Indian Journal of Engineering & Materials Sciences
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VOLUME 17

NUMBER  2

APRIL 2010

CODEN : IEMSEW 

ISSN : 0971-4588

 

                           CONTENTS       

 

Engineering

 

Effect of cooling water flow direction on performance of an acetylene fuelled HCCI engine

79

        K Sudheesh & J M Mallikarjuna

 

 

 

An experimental study on buckling and post-buckling behaviour of cylindrical panels with clamped and simply supported ends

86

        M Shariati, M Sedighi, J Saemi & H R Eipakchi

 

 

 

Analysis and evaluation of heat affected zones in electric discharge machining of EN-31 die steel

91

        Rajesh Choudhary, H Kumar & R K Garg

 

 

 

Novel current-mode and voltage-mode universal biquad filters using single CFTA

  99

        Worapong Tangsrirat

 

 

 

A two-stage methodology of optimal capacitor placement for the reconfigured network

105

        M Damodar Reddy & V C Veera Reddy

 

 

 

Mitigation of voltage sags in a distribution system due to three phase to ground fault using DVR

113

        D Deepak Chowdary & G V Nagesh Kumar

 

 

 

Materials Science

 

Preparation of some metal chloride doped silver phosphate glass electrolytes–Application to solid state batteries

123

        S S Das, Pankaj Kumar Srivastava, N P Singh & Vibha Srivastava

 

 

 

Synthesis and characterization of cation-doped BiFeO3 materials  for photocatalytic applications

131

        C Madhu, Manjunath B Bellakki & V Manivannan

 

 

 

Effect of Class-F fly ash as partial replacement with cement and fine aggregate in mortar

140

        C Freeda Christy  & D Tensing

 

 

 

Strength and capillary water absorption of lightweight concrete under different curing conditions

145

        Nusret Bozkurt & Salih Yazicioglu

 

 

 

 

               AUTHOR INDEX

Bellakki Manjunath B

131

Bozkurt  Nusret

145

 

 

Choudhary  Rajesh

91

Chowdary D Deepak

113

Christy C Freeda

140

 

 

Damodar Reddy M

105

Das S S

123

 

 

Eipakchi H R

86

 

 

Garg R K

91

 

 

Kumar H

91

 

 

Madhu C

131

Mallikarjuna J M

79

Manivannan V

131

 

 

Nagesh Kumar G V

13

 

 

Saemi J

86

Sedighi M

86

Shariati M

86

Singh N P

123

Srivastava Pankaj Kumar

123

Srivastava Vibha

123

Sudheesh K

79

 

 

Tangsrirat Worapong

99

Tensing D

140

 

 

Veera Reddy V C

105

 

 

Yazicioglu Salih

145


 

 

 

                                                                                                                                             

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 79-85

 

Effect of cooling water flow direction on performance of an acetylene
fuelled HCCI engine

K Sudheesh & J M Mallikarjuna

 

This paper deals with experimental investigations carried out on an acetylene-fuelled engine operated in homogeneous charge compression ignition (HCCI) mode to study effect of cooling water flow direction on intake charge temperature and heating requirements, and performance of the engine. In this study, in a possible load range, experiments are conducted on a single-cylinder, water-cooled, acetylene fuelled HCCI mode with conventional and reverse cooling water flow directions using different intake charge temperatures at different loads. At every load condition, best possible intake charge temperature is determined based on brake thermal efficiency. Results obtained in two cases of cooling water flow directions of HCCI mode are compared with those of conventional diesel CI mode. From the results, it is found that, reverse cooling water flow direction shows about 14 to 50% reduction in external intake charge heating at different load conditions as compared to conventional cooling water flow direction. There is an improvement in brake thermal efficiency by about 5 to 10% at different load conditions. Nitric oxide (NO) and smoke emissions are very low in both cases. However, hydrocarbon (HC) and carbon monoxide (CO) levels are higher than conventional CI mode in both the cases.

Keywords: HCCI, Acetylene, Reversed cooling water flow

 

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 86-90

 

An experimental study on buckling and post-buckling behaviour of cylindrical panels with clamped and simply supported ends

M Shariati, M Sedighi, J Saemi & H R Eipakchi

 

The effects of the length, sector angle and boundary conditions on the buckling load and post-buckling behaviour of cylindrical panels have been studied experimentally by applying a compressive axial load on the panels using a  servo-hydraulic machine.

