Thermal Reformation of Polystyrene Using Metal Oxide as Redox Catalyst

While plastic has been regarded as a useful and cost-effective material, there is growing global concern about its disposal. Chemical recycling presents a promising solution to this issue. This study explores the utilization of vanadium oxide as a redox catalyst to effectively decompose polystyrene into industrially useful CO. By heating polystyrene with V2O5 under an inert gas atmosphere, CO was successfully produced accompanied with CO2 as the primary by-product. Adding 5 wt% iron to V2O5 improved the selectivity of CO production without compromising gas yield. X-ray diffraction analysis indicated that V2O5 acted as an oxygen source and turned into V2O4 and V6O13 after the reaction. This process enables polymer reformation at lower temperatures than conventional methods, making it an energy-efficient chemical recycling strategy. Additionally, V2O4 and V6O13 generated during the process were easily oxidized to V2O5 through heating under atmospheric conditions. As both polymer reformation and oxidation are exothermic reactions, the proposed reaction scheme can be used as a thermally efficient chemical recycling process

Verification of the Addiction Severity Index Japanese Version (ASI-J) as a Treatment-Customization, Prediction, and Comparison Tool for Alcohol-Dependent Individuals

Objective: To demonstrate the usefulness of the Addiction Severity Index Japanese Version (ASI-J) in Japanese alcohol-dependent individuals. The ASI is a frequently used clinical and research instrument that measures severities in seven functional domains in people with substance abuse disorders. Methods: A total of 370 male inpatients with a history of alcohol dependence participated in the study. Forty-nine participants were excluded in the final analysis due to lack of reliability (i.e., patient misrepresentation or inability to understand). We used the ASI-J and a series of indexes that determined patient states during and post-treatment. Results: The correlations between ASI Composite Scores (CSs), which were calculated through a weighted formula and indicated the severity of each problem area, were significant but low in eight relations and not significant in 13 relations, indicating substantial independence of the problem areas. Significant differences were found in Family/Social CSs between abstinent and relapsed alcohol-dependent individuals. The questions of undesirable attitude were significantly related to the CSs of Employment, Drug use, Family/Social, and Psychiatric sections. Significant differences were observed in patient demographics, CS, and ASI Severity Rating (SR) and interviewer’s subjective scoring between alcohol-dependent individuals and drug abusers. CSs in Japanese alcohol-dependent individuals were generally similar to corresponding CSs in individuals from other countries, with the exception of The Netherlands. Conclusions: This study demonstrated that the ASI-J is useful for understanding individual profiles of problems for each patient and planning customized treatment. The ASI-J served as a predictive tool for relapse and compliance to treatment afterward and was shown to be useful as a comparison tool in clarifying similarities and differences between substance abuser groups