Artificial neural nets for prediction of silicon content of blast furnace hot metal

Conventional models for prediction of silicon content of blast furnace hot metal are briefly reviewed. Four different artificial neural net (ANN) models, namely, back propagation algorithm (BPA), dynamic learning rate algorithm, functional link network (FLN) and fuzzy neural network (FNN), are trained and tested on operational data from blast furnace (BF1) at Visakhapatnam Steel Plant. FNN can predict silicon mass content of hot metal with a standard error (actual versus predicted) of 0.09% and correlation coefficient of 0.86; standard back propagation predicts with a standard error of 0.08 % and correlation coefficient of 0.79.     

可编程光处理器加速WDM向动态发展

目前，波分复用在电信网的扩容中扮演着关键角色。然而，也正是在这种重要性与日俱增的同时，光学所起的作用在很大程度上还仅仅是传输，信息的交换和处理功能仍然需要在电域上实现。最近，随着技术的进步，系统集成商开发的光系统已经能提供更多的功能，即不仅仅限于将数据从A地传送到B地的功能，主要进展还表现在将那些原先只能在电域上处理的交换和路由功能引入到光层。城域网中的交换，远比在长途传输网中采用WDM进行扩容要困难得多。实际上，在交换机将OC-192或OC-48乃至更低容量的信号送到企业或集团用户之前，城域网设备首先应将…     

Liquid Phase Sintering of Alumina, III. Effect of Trapped Gases in Pores on Densification

The microstructure evolution and densification kinetics of alumina containing 10 and 20 vol% calcium aluminosilicate glass were studied, for sintering under vacuum and air at 1600°C. Residual porosity was always present in the air-fired samples. The kinetic analysis lent strong support to the notion that trapped gases inhibited the densification and limited the attainment of full density. The samples containing 20 vol% glass were able to reach full density during vacuum sintering. However, the samples containing 10 vol% glass contained some residual porosity even after vacuum sintering, which was attributed to the preferential volatalization of liquid phase.     

In‐Situ Raman Spectroscopy Study of Photoinduced Structural Changes in Ge‐rich Chalcogenide Films

Very few studies have been directed at the compositional dependence of the intrinsic photostability of the Ge_xSe_1?x binary ChG films especially for the Ge‐rich films with the mean coordination number (MCN) larger than 2.67. Here, by measuring the in‐situ transmission changes, it shows that the photosensitivity (e.g., photobleaching, PB) of the Ge‐rich films (as compared to the GeSe₂ film) is attenuated, in fact almost completely eliminated in the film with the largest MCN. A straightforward technique, in‐situ Raman spectroscopy, is used to record the time‐resolved intrinsic structural changes during the irradiation of the films. The result indicates a transition from PB towards photostability occurs at the critical composition of GeSe₂ corresponding to the structural phase transition. The stressed rigid structures of the Ge‐rich films inhibit any significant photo‐structural changes.     

Creation of Nano–Macro-Interconnected Porosity in a Bioactive Glass–Ceramic by the Melt-Quench-Heat-Etch Method

We demonstrate that suitable thermal treatment of biocompatible CaO–Na₂O–P₂O₅–SiO₂ glasses prepared by the usual melt-quench results in spinodal phase separation and crystallization of phases at very different length scales. Selective chemical leaching of these phases allows the formation of interconnected multi-modal porosity, with pore size ranging from several nanometers to tens of micrometers. Such novel nano–macroporous glasses have potential applications as superior bioscaffolds.     

Electricity demand for Sri Lanka: A time series analysis

This study estimates electricity demand functions for Sri Lanka using six econometric techniques. It shows that the preferred specifications differ somewhat and there is a wide range in the long-run price and income elasticities with the estimated long-run income elasticity ranging from 1.0 to 2.0 and the long-run price elasticity from 0 to −0.06. There is also a wide range of estimates of the speed with which consumers would adjust to any disequilibrium, although the estimated impact income elasticities tended to be more in agreement ranging from 1.8 to 2.0. Furthermore, the estimated effect of the underlying energy demand trend varies between the different techniques; ranging from being positive to zero to predominantly negative. Despite these differences, the forecasts generated from the six models up until 2025 do not differ significantly. It is therefore encouraging that the Sri Lanka electricity authorities can have some faith in econometrically estimated models used for forecasting. Nonetheless, by the end of the forecast period in 2025 there is a variation of around 452 MW in the base forecast peak demand that, in relative terms for a small electricity generation system like Sri Lanka's, represents a considerable difference.     

Reverse running pumps analytical,experimental and computational study: A review

A pump can be used as turbine and has good application in micro-hydropower schemes. Pump as turbine (PAT) is one of the best alternatives for fulfilling the energy demands and providing the electricity in remote and rural areas. In this study a review on the work done in the area of pump working as turbine has been explained. Based upon the literature survey, analytical, experimental and computational works on pump as turbine have been discussed. Several methods for predicting the behaviour of pumps in turbine mode have been developed but no method is appropriate for the entire range of specific speeds. Computational fluid dynamics (CFD) is also used to study the reverse operation of centrifugal pumps, but still results are not yet acceptable.     

Gas absorption with filled polymer systems

This paper deals with the gas absorption behavior of polymer systems. The emphasis is on the difference between filled and unfilled polymers to explain heterogeneous nucleation in filled polymers. A Foaming Process Simulator has been built to study the gas absorption. It consists of a test chamber that holds the polymer samples. The chamber can be pressurized with gas up to 5000 psi and heated up to 450°F. The gas pressure is monitored by a high‐accuracy pressure transducer and recorded by a data acquisition system. The amount of gas absorbed by a polymer is determined from the pressure change in the test chamber. A rotor applies shear to the polymer melt to investigate the shear effects. Two polymer systems were tested: HDPE with/without talc, and PVC with/without calcium carbonate. The fillers were well dispersed as verified with scanning electron microscope. The tests were done at the melt temperatures from 120°C to 177°C and a saturation pressure of about 18.9 MPa. It was found that the filled polymers absorb more gas compared to the unfilled ones. It is suggested that there is a certain amount of gas accumulated in the filler‐polymer interface. This accumulated gas helps to create cells during the foaming process.     

Substituent effects on the colour,dyeing and fastness properties of 4-N-β-cyanoethyl-N- β-hydroxyethylaminoazobenzenes part I—monosubstituted derivatives

Data on a series of 40 monosubstituted derivatives of 4-N-β-hydroxyethyl-N-β- cyanoethylaminoazobenzene are reported. Structure-property relationships with respect to electronic spectra of the dyes, coloration and fastness properties on cellulose secondary acetate and polyester fibres are investigated. Reasons for the anomalous properties of the 2′-nitro derivative in exhibiting low lightfastness on synthetic polymer fibres are presented. The coloration of polyester fibres is additionally assessed in terms of data derived from tristimulus values of dyed fibres, and the effect of substituents on such data is discussed.