Keywords: Buckling, Post-buckling, Cylindrical panels, Experimental test

 

 

Indian Journal of Engineering & Materials Sciences

Vol 17, April 2010, pp. 91-98

 

 

Analysis and evaluation of heat affected zones in electric discharge machining of EN-31 die steel

Rajesh Choudhary, H Kumar & R K Garg

 

In this paper investigations are conducted on the machining of EN-31 die steel with different electrode materials (copper, brass and graphite) with electrical discharge machining (EDM) process. This study presents the analysis and evaluation of heat affected zones (HAZ) of the workpiece surfaces machined using different tool electrodes by EDM. The kerosene oil of commercial grade has been used as dielectric fluid. The effect of various important EDM parameters such as pulse duration, peak current and discharge gap voltage has been investigated to yield the responses in terms of material removal rate (MRR) and surface roughness (SR). Further the detailed analysis of heat affected regions has been carried out by using scanning electron microscopy (SEM) and optical microscopy (OM). Experimental results indicate that copper as a tool electrode shows a good response towards MRR, whereas brass gives superior surface finish as compared to other tool electrodes. From the microstructural analysis study it has been observed that heat affected zone is much deeper in the specimen machined by graphite electrode as compared to other tool electrodes.

Keywords: Electrical discharge machining; Surface integrity; Metal removal rate; Surface roughness; Heat affected zone

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 99-104

 

Novel current-mode and voltage-mode universal biquad filters using single CFTA

Worapong Tangsrirat

 

This paper presents two novel electronically tunable universal filter configurations employing a single new active device, namely the current follower transconductance amplifier (CFTA). The first proposed current-mode universal filter with single input and three outputs consists of one CFTA, one virtually grounded resistor and two grounded capacitors. It can simultaneously realize low-pass, band-pass and high-pass responses with no need to impose component choice. A new three-input single-output universal voltage-mode biquad using one CFTA, two resistors and two capacitors is also proposed as a second proposed circuit. The latter circuit can be configured to realize all the five standard biquadratic filter functions; low-pass, band-pass, high-pass, band-stop and all-pass, without changing the circuit configuration. Both two universal biquad filters also offer the advantage features of the use of minimum number of passive components, and independent electronic tuning of the important filter parameters (wo and BW), as well as low active and passive sensitivities. To demonstrate the performances of the proposed filters and verify the theory, PSPICE simulations are accomplished.

Keywords: Current follower transconductance amplifier (CFTA), Biquad filter, Current-mode circuit, Voltage-mode circuit

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 105-112

 

A two-stage methodology of optimal capacitor placement for
the reconfigured network

M Damodar Reddy* & V C Veera Reddy

Department of Electrical & Electronics Engineering, S V University, Tirupati 517 502, India

Received 7 March 2008; accepted 19 March 2010

This paper describes a two-stage methodology of optimal capacitor placement for the reconfigured network. A two-stage methodology is used to reduce the losses and to improve the voltage profile of the balanced radial distribution networks. In the first stage, an improved fuzzy multi-objective algorithm is used for the network reconfiguration of the original network. In the second stage, capacitors are placed optimally for the reactive power compensation of the reconfigured network. Fuzzy approach is used to find the optimal capacitor locations and analytical method is used to find the sizes of the capacitors. The proposed method is tested on 11-bus, 33-bus and 69-bus test systems and the results indicate that considerable loss reduction is possible with substantial improvement in the voltage profile.

Keywords: Two-stage methodology, Network reconfiguration, Fuzzy multi-objective approach, Optimal capacitor placement, Fuzzy and analytical method

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 113-122

 

 

Mitigation of voltage sags in a distribution system due to three phase to
ground fault using DVR

D Deepak Chowdary & G V Nagesh Kumar

 

Voltage sags defined as short-duration reductions in the rms voltage on one or more electrical phases are becoming the most important power quality concern to electric utility customers with sensitive loads. They are characterized by their magnitude and duration (which is typically 0.5 to 30 cycles). Sags are predominantly caused by faults that are unavoidable on the distribution systems due to the interconnectivity of the utility systems. The distribution-class dynamic voltage restorer (DVR) is a series connected power electronics device which can compensate for distribution system sags and swells. By enhancing the voltage, the DVR can increase the availability of sensitive loads. For a successful compensation, the DVR must be able to detect the voltage sag and control the inverter to restore the voltage. The sliding mode control is used for the DVR. Using sliding mode control to the DVR, additional sag detection method is eliminated. This improves the dynamic response of the DVR and also DVR is able to compensate for any variation in source voltage. In this paper, a DVR with sliding mode control strategy is used to alleviate the voltage sags caused due to faults occurring on the parallel feeders in a single-phase distribution system. The DVR along with the other parts of the distribution system are simulated using MATLAB/SIMULINK.

