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VOLUME 14 CODEN : IEMSEW |
NUMBER 2 |
APRIL 2007 ISSN : 0971-4588 |
Engineering
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Thermoelastic analysis of a laminated composite skew plate with a
circular cutout subjected to linearly varying temperature across the
thickness |
95 |
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[IPC Code: C08] |
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Effect of orientation angle of elliptical hole on residual stresses
and expansion of plastic zone in thermoplastic composite plates under
in-plane loading |
103 |
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[IPC Code: B29] |
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Development of potassium-selective ion-sensitive field-effect
transistor (ISFET) by depositing ionophoric crown ether membrane on the gate
dielectric, and its application to the determination of K+-ion
concentrations in blood serum |
112 |
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V K Khanna, S Ahmad, Y K
Jain, M Jayalakshmi, S Vanaja, S S Madhavendra, |
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[IPC Code: C12, C25,
G01, H01L21/535] |
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Practical aspects which affect an electrical measurement |
119 |
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[IPC Code: H03] |
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Fabrication of narrow bandpass filters for wavelength division
multiplexing applications — A feasibility study |
125 |
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[IPC Code: G02B1/10,
G02B2/28] |
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Seismic behaviour of cylindrical elevated tanks
with a frame supporting system on various subsoil |
133 |
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[IPC Code: E03B11/12] |
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Materials Science
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Drying shrinkage of cementitious composites with mineral admixtures |
146 |
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[IPC Code: C04B] |
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Investigation of the low temperature performances of polymer and
fiber modified asphalt mixtures |
151 |
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[IPC Code: C10C] |
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Effect of cement and EPS beads ratios on compressive strength and
density of lightweight concrete |
158 |
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[IPC Code: C04B26/02] |
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Strain induced non-linear conduction in epitaxial La0.7A0.3MnO3
manganite thin films |
163 |
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P S Vachhani, P S
Solanki, J H Markna, R N Parmar, J A Bhalodia & |
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[IPC Code: H01F10/00] |
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Dielectric relaxation studies of binary mixtures of N-methylformamide
and benzonitrile in benzene solution using microwave absorption data |
167 |
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Rajesh Kumar, Nagesh
Thakur, D R Sharma, V S Rangra & N S Negi |
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[IPC Code: G01R27/26] _______________ |
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IPC:
International Patent Classification |
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Int. Cl.8:
International Classification 8th edition, 2006 |
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Indian
Journal of Engineering & Materials Sciences
Vol. 14, April 2007, pp. 95-102
Thermoelastic analysis of a laminated composite skew plate with a circular cutout subjected to linearly varying temperature across the thickness
A V Sudhakar, K Mohana Rao & V Ramachandra Raju
The behaviour of a
laminated composite skew plate with hole subjected to temperature as well as
combined temperature and transverse pressure loading has been investigated. A
finite element method which works on the basis of three-dimensional theory of
elasticity is employed to evaluate the transverse deflection, in-plane stresses
and interlaminar stresses. The results obtained by varying the skew angle and
the hole diameter are discussed. It has been observed that the magnitude of the
stresses and deflection in case of combined loading is more when compared with
the respective values in case of pure thermal loading. The magnitudes of the
transverse deflection and in-plane stresses for combined loading are observed
to be less at higher skew angles, because
the distance between opposite sides of the plate decreases with increase in
skew angle causing for increase in the stiffness of the plate.
The solutions of skew
structures considered in the present analysis will be useful for the construction
of safe and efficient structures like skew bridges and swept wings of aircraft
structures.
IPC Code: C08
Indian
Journal of Engineering & Materials Sciences
Vol. 14, April 2007, pp. 103-111
Effect of orientation angle of elliptical hole on residual stresses and expansion of plastic zone in thermoplastic composite plates under in-plane loading
Mehmet Aktas & Ramazan Karakuzu
In this study, residual stress variations and expansion of plastic zone of woven steel fiber reinforced laminated thermoplastic composite plates with central elliptical hole which is subjected to in-plane loading are investigated for different loads. Numerical simulation is performed using a commercial packet programme ANSYS. To investigate the effects of orientation angle of elliptical hole in the composite laminated plate under various in-plane loads, elliptical hole is rotated from 0° to 90° by 15° increments counterclockwise. The in-plane loads are chosen as 5.5 MPa, 6.0 MPa and 6.5 MPa. Laminated plates are composed of [0/±30/±45/90]2 fiber orientation in symmetric and antisymmetric manner.
