Jacob, Philip; Alex,A V(Indian Academy of Sciences, January , 2004)
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Abstract:
Certain organic crystals are found to possess high non- linear optical coefficients,often one to two orders of magnitude higher than those of the well known inorganic non-linear optical materials.Benzoyl glycine is one such crystal whose optical second-harmonic generation efficiency is much higher than that of potassium dihydrogen phosphate. Single crystals of benzoyl glycine are grown by solvent evaporation technique using N,N-dimethyl formamide as the solvent.All the nine second-order elastic stiffness constants of this orthorhombic crystal are determined from ultrasonic wave velocity measurements employing the pulse echo overlap technique.The anisotropy of elastic wave propagation in this crystal is demonstrated by plotting the phase velocity, slowness,Young's modulus and linear compressibility surfaces along symmetry planes.The volume compressibility, bulk modulus and relevant Poisson's ratios are also determined. Variation of the diagonal elastic stiffness constants with temperature over a limited range are measured and reported.
Kannan, Balakrishnan; Simily, Joseph; Balachandran Nair, M R; Reji, Rajan Varghese(MECS, May , 2013)
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Abstract:
Speckle noise formed as a result of the coherent nature of ultrasound imaging affects the lesion detectability. We have proposed a new weighted linear filtering approach using Local Binary Patterns (LBP) for reducing the speckle noise in ultrasound images. The new filter achieves good results in reducing the noise without affecting the image content. The performance of the proposed filter has been compared with some of the commonly used denoising filters. The proposed filter outperforms the existing filters in terms of quantitative analysis and in edge preservation. The experimental analysis is done using various ultrasound images
Description:
I.J. Information Technology and Computer Science, 2013, 06, 1-9
Deepti Das, Krishna; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Electronics Letters, August , 2008)
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Abstract:
An ultra-wideband (UWB) printed slot antenna, suitable for integration with the printed circuit board (PCB) of a wireless universal serial-bus (WUSB) dongle is presented. The design comprises a near-rectangular slot fed by a coplanar waveguide printed on a PCB of width 20 mm. The proposed design has a large bandwidth covering the 3.1-10.6 GHz UWB band, unaffected by the ground length, and omnidirectional radiation patterns. A linear phase response throughout the band further confirms its suitability for high-speed wireless connectivity.
Deepti Das, Krishna; Gopikrishna, M; Aanandan,C K; Mohanan, P; Vasudevan, K(Wiley InterScience, June , 2009)
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Abstract:
A compact ultra-wideband (UWB) printed slot antenna is described, suitable for integration with the printed circuit board (PCB) of a wireless, universal, serial-bus dongle. The design comprises of a near-rectangular slot fed by a coplanar waveguide (CPW) printed on a PCB of size 20 × 30 mm2. It has a large bandwidth covering the 3.1–10.6 GHz UWB band, with omnidirectional radiation patterns. Further, a notched band centered at 5.45 GHz wireless local area network bands is obtained within the wide bandwidth by inserting a narrow slot inside the tuning stub. Details of the antenna design are described, and the experimental results of the constructed prototype are presented. The time domain studies on the antenna shows a linear phase response throughout the band except at the notched frequency. The transient analysis of the antenna indicates very little pulse distortion confirming its suitability for high speed wireless connectivity.
Kannan, Balakrishnan; Jomy, John; Pramod, K V(Elsevier, December 31, 2012)
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Abstract:
This paper presents the application of wavelet processing in the domain of handwritten character recognition. To
attain high recognition rate, robust feature extractors and powerful classifiers that are invariant to degree of variability
of human writing are needed. The proposed scheme consists of two stages: a feature extraction stage, which is based
on Haar wavelet transform and a classification stage that uses support vector machine classifier. Experimental results
show that the proposed method is effective
Harikrishnan, K P; Nandakumaran, V M(Elsevier, December 7, 1987)
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Abstract:
We study the period-doubling bifurcations to chaos in a logistic map with a nonlinearly modulated parameter and show that the bifurcation structure is modified significantly. Using the renormalisation method due to Derrida et al. we establish the universal behaviour of the system at the onset of chaos.
Louis, Godfrey; Santhosh Kumar, A(Society of Photo-Optical Instrumentation Engineers, 2008)
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Abstract:
The red cells found in the red rain in Kerala, India are now considered as a possible case of extraterrestrial life form.