Keywords: DVR, Sliding mode control, Voltage sag, Power quality

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 123-130

 

Preparation of some metal chloride doped silver phosphate glass
electrolytes–Application to solid state batteries

S S Das, Pankaj Kumar Srivastava, N P Singh & Vibha Srivastava

 

Silver phosphate glasses doped with various compositions (0, 1, 5, 10 and 15 wt%) of some metal chlorides, viz, lithium, sodium, magnesium, lead and copper are prepared by melt quenching technique. These glasses are characterized by X-ray diffraction analysis, FTIR spectra, transference number measurements and electrical conductivity studies. The glasses exhibiting maximum electrical conductivity are used as solid electrolytes for the fabrication of solid-state batteries with the cell configurations: Ag || Ag2O – P2O5 – MCly || (C + I2) (where y = 1 when M is Li or Na; y = 2 when M is Mg, Pb or Cu). The open circuit voltage (OCV) and discharge characteristics of all the fabricated batteries have been studied. The addition of metal chlorides to silver phosphate glass matrix results in a substantial increase in the OCV. The cell with the configuration Ag || Ag2O – P2O5 – (15%) Li Cl || (C + I2) gives the best performance. The results have been discussed on the basis of FTIR and electrical conductivity studies.

Keywords: Silver phosphate glass, Solid state battery, Glass electrolyte, Ion conducting glasses

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 131-139

 

 

Synthesis and characterization of cation-doped BiFeO3 materials
for photocatalytic applications

C Madhu, Manjunath B Bellakki & V Manivannan

 

A sol-gel method was applied to synthesize Bi1-xMxFeO3 (M = Mg, Al, Y) ceramic materials. Subsequently, these materials were structurally characterized by applying Rietveld refinement techniques. The magnetic properties of the synthesized materials were determined by SQUID measurements and their optical properties (band-gap) were determined by applying diffused reflectance (DR) techniques. The low band-gap nature of these materials enabled to them exhibit photocatalytic activity and accordingly 2% Y doped BiFeO3 samples exhibited higher photocatalytic effect (18% compared to 14% for undoped). Under identical conditions, TiO2 standard exhibited only 7% degradation indicating superior properties of cation-doped bismuth ferrites.

Keywords: Oxides, Chemical synthesis, Crystal structure, Magnetic properties, Photocatalytic properties

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 140-144

 

Effect of Class-F fly ash as partial replacement with cement and
fine aggregate in mortar

 C Freeda Christy & D Tensing

 

Fly ash is investigated for its use as a replacement for cement and fine aggregate in cement mortar. This paper presents the results of the cement mortar of mix proportion 1:3, 1:4.5 and 1:6 cement mortar in which cement is partially replaced with Class-F fly ash as 0%, 10%, 20%, 25% and 30% by weight of cement. Richer the mix, higher the compressive strength has been obtained even with partial replacement of fly ash with cement. Test results indicate the significant improvement in the strength properties of mortar with fly ash as partial replacement with fine aggregate and with the cement in the cement mortar 1:6. It can be effectively used in masonry with the compressive strength of the brick unit ranges between
3-20 N/mm2.

Keywords: Fly ash, Partial replacement, Compressive strength, Cement, Fine aggregate

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 17, April 2010, pp. 145-151

 

 

 

Strength and capillary water absorption of lightweight concrete under different curing conditions

Nusret Bozkurt & Salih Yazicioglu

 

This paper reports an experimental study carried out to investigate the influence of addition of pozzolanic materials and curing regimes on the mechanical properties and the capillary water absorption (sorptivity) characteristics of lightweight concrete. A control lightweight concrete mixture made with lightweight volcanic pumice containing only Portland cement (PC) and fly ash lightweight concrete mixture containing 20% of fly ash (FA) and 10% of silica fume (SF) as a replacement of the cement by weight is prepared. The specimens are prepared and cured in three different curing conditions (standard 20°C water, sealed and air cured) for the periods of 3, 7 and 28 days. At the end of each curing period, compressive and tensile strengths and ultrasonic pulse velocity (UPV) values are determined; sorptivity coefficients are recorded at 28 days. The results indicate that SF specimens give higher compressive and tensile strength and lower sorptivity coefficient values than corresponding PC and FA concrete specimens, regardless of curing regime and age of concrete. The results also show a good correlation between the strength development of concrete and its sorptivity, i.e., as the compressive and tensile strengths increased due to the hydration, the sorptivity coefficients decreased significantly. 

Keywords: Lightweight concrete, Curing regime, Mineral admixture, Sorptivity coefficient, Fly ash, Silica fume