Indian Journal of Engineering & Materials Science

 


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VOLUME 12

CODEN : IEMSEW

NUMBER 6

DECEMBER 2005

ISSN : 0971-4588

 

CONTENTS

Engineering 

A new design proposal for intelligent routers to avoid congestion in TCP/IP networks

481

        Ramachandra V Pujeri & S N Sivanandam

 

        [IPC Code: G06F 13/42, H04L]

 

 

 

CFD study of isothermal flow in an afterburner system

487

        S Ganesan, S Kishore Kumar & V Ganesan

 

        [IPC Code: F15D]

 

 

 

A novel concept in the design of a psychrometer

498

        Sunit Kumar Sen

 

        [IPC Code: G01N 25/62]

 

 

 

Optimizing diesel engine parameters for emission reduction using Taguchi method: variation risk analysis approach – Part II

505

        M Nataraj, V P Arunachalam & N Dhandapani

 

        [IPC Code: F02B]

 

 

 

Influence of shot peening intensity on fatigue design reliability of 65Si7 spring steel

515

        M L Aggarwal, R A Khan & V P Agrawal

 

        [IPC Code: C22F 1/00, G01N 3/00]

 

 

 

Flexural vibrations of non-homogeneous elliptic plates

521

        S Chakraverty, Ragini Jindal & V K Agarwal

 

        [IPC Code: G01H]

 

 

 

Materials Science

 

 

 

Carbon nanotube and its possible applications

529

        Zishan Husain Khan & M Husain

 

        [IPC Code: B82B]

 

 

A comparative analysis of PBZT synthesized by co-precipitation and sol-gel method

552

        P Goel & K L Yadav

 

        [IPC Code: G01N 33/38]

 

Relative role of plasticizer and nano size fumed silica on the conductivity behaviour of PEO-NH4PF6 polymer electrolytes

557

        Jitender Paul Sharma & S S Sekhon

 

        [IPC Code: C08L 23/04]

 

 

Mechanical properties of glass/palmyra fiber waste sandwich composites

563

        R Velmurugan & V Manikandan

 

        [IPC Code: C03C 14/00]

 

 

 

Calorimetric studies of thermal crystallization in glassy Se80Te20 and Se80In20 alloys

571

        N Mehta, V S Kushwaha & A Kumar

 

        [IPC Code: C22C 29/00]

 

 

 

Effect of annealing temperature on the magnetic behaviour of Ni-rich permalloy magnetic materials

577

        Kiran Gupta, K K Raina & S K Sinha

 

        [IPC Code: C22C 19/03, G01R]

 

 

 

Phase transition in Pb[(Mg3/4Cu1/4)1/3Nb2/3]O3 ceramic

586

        Amit Kumar, K Prasad, S N Choudhary & T P Sinha

 

        [IPC Code: C04B 33/00, G01N 33/38]

 

 

 

Laser light scattering microscopy : Interpretation of images

591

        P B V Prasad & P B Shashikanth

 

        [IPC Code: G01N 13/10]

 

__________________

 

IPC: International Patent Classification

 

Int. Cl.7: International Classification 7th edition, 1999

 

  

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 481-486

 A new design proposal for intelligent routers to avoid congestion in TCP/IP networks
Ramachandra V Pujeri & S N Sivanandam
 

In this paper, the various methods to detect network congestion and a method to avoid and recover from such congestion are discussed. This is a proposal to embed intelligence within routers, which will enable them to periodically check each of their communication paths for congestion and correspondingly update their router table and heuristic knowledge base. This is done using a new artificial intelligence concept called the software agents. This method provides a level of abstraction thereby minimizing the visible complexity, so that the source and destination can be designed more easily.
IPC Code
: G06F13/42, H04L

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 487-497

 

CFD study of isothermal flow in an afterburner system
S Ganesan, S Kishore Kumar & V Ganesan

