G.de Val Davis [34]

1.118

2.243

4.519

8.799

Markatos and perikleous [35]

1.108

2.201

4.430

8.754

G.V.Hadjisophcleous et al. [36]

1.141

2.290

4.964

10.390

R.K. Tiwari, M.K. Das [12]

1.087

2.195

4.450

8.803

I. El Bouihi and R. Sehaqui [14]

1.042

2.024

4.520

8.978

Present work

1.012

2.214

4.103

8.293

Difference with I. El Bouihi %

2.87

9.38

9.22

7.62