch fractal Yagi-Uda antenna resonance at frequency of 7.81 GHz, 8.54 GHz and 9.42 GHz with gain of 9.67 dB, 10.4 dB and 10.61dB respectively. Parameter of antenna such as return loss, input impedance, smith chart, radiation pattern is analyzed for performance evaluation of Koch fractal Yagi-Uda antenna.DOI:http://dx.doi.org/10.11591/ijece.v3i4.257
Mass spectra of doubly heavy Omega_QQ' baryons
We evaluate the masses of baryons composed of two heavy quarks and a strange
quark with account for spin-dependent splittings in the framework of potential
model with the KKO potential motivated by QCD with a three-loop beta-function
for the effective charge consistent with both the perturbative limit at short
distances and linear confinement term at long distances between the quarks. The
factorization of dynamics is supposed and explored in the nonrelativistic
Schroedinger equation for the motion in the system of two heavy quarks
constituting the doubly heavy diquark and the strange quark interaction with
the diquark. The limits of approach, its justification and uncertainties are
discussed. Excited quasistable states are classified by the quantum numbers of
heavy diquark composed by the heavy quarks of the same flavor.Comment: 14 pages, revtex4-file, 3 eps-figures, 5 tables, typos correcte
Linear Stability of Equilibrium Points in the Generalized Photogravitational Chermnykh's Problem
The equilibrium points and their linear stability has been discussed in the
generalized photogravitational Chermnykh's problem. The bigger primary is being
considered as a source of radiation and small primary as an oblate spheroid.
The effect of radiation pressure has been discussed numerically. The collinear
points are linearly unstable and triangular points are stable in the sense of
Lyapunov stability provided . The effect of
gravitational potential from the belt is also examined. The mathematical
properties of this system are different from the classical restricted three
body problem
Generalized Gravi-Electromagnetism
A self consistant and manifestly covariant theory for the dynamics of four
charges (masses) (namely electric, magnetic, gravitational, Heavisidian) has
been developed in simple, compact and consistent manner. Starting with an
invariant Lagrangian density and its quaternionic representation, we have
obtained the consistent field equation for the dynamics of four charges. It has
been shown that the present reformulation reproduces the dynamics of individual
charges (masses) in the absence of other charge (masses) as well as the
generalized theory of dyons (gravito - dyons) in the absence gravito - dyons
(dyons). key words: dyons, gravito - dyons, quaternion PACS NO: 14.80H
Oilseed brassica in India: Demand, supply, policy perspective and future potential☆
India is the largest agrarian subcontinent supporting 26% world’s agricultural population on 12% arable land. India is also the fifth largest vegetable oil economy accounting 7.4% oilseeds, 5.8% oils and 6.1% oil meal production, and 9.3% of edible oil consumption in the world. Oilseeds are the second most important agricultural economy in India next to cereals growing at a pace of 4.1% per annum in the last three decades. Oilseed brassica shares 23.5% area and 24.2% production of total oilseeds in the country. Despite being the third largest producer (11.3%) of oilseed brassica after Canada and China in the world, India meets 57% of the domestic edible oil requirements through imports and ranked 7th largest importer of edible oils in the world. Oilseed brassica achieved significant growth in India in the past, however, the productivity levels are still low owing to large cultivation under rainfed situation, biotic and abiotic stresses, and resources crunch. It is also facing the challenges of low genotypic potential, climate change and price fluctuation. Though, it embraces the immense scope to increase the production in traditional and non-traditional areas in India with proper inputs, technological interventions, and suitable policy framework. This needs to develop strategies in a well-planned, targeted manner with multi-scientific inputs, policy interface and stable price systems to bring the desired growth in oilseeds brassica production, and to reduce the import of edible oils in the country
Electric field gradients in MgB synthesized at high pressure: Cd TDPAC study and ab initio calculation
We report the high-pressure synthesis of novel superconductor MgB and
some related compounds. The superconducting transition temperature of our
samples of MgB is equal to 36.6 K. The MgB lattice parameters
determined via X-ray diffraction are in excellent agreement with results of our
ab initio calculations. The time-differential perturbed angular correlation
(TDPAC) experiments demonstrate a small increase in quadrupole frequency of
