Hyperasymptotic solutions for certain partial differential equations

