Solving Nonlinear Constrained Minimization Problems with a New Interval Valued Function

The paper represents a continuation of the work the author previously published in this journal for unconstrained problems. An interval (box) valued function, the so-called zone function, is introduced in the first section. The next section uses the new notion for finding global minima of continuous multivariate real functions over a set given by nonlinear inequality constraints. Two numerical examples are presented in the third section. The second numerical example gives a better approximation to a welded tubular structure problem than one that has appeared in the literature.     

Using S-graph to address uncertainty in batch plants

Processes and markets uncertainties make batch plants a complex environment to manage production activities. Uncertainties may cause deviations and infeasibilities in predefined schedules; this may result in poor planning and inefficient utilization of materials. Consequently, the relevance of explicitly incorporating variability in the scheduling formulation in order to offer more efficient plans and robust decisions to changes has become recognized. This work addresses the batch plants scheduling under exogenous uncertainty. The most widely utilized approach to tackle this problem is stochastic programming; however its solution results in high computational expenses. From another standpoint S-graph, a graph-theoretic approach, has proved to be very efficient to deal with deterministic scheduling. In this work, the S-graph framework is enhanced so that stochastic scheduling problems can be handled. For this purpose, a LP model that is used as performance evaluator has been coupled with S-graph framework. One of the main advantages of the proposed approach is that the search space does not increase according to the number of scenarios considered in the problem. Finally, the potential of the proposed framework is highlighted through two illustrative examples.     

Optimization of a Phenylacetaldehyde-Based Attractant for Common Green Lacewings (<Emphasis Type="Italic">Chrysoperla carnea s.l.</Emphasis>)

In field trapping tests, the catch of Chrysoperla carnea sensu lato (Neuroptera: Chrysopidae) increased when acetic acid was added to lures with phenylacetaldehyde. The addition of methyl salicylate to the binary mixture of phenylacetaldehyde plus acetic acid increased catches even further. The ternary blend proved to be more attractive than β-caryophyllene, 2-phenylethanol, or 3-methyl eugenol (compounds previously described as attractants for chrysopids) on their own, and no influence on catches was recorded when these compounds were added as fourth components to the ternary blend. There were minimal changes in activity when (E)-cinnamaldehyde or methyl anthranylate (both evoking large responses from female or male antennae of C. carnea in this study) were added, although both compounds showed significant attraction on their own when compared to unbaited traps. In subtractive field bioassays with the ternary mixture, it appeared that the presence of either phenylacetaldehyde or methyl salicylate was important, whereas acetic acid was less so in the ternary mixture. The ternary blend attracted both female and male lacewings at sites in southern, central, and northern Europe. Possible applications of a synthetic attractant for lacewings are discussed.     

Synchrotron infrared radiation for electrochemical external reflection spectroscopy: a case study using ferrocyanide

Synchrotron infrared radiation has been successfully coupled through an infrared (IR) microscope to a thin-cavity external reflectance cell to study the diffusion controlled redox of a ferrocyanide solution. Excellent signal-to-noise ratios were achieved even at aperture settings close to the diffraction limit. Comparisons of noise levels as a function of aperture size demonstrate that this can be attributed to the high brilliance of synchrotron radiation relative to a conventional thermal source. Time resolved spectroscopic studies of diffusion controlled redox behavior have been measured and compared to purely electrochemical responses of the thin-cavity cell. Marked differences between the two measurements have been explained by analyzing diffusion in both the axial (linear) and radial dimensions. Whereas both terms contribute to the measured current and charge, only species that originate in the volume element above the electrode and diffuse in the direction perpendicular to the electrode surface are interrogated by IR radiation. Implications for the use of ultramicroelectrodes and synchrotron IR (SIR) to study electrochemical processes in the submillisecond time domain are discussed.     

Biological systems: Stochastic,deterministic or both

Many systems in nature, including biological systems, have very complex dynamics which generate random-looking time series. To better understand a particular dynamical system, it is often of interest to determine whether the system is caused by deterministic subsystems (e.g. chaotic systems), stochastic subsystems, or both. Although there are now several different approaches to determine this from time series data (e.g. correlation dimension and Lyapunov exponent calculations), these methods often require large amounts of stationary data (biological data is frequently nonstationary for long time scales), can often mis-identify certain systems, and can be subject to other technical problems. Alternatively, one can use methods that measure the complexity in a particular system which seldom make assumptions about a particular system, such as assuming the presence of stationarity. Additionally, mathematical and computational modeling techniques can be used to test different hypothesis about the dynamics of biological systems.     

PRES 2006—Energy resources and management: Heat integration,heat pumps,emissions and waste to energy

This editorial introduces and provides an overview of a Special Issue dedicated to the 9th conference of Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction—PRES 2006. It contains 11 selected papers covering various fields of energy related issues focusing on recent developments and includes energy resources, management and use, heat integration, heat pumps, emission treatment and waste to energy. The selected papers include interesting applications in the power generation, food industry, building materials production, oil refining, district heating, waste treatment and hydrogen production.     

Frequency of loci of HLA-DRB1* and -DQB1* alleles in the Slovak population]

Results on HLA-DRB1* and HLA-DQB1* allele frequencies in the Slovak population by PCR-SSP method are presented. HLA-DRB1* alleles were determined in 130 and HLA-DQB1* alleles in 143 healthy unrelated individuals. The highest frequency was observed for the alleles HLA-DRB1*1101-13 (0.203), HLA-DRB1*0701 (0.142), HLA-DQB1*0301 (0.244), and HLA-DQB1*0201 (0.209). The least frequent alleles were HLA-DRB1*1402-6-9, HLA-DRB1*0901 (both 0.0038), HLA-DQB1*0401 (0.007), and HLA-DQB1*0601 (0.0035). The results obtained by DNA-typing were compared with those calculated from the serological study. No statistically significant differencies were found. The allele frequencies obtained in our study were also compared with those of the Czech and Austrian populations. No statistically significant differencies were observed. (Fig. 2, Tab. 3, Ref. 13.)     

New application of an anchored Ru(II)-N-heterocyclic carbene complex

A new, heterogenized Ru(II)-N-heterocyclic carbene complex was prepared via the method developed by Augustine. The anchored catalyst was characterized by spectros-copic methods and was applied in the hydrogenation of different olefins, aldehydes and ketones. The hydrogenations were performed both in alcohol and in aqueous media on homogeneous and heterogenized complexes. The immobilized complex had a reasonable activity in both conditions and at the same time it was possible to filter out from the reaction mixture and to recycle in several subsequent runs.