a fourth-generation ziegler-natta catalyst was prepared to synthesize polypropylene (pp), which was stabilized by in situ polymerization employing lignin as antioxidant. the antioxidant properties of lignin were compared with those of the commercial antioxidant irganox 1010. the presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. the isotacticity...

BACKGROUND Atlantic salmon production in Tasmania (Southern Australia) occurs near the upper limits of the species thermal tolerance. Summer water temperatures can average over 19 °C over several weeks and have negative effects on performance and health. Liver tissue exerts important metabolic functions in thermal adaptation. With the aim of identifying mechanisms underlying liver plasticity in...

In the present paper, the evolution of an oxidation process has been associated to the collective atomic arrangement, the microstructure one. This microstructural analysis encompasses a metallographic examination and a relation of electricity to chemical changes in salt-water solution. The electrochemical experimental techniques used include corrosion potential measurements. To seek a deeper un...

When wood is exposed to elevated temperatures, changes can occur in its chemical structure that affect its performance. The extent of the changes depends on the temperature level and the length of time under exposure conditions. The changes in chemical structure may be manifested only as reduced strength, and hydroscopic water and volatile oil weight loss. In contrast, very drastic chemical cha...

the principal effects of mass degradation on polymer matrix composites (pmcs) are the decay of mechanical properties such as strength, elongation, and resilience. this degradation is a common problem of the pmcs under thermal cycling conditions. in this article, composite degradation was investigated by measurement of total mass loss (tml) using the taguchi approach. thermal cycling tests were ...

Low-temperature tenderization is an important aspect in the processing of sea cucumber. Oxidative reactions induce protein aggregation or degradation during thermal treatment. However, whether oxidation occurs cucumber unclear. Moreover, effects heat treatment on structure have not been well explored. In this study, Apostichopus japonicus body wall (AJBW) were tenderized at 37 °C and changes mi...

Solid deposits from commercially available high-pressure diesel injectors (HPDI) were analyzed to study the solid deposition from diesel fuel during engine operation. The structural and chemical properties of injector deposits were compared to those formed from the thermal oxidative stressing of a diesel fuel range model compound, n-hexadecane at 160 degrees C and 450 psi for 2.5 h in a flow re...