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The article discusses challenges with injection molding, also known as "Stefan problems" or "moving-boundary problems." The authors simulate the two-dimensional phase-change heat conduction of the injection molded high density polyethylene (HDPE) parts with thick walls during the cooling stage by means of the Faghri and Cao's enthalpy transformation method. Other topics include predicting the temperature distributions occurring in the cavity during the cooling process as well as the polymer extended phase change temperature range (mushy zone).

Investigates the influence of the high interfacial contact on the mechanical properties and the morphology developed during elongation of poly(ethylene terephthalate)/polyethylene and polycarbonate/polyethylene blends. Tensile strength of the blends; Macroscopic morphology development of both blends; Recoil of partially elongated specimens.

Erbium doping into potassium titanyl phosphate (KTiOPO[sub 4] or KTP) was performed by pulsed laser deposition. Waveguide laser film in Er-doped KTiOPO[sub 4] was formed using both KTiOPO[sub 4] and erbium as targets and optically polished KTiOPO[sub 4] as a substrate. Rutherford backscattering, photoluminescence spectrometry, x-ray diffraction, and prism coupling method are used to investigate the properties of Er-doped KTiOPO[sub 4]. The results show that (1) Er-doped KTiOPO[sub 4] emits the characteristic photoluminescence of Er[sup 3+] around 1.54 μm corresponding to transition between the [sup 4]I[sub 13/2] and [sup 4]I[sub 15/2] manifolds of the Er[sup 3+] ions in KTiOPO[sub 4] host. (2) two bright modes in Er-doped KTiOPO[sub 4] were observed. This approach may be useful for direct fabrication of thin film waveguide laser for other optoelectrical materials. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]