This paper focuses a detailed numerical prediction of non-reacting flow analysis in a practical 1/3 scaled model gas turbine afterburner system. The analysis is performed using SIMPLE algorithm in a body-fitted multi-block grid using STAR-CD software. The turbulence is simulated using standard k-e model. The validation of software is carried out in a afterburner model by comparing axial, radial and circumferential velocities at various axial locations. The agreement between the prediction and experimental data are quite reasonable. The analysis is extended to the flow in a practical afterburner system. The afterburner system consists of an annular diffuser, a complex three-dimensional flame stabilizer, a liner with chute, screech and cooling rings holes and a convergent nozzle. The wall static pressures are compared with experimental data obtained from rig results for both core and bypass casing. The agreement between CFD prediction and experimental data are in close agreement. The predicted length of the re-circulation zone of the lower radial gutter is larger (2.7 times width of the gutter) than upper radial gutter, which is about 2.3 times width. This is due to combined effect of annular diffuser and lower radial gutter. But the length of the re-circulation zone of the annular ring is slightly less than (0.94 times) the width of the v-gutter. The effect of different mass flow rates on the afterburner performance is also evaluated and it is observed that mass flow rate does not affect the re-circulation zone characteristics. An increase of 20% in mass flow rate increases the exit nozzle velocity by 35%.

IPC Code: F15D

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 498-504

 A novel concept in the design of a psychrometer
 
Sunit Kumar Sen 

A novel psychrometric method for measurement of humidity of a process is proposed. The design of a psychrometer is a complex one due to simultaneous introduction of two variables at the same time, viz., the meter current is dependent on both the relative humidity and ambient temperature. The circuit design has been so made that the said current would depend only on the relative humidity of air and independent of temperature variations at the place of measurement. Theoretical calculations show that the maximum error in the measurement of the meter current would be limited to within +1.6% at 120°F and -2% at 60°F for 100% relative humidity while the same would be within ±1.75% for the entire temperature range 60°-120°F for 0% relative humidity.

IPC Code: G01N25/62

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 505-514

 Optimizing diesel engine parameters for emission reduction using Taguchi method: Variation risk analysis approach – Part  II
M Nataraj, V P Arunachalam & N Dhandapani 

Taguchi parameter design research methodology allows one to make products or processes robust to uncontrollable noise factors and will also reduce the number of experiments to be carried out to arrive an optimized system. The main objective of this work is to study the various operating parameters of diesel engine to propose modified engine parameter (optimum) settings for reduction in NOX, HC, CO and smoke concentrations simultaneously in diesel emission by applying Taguchi parameter design concept. Taguchi L18 (21´37) quality design concept mixed orthogonal array has been used to determine the S/N ratio (dB), analysis of variance (ANOVA) and F0 test values for recognizing most significant engine operating parameters that influence exhaust emission. The experimental results give an idea about how the variations in engine settings like nozzle spray holes, piston-to-head clearance, nozzle protrusion, injection control pressure, start of injection timing and swirl level alter the pollutant (NOX, HC, CO and smoke) intensity in emission. Considering these significant engine-operating parameters, verification of the improvement in the quality characteristics for emission reduction has been done through confirmation test with reference to the chosen initial or reference parameter settings. These confirmation test results prove that the optimal combination of diesel engine parameters obtained from the investigation reducing the pollutant levels in exhaust emission in reality.

IPC Code: F02B

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 515-520

 Influence of shot peening intensity on fatigue design reliability of 65Si7 spring steel
M L Aggarwal,  R A Khan  & V P Agrawal

 A lot of research has been done to improve the fatigue strength of metallic materials by creating compressive residual stress field (CRSF) in their surface regions through shot peening. In this paper, the axial fatigue strength of 65Si7 spring steel is evaluated experimentally as a function of shot peening intensity for the application in the automotive vehicles. Fatigue life at various shot peening conditions is determined with S/N curves and optimum shot peening intensity is also determined. The effect of Almen intensity on compressive residual stress and relaxation of compressive residual stress have been discussed for fatigue life extension. Shot peening of leaf springs is illustrated to cause improvement in fatigue strength, reduction in weight and reliability. A flow chart has been developed for improvement in fatigue design of components for economy.

IPC Code: C22F1/00, G01N3/00

 
Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 521-528

 Flexural vibrations of non-homogeneous elliptic plates
S Chakraverty, Ragini Jindal & V K Agarwal
 

The effect of non-homogeneity of material for complex shaped plates on their vibration frequencies is analyzed. Corresponding mathematical model has been developed. The results have been included for the first few frequencies of the plate element that are important to know before finalizing the design of a structure. Rayleigh Ritz method with generation of orthogonal polynomials using Gram-Schmidt process is used. In the numerical results, present solution is carefully examined by a convergence test and comparison with known results for special cases are carried out.

