Effect of Residual Trace Amounts of Fe and Al in Li[Ni1/3Mn1/3Co1/3]O2 Cathode Active Material for the Sustainable Recycling of Lithium-Ion Batteries

As the explosive growth of the electric vehicle market leads to an increase in spent lithium-ion batteries (LIBs), the disposal of LIBs has also made headlines. In this study, we synthesized the cathode active materials Li[Ni_1/3Mn_1/3Co_1/3]O₂ (NMC) and Li[Ni_1/3Mn_1/3Co_1/3Fe_0.0005Al_0.0005]O₂ (NMCFA) via hydroxide co-precipitation and calcination processes, which simulate the resynthesis of NMC in leachate containing trace amounts of iron and aluminum from spent LIBs. The effects of iron and aluminum on the physicochemical and electrochemical properties were investigated and compared with NMC. Trace amounts of iron and aluminum do not affect the morphology, the formation of O3-type layered structures, or the redox peak. On the other hand, the rate capability of NMCFA shows high discharge capacities at 7 C (110 mAh g⁻¹) and 10 C (74 mAh g⁻¹), comparable to the values for NMC at 5 C (111 mAh g⁻¹) and 7 C (79 mAh g⁻¹), respectively, due to the widened interslab thickness of NMCFA which facilitates the movement of lithium ions in a 2D channel. Therefore, iron and aluminum, which are usually considered as impurities in the recycling of LIBs, could be used as doping elements for enhancing the electrochemical performance of resynthesized cathode active materials.     

Does Deinstitutionalization Increase Suicide?

Objectives. (1) To test whether public psychiatric bed reduction may increase suicide rates; (2) to investigate whether the supply of private hospital psychiatric beds—separately for not-for-profit and for-profit—can substitute for public bed reduction without increasing suicides; and (3) to examine whether the level of community mental health resources moderates the relationship between public bed reduction and suicide rates.
Methods. We examined state-level variation in suicide rates in relation to psychiatric beds and community mental health spending in the United States for the years 1982–1998. We categorize psychiatric beds separately for public, not-for-profit, and for-profit hospitals.
Principal Findings. Reduced public psychiatric bed supply was found to increase suicide rates. We found no evidence that not-for-profit or for-profit bed supply compensates for public bed reductions. However, greater community mental health spending buffers the adverse effect of public bed reductions on suicide. We estimate that in 2008, an additional decline in public psychiatric hospital beds would raise suicide rates for almost all states.
Conclusions. Downsizing of public inpatient mental health services may increase suicide rates. Nevertheless, an increase in community mental health funding may be promising.     

A structural model of stress, motivation, and academic performance in medical students

Objective

The purpose of the present study was 1) to identify factors that may influence academic stress in medical students and 2) to investigate the causal relationships among these variables with path analysis.

Methods

One hundred sixty medical students participated in the present study. Psychological parameters were assessed with the Medical Stress Scale, Minnesota Multiphasic Personality Inventory, Hamilton Depression Scale, Beck Depression Inventory, and Academic Motivation Scale. Linear regression and path analysis were used to examine the relationships among variables.

Results

Significant correlations were noted between several factors and Medical Stress scores. Specifically, Hamilton Depression Scale scores (β=0.26, p=0.03) and amotivation (β=0.20, p=0.01) and extrinsically identified regulation (β=0.27, p<0.01) response categories on the Academic Motivation Scale had independent and significant influences on Medical Stress Scale scores. A path analysis model indicated that stress, motivation, and academic performance formed a triangular feedback loop. Moreover, depression was associated with both stress and motivation, and personality was associated with motivation.

Conclusion

The triangular feedback-loop structure in the present study indicated that actions that promote motivation benefit from interventions against stress and depression. Moreover, stress management increases motivation in students. Therefore, strategies designed to reduce academic pressures in medical students should consider these factors. Additional studies should focus on the relationship between motivation and depression.     

Effect of Noise on Sleep and Autonomic Activity in Children according to Source

BackgroundNoise has been a major issue in children due to its effect on emotional symptoms and sleep problems. The present study investigated the effect of noise on sleep and autonomic activity in children according to three variables, namely, road traffic noise, aircraft noise, and noise sensitivity (NS).MethodsThe study is epidemiological in nature. A total of 474 subjects of four elementary schools were evaluated in conjunction with the 2014 noise map data gathered from two metropolitan regions, Seoul and Ulsan, in South Korea. Each subject completed the children''s sleep habits questionnaire, and heart rate variability (HRV) was recorded. Analysis of covariance was performed using monthly income as a covariate.ResultsAircraft noise was associated with night waking (P = 0.047), whereas no significant association was observed between sleep and road traffic noise. After stratifying by NS, no significant results were obtained for road traffic noise. However, high levels of aircraft noise in the high-NS group were associated with high degrees of bedtime resistance (P = 0.049). In terms of HRV, no significant difference was observed in the results between groups.ConclusionRoad traffic noise did not significantly alter sleep or autonomic activity in children, whereas aircraft noise exerted a negative effect on sleep. The findings suggest that the impact of noise on sleep in children varies depending on noise sources.