The effects of stearic acid treatment on the crystallization, morphology, thermal, and mechanical properties of polypropylene (PP)/montmorillonite (Mm) nanocomposites were investigated. Stearic acid was used as a new surface modifier for Mm, and also small amounts of this acid were used as a new interface modifier. Nanocomposites containing 1.5, 2.5, 5, and 10% in weight of the unmodified and modified Mm were prepared by melt blending. The tensile and impact properties of nanocomposites were evaluated. Wide-angle Xray diffraction was used to study both the generated PP b crystals and the dispersion state of the nanocomposites. Differential scanning calorimeter was used to detect the melting and crystallization behavior of the samples. The toughness of some nanocomposites was higher than the pure PP. b phase of PP was observed with the addition of Mm. Stearic acid favored the dispersion of the nanocomposites when used as interface modifier. Nanocomposites with better dispersion exhibited crystallization temperatures similar to pure PP. POLYM. COMPOS., 35:1-9,

Blends of poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) with and without a compatibilizing agent were studied. Both materials are widely used in the soft drink bottle industry. The compatibilizing agent was a copolymer of ethylene and methacrylic acid partially neutralized with zinc (Surlyn). The olefinic segment of Surlyn is compatible with HDPE, whereas the Surlyn carboxylic acid groups is affine with the PET carbonyl groups. The effectiveness of the compatibilizing agent was evaluated using different techniques, such as infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and mechanical properties.

The high cost of page accessing implies a need for for more careful data organization in a paged memory than is typical of most inverted file and similar approaches to multi-key retrieval. This article analyses that cost and proposes a method called multiple key hashing which attempts to minimize it. Since this approach is not always preferable to inversion, a combined method is described. The exact specifications of this combination for a file with given data and traffic characteristics is formulated as a mathematical program. The proposed heuristic solution to this program can often improve on a simple inversion technique by a factor of 2 or 3.

The aim of this study is to evaluate the diagnostic performance of human epididymis protein 4 (HE4), cancer antigen 125 (Ca125) and the risk of ovarian malignancy algorithm (ROMA) in discriminating ovarian cancer from other benign gynaecological diseases. Serum levels of HE4 and Ca125 were measured in 119 women with benign gynaecological diseases, 29 patients with primary ovarian cancer, 32 patients with ovarian cancer on chemotherapy treatment (18 of them with progressive disease), 6 patients treated and free of disease and 32 healthy women. Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios (LR ±) were calculated. Receiver operator characteristic (ROC) curves were constructed, and the areas under the curve (AUC) were calculated. High serum levels for HE4, Ca125 and ROMA were observed in cancer patients. HE4 was elevated in 12.6 %, Ca125 in 21 % and ROMA in 9.2 % in the benign group, but HE4 was not elevated in endometriosis. The AUC values for HE4, Ca125 and ROMA were 0.92, 0.911 and 0.945 respectively. The sensitivity for discriminating ovarian cancer from benign gynaecological diseases was 86.2 % for HE4 and Ca125 and 93.1 % for ROMA. The specificity was 87.4, 78.9 and 90.7 % for HE4, Ca125 and ROMA. The overall positive likelihood ratio (LR+) was 6.84 for HE4, 4.1 for Ca125 and 10.01 for ROMA. In premenopausal women, LR + was 11.86 for HE4, 5.11 for ROMA and 2.02 for Ca125. HE4 might be significant in the differential diagnosis of ovarian cancer. HE4 seems to be superior to Ca125 in terms of diagnostic performance of all premenopausal women. ROMA could help to discriminate in cases with any doubt with a high diagnostic accuracy.

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