These cells can undergo rapid replication even at an extreme high temperature of 300 deg C. They can also be cultured in
diverse unconventional chemical substrates. The molecular composition of these cells is yet to be identified. This paper
reports the unusual autofluorescence characteristic of the cultured red rain cells. A spectrofluorimetric study has been
performed to investigate this, which shows a systematic shift of the fluorescence emission peak wavelength as the
excitation wavelength is increased. Conventional biomolecules are not known to have this property. Details of this
investigation and the results are discussed.
Anantharaman, M R; Al-Harthi, S H; Mohammed, Elzain; Muataz, Al-Barwani; Amal, Kora'a; Thomas, Hysen; Myo, Tay Zar Myint(Springer, 2012)
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Abstract:
Roughness and defects induced on few-layer graphene (FLG) irradiated by Ar+ ions at different energies were
investigated using X-ray photoemission spectroscopy (XPS) and atomic force microscopy techniques. The results
provide direct experimental evidence of ripple formation, sp2 to sp3 hybridized carbon transformation, electronic
damage, Ar+ implantation, unusual defects and edge reconstructions in FLG, which depend on the irradiation
energy. In addition, shadowing effects similar to those found in oblique-angle growth of thin films were seen.
Reliable quantification of the transition from the sp2-bonding to sp3-hybridized state as a result of Ar+ ion irradiation
is achieved from the deconvolution of the XPS C (1s) peak. Although the ion irradiation effect is demonstrated
through the shape of the derivative of the Auger transition C KVV spectra, we show that the D parameter values
obtained from these spectra which are normally used in the literature fail to account for the sp2 to sp3 hybridization
transition. In contrast to what is known, it is revealed that using ion irradiation at large FLG sample tilt angles can
lead to edge reconstructions. Furthermore, FLG irradiation by low energy of 0.25 keV can be a plausible way of
peeling graphene layers without the need of Joule heating reported previously
Description:
Al-Harthi et al. Nanoscale Research Letters 2012, 7:466
Rani, Joseph(OPA (Overseas Publishers Association), May 28, 1995)
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Abstract:
Amine Terminated Liquid Natural Rubber (ATNR) was used as a plasticiser in filled NR and NBR
compounds replacing oil/DOP. The scorch time and cure time were found to be lowered when ATNR
was used as the plasticiser. ATNR was found to improve the mechanical properties like tensile strength,
tear strength and modulus of the vulcanizates . The ageing resistance of the vulcanizates containing ATNR
was superior compared to the vulcanizates containing oil/DOP.
Radhakrishnan, P; Nampoori, V P N; Girijavallabhan, C P; Nibu, A George; George, A K(Applied Physics B Lasers and Optics, July 18, 2001)
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Abstract:
In this paper, we describe the use of an open cell
photoacoustic configuration for the evaluation of the thermal
effusivity of liquid crystals. The feasibility, precision and reliability
of the method are initially established by measuring
the thermal effusivities of water and glycerol, for which the
effusivity values are known accurately. In order to demonstrate
the use of the present method in the thermal characterization
of liquid crystals, we have measured the thermal
effusivity values in various mesophases of 4-cyano-4 -
octyloxybiphenyl (8OCB) and 4-cyano-4 -heptyloxybiphenyl
(7OCB) liquid crystals using a variable temperature open
photoacoustic cell. A comparison of the measured values for
the two liquid crystals shows that the thermal effusivities of
7OCB in the nematic and isotropic phases are slightly less
than those of 8OCB in the corresponding phases
V P N Nampoori; Radhakrishnan, P; Girijavallabhan, C P; Nibu, A George; George, A K(Applied Physics B Lasers and Optics, June 18, 2001)
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Abstract:
In this paper, we describe the use of an open cell
photoacoustic configuration for the evaluation of the thermal
effusivity of liquid crystals. The feasibility, precision and reliability
of the method are initially established by measuring
the thermal effusivities of water and glycerol, for which the
effusivity values are known accurately. In order to demonstrate
the use of the present method in the thermal characterization
of liquid crystals, we have measured the thermal
effusivity values in various mesophases of 4-cyano-4 -
octyloxybiphenyl (8OCB) and 4-cyano-4 -heptyloxybiphenyl
(7OCB) liquid crystals using a variable temperature open
photoacoustic cell. A comparison of the measured values for
the two liquid crystals shows that the thermal effusivities of
7OCB in the nematic and isotropic phases are slightly less
