Z = - 31.27056 + 451.7909 EPS - 18.0745 DR + 272.889 ROE - 24.0742 QR - 132.953 PBTP - 350.049 ROA + 760.2231 OP - 179.198 OEOI, (4)
where Z is discriminant score; EPS is earning per share; DR is total liability to total assets (debt rtio); ROE is return on equity (return on shareholders' equity); QR is acid test ratio (quick ratio); PBTP is profit before tax to paid-in capital (return on capital); ROA is return on assets (return on total assets); OP is operating profit; and OEOI is operating expense to operating income.
Z = - 3.27268 - 6.90053 EPS - 5.20153 DR - 50.8526 ROE + 13.08423 QR + 63.9662 PBTP + 4.54677 ROA - 11.10492 OP + 0.49265 OEOI, (7)
Materials used in this study were unfilled polyamide 6, Durethan B 30 S, and glass-filled PBTP, Pocan B3225, containing 20% glass fibers (GF), both materials received from Bayer.
The core, consisting of glass fiber-reinforced PBTP, displayed a well-known layered structure, Fig.
It is possible to identify the first peak with crack initiation of the (brittle) PBTP core, and the following peaks with cracks propagating through the lower and upper skins.