New poly(butylene succinate)/layered silicate nanocomposites: preparation and mechanical properties

New poly(butylene succinate) (PBS)/layered silicate nanocomposites have been successfully prepared by simple melt extrusion of PBS and octadecylammonium modified montmorillonite (C18-mmt) at 150 degrees C. The d-spacing of both C18-mmt and intercalated nanocomposites was investigated by wide-angle X-ray diffraction analysis. Bright-field transmission electron microscopic study showed several stacked silicate layers with random orientation in the PBS matrix. The intercalated nanocomposites exhibited remarkable improvement of mechanical properties in both solid and melt states as compared with that of PBS matrix without clay.     

Electrokinetic remediation of clayey soils containing copper(II)-oxinate using humic acid as a surfactant

The utility of humic acid (HA) as a surfactant for use in the electrokinetic remediation (ER) of the clayey soils containing copper(II)-oxinate (Cu(OX)(2)) was examined. A small simulator of ER was devised, which consisted of three types of artificial soils on the basis of the commercial kaolin: kaolin, kaolin + HA and kaolin + Cu(OX)(2). The layers of kaolin containing HA and Cu(OX)(2) were sandwiched between two kaolin layers. In all experiments, a constant dc voltage gradient of 2.2V/cm was applied through the soil for 30h, and the pH of the solution in the anodic chamber was maintained at 7.0. Generally, HA has a negative charge at a neutral pH. However, the HA was mainly transferred to the cathodic chamber. This shows that the driving force of the HA in the system used herein is predominantly due to electroosmotic flow. Moreover, the amount of Cu(OX)(2) removed from the clayey soils in the presence of HA was three times larger than those in the absence of HA. This can be attributed to the fact that the water solubility of Cu(OX)(2) is enhanced by the presence of HA. Thus, we conclude that HA has a potential for use as an amendment for the ER of hydrophobic chemicals, such as Cu(OX)(2).     

Nonisothermal crystallization of poly(ethylene terephthalate) and its blends in the injection-molding process

We investigated the nonisothermal crystallization during the cooling process of injection molding of poly(ethylene terephthalate) (PET), PET/talc, and PET/Surlyn blends. We applied the isothermal crystallization parameters obtained by the Hoffman–Lauritzen theory to the kinetics of nonisothermal crystallization and then calculated the relative crystallinity χ/χ_c as a function of the mold temperature. χ/χ_c were nicely interpreted by calculation without effect of the pressure history on crystallization in PET and PET/talc (1 wt %) blends. In contrast, in the PET/Surlyn (3 wt %) blend, crystallization occurred at a lower mold temperature than predicted by our calculation. The transmission electron micrograph near the surface of the injection-molded PET/Surlyn blend showed deformation and stretching of dispersed Surlyn particles, suggesting that orientation of the PET matrix proceeds with the flow in processing. The orientation of the PET matrix resulted in acceleration of the crystallization in the injection molding. © 1995 John Wiley & Sons, Inc.     

Reflectance spectra of extreme ultraviolet mirrors for synchrotron radiation

Reflectance spectra have been measured for many materials in the wavelength range from 90 Å to 400 Å. The angle of incidence ranged from 20° to 85°. The samples were chemical-vapor-deposited silicon carbide (CVD-SiC), a single crystal of silicon with (100) surface, fused quartz, zerodur, pyrex, gold, platinum, copper and two kinds of steel. To obtain reflectances for surfaces for practical use, measurements were made on surfaces sufficiently exposed to air. Reflectances for s-polarized light (R_s) were measured for all samples. On CVD-SiC, gold and platinum, reflectances for p-polarized light (R_P) were also observed. At short wavelengths and large angles of incidence, the difference between R_s and R_P is small, and R_P happened to exceed R_s in contrast to the result from the Fresnel equation. This may be due to the deviation of the present surfaces of mirrors from an ideal plane. Reflectance spectra of surfaces prepared by some feasible techniques are also presented.     

Educational intervention enhances consumers' readiness to adopt food thermometer use when cooking small cuts of meat: an application of the transtheoretical model

An intervention to promote use of food thermometers when cooking small cuts of meat was conducted using the Transtheoretical Model. Objectives were to (i) increase use of food thermometers by home food preparers, (ii) improve consumers' attitudes regarding use of a food thermometer, and (iii) examine relationships between stages of change and decisional balance, self-efficacy, and processes of change. A randomly selected group of residents of Washington and Idaho (n = 2,500) were invited to participate in the research; 295 persons completed all phases of the multistep intervention. Following the intervention program, there was a significant increase in food thermometer use when cooking small cuts of meat (P < 0.01); those persons classified in action and maintenance stages increased from 9 to 34%. Ownership of thermometers also significantly increased (P < 0.05). The three constructs related to the Transtheoretical Model that were used in the study (decisional balance, self-efficacy, and processes of change) were very useful for examining differences among people at different stages of change because the responses for each set of questions differed positively and significantly (P < 0.01) as stages of change classifications advanced from precontemplation (no interest in thermometer use) to action and maintenance (individuals who use food thermometers). Additional educational campaigns designed to increase use of food thermometers are needed. Because most consumers are currently in the precontemplation stage, food thermometer campaigns will be most effective when they are focused on raising awareness of the food safety risks and the benefits of using food thermometers when cooking small cuts of meat.