Some aspects of mathematical and chemical modeling of complex chemical processes

Some theoretical questions involved in the mathematical modeling of the kinetics of complex chemical process are discussed. The analysis is carried out for the homogeneous oxidation of ethylbenzene in the liquid phase. Particular attention is given to the determination of the general characteristics of chemical systems from an analysis of mathematical models developed on the basis of linear algebra

Композиционные силикатные краски с улучшенными технологическими сойствами

The composition of one-packing silicate paint on the basis of liquid glass modified by acrylic dispersion in number of 5%, including inactive filler in number of 15% in the form of talc and chalk, zinc oxide ranging from 5 to 9% as a hardener, and an active silica component which contents changes depending on its nature was developed. Liquid glass compositions with usage of aerosol and activated quartz sand was received. They improved characteristics and increased viability approximately to one year

Cost Analysis on Imaging Diagnostic Techniques in Cerebral and Abdominal Neonatal Pathology

Background: Improvement of health care quality and cost control are the main aims of the health care reform in Romania. Objective: The aims of the research are to analyse the trend of costs for imaging techniques used as diagnostic tools for cerebral and abdominal neonatal pathology and to study the relationship between cost and diagnostic benefits. Design: This is a retrospective observational study design without a control group, conducted in the Radio-Imaging Department, Cluj District University Hospital, Romania, from October 2000 to February 2006. Patients: The study population was represented by neonates investigated in the Radio-Imaging Department, Cluj District University Hospital. Intervention: Five imaging diagnostic techniques used in the diagnosis of cerebral and abdominal neonatal pathology were investigated. Measurements: The costs of the investigated techniques were calculated. The concordance between clinical and imaging diagnostic was recorded. Results: Magnetic resonance proved to be the most expensive investigation. The rate between the raising of costs on investigation type on year was constant. The average cost of imaging investigations for patients with identified pathological aspects (€ 42.72) was not statistically significant (p > 0.05) compared with the average cost for patients with no pathologic imaging aspects (€ 37.62). The concordance between the clinical suspicion and the radio-imaging diagnosis was of 52.35%. Conclusions: The raise of radio-imaging investigation costs had a decreasing tendency over the years studied, decrease explained by the stabilization of the Romanian monetary market. The results on concordance analysis lead to the necessity of training of both clinicians and radiologists

Frustration-induced exotic properties of magnetic molecules

Geometric frustration of interacting spin systems is the driving force of a variety of fascinating phenomena in low-dimensional magnetism. In this contribution I will review recent results on frustration-induced effects in magnetic molecules, i.e. zero-dimensional magnetic systems, as well as in a recently synthesized frustrated molecule-based spin tube, i.e. a one-dimensional spin system.Comment: 5 pages, 9 eps figures; proceedings of the symposium on "Spin- and charge-correlations in molecule-based materials", October 2005, Koenigstein (Taunus), German

Large-scale numerical investigations of the antiferromagnetic Heisenberg icosidodecahedron

We present up to date investigations of the antiferromagnetic Heisenberg icosidodecahedron by means of the Density Matrix Renormalization Group method. We compare our results with modern Correlator Product State as well as Lanczos calculations.Comment: 20 pages, 11 figure