The Canadian Safe Driving Study—Phase I pilot: Examining potential logistical barriers to the full cohort study

Multiple organizations and task forces have called for a reliable and valid method to identify older drivers who are medically unfit to drive. The development of a clinical decision rule for this type of screening requires data from a longitudinal prospective cohort of older drivers. The aim of this article is to identify potential design, sampling and data collection barriers to such studies based on an analysis of the Canadian Safe Driving Study—phase I pilot (Candrive I). A convenience sample of 100 active older drivers aged 70 years or more was recruited through the aid of a seniors’ organization, 94 of whom completed the full study (retention rate 94%). Data were collected over the course of 1 year on various driving behaviours, as well as on cognitive, physical and mental functioning. Driving patterns were recorded using driving diaries, logs and electronic devices. Driving records from the Ministry of Transportation of Ontario (MTO) were obtained for the 3-year period preceding the study initiation and up to 1 year following study completion. An increased burden of illness was observed as the number of medical diagnoses and medication use increased over the study period. Study participants were involved in a total of five motor vehicle collisions identified through MTO records, which was comparable to the Ontario annual collision rate of 4.1% for drivers aged 75 years or older. In sum, many of the relevant logistical and practical barriers to studying a large sample of older drivers longitudinally have been shown to be addressable, supporting the feasibility of completing a large prospective cohort study of older drivers.     

高压柱塞泵的改进

介绍了高压柱塞泵＋蓄水罐型式的高压水除鳞系统中高压柱塞泵和循环阀组存在的一些问题,相应的改造措施,以及改造后的使用效果,有其独到之处.     

自适应系统中导频设计方案的研究

该文的目的是在导频辅助的自适应编码调制系统中,实现导频资源的优化配置,并研究新的设计方案对自适应系统性能的影响。利用衰落信道的二阶统计特性,以及信道的采样定理原理,推导出用以确定导频符号间隔的新算法,并由此定义了导频间隔的局部量和全局量,最终证明由新的导频间隔定义算法得到的局部量具有自适应特性,并且全局量是导频间隔的一个更紧更有效的上界。     

特高压工程高抗中性点绝缘水平及小电抗选择

为限制1000kV输电线路在各种运行方式下的潜供电流和恢复电压,必须正确地选择中性点小电抗的参数和高压并联电抗器中性点的绝缘水平。中性点小电抗的参数应根据全容量补偿的条件确定,根据实测的线路参数和线路高抗参数计算了小电抗的参数,建议调整4台小电抗的抽头,以便取得限制潜供电流和恢复电压的最佳效果。并联电杭器中性点和中性点小电杭的绝缘水平主要决定于出现在小电抗上的最大工频电压,补偿度愈大,电抗器端部对地的零序电压愈小,则并联电抗器中性点和小电抗相应的绝缘水平愈低。通过工频过电压分析和特高压试验示范工程系统调试期间实测数据的分析,根据2次单相人工接地试验和单开关空载运行单相偷跳的试验结果校核了高抗中性点及小电抗绝缘水平,可供后续特高压交流工程参考。     

Fe-Zeolite as on-Site Regenerable Adsorber for Chlorohydrocarbons in Groundwater – from Laboratory to Pilot Test

This study describes the design and upscaling of an on-site regenerable adsorbent fixed bed of Fe-loaded MFI zeolite for removal of chlorinated hydrocarbons (CHCs) from contaminated groundwater from laboratory studies to pilot scale. The zeolite has an excellent adsorption performance for the hydrophilic CHCs and can be regenerated on-site by flushing with H₂O₂ to degrade adsorbed contaminants by a catalytic Fenton-like reaction. In the pilot test, the Fe-zeolite (30 kg) maintained its performance over treatment of 1470 m³ of groundwater in 12 adsorption/regeneration cycles.     

Simulationsstrategie zur belastbaren Auslegung der Essigsäure-Rückgewinnung aus Abwässern der industriellen Celluloseacetatherstellung

Large quantities dilute acetic acid are generated during the industrial acetylation of cellulose. In the light of sustainability and circularity, it is crucial to recover and recycle the acetic acid (closed loop) released during this production. In this work, a simulation strategy for the robust design of the recovery of acetic acid from cellulose acetate production wastewater was developed and experimentally validated. The corresponding models (NRTL & UNIFAC) were discussed and used for simulation trials. The practical values confirmed the assumption of the applicability of a NRTL activity coefficient of α_ij = 0.2.     

Opportunities of experiential education in chemical technology and engineering

The University of Chemistry and Technology Prague, the Czech Technical University in Prague and ORLEN Unipetrol have established a common University center in the production facility of the refinery-petrochemical complex in Litvínov, Czech Republic. The university center offers higher education to more than 50 students in bachelor and master programs. The connection between the chemical industry and the academic environment has created a unique opportunity to apply experiential learning in many areas of teaching. The University center uses a newly built Training facility, which is equipped with several modules for training operators, engineers and, currently, students. Thanks to the attractiveness of the environment of the training facility premises, the target group of students has been extended to secondary and even primary schools. The University center organizes regular practice for secondary and primary schools at the training facility. The aim of these activities is to practice systematically modern methods of education through experience and to make technical disciplines as popular as possible among young students. Regionally, this experiential education system has achieved high popularity and, in addition to the University center own students, more than 500 students from around 30 secondary and primary schools go through the program every year.     

中压共轨式电控柴油喷射系统实现预喷的研究

本文提出了一种在中压共轨式燃油系统上利用柱塞中的泄流通道来实现预喷的方法，介绍了该方法的原理和结构特点，首先对泄流通道的结构尺寸进行预选，并从喷油率曲线中，计算出预喷量与总喷油量的比值；通过试验，得出了共轨压力，负荷，转速等因素对喷油特性的影响，研究表明，该方法在中压共轨式柴油机系统中实现预喷射具有一定的作用。     

孤东小井距复合驱采出液预处理试验研究

复合驱采出液的处理是复合驱油工艺的配套技术，本文分析了孤东小井距复合驱采出液对孤东一号联合站原油脱水的影响，介绍了孤东小井距复合驱采出液顶处理工艺流程，化学处理剂评选及预处理现场试验中取得的明显效果，复合驱采出液预处理是有效的，可行的。     

预开孔对钢铝热熔自攻丝接头力学性能的影响北大核心

热熔自攻丝技术(Flow Drill Screw,FDS)作为混合材料车身中单边连接的主要连接方式,在上层板材预开孔是其常用的辅助连接方法。以HC340/590DP高强钢和6063-T6挤压铝合金为研究对象,通过剪切拉伸实验,研究了上层板材厚度及预制孔尺寸对接头剪切强度及失效模式的影响。结果表明,当上层钢板厚度为0.8 mm,预制孔直径为5.5 mm时,FDS接头剪切峰值载荷及吸能能力大大降低。当预制孔直径小于5.5 mm时,相同预制孔直径下FDS接头吸收能量能力随上层板厚度增大呈减小趋势。此外,上层钢板厚度与预制孔直径之比f影响FDS接头失效模式及力学性能,当f大于0.27时,FDS接头失效模式为螺钉断裂,剪切峰值载荷基本不变;当f小于0.27时,FDS接头失效模式为上板撕裂,剪切峰值载荷随f增大而增大。