Air bag effectiveness as function of impact speed

An investigation was conducted to estimate the effectiveness of air bags as a function of velocity. The study consisted of three parts: a theoretical idealization, an analysis of National Automotive Sampling System/Crashworthiness Data System (NASS/CDS), and a reanalysis of previously published Fatality Analysis Reporting System (FARS) data. The theoretical analysis looked at idealized risk curves as a function of velocity; assuming that the air bag offers a benefit for both belted and unbelted occupants. Analysis of the NASS/CDS data looked at the effectiveness of air bags as a function of velocity for Maximum Abbreviated Injury Scale (MAIS) 3+ injuries. The reanalysis of the previously published FARS data looked at the effectiveness of the air bag as a function of velocity for fatalities. The theoretical analysis indicates that the air bag effectiveness should be greatest at the low velocities. The field data analysis of both NASS/CDS and FARS were consistent with the theoretical analysis, indicating that air bags are most effective at the lower velocities, below 40 kph (25 mph), for both belted and unbelted occupants. Although it was not possible to estimate a different effect for belted and unbelted for fatalities using FARS, it was possible for MAIS 3+ using NASS/CDS. For unbelted occupants the effectiveness goes to zero or becomes negative above 40 kph (25 mph) for MAIS 3+, and for belted occupants the effectiveness stays positive but with significantly lower magnitude for speeds above 40 kph (25 mph).     

Assessment of older drivers: relationships among on-road errors, medical conditions and test outcome

PROBLEM: It is essential that driver licensing authorities have a valid and reliable system for evaluating older drivers' continuing competency; road tests are usually required as part of such a system. This study sought to find information about the nature of driving errors made during license review tests, and about relationships between error type and test outcome for older drivers. METHOD: Data from licensing authority files from 533 road tests during a 12-month period were analyzed; medical and other referral information was included. Average driver age was 76 years. Performance scores were generated for intersection negotiation, lane changing, low speed manoeuvres, positioning and speed control, safety margin, and car control. RESULTS: Logistic regression analysis showed that test outcome was well predicted by a subset of driving performance scores; adding driver age to the model explained very little variance. Age alone was strongly associated with outcome. Relationships between referral information and test outcome are also reported. IMPACT: Results highlight several factors relevant to the development of more valid and reliable road tests for older drivers.     

Assessment of the leaching of metallic elements in the technology of solidification in aqueous solution

Results are presented of experiments performed to optimize the solidification/stabilization system for metallic elements in aqueous solution. This system involves mixing cement and a solution of metallic elements in a conventional mixer: the paste thus obtained is transferred drop by drop into a recipient filled with an aqueous solution of NaOH at 20% by weight, in which it solidifies immediately. The separate use of chloride solutions of Li+, Cr3+, Pb2+ and Zn2+ makes it possible to obtain granules displaying various levels of compressive strength. Three different inertization matrices were used in the experiments, the first consisting solely of Portland cement, the second of Portland cement and a superplasticizer additive, and the third of Portland cement partially replaced with silica-fume and superplasticizer. The results of the tests performed showed a very low level of leaching into the alkaline solidification solution for Cr3+, the quantity leached being under 2% as against higher levels for the other metallic elements. For all the considered elements, the best results were obtained by using silica-fume in the inertization matrix.     

Origin of the Henze solution/precipitate from morula cells of the blood of the ascidian Phallusia mammillata

 The "Henze solution", derived originally from the aqueous extraction of pelleted whole blood from the ascidian Phallusia mammillata, was examined using spectral studies. The aqueous extraction of fractionated blood cells including compartment cells, signet ring cells, and morula cells obtained using cell separation techniques were also examined. It was found that this Henze solution, and the Henze precipitate itself derived from this solution, emanated solely from the morula cells. Furthermore, it was found that this solution is formed independently of the vanadium metal ions otherwise associated with the vanadocytes. Observation of the Henze precipitate by light microscopy shows that this material partially forms crystallites or microglasses. Received: 27 July 1999 / Accepted in revised form: 28 February 2000     

铁路中小站段污水排放规律及处理匹配技术研究

随着铁路通车里程的增长，铁路中小站段随之增加。但是大部分站段污水经过简单处理或不经处理排放，造成了环境的污染。通过对沈阳铁路局下属中小站站段调研，找出典型站段污水排放规律，并提出与之相匹配的污水处理技术。     

呼和浩特强对流天气的数值模拟分析

利用三维积云数值模式模拟了呼和浩特地区强对流天气的发展过程，并结合实时雷达回波资料进行了对比分析，指出模式输出的部分物理量与理论值、雷达回波或地面天气及降雹（水）实况符合得较好。从对模式输出的几个物理量的统计分析，得出利用三维积云数值模式预测强冰雹过程的概念模型。结果表明，三维积云数值模式能用于模拟对流云特别是强对流云的发展过程，可在人工影响天气业务工作中应用并不断发展。     

在线衍生化吹扫捕集-气相色谱/质谱分析水中的五氯酚

建立了通过乙酸酐衍生化-吹扫捕集-气相色谱／质谱分析水中五氯酚的新方法，探讨了吹扫时间、样品池温度、离子强度以及衍生化试剂的加入量等条件对捕集效果的影响。结果表明：采用吹扫时间25min、样品池温度60℃、离子强度20％氯化钠以及衍生化试剂的量200μl等条件对水中的五氯酚有较好的捕集效果，用于水中五氯酚的测定，结果满意。     

The structure of turbulence near a tall forest edge: the backward-facing step flow analogy revisited

Flow disturbances near tall forest edges are receiving significant attention in diverse disciplines including ecology, forest management, meteorology, and fluid mechanics. Current theories suggest that near a forest edge, when the flow originates from a forest into a large clearing, the flow retains its forest canopy turbulence structure at the exit point. Here, we propose that this framework is not sufficiently general for dense forested edges and suggest that the flow shares several attributes with backward-facing step (BFS) flow. Similar analogies, such as rotor-like circulations, have been proposed by a number of investigators, though the consequences of such circulations on the primary terms in the mean momentum balance at the forest clearing edge have rarely been studied in the field. Using an array of three triaxial sonic anemometers positioned to measure horizontal and vertical gradients of the velocity statistics near a forest edge, we show that the flow structure is more consistent with an intermittent recirculation pattern, rather than a continuous rotor, whose genesis resembles the BFS flow. We also show that the lateral velocity variance, v'2, is the moment that adjusts most slowly with downwind distance as the flow exits from the forest into the clearing. Surprisingly, the longitudinal and vertical velocity variances (u'2 and w'2) at the forest edge were comparable in magnitude to their respective values at the center of a large grass-covered forest clearing, suggesting rapid adjustment at the edge. Discussions on how the forest edge modifies the spectra and co-spectra of momentum fluxes, effective mixing length, and static pressure are also presented.