Kinetics of phenol degradation by activated sludge: Value of measurements in a batch reactor

Kinetic measurements on the degradation of phenol in a batch reactor were done at 20°C using an activated sludge taken from a continuous reactor where the process had shown Monod-type kinetics without substrate inhibition. When employing a sludge sample, adapted to the substrate steady concentration C_s¹, for runs with initial substrate concentration C_s⁰, observed batch rates were as high as expected for C_s⁰ = C_s¹, but lower than expected in runs carried out at C_s⁰ > C_s1¹, with indications of a transient inhibitory effect instead of a positive response to the increased substrate concentration. It is concluded that kinetic data collected in a batch reactor are of limited value for the design of a continuous biodegradation process.     

The fate of cognition in very old age: Six-year longitudinal findings in the Berlin Aging Study (BASE).

The authors report full-information longitudinal age gradients in 4 intellectual abilities on the basis of 6-year longitudinal changes in 132 individuals (mean age at T? = 79.27, age range = 70-100) from the Berlin Aging Study. Relative to the cross-sectional parent sample (N = 516, mean age at T? = 84.92 years), this sample was positively selected because of differential mortality and experimental attrition. Perceptual speed, memory, and fluency declined with age. In contrast, knowledge remained stable up to age 90, with evidence for decline thereafter. Age gradients were more negative in old old (n = 66, mean age at T? = 83.04) than in old (n = 66, mean age at T? = 73.77) participants. Rates of decline did not differ reliably between men and women or between participants with high versus low life-history status. They conclude that intellectual development after age 70 varies by distance to death, age, and intellectual ability domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mesures en impulsions pour faisceaux hertziens en visibilité directe

This work is providing an experimental tool for investigating the transmission characteristics of the propagation path of line-of-sight radio relay links in the 6 GHz band, resorting to a direct observation of its impulse response. Two circuit models are respectively representing the propagation characteristics (multipath scintillation) and the action upon transmitted signals. The timevariant impulse response is the most fitting system function for both propagation anomalies identification and message impairment’s evaluation. A measuring equipment for direct observation of the impulse response in the signal bandwidth is described. The data processing procedures leading to relative accuracies which are indicated satisfactory in all practical cases. Some experimental results are shown.     

The onset of droplet entrainment in annular downward flows

The point of onset of large disturbance waves and droplet entrapment has been determined for the annular downward flow of air-water mixtures in a 24 mm ID tube. Experimental results are in a good qualitative agreement with the previous work by Webb and Hewitt¹. These results indicate that

• 1 the critical gas velocity at the onset of entrainment is lower than the value predicted by available correlations
• 2 the critical gas velocity continuously decreases at increasing the liquid Reynolds number
• 3 below a liquid Reynolds number of 270 no entrainment occurs even at gas velocities as high as 80 m/sec

A correlation for the critical gas velocity which is based on a simple physical model of atomization, is also proposed.     

Electrical conductivity in poly(vinyl chloride)

An interpretation by mathematical theory of experimental data already published by the author is given, concerning the electrical conductivity measurement, in direct current, of PVC and plasticizer compositions. The electrical conduction in PVC is due to two mechanisms: one of polarization, which predominates at low temperature, below a transition temperature T₀ and one of ionic conduction which predominates at high temperature above T₀. The mathematical expressions for polarization conductivity k_p and ionic conductivity k₀, agree very well with the experimental data and justify also the great difference in activation energy between the two mechanisms and the independence of activation energy of ionic conductivity from the system viscosity and type of ions.     

Techniques for integrating sensors into the enterprise network

Cheap programmable sensor devices are becoming commercially available. They offer the possibility of transforming existing enterprise applications and enabling entirely new ones. The merging of sensor networks into the enterprise network poses some distinct problems. In particular, information from theses devices must be obtained in a way which minimizes their energy use and must be aggregated and filtered before being sent to the application server to prevent it from being overwhelmed. We describe a range of complementary techniques for integrating sensors into an enterprise network. These comprise new architectural entities within the enterprise network — edge server — new means of sharing information within the enterprise network — messaging binning — and new protocols for extracting information from the sensor network — Messo.     

先进的连续叠层技术赋予非织造材料附加值

对如何高速有效地进行稳定连续不停机的卷绕和使用A.Celli非织造公司制造的可与市场上已有的不同工艺相结合的卷绕设备作了说明,与传统的生产线相比,该生产线的投资少,且灵活性好,特别是可增加产品附加值,因而该工艺过程不再是一个更薄弱的环节,而变成了增加附加值的一个契机。