Misalignment effects on steady‐state and dynamic behaviour of compliant journal bearings lubricated with couple stress fluids

This work concerns the steady‐state and dynamic analysis of misaligned compliant journal bearings considering the effects of couple stresses arising from the lubricant blended with polymer additives. Based on the Stokes micro‐continuum theory, a modified form of the Reynolds equation is derived. The displacement field at the fluid film–bearing liner interface due to pressure forces is determined using the elastic thin liner model. The effects of the misalignment and the couple stress parameters on static and dynamic performances such as pressure distribution, load‐carrying capacity, power loss, side leakage flow, misalignment moment, critical mass and whirl frequency are presented and discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Rapid small‐scale starch isolation using a combination of ultrasonic sonication and sucrose density separation

The proposed rapid small‐scale starch isolation technique in the laboratory was a combination of dry grinding of grain, suspension of the resulting flour in extraction buffer, application of ultrasonic sonication, then separation by sucrose density centrifugation. Light microscopy of separated fractions showed intact starch granules in the pellet and proteins and damaged starch in the top layer. The extraction method yielded 61% starch from sorghum and 63% from maize. The isolated starch showed lower starch damage and proteins content than by the conventional method. The gelatinization enthalpy of isolated starch was slightly higher than by wet grinding conventional method. In addition to low amount of starting flour (100 mg) the new starch isolation method was performed in less than 2 h from dry grinded seed to dried starch. Thus, it could be a useful method for cereal chemists and plant genetists.     

Ultraviolet radiation aging impact on physicochemical properties of crosslinked polyethylene cable insulation

This article deals within the study of the effect of artificial radiations on physical and chemical properties of the crosslinked polyethylene (XLPE) material, widely used for manufacturing high-voltage cables. Within this framework, several experimental tests, using essential characterization techniques, were performed to study XLPE behavior under ultraviolet (UV) aging. Attenuated total reflection Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy were thus carried out to identify the main structure changes of the material before and after exposure to UV. In addition, appearance changes and DC (Direct Current) volume resistivity were evaluated. The obtained results showed that UV radiation has a great effect on the physicochemical properties of XLPE cable insulation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48575.