Objective: This research examined the extent to which teenagers who engaged in one form of risky driving also engaged in other forms and whether risky driving measures were reciprocally associated over time.
Methods: The data were from waves 1, 2, and 3 (W1, W2, and W3) of the NEXT Generation study, with longitudinal assessment of a nationally representative sample starting with 10th graders starting in 2009–2010. Three measures of risky driving were assessed in autoregressive and cross-lagged analyses: driving while alcohol/drug impaired (DWI), Checkpoints Risky Driving Scale (risky and unsafe driving), and secondary task engagement while driving.
Results: In adjusted autoregression models, the risk variables demonstrated high levels of stability, with significant associations observed across the 3 waves. However, associations between variables were inconsistent. DWI at W2 was associated with risky and unsafe driving at W3 (β = 0.21, P < .01); risky and unsafe driving at W1 was associated with DWI at W2 (β = 0.20, P < .01); and risky and unsafe driving at W2 is associated with secondary task engagement at W3 (β = 0.19, P < .01). Over time, associations between DWI and secondary task engagement were not significant.
Conclusions: Our findings provide modest evidence for the covariability of risky driving, with prospective associations between the Risky Driving Scale and the other measures and reciprocal associations between all 3 variables at some time points. Secondary task engagement, however, appears largely to be an independent measure of risky driving. The findings suggest the importance of implementing interventions that addresses each of these driving risks. 相似文献
Gasification of polyvinyl alcohol(PVA)-contaminated wastewater in supercritical water(SCW)was investigated in a continuous flow reactor at 723-873 K,20-36 MPa and residence time of 20-60 s.The gas and liquid products were analyzed by GC/TCD,and TOC analyzer.The main gas products were H_2,CH_4,CO and CO_2.Pressure change had no significant influence on gasification efficiency. Higher temperature and longer residence time enhanced gasification efficiency,and lower temperature favored the production of H_2. The effects of KOH catalyst on gas product composition were studied,and gasification efficiency were analyzed.The TOC removal efficiency(R_(TOC)),carbon gasification ratio(R_(CG))and hydrogen gasification ratio(R_(HG))were up to 96.00%,95.92% and 126.40% at 873 K and 60 s,respectively,which suggests PVA can be completely gasified in SCW.The results indicate supercritical water gasification for hydrogen generation is a promising process for the treatment of PVA wastewater. 相似文献
The microbial immobilization method using polyvinyl alcohol(PVA)gel as an immobilizing material was improved and used for entrapment of activated sludge.The oxygen uptake rate(OUR)was used to characterize the biological activity of immobilized activated sludge.Three kinds of PVA-immobilized particles of activated sludge,that is,PVA-boric acid beads,PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared,and their biological activity was compared by measuring the OUR value.The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH_4~ -N).The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation.With respect of the bioactivity and the mechanical stability,the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization. 相似文献
The biosorption of copper by the brown seaweed Sargassum baccularia,immobilized onto polyvinyl alcohol(PVA)gel beads, was investigated with fixed-bed experiments.Laboratory-scale column tests were performed to determine breakthrough curves with varying flow rates and feed concentrations.A theoretical fixed-bed model,known as the Bohart-Adams equation,was evaluated in simulating the experimental breakthrough curves.The Bohart-Adams model qualitatively predicted the breakthrough trends.PVA- immobilized seaweed biomass beads were amenable to efficient regeneration with aqueous solution containing the chelating agent ethylenediaminetetraacetic acid(EDTA).The biosorbent retained most of its original uptake capacity over three cycles of use.The excellent reusability of the biosorbent could lead to the development of a viable metal remediation technology. 相似文献