than those of 8OCB in the corresponding phases
Girijavallabhan, C P; Radhakrishnan, P; Nampoori, V P N; Nibu, A George; George, A K(Applied Physics B Lasers and Optics, July 18, 2001)
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Abstract:
In this paper, we describe the use of an open cell
photoacoustic configuration for the evaluation of the thermal
effusivity of liquid crystals. The feasibility, precision and reliability
of the method are initially established by measuring
the thermal effusivities of water and glycerol, for which the
effusivity values are known accurately. In order to demonstrate
the use of the present method in the thermal characterization
of liquid crystals, we have measured the thermal
effusivity values in various mesophases of 4-cyano-4 -
octyloxybiphenyl (8OCB) and 4-cyano-4 -heptyloxybiphenyl
(7OCB) liquid crystals using a variable temperature open
photoacoustic cell. A comparison of the measured values for
the two liquid crystals shows that the thermal effusivities of
7OCB in the nematic and isotropic phases are slightly less
than those of 8OCB in the corresponding phases
Carboxy Terminated Liquid Natural Rubber (CTNR) was
prepared by photochemical reaction using maleic anhydride and masticated
natural rubber (NR). The use of CTNR as an adhesive in bonding rubber to
rubber and rubber to metal was studied. The peel strengths and lap shear
strengths of the adherends which were bonded using CTNR were determined.
The effect of using a tri isocyanate with CTNR in rubber to metal bonding was
also studied. It is found that CTNR can effectively be used in bonding rubber to
rubber and rubber to mild steel.
This paper studies the use of E•rescurces by the faculty and research
scholars of Cochin University of Science and TechnologytI'he: use of E resources
under INDEST.consortinm;_UGC.lnfonet :project,.and the
databases.subscribed.to.in theCUSAT Library are.studied.in the.survey,
The:survey•covers various aspects jike.awareness-of the .users, user
satisfaction, use pattem of Eoresources,preferenee.for print or electronic
version.etc. The problems-faced-are stressed :and possible solutions are
suggested
Bright Singh, I S; Rosamma, Philip(Central ^Aarine Fisheries Research Institute, November , 2002)
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Description:
Winter School on
'RECENT ADVANCES IN
DIAGNOSIS AND
MANAGEMENT OF DISEASES
IN MARICULTURE'
7-27 November, 2002
Course Manual Indian Council of Agricultural Research
Central ^Aarine Fisheries Research Institute
Nampoori, V P N; Vallabhan, C P G; George, A K; Radhakrishnan, P; Rajasree, K; Vidyalal, V(Elsevier, July , 1998)
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Abstract:
he phenomenon of single beam mirage effect, otherwise known as photothermal deflection (PTD) effect using a He–Ne laser beam has been employed to detect phase transitions in some liquid crystals. It has been observed that anomalous changes in amplitude occur in the PTD signal level near the transition temperature. The experimental details and the results of measurements made in liquid crystals E8, M21 and M24 are given in this paper.
Rajasree, K; Vidyalal, V; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(IOP, 1993)
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Abstract:
The phenomenon of mirage effect suffered by a He-Ne laser beam has been utilized to detect phase transitions in solids. It has been observed that anomalous fluctuations of large amplitude occur in the signal level near the transition temperature. The mean square value of the fluctuation is found to exhibit a well-defined peak at this point. Results of measurements made in the case of crystals of TGS ((NH2CH2COOH)3.H2SO4) and a ceramic sample (BaTiO3) are given to illustrate this technique.
Sheena, Mathew; Poulose Jacob,K(International Journal of Computer and Information Engineering, 2008)
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Abstract:
Extensive use of the Internet coupled with the
marvelous growth in e-commerce and m-commerce has created a
huge demand for information security. The Secure Socket Layer
(SSL) protocol is the most widely used security protocol in the
Internet which meets this demand. It provides protection against
eaves droppings, tampering and forgery. The cryptographic
algorithms RC4 and HMAC have been in use for achieving security
services like confidentiality and authentication in the SSL. But recent
attacks against RC4 and HMAC have raised questions in the
confidence on these algorithms. Hence two novel cryptographic
algorithms MAJE4 and MACJER-320 have been proposed as
substitutes for them. The focus of this work is to demonstrate the
performance of these new algorithms and suggest them as dependable
alternatives to satisfy the need of security services in SSL. The
performance evaluation has been done by using practical
implementation method.