Aanandan,C K; Mohanan, P; Vasudevan, K; Shynu, S V; Gijo,Augustin(Department of Electronics, 2004)
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Abstract:
A novel design of a computer electronically reconfigurable dual frequency dual polarized single feed hexagonal slot loaded microstrip antenna in L-band is introduced in this chapter. pin diodes are used to switch the operating frequencies considerably without much affecting the radiation characteristics and gain. the antenna can work with a frequency ratio varying in the wide range from 1.2 to 1.4. the proposed design has an added advantage of size reduction up to 72.21% and 46.84% for the two resonating frequencies compared to standard rectangular patches. the design also gives considerable bandwidth of up to 2.82% and 2.42 % for the operating frequencies.
Manju,Paulson; Sona,Kundukulam O; Aanandan,C K; Mohanan, P; Vasudevan, K(Microwave and Optical Technology Letters, October 28, 2002)
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Abstract:
An arrow-shaped microstrip antenna with a pair of narrow
slots embedded near the non-radiating edges gives wide impedance bandwidth.
The experimental and simulated (!E3D) results show that antenna
bandwidth is -3.5 times that of a conventional patch with the added advantage
of reduced antenna size. The radiation characteristics are found to he uniform throughout the operating band
Mridula, S; Shameena, V A; Aanandan,C K; Mohanan, P; Vasudevan, K; Jacob, S(IEEE, September , 2011)
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Abstract:
A Coplanar waveguide fed compact planar
monopole antenna with a modified ground plane is presented.
Measured and simulated results reveal that the antenna operates
in the Ultra Wide Band with almost constant group delay
throughout the band. Developed design equations of the antenna
are validated for different substrates. Time domain performance
of the antenna is also discussed in order to assess its suitability
for impulse radio applications
Description:
General Assembly and Scientific Symposium, 2011 XXXth URSI
Dongsheng,Qi; Binhong,Li; Yabin,Zhang; Haitao,Liu(Microwave and Optical Technology Letters, February 3, 2004)
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Abstract:
A novel compact single-layer dual frequency microstrip
antenna which uses an H-shaped geometry with two U-shaped slots embedded
near the radiation edges, is presented. By changing the design parameters, the lower and higher resonant frequencies can be controlled
easily, and a range of frequency ratios (1.716-2.363) can be
obtained in this design. For the two operating frequencies of the proposed
antenna, the same polarization planes and broadside radiation
patterns are achieved. Compared to the regular dualfrequency patch
antenna, this antenna can realize a significant size reduction
Thomas, Paulbert; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Wiley InterScience, October , 2010)
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Abstract:
Design of a compact microstrip-fed ultra-wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni-directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 × 30 mm2 on FR4 substrate with permittivity 4.4.
A compact single –feed multiband planar antenna configuration
Suitable for GPS, DCS. 2.4/5.8 GHz WLAN applications are presented.
The antenna has dimensions 38 x 3 x 1.6 mm and offers good
radiation and reflection characteristics in the above frequency bands.
The antenna has a simple geometry and can be easily fed using a 50
coaxial probe
Mohanan, P; Raj,R K; Joseph,M; Paul,B(Department of Electronics, March 17, 2000)
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Abstract:
A compact single - feed muttiband planar antenna configuration suitable
for GPS, DCS. 2.4/5.8 GHz WLAN applications is presented.
The antenna has dimensions 38 x 3 x 1.6 mm and offers good
radiation and reflection characteristics in the above frequency bands.
The antenna has a simple geometry and can be easily fed using a 50
coaxial probe.
A dual band RFID applications in 800 900
MHz and 2400 MHz band is presented. The
Asymmetric Coplanar Strip (ACS) fed antenna
consists of inverted L shaped monopole with a
capacitive loading to provide necessary impedance
matching and current distribution. The antenna has
wide bandwidth from 790 MHz tol050 MHz and
from 2350 MHz to 2640 MHz coving the RFID UHF
and Microwave frequencies. The uniplanar antenna
having overall dimensions of 48 mm x 14 mm is
printed on one side of a substrate of dielectric
constant 4.4 and height 1.6 mm.
Description:
Recent Advances in Microwave Theory and Applications, 2008. MICROWAVE 2008. International Conference on
Deepu, V; Rohith, K R; Manoj, J; Suma,M N; Vasudevan, K; Aanandan,C K; Mohanan, P(Electronics Letters, January 18, 2007)
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Abstract:
A compact dual-band uniplanar antenna for operation in the 2.4/5.2/5.8 GHz WLAN/HIPERLAN2 communication bands is presented. The dual-band antenna is obtained by modifying one of the lateral strips of a slot line, thereby producing two different current paths. The antenna occupies a very small area of 14.5times16.6 mm2 including the ground plane on a substrate having dielectric constant 4.4 and thickness 1.6 mm at 2.2 GHz. The antenna resonates with two bands from 2.2 to 2.52 GHz and from 5 to 10 GHz with good matching, good radiation characteristics and moderate gain
Binu, Paul; Mridula, S; Mohanan, P; Bijumon, P V; Sebastian,M T(Microwave and Optical Technology Letters, October 20, 2004)
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Abstract:
very-high-permittivity (e, = 100) multiband dielectrice>
e resonator antenna is presented. The compact antenna, excited by a
m:'crostrip line, resonates at two frequencies centered around the 1.9-
GHz and 2.4-GHz bands with identical polarization . The behavior of the
antenna at different positions along the feed line is studied and optimized.