Cd probe with decreasing temperature from 293 to 4.2 K. The electric
field gradient (EFG) at the B site calculated from first principles is in fair
agreement with EFG obtained from B NMR spectra of MgB reported in the
literature. It is also very close to EFG found in our Cd TDPAC
measurements, which suggests that the Cd probe substitutes for boron in
the MgB lattice.Comment: 10 pages, 3 figure
Evaluation of global composite collection reveals agronomically superior germplasm accessions for chickpea improvement
The rich genetic diversity existing within exotic, indigenous, and diverse germplasm lays the foundation for the continuous improvement of crop cultivars. The composite collection has been suggested as a gateway to identifying superior germplasm for use in crop improvement programs. Here, a chickpea global composite collection was evaluated at five locations in India over two years for five agronomic traits to identify agronomically superior accessions. The desi, kabuli, and intermediate types of chickpea accessions differed significantly for plant height (PLHT) and 100-seed weight (100 SW). In contrast, the intermediate type differed substantially from kabuli for days to maturity (DM). Several highly significant trait correlations were detected across different locations. The most stable and promising accessions from each of the five locations were prioritised based on their superior performance over the best-performing check cultivar. Accordingly, the selected germplasm accessions of desi type showed up to 176% higher seed yield (SY), 29% lower flowering time, 21% fewer maturity days, 64% increase in PLHT, and 183% larger seeds than the check cultivar JG11 or Annigeri. The prioritised kabuli accessions displayed up to 270% more yield, 13% less flowering time, 8% fewer maturity days, 111% increase in PLHT, and 41% larger seeds over the check cultivar KAK2. While the intermediate type accessions had up to 169% better yield, 1% early flowering, 3% early maturity, 54% taller plants, and 25% bigger seeds over the check cultivar JG 11 or KAK2. These accessions can be utilised in chickpea improvement programs to develop high-yielding, early flowering, short duration, taller, and large-seeded varieties with a broad genetic base
The Effect of Radiation Pressure on the Equilibrium Points in the Generalised Photogravitational Restricted Three Body Problem
The existence of equilibrium points and the effect of radiation pressure have
been discussed numerically. The problem is generalized by considering bigger
primary as a source of radiation and small primary as an oblate spheroid. We
have also discussed the Poynting-Robertson(P-R) effect which is caused due to
radiation pressure. It is found that the collinear points deviate
from the axis joining the two primaries, while the triangular points
are not symmetrical due to radiation pressure. We have seen that
are linearly unstable while are conditionally stable in the sense of
Lyapunov when P-R effect is not considered. We have found that the effect of
radiation pressure reduces the linear stability zones while P-R effect induces
an instability in the sense of Lyapunov
The Influence of Free Quintessence on Gravitational Frequency Shift and Deflection of Light with 4D momentum
Based on the 4D momentum, the influence of quintessence on the gravitational
frequency shift and the deflection of light are examined in modified
Schwarzschild space. We find that the frequency of photon depends on the state
parameter of quintessence : the frequency increases for and
decreases for . Meanwhile, we adopt an integral power number
() to solve the orbital equation of photon. The photon's
potentials become higher with the decrease of . The behavior of
bending light depends on the state parameter sensitively. In
particular, for the case of , there is no influence on the
deflection of light by quintessence. Else, according to the H-masers of GP-A
redshift experiment and the long-baseline interferometry, the constraints on
the quintessence field in Solar system are presented here.Comment: 12 pages, 2 figures, 4 tables. European Physical Journal C in pres
Relativistic wave equations for interacting massive particles with arbitrary half-intreger spins
New formulation of relativistic wave equations (RWE) for massive particles
with arbitrary half-integer spins s interacting with external electromagnetic
fields are proposed. They are based on wave functions which are irreducible
tensors of rank n=s-\frac12$) antisymmetric w.r.t. n pairs of indices,
whose components are bispinors. The form of RWE is straightforward and free of
inconsistencies associated with the other approaches to equations describing
interacting higher spin particles
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