Feature-based classifiers for design optimization

We present a design optimization method for systems with high-dimensional parameter spaces using inductive decision trees. The essential idea is to map designs into a relatively low-dimensional feature space, and to derive a classifier to search for high-performing design alternatives within this space. Unlike learning classifier systems that were pioneered by Holland and Goldberg, classifiers defined by inductive decision trees were not originally developed for design optimization. In this paper, we explore modifications to such classifiers to make them more effective in the optimization problem. We expand the notions of feature space, generalize the tree construction heuristic beyond the original information-theoretic definitions, increase the reliance on domain expertise, and facilitate the transfer of design knowledge between related systems. There is a relatively small but rapidly growing body of work in the use of inductive trees for engineering design; the method presented herein is complementary to this research effort.     

Mixing and solid-liquid mass-transfer rates in a creusot-loire uddeholm vessel: A water model case study

The process of mixing and solid-liquid mass transfer in a one-fifth scale water model of a 100-ton Creusot-Loire Uddeholm (CLU) converter was investigated. The modified Froude number was used to relate gas flow rates between the model and its protoype. The influences of gas flow rate between 0.010 and 0.018 m³/s and bath height from 0.50 to 0.70 m on mixing time were examined. The results indicated that mixing time decreased with increasing gas flow rate and increased with increasing bath height. The mixing time results were evaluated in terms of specific energy input and the following correlation was proposed for estimating mixing times in the model CLU converter: T _mix=1.08Q ^−1.05 W ^0.35, where Q (m³/s) is the gas flow rate and W (tons) is the model bath weight. Solid-liquid mass-transfer rates from benzoic acid specimens immersed in the gas-agitated liquid phase were assessed by a weight loss measurement technique. The calculated mass-transfer coefficients were highest at the bath surface reaching a value of 6.40 × 10⁻⁵ m/s in the sprout region. Mass-transfer coefficients and turbulence parameters decreased with depth, reaching minimum values at the bottom of the vessel.     

A preliminary study on boron removal from Kizildere/Turkey geothermal waste water

A study is made of boron removal from Kizildere/Turkey geothermal waste water using the boron selective resin Amberlite IRA 743. The resin in salt form has no boron removal capacity if the solution is unable to neutralize the released acid during the exhaustion period. In the case of Kizildere waste water, with a pH value of 8.9 and high HCO₃⁻ content, single stage regeneration is feasible and the exhausted resin can be regenerated economically. According to a preliminary estimate, the electricity production cost would rise by 1 ¢/kWh.     

Tensile behaviour in natural building stone: Serena sandstone

The tensile behavior of Serena sandstone is investigated by means of uni-axial tensile and bending tests. In order to obtain an overall characterisation of a quasi-brittle material, such as Serena sandstone, it is necessary to investigate the post-peak softening branch by adopting a stable control system. Test results on different size specimens are presented. Also analysed in this paper is the effect of the boundary conditions in a uni-axial tensile test by comparing free and fixed platens tests. A laser interferometry technique (ESPI) was adopted to investigate the strain field and crack propagation in the material.A notable outcome of the research is the location of crack penetration before the peak load, that in the case of the bending test is almost constant in specimens of different size.     

Accumulation of hydrogen and its influence on the microstructure and mechanical properties of Kh18N10T steel

By the methods of thermal-desorption spectrometry and nuclear reactions, we study the processes of trapping, thermal desorption, and evolution of the profiles of distribution of deuterium ionically implanted with an energy of 12 keV into Kh18N10T steel at room temperature. The evolution of the microstructure of steel under the conditions of irradiation of samples with D₂⁺ ions up to doses of 1 · 10¹⁸ D/m²−2 · 10²² D/m² is studied by the method of electron microscopy. The regularities of changes in the mechanical properties of steel after irradiation are determined. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 5, pp. 117–121, September–October, 2007.     

Mechanoluminescent pulse pressure sensors. Processing of output optical signal

The process of mechanoluminescence transformation of a pulse pressure sensor is considered. The process consists in excitation of emission under the action of mechanical loading. An algorithm for use in processing the output optical signal of the sensor that makes it possible to determine an input shock pulse is presented. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 28–31, October, 2007.     

RF antenna analysis with the ICANT code

The ICANT code computes self-consistently the surface current distribution on a 3D antenna model radiating in a plasma or vacuum and has been used to analyze the coupling properties of various antenna models. In this work it is used to assess near-fields generated by different versions of the TCABR (Tokamak Chauffage Alfvén wave heating experiment in Brazil) antenna as well as coupling properties of the TEXTOR tokamak in Forshungszentrum Jülich. Two different strap models planned for the TCABR antenna are shown to be practically equivalent in terms of maximum electric field. Textor coupling calculations are close to experimental values.     

Effect of biochemical storage on the denitrification potential of acetate in sequencing batch reactors.

This study evaluates the effect biochemical storage on the denitrification potential (N(DP)) of acetate. The fate of bacterial storage is evaluated in a sequencing batch reactor system operated in a sequence of anoxic/aerobic phases, fed with acetate as a pulse and continuously under anoxic conditions. N(DP) is defined based on system stoichiometry both for direct growth and storage on acetate. Experimental results do not support conceptual calculations based on system stoichiometry, yielding a higher denitrification potential, N(DP), for continuous feeding than the N(DP) obtained with pulse feeding, due to partial utilisation of the stored PHB within the anoxic phase. The nitrate, acetate and poly-beta-hydroxybutyrate (PHB) profiles obtained in the experimental studies were used in model calibrations for two different feeding patterns. Results of model simulations confirm the experimental results and evaluate the effects imposed on the denitrification potential by sludge age and the anoxic volume ratio.     

Phytochemical and biological investigation of <Emphasis Type="Italic">Stevia rebaudiana</Emphasis> Bertoni; 1-labdane-type diterpene

Five labdane diterpenoids, austroinulin, iso-austroinulin, sterebin E, sterebin E acetate, and sterebin A acetate, along with hydrocarbons, aliphatic alcohols, β-amyrin, β-sitosterol and stigmasterol were isolated from the chloroform soluble fraction of the methanol extract of Stevia rebaudiana leaves. Chlorogenic and caffeic acids were isolated from the EtOAc fraction. All the isolated compounds were identified using spectral tools. The chloroform and methanol extracts proved significant anti-inflammatory effect and caused marked inhibition of carrageenan-induced paw oedema in rats.