Multiple resonances with the same polarization and broad radioticn
patterns suggest the suitability of the antenna for multiband wireless
application
Mohanan, P; Joseph,M; Paul,B; Raj,R K(Department of Electronics, November 11, 2004)
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Abstract:
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band is presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of -5 dBi. The antenna can be excited
directly using a 50 coaxial probe
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band are presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of~5 dBi. The antenna can be excited
directly using a 50 coaxial probe
Bright Singh, I S; Shibu, K Mani; Ranjit, Kanjur; Robert, Reed H(Elsevier, November 23, 2005)
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Abstract:
This study investigated the enhancement of solar disinfection using custom-made batch
reactors with reflective (foil-backed) or absorptive (black-backed) rear surfaces, under a
range of weather conditions in India. Plate counts of Escherichia coli ATCC11775 were made
under aerobic conditions and under conditions where reactive oxygen species (ROS) were
neutralised, i.e. in growth medium supplemented with 0.05% w/v sodium pyruvate plus
incubation under anaerobic conditions. While the addition of either an absorptive or a
reflective backing enhanced reactor performance under strong sunlight, the reflective
reactor was the only system to show consistent enhancement under low sunlight, where
the process was slowest. Counts performed under ROS-neutralised conditions were slightly
higher than those in air, indicating that a fraction of the cells become sub-lethally injured
during exposure to sunlight to the extent that they were unable to grow aerobically.
However, the influence of this phenomenon on the dynamics of inactivation was relatively
small
There is a growing commercial interest in the ¢sh,
Puntius ¢lamentosus, in the ornamental ¢sh trade in
India and elsewhere.The trade is, however, hampered
by severe mortalities during transport of the ¢sh owing
to insu⁄cient data available on the use of anaesthetics.
To resolve this problem, we evaluated the
e⁄cacy of two anaesthetics, MS-222 and benzocaine,
in sedating P. ¢lamentosus in simulated transportation
experiments and used stress response parameters
such as cortisol and blood glucose levels to
perform assessments. We observed that MS-222 at
40 mg L 1 and benzocaine at 20mg L 1 were su⁄-
cient to induce sedation for 48 h. Above these concentrations,
both the anaesthetics adversely a¡ected
the ¢sh and resulted inmortalities. Both anaesthetics
signi¢cantly lowered the blood cortisol and glucose
levels compared with the unsedated controls. Importantly,
the anaesthetics treatment signi¢cantly lowered
the post-transport mortality in the ¢sh.
The results of the study show that MS-222 and benzocaine
could be used as sedatives to alleviate transport-
related stress in P. ¢lamentosus to improve
their post-transport survival and hence reduce
economic loss.
Jinesh, Mathew; Mahesh, V V; Radhakrishnan, P(International Frequency Sensor Association, August , 2008)
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Abstract:
The design and fabrication of fiber based ammonia sensors employing Bromothymol blue
and Chitosan as sensing elements are presented in this paper. In the presence of ammonia gas the
absorption of Bromothymol blue changes while in the case of Chitosan the refractive index changes
which in turn modulates the intensity of light propagating through a fiber.
Sumam, Mary Idicula; Mohanty, U C; Litta, A J(November , 2011)
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Abstract:
Severe local storms, including tornadoes, damaging hail and wind gusts, frequently occur over the eastern and northeastern states of India during the pre-monsoon season (March-May). Forecasting thunderstorms is one of the most difficult tasks in weather prediction, due to their rather small spatial and temporal extension and the inherent non-linearity of their dynamics and physics. In this paper, sensitivity experiments are conducted with the WRF-NMM model to test the impact of convective parameterization schemes on simulating severe thunderstorms that occurred over Kolkata on 20 May 2006 and 21 May 2007 and validated the model results with observation. In addition, a simulation without convective parameterization scheme was performed for each case to determine if the model could simulate the convection explicitly. A statistical analysis based on mean absolute error, root mean square error and correlation coefficient is performed for comparisons between the simulated and observed data with different convective schemes. This study shows that the prediction of thunderstorm affected parameters is sensitive to convective schemes. The Grell-Devenyi cloud ensemble convective scheme is well simulated the thunderstorm activities in terms of time, intensity and the region of occurrence of the events as compared to other convective schemes and also explicit scheme
Description:
International Journal of Computer Applications (0975 – 8887)
Volume 33– No.6, November 2011
Kailasnath, M; John, P R; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(Elsevier, 2008)
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Abstract:
This study was conducted to identify the concentration dependence of the operating wavelengths and the relative intensities in which a dye
mixture doped polymer optical fibre can operate. A comparative study of the radiative and Forster type energy transfer processes in Coumarin
540:Rhodamine 6G, Coumarin 540:Rhodamine B and Rhodamine 6G:Rhodamine B in methyl methacrylate (MMA) and poly(methyl methacrylate)
(PMMA) was done by fabricating a series of dye mixture doped polymer rods which have two emission peaks with varying relative intensities.
These rods can be used as preforms for the fabrication of polymer optical fibre amplifiers operating in the multi-wavelength regime. The 445 nm
line from an Nd:YAG pumped optical parametric oscillator (OPO) was used as the excitation source for the first two dye pairs and a frequency
doubled Nd:YAG laser emitting at 532 nm was used to excite the Rh 6G:Rh B pair. The fluorescence lifetimes of the donor molecule in pure
form as well as in the mixtures were experimentally measured in both monomer and polymer matrices by time-correlated single photon counting
technique. The energy transfer rate constants and transfer efficiencies were calculated and their dependence on the acceptor concentration was
analysed. It was found that radiative energy transfer mechanisms are more efficient in all the three dye pairs in liquid and solid matrices.
Jinesh, Mathew; Thomas, K J; Nampoori, V P N; Radhakrishnan, P(IFSA, 2007)
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Abstract:
A comparative study of two biopolymer based fiber optic humidity sensors is presented in this paper. Sensing elements Agarose and Chitosan swells in the presence of water vapour and undergoes changes in refractive index and modulates the intensity of light propagating through a fiber with Agarose or Chitosan as cladding.