On nonspecific evidence

When simultaneously reasoning with evidences about several different events it is necessary to separate the evidence according to event. These events should then be hand independently. However, when propositions of evidences are weakly specified in the sense that it may not be certain to which event they are referring, this may not be directly possible. In this article a criterion for partitioning evidences into subsets representing events is established. This criterion, derived from the conflict within each subset, involves minimizing a criterion function for the overall conflict of the partition. an algorithm based on characteristics of the criterion function and an iterative optimization among partitionings of evidences is proposed. © 1993 John Wiley & Sons, Inc.     

Pollutant adsorption during activated carbon and steam regeneration in technical columns (experiments, modelling) Part I. Influence of radial maldistribution in activated carbon beds during adsorption and desorption of air pollutants

Adsorption experiments in activated carbon columns of technical scale show that, with fresh carbon, the radial maldistribution — caused by higher bed porosity near the wall than in the bulk — influences the local exit concentrations of pollutants, especially at environmentally relevant low concentrations. This effect leads to an earlier pollutant breakthrough near the wall thus increasing the median exit pollutant concentrations markedly even at columns diameters 100 particle diameter.

The modelling of pollutant adsorption, including the maldistribution effects in an activated carbon bed, correlates well with measured values. Yet the same maldistribution effects lead, during pollutants desorption with saturated steam, to better desorption of the wall-near zone compared with the bulk, so that local pollutant breakthrough during the following adsorption step occurs later in the wall-near zone.

If the upper part of the carbon bed is preheated before desorption and in addition, superheated steam is taken for desorption, the residual pollutant concentration becomes so low all over the cross section that, during the following adsorption step, local pollutant breakthrough can occur earlier in the wall-near zone again.     

Nanoscience and nanotecnology on the balance

A number of advantages of nanostructured materials over bulk materials and their potential applications in many scientific and technological fields have been revealed in recent years. To find out the main growth and trends of this exciting new scienence and technology fields the growth rate of the nano-prefixed terms in the title of journal papers has been measured. It has been shown that the investigations dealing with graphite nanotubes represent kinetically the most active field of research in the nanosciences.     

A dynamic look at a class of skew distributions. A model with scientometric applications

A theoretical model of repetitive events is presented and applied to the scientific publication process. Based on three simple postulates, a relation between population growth and distribution of authors by publication productivity in a scientific community is established. Predictions of the model are supported by empirical evidences.     

The migration from the internal coatings of food cans; summary of the findings and call for more effective regulation of polymers in contact with foods: a review

The analysis of migrates from the internal coatings of food cans showed that the present regulation is not sufficient to ensure safety of food contact polymers. The migrates often consist of complex mixtures of reaction products and impurities, and their harmlessness cannot be deduced from the use of non-toxic starting substances compiled in positive lists. The regulation proposed herein asks producers to analyse the composition of the migrates. It includes an upper limit for the molecular weight (e.g. 1000Da) and thresholds defining concentrations in the foods down to which components must be identified and evaluated. Primarily considering feasibility at reasonable costs, thresholds of 30 mu g/kg for individual components and 300 mu g/kg for the sum of the unidentified materials are proposed. Producers must be able to demonstrate that the individual components or mixtures exceeding this limit, including reaction products with food components, have no toxic effect.     

31P-magnetic resonance spectroscopy (31P-MRS) of human allografts after renal transplantation

BACKGROUND: 31P-Magnetic resonance spectroscopy (31P-MRS) can be used as a non-invasive tool for measuring the relative intracellular concentrations of several phosphorus metabolites in different organs. Various pathological conditions are characterized by different metabolic patterns. We studied the value of 31P-MRS after renal transplantation with both an uneventful and a clinically complicated course. METHODS: We determined the relative concentrations of phosphate-containing metabolites in renal allografts of humans with 31P-MRS (1.5 Tesla) in the first few weeks after transplantation; 18 patients with an uneventful clinical course and 10 patients who required dialysis after transplantation were examined. Six patients with a stable allograft function 2-3 months after transplantation served as controls. RESULTS: In patients with primary allograft function, we found a significant correlation between the phosphomonoester/phosphodiester-ratio (PME/PDE) (r = 0.66, r < 0.01) and the time after transplantation, but no correlation between the nucleoside triphosphate (beta-NTP)-concentration (r = -0.11) and the time course. In the patients with primary or early allograft dysfunction caused by histologically proven rejection (n=5), we found a low beta-NTP compared to patients with an uncomplicated clinical course (0.09+/-0.01 vs 0.15+/-0.03), but no differences in the PME/PDE ratio (0.73+/-0.21 vs 0.80+/-0.21). In contrast, the PME/PDE ratio was lowered in three patients with delayed graft function caused by acute tubular necrosis (0.45+/-0.07 vs 0.80+/-0.21), but the beta-NTP concentration was not reduced (0.15+/-0.003 vs 0.15+/-0.03). The 31P-MR spectrum of two patients with cyclosporin A damage was not altered compared to the controls. CONCLUSIONS: 31P-MRS can be used in patients in the early period after renal transplantation. A significant correlation between the PME/PDE ratio and the time course but no change in the beta-NTP concentration was found in patients with primary allograft function in the first 4 weeks after renal transplantation. Different patterns of 31P-MR spectra were observed depending on the different causes of primary and early transplant dysfunction.     

Introduction to a new class of high performance light stabilizers and the influence of light stabilizers structure on the polymer's life time

The mode of action of two classes of UV absorbers (2-(hydroxyphenyl)benzotriazoles and 2-(2′-hydroxyphenyl)-1,3,5-triazines) is discussed. Theoretical explanations for the superior light stability of the latter are given and confirmed by measured half life times in polycarbonate and solution. A mathematical model for the quantitative prediction of light protection factors is proposed.     

From inductive inference to algorithmic learning theory

We present two phenomena which were discovered in pure recursion-theoretic inductive inference, namely inconsistent learning (learing strategies producing apparently “senseless” hypotheses can solve problems unsolvable by “reasonable” learning strategies) and learning from good examples (“much less” information can lead to much more learning power). Recently, it has been shown that these phenomena also hold in the world of polynomial-time algorithmic learning. Thus inductive inference can be understood and used as a source of potent ideas guiding both research and applications in algorithmic learning theory.