Determination of siphon operating regimes

Necessary and sufficient conditions are found for continuous and periodic liquid motion in systems containing siphons.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. 6, pp. 916–920, June, 1987.     

Parathion degradation and toxicity reduction in solar photocatalysis and photolysis.

The solar photocatalytic degradation of methyl parathion was investigated using a circulating TiO2/solar light reactor. Under solar photocatalysis condition, parathion was more effectively degraded than solar photolysis and TiO2-only conditions. With solar photocatalysis, 20 mg/L of parathion was completely degraded within 60 min with a TOC decrease of 63% after 150 min. The main ionic byproducts during photocatalysis recovered from parathion degradation were mainly as NO3-, NO2- and NH4+, 80% of the sulphur as SO4(2-), and 5% of phosphorus as PO4(3-). The organic intermediates 4-nitrophenol and methyl paraoxon were also identified, and these were further degraded in solar photocatalytic condition. Two different bioassays (Vibrio fischeri and Daphnia magna) were used to test the acute toxicity of solutions treated by solar photocatalysis and photolysis. The Microtox test using V. fischeri showed that the toxicity expressed as EC50 (%) value increased from 5.5% to >82% in solar photocatalysis, indicating that the treated solution is non-toxic, but only increased from 4.9 to 20.5% after 150 min in solar photolysis. The acute toxicity test using D. magna showed that EC50 (%) increased from 0.05 to 1.08% under solar photocatalysis, but only increased to 0.12% after 150 min with solar photolysis, indicating the solution is still toxic. The pattern of toxicity reduction parallels the decrease in TOC and the parathion concentrations.     

The 'Conceptual Change In Science' project

Abstract This paper outlines the work of the Conceptual Change in Science project, funded as part of the ESRC InTER programme. The aims of this research project are to clarify and describe the process of change in learners' conceptual understandings of natural phenomena. The domain of reasoning selected for study is that of mechanics. Computer software which may be useful in exploring and developing pupils' reasoning and promoting conceptual change in this domain is being developed and evaluated. The group that is carrying out the research is based at the Universities of Leeds, Glasgow and the Open University.     

Reconstruction of the friction units of turbine guide vanes

Conclusions After the almost 2-yr operation of the gate apparatus since the start of reconstruction of friction units of the vanes, we can make a preliminary evaluation of the effectiveness of the works:There is practically no leakage of water through the gate vanes to the turbine cover, which led to a complete unloading of the drainage pumps on the turbine cover and the efficiency of operating the gate apparatus increased considerably.Repair of the gate apparatus is not required during maintenance.There is no vibration of the gate vanes, since the gaps in the friction units of the journals of the gate vanes are minimum and stable.The operating personnel objectively evaluate highly the work of the gate apparatus of the turbine after reconstruction and will continue this work on the remaining turbines.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 12–14, September, 1985.     

Changing the hydrogen content of alloy steel in relation to the technology used to cool cast slabs

Results are reported from the production of two trial heats of alloy steel in which the cast slabs were cooled in a thermostatted chamber and in a dense stack. It is shown that cooling slabs in such a chamber makes it possible to reduce the hydrogen content of the steel 30% compared to slabs that are cooled while stacked.     

Time-series detection of perspiration as a liveness test in fingerprint devices

Fingerprint scanners may be susceptible to spoofing using artificial materials, or in the worst case, dismembered fingers. An anti-spoofing method based on liveness detection has been developed for use in fingerprint scanners. This method quantifies a specific temporal perspiration pattern present in fingerprints acquired from live claimants. The enhanced perspiration detection algorithm presented here improves our previous work by including other fingerprint scanner technologies; using a larger, more diverse data set; and a shorter time window. Several classification methods were tested in order to separate live and spoof fingerprint images. The dataset included fingerprint images from 33 live subjects, 33 spoofs created with dental material and Play-Doh, and fourteen cadaver fingers. Each method had a different performance with respect to each scanner and time window. However, all the classifiers achieved approximately 90% classification rate for all scanners, using the reduced time window and the more comprehensive training and test sets.     

Effective parameters of static coupled physicomechanical field in matrix composites

Conclusions It is shown that the problem of evaluating the effective parameters of composites for a wide range of stationary coupled fields is reduced to examining uncoupled fields.The multiparticle method of the effective field was generalized with special reference to the problems of examining the static coupled physicomechanical fields in composites.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 27, No. 4, pp. 105–111, July–August, 1991.     

Analysis of the formation of glass waste in the electric lamp industry

Translated from Steklo i Keramika, No. 1, pp. 6–7, January, 1991.