IPC Code: B29
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 112-118
Development of potassium-selective ion-sensitive field-effect transistor (ISFET) by depositing ionophoric crown ether membrane on the gate dielectric, and its application to the determination of K+-ion concentrations in blood serum
V K Khanna, S Ahmad, Y K Jain, M Jayalakshmi, S Vanaja, S S
Madhavendra,
s v Manorama & M
Lakshmi Kantam
This paper reports the fabrication and characterization of potassium ISFET (ion-sensitive field-effect transistor) by deposition of a crown ether layer on the gate. This ISFET is referred to as potassium MEMFET (membrane field-effect transistor) or potassium-selective MEMFET device. Calibration of ISFET in standard KCl solutions has shown that the sensitivity of crown ether-ISFET towards potassium (2.3 mV/mg/L) was approximately double that of the nitride-gate ISFET (1 mV/mg/L) in the 100-400 mg/L range. The mechanism of ISFET potassium sensitivity enhancement by the ionophoric crown ether layer on the gate has been explained. Use of the device for potassium concentration measurements in human blood serum has been demonstrated. The distribution of potassium ion concentrations (151-210 mg/L) in a series of human blood serum samples has been determined from the reference value obtained by atomic absorption spectroscopy and the ISFET sensitivity measured with KCl solutions. These diluted samples showed a constant pH ~ 7.0-7.1, confirming the maintenance of pH within close tolerance by the human body; therefore any errors due to pH variation amongst the samples were eliminated. Sensitivity of the ISFET with/without crown ether coating on the gate towards sodium ions (0.34 mV/mg/L) has been found to be comparatively less than that of the crown ether ISFET for potassium, showing that sodium ions in blood serum do not interfere with the measurements.
IPC Code: C12, C25, G01, H01L21/335
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 119-124
Practical aspects which affect an electrical measurement
K B Ravat & S K Mahajan
This paper focuses on some of the practical considerations for electrical measurement. Though these are not measurement techniques but have a very significant effect on precision measurement. Some of these are leakage currents, thermal effects, contact resistance, transients, grounding, shielding, earthing, guarding and drift. The precision measurement depends on control of all these important but sometimes subtle factors.
IPC Code: H03
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 125-132
Fabrication of narrow bandpass filters for wavelength
division multiplexing applications – A feasibility study
A Basu, K M K Srivatsa, T K Chakraborty & T K Bhattacharya
Thin film multilayer narrow bandpass interference filters are widely used in wavelength division multiplexing (WDM) applications in fibre optic communication systems. These filters must have sharp cut-on and cut-off on either side of the passband and practically zero transmittance outside the passband, over the wavelength range of the application. In an effort to demonstrate the feasibility of fabrication of WDM filters, the simpler designs for these filters (involving deposition of multilayers with 30-35 layers) have been examined and their fabrication has been demonstrated using a vacuum coating system with limited capabilities, at several wavelengths in the range of interest. This experience has shown that with the use of modern vacuum coating plants equipped with sophisticated coating and monitoring facilities, the fabrication of WDM filters with more complex designs and meeting commercial specifications [at least coarse WDM (CWDM) filters with somewhat less stringent specifications] can be a feasible proposition.
IPC Code: G02B 1/10, G02B 5/28
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 133-145
Seismic behaviour of cylindrical elevated
tanks with a frame supporting
system on various subsoil
Ramazan
Livaoglu & Adem Dogangun
The seismic responses of an elevated tank with a frame supporting system on various subsoils are investigated. The finite element method is used for the modelling of the elevated tank and subsoil system. Fixed-base and elastic media assumptions are made for subsoil. The tank fluid has been modelled as lumped masses such as impulsive and convective masses proposed by Housner. An added mass approach is used for fluid-structure interaction by representing both the impulsive mass and the convective mass. For estimating the seismic response of elevated tanks, response spectrum analysis with mode superposition is used. The results obtained from modelling the elevated tanks on a fixed base and on an elastic medium are compared. It has been observed that the seismic response of the elevated tank is altered significantly depending on the properties of the subsoil. The soil-structure interaction especially affects the impulsive modes and lateral displacement of elevated tanks rather than the torsional modes. It is proposed that the coupling effect for perpendicular directions in the axisymmetrical plan geometry should be considered in the seismic design of the elevated tanks.
IPC Code: E03B11/12
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 146-150
Drying shrinkage of cementitious composites with mineral admixtures
R Malathy & K Subramanian
This paper emphasises on the influence of mineral admixtures (MA) like silica fume, metakaoline and fly ash on the drying shrinkage of cement mortars incorporated with MA as cement replacement material. MA has been varied at different percentages from 0 to 15% at the constant increment of 5%. The water-binder (cement + MA) ratio and binder-sand ratios are 0.5 and 1:3 respectively. The short-term and long-term ultimate drying shrinkage of mortar has been studied. The effect of size of sand particles has been studied with different sizes of particles fractions. The highest drying shrinkage has been observed in mortars with higher silica fume contents at the age of 28 days. At the early ages, this has been due to the high pozzolanic reaction of silica fume, as a result of pore-size refinement mechanism of silica fume. However, the effect of silica fume has not been significant on the long-term drying shrinkage. The effect of grain size demonstrates that the ultimate drying shrinkage decreases as the size of sand particles increases.
IPC Code: C04B
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 151-157
Investigation of the low temperature performances of polymer
and fiber modified asphalt mixtures
Yuksel Tasdemir & Emine Agar
In this study, effects of
polymer and fiber modification on low temperature properties of bituminous
mixtures were studied. One aggregate, one asphalt binder type, three additives
(polymer, synthetic fiber and loose cellulose fiber) and three
IPC Code: C10C
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 158-162
Effect of cement and EPS beads ratios on compressive
strength and
density of lightweight concrete
Abdulkadir Kan & Ramazan Demirboğa
The compressive strengths and slump values of concretes made up of mixtures of expanded polystyrene (EPS) beads and cement were investigated. To determine the effect of Portland cement (PC)/EPS ratio, on the compressive strength of EPS concrete, 1/0 (control sample), 1:4, 1:2, 3:4 and 1:1 mix proportion by volume were used. EPS beads content for the mixtures were kept constant at 0.05 m3. The analysis of the test results leads to the conclusion that with the increase of cement to EPS beads ratio in the mixes, both density and compressive strength of concretes increased up to 4 and 350 times respectively, when compared to the control sample. Hardened concrete densities and compressive strength varied from 464 to 1940 kg/m3, and 0.11 to 38.50 MPa, respectively. Slump values of the mixes were changed from 8 to 43 mm.
IPC Code: C04B26/02
Indian
Journal of Engineering & Materials Sciences
Vol. 14, April 2007, pp. 163-166
Strain induced non-linear conduction in epitaxial La0.7A0.3MnO3
manganite thin films
P S Vachhani, P S Solanki, J H Markna, R N Parmar, J A Bhalodia & D G Kuberkar
In this paper, the current-voltage (I-V) properties of La0.7A0.3MnO3 (A = Ca, Sr, Ba) manganite thin films grown on single crystalline LAO (100) substrate using chemical solution deposition (CSD) technique have been reported. Epitaxial nature of all the films has been confirmed from XRD measurements. The I-V measurements carried out on La0.7Ba0.3MnO3 (LBMO) films show an unusual non-linear transport behaviour contrary to that observed for La0.7Ca0.3MnO3 (LCMO) and La0.7Sr0.3MnO3 (LSMO) films. This non-linearity has been explained in terms of non-uniform strain distribution resulting due to mismatch in the lattice parameters of LBMO film and substrate. The conductance data for all the films have been fitted using Simmon’s model and the possible mechanism of charge conduction in the films has been discussed.
IPC Code: H01F10/00
Indian
Journal of Engineering & Materials Sciences
Vol.
14, April 2007, pp. 167-172
Dielectric relaxation studies of binary mixtures of N-methylformamide and benzonitrile in benzene solution using microwave absorption data
Rajesh Kumar, Nagesh Thakur, D R Sharma, V S Rangra & N S Negi
Using standard standing wave microwave techniques and following the single frequency (9.885 GHz) concentration variational method, the dielectric relaxation time (τ) and dipole moment (μ) of binary mixtures of different molar concentrations of N-methylformamide (NMF) in the binary mixtures of N-methylformamide (NMF) and benzonitrile (C6H5CN) in benzene solutions have been calculated at different temperatures (25, 30, 35 and 40°C). The energy parameters (ΔHε, ΔFε, ΔSε) for the dielectric relaxation process of binary mixtures containing 50 mol% of NMF have been calculated at different temperatures and comparison has been made with the corresponding energy parameters (ΔHη, ΔFη, ΔSη) for the viscous flow process. Based on these studies, it is inferred that dielectric relaxation process can be treated as a rate process just like the viscous flow process. Solute-solvent molecular associations have been proposed.
IPC Code: G01R27/26