Characterization Of Water Quality Criteria for Ozonation Processes. Part II: Lifetime of Added Ozone

The lifetime value of ozone in a water is one of the key parameters for describing the characteristics of a water considering an ozonation process and for planning, optimizing, and steadily adapting the ozonation process. This lifetime is highly sensitive with respect to the chemical composition of the water. Interferences of different radical-type chain reactions make it difficultto predict it solely from analytical characterizations. The waters with respect to the lifetime of ozone, therefore, have to be characterized by direct laboratory experiments. However, because the half-life times depend on the type of operation used for the measurement, it is appropriate to formulate corresponding standardized guidelines that allow comparison whenever the responses of different waters have to be compared, and whenever characterizations have to be followed during the decades during which a water utility applies a process.     

Financial Viability of Fiber-Reinforced Polymer (FRP) Bridges

The application of fiber-reinforced polymer (FRP) technology to bridges can provide performance enhancements at a time when there is a large and growing need to replace aging bridges in the United States. However, construction costs are significantly higher than with traditional methods, and it is not clear if this technology can become competitive in the standard short-span bridge market. This study investigates current and future costs to determine how cost competitive this technology is likely to become, taking into account the expected improvements in manufacturing, transport, and installation, as well as life-cycle differences. Based on two demonstration FRP bridges and the learning curve approach, the results show that anticipated improvements would not be sufficient to compete on cost with reinforced-concrete bridges. Unless significant improvement also occurs in the cost of component material, this technology will not be cost competitive for the standard short-span bridge, and the application of FRP technology will be limited to other segments of the market, such as bridge deck construction and bridge repair.     

Facilitation of extinction by an increase or a decrease in trial duration.

Five experiments examined the effects of altering the duration of a conditioned stimulus (CS) for extinction. For the first 3 experiments, rats received conditioning with a 10-s CS before different groups received extinction with a CS that was either the same duration or longer than that used for conditioning. For the remaining 2 experiments, conditioning was conducted with a 60-s CS before different groups received extinction with a CS of either the same duration or a shorter duration than that used for conditioning. In all experiments, extinction progressed more readily when the CS duration was different for the 2 stages than when it was constant. The results are discussed in terms of rate expectancy theory and associative learning theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preventing adolescent depression: An evaluation of the Problem Solving For Life program.

This study evaluated the effectiveness of the Problem Solving For Life program as a universal approach to the prevention of adolescent depression. Short-term results indicated that participants with initially elevated depressions scores (high risk) who received the intervention showed a significantly greater decrease in depressive symptoms and increase in life problem-solving scores from pre- to postintervention compared with a high-risk control group. Low-risk participants who received the intervention reported a small but significant decrease in depression scores over the intervention period, whereas the low-risk controls reported an increase in depression scores. The low-risk group reported a significantly greater increase in problem-solving scores over the intervention period compared with low-risk controls. These results were not maintained, however, at 12-month follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

半石墨化阴极碳块在135kA大型铝电解槽上的应用

半石墨化阴极碳块应用在135kA大型铝电解槽上,可使阴极电压降降低48mV、节约了电能,并提高了电解槽的使用寿命,实践证明,半石墨化阴极碳块是较好的阴极材料。     

绿色包装的评价手段——生命周期评价法

将运用纸和塑料包装的具体事例进行绿色包装评估体系的介绍-生命周期评估方法（LifeCycleAssessment)，它作为一种新型的管理工具，注重对包装的全过程分析，通过对生命周期评估方法的目标和范围界定，清单分析，影响评价和改善评价在纸塑包装上的初步探讨，为包装开发生产提供决策支持，使LCA这一环境管理工具得到重视，从而促进可持续发展和国际贸易的需要。     

Gold Medal Award for Life Achievement in Psychological Science: Raymond B. Cattell.

The American Psychological Foundation (APF) Gold Medal Awards recognize distinguished and enduring records of accomplishment in 4 areas of psychology. The 1997 recipient of the Gold Medal Award for Life Achievement in Psychological Science is Raymond B. Cattell. Raymond B. Cattell has made prodigious, landmark contributions to psychology, including factor analytic mapping of the domains of personality, motivation, and abilities; exploration of three different medias of assessment; separation of fluid and crystallized intelligence; and numerous methodological innovations. Thus, Cattell became recognized in numerous substantive areas, providing a model of the complete psychologist in an age of specialization. It may be said that Cattell stands without peer in his creation of a unified theory of individual differences integrating intellectual, temperamental, and dynamic domains of personality in the context of environmental and hereditary influences (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A self-consistent approximation for crack bridging by elastic/perfectly plastic ligaments

In several contexts where the effectiveness of crack-bridging reinforcements degrades when the static or cyclic stress transmitted by the reinforcements exceeds a threshold value, the reinforcements can be idealized as elastic/perfectly plastic springs with the yield stress corresponding to the threshold stress for degradation. A self-consistent procedure is proposed for estimating the net crack tip stress intensity factor k_tip for a given applied stress, crack length and length of unbridged zone. Plausible analytical representations are postulated for the crack profile over the intervals where the crack-bridging springs respond elastically. The representations involve k_tip as a scaling factor, and lead to implicit formulae for k_tip. When the applied stress exceeds the threshold for degradation, further simplifications yield explicit formulae for k_tip. The best results obtained from these formulae agree closely over much of the parameter space with those obtained more laboriously by solving a non-linear integral equation.

The approximations can be used to assess the influence of cyclic debonding on the effectiveness of externally bonded repairs, or of fiber reinforcement in metal laminates and metal-matrix composites. One of the approximations is an upper bound for k_tip and can therefore offer conservative estimates for the effectiveness of the bonded repair or fiber reinforcement.     

CRACK INITIATION AND SMALL FATIGUE CRACK GROWTH BEHAVIOUR OF SQUEEZE-CAST Al-Si ALUMINIUM ALLOYS

Abstract— Fatigue strength, crack initiation and small crack growth behaviour in two kinds of squeeze-cast aluminium alloys, AC8A-T6 and AC4C-T6 were investigated using smooth specimens subjected to rotatary-bending fatigue at room temperature. Fatigue resistance of these alloys was almost the same as that of the wrought aluminium alloys because of their fine microstructure and of the decrease in defect size due to squeeze-casting. Fatigue crack initiation sites were at the eutectic silicon particles on the surface of specimens or at internal microporosity in the specimens. Crack initiation life, defined as a crack length of 50 μm on the specimen surface, was successfully estimated from an evaluation of initiation sites using fracture mechanics and the statistics of extrema. Small fatigue crack growth in the two kinds of alloys obeys the relation proposed by Nisitani et al. , namely that d(2c)/d N = C (σ_a/σ_B)ⁿ· (2 c ), where C is a constant and σ_B is the ultimate tensile strength. It is pointed out that an improvement in fatigue strength of cast aluminium alloys can be expected by refining the eutectic silicon rather than by an increase in static strength.     

设备设计的系统经济分析

对连续运转的大型设备，应使实现产品功能的各个零部件的寿命大体相同，趋于一次性使用，以降低故障损失费和维修费。通过建立设备系统寿命的数学模型．定量的分析设备的系统经济性。