IPC Code: G01H

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 529-551

 Carbon nanotube and its possible applications
 Zishan Husain Khan  & M Husain

 Carbon nanotubes are the closed tabular structures consisting of nested cylindrical graphitic layers capped by fullerene-like ends with a hollow internal cavity, which were first discovered by Iijima in 1991. It consists of either one cylindrical graphene sheet, i.e., single-wall nanotube (SWNT)) or of several nested cylinders with an interlayer spacing of 0.34-0.36 nm, i.e., multiwall nanotube (MWNT)). The lengths of SWNTs and MWNTs are usually well over 1 mm and diameters range from ~1 nm (for SWNTs) to ~50 nm (for MWNTs). SWNTs are usually closed at both ends by fullerene-like half spheres that contain both pentagons and hexagons. Carbon nanotubes show exceptional electronic and mechanical properties. They are flexible but very hard to stretch and have extremely low turn-on fields and high current densities ranking them among the best electron field emitters for future field emission displays. This article presents an overview of current state of research on carbon nanotubes. In this review, we have focused on different synthesis routes for carbon nanotubes growth, used during last 12 years and possible future applications of carbon nanotubes especially in fuel cell and field emission displays. We have also discussed various parametric studies reported by several groups and extracted from their observations the common factors, which seem to be important towards a controlled production of carbon nanotubes. The limitations of these approaches, compatibility between an up-scaled production, the quality of the grown nanotube materials as well as the question of an economic production, have also been addressed.

IPC Code: B82B

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 552-556

 A comparative analysis of PBZT synthesized by co-precipitation and
sol-gel method

P Goel  & K L Yadav

A comparative structural and dielectric analysis of bismuth doped PZT ceramics [Pb0.98Bi0.02 (Zr0.52Ti0.48)O3] prepared by co-precipitation and sol-gel methods has been done. The thermal and crystallization behaviour of the as prepared powders, structural evolution of the ceramics and dielectric properties of the sintered ceramics have been analyzed and compared. Different stages of phase formation have been observed by X-ray diffractogram (XRD) of the samples calcined at various temperatures. Thermal analysis and XRD both confirm that the temperature as low as 250ºC is sufficient to achieve the desired phase in the compounds synthesized by sol-gel method whereas a higher temperature (~ 500ºC) is required to achieve the pure perovskite phase in case of the samples derived by chemical co-precipitation method. Ferroelectric transition temperature (Tc) and ferro-paraelectric phase transition nature remained the same for both of the samples. Hence, the sol-gel prepared material PBZT may be used for silicon based memory device application, where a low synthesis temperature is a major requirement.

IPC Code: G01N33/38

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 557-562

 Relative role of plasticizer and nano size fumed silica on the conductivity behaviour of PEO-NH4PF6 polymer electrolytes
Jitender Paul Sharma & S S Sekhon

 

The conductivity of proton conducting polymer electrolytes obtained by the complexation of ammonium hexafluorophosphate (NH4PF6) with polyethylene oxide (PEO) increases with the addition of propylene carbonate (PC) (plasticized polymer electrolyte) and nano size fumed silica (nano composite polymer electrolytes). Plasticized polymer electrolytes have higher conductivity whereas nanocomposite polymer electrolytes have better mechanical properties. The simultaneous addition of PC and fumed silica leads to the formation of electrolytes with higher conductivity (4.50´10-5 S/cm at 25oC) as well as better mechanical strength. The curved nature of log conductivity versus reciprocal temperature plot suggests the amorphous nature of these electrolytes and a small change in conductivity observed over the 20oC to 100oC temperature range is also suitable for their use in applications.

IPC Code: C08L23/04

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 563-570

 Mechanical properties of glass/palmyra fiber waste sandwich composites
R
Velmurugan & V Manikandan 

Uses of natural fibers as reinforcement in polymers have gained importance in the recent years due to the eco-friendly nature. This paper deals with the mechanical properties of the composites made up of palmyra fiber waste [pfw] and the pfw/glass fiber hybrid composites. Composite plates were prepared with 30%, 38%, 45%, 50%, 58%, 65% and 70% wt of fiber waste. Tensile, flexural, shear and impact properties were studied. Composites with 58-65-wt% fibers showed marginal improvement in flexural strength. Tensile strength was decreased and there was considerable improvement in shear and impact properties than that of resin. The properties of the natural fiber reinforced composites can be improved by hybridizing with high strength synthetic fibers such as glass. In this study, the palmyra fiber waste was hybridized with glass fiber in the polyester matrix. Samples were prepared by sandwiching the fiber waste between chopped strand glass fiber mats by varying both glass fibers and waste material content, keeping total fiber content as 60% by weight. Specimens were cut as per ASTM standards and tested in Instron universal testing machine. Mechanical properties of the composites were found to be increased with increase in the amount of glass fiber in the hybrid. Hybrid composites containing 48% waste, 10% glass fiber showed good reinforcement effect than the composites reinforced with 11 wt % glass fiber. The resin used was isophthalic roof light resin, the catalyst and accelerator were methyl ethyl ketone peroxide (MEKP) and cobalt napthanate, respectively.

IPC Code: C03C14/00

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 571-576

 Calorimetric studies of thermal crystallization in glassy Se80Te20 and Se80In20 alloys
N Mehta, V S Kushwaha & A Kumar 

Different methods have been used by various workers to determine the activation energy of thermal crystallization (Ec) in chalcogenide glasses using non-isothermal DSC data. In the present work, the crystallization kinetics of two important binary alloys Se80Te20 and Se80In20 is studied, using non-isothermal DSC data. DSC thermograms of these alloys have been taken at five different heating rates. The values of activation energy of crystallization (Ec) have been determined by four different methods, i.e., Kissinger’s relation, Matusita and Sakka theory, Augis and Bennett’s approximation and Ozawa’s equation. The results obtained have been compared with each other to see the effect of using different methods in the determination of Ec. The composition dependence of Ec has also been discussed.

IPC Code: C22C29/00

 

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 577-585

 Effect of annealing temperature on the magnetic behaviour of Ni-rich permalloy magnetic materials

Kiran Gupta, K K Raina & S K Sinha 

Magnetic properties have been investigated in Ni-rich permalloy (Ni @ 80%) material in which process conditions have been controlled under hydrogen annealing by varying holding time, cooling rate and annealing temperature. The material thus prepared has been characterized for various magnetic parameters under different annealing profile conditions. The results indicate that Ni-rich permalloy material shows better magnetic properties at 300 Hz over 1 kHz under controlled conditions.

IPC Code: C22C19/03, G01R

 Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 586-590

 

Phase transition in Pb[(Mg3/4Cu1/4)1/3Nb2/3]O3 ceramic
Amit Kumar, K Prasad, S N Choudhary & T P Sinha

 Single phase perovskite-type cubic ceramics of Pb[(Mg3/4Cu1/4)1/3Nb2/3]O3 (PMCN) were synthesized by high temperature double step solid state reaction technique. Dielectric studies show relaxor behaviour with diffuse phase transition. The phase transition (Tm) occurs at -22°C at 10 kHz. The frequency dependence of Tm has been modeled using Vogel-Fulcher relation. The dielectric relaxation in PMCN is found analogous to the magnetic relaxation in spin-glass system. The relaxor behaviour in PMCN has also been examined through admittance spectroscopy.

IPC Code: C04B33/00, G01N33/38

Indian Journal of Engineering & Materials Sciences
Vol. 12, December 2005, pp. 591-594

 Laser light scattering microscopy: Interpretation of images
P B V Prasad & P B Shashikanth

Images obtained through laser light scattering microscopy are examined from the viewpoint of their acceptability as true representatives of the surface features. This is accomplished by considering the parameters that can modify the images. The meaning of laser light scattering microscopy (LLSM) images is explained, by comparing them with the monochromatic-incoherent light microscopy (MILIM) images and superimposed images. The changes induced in grains by slow increase in temperature are explained, in terms of modification of (i) surface of grain and (ii) grain itself (around and after solid-liquid phase transition).

IPC Code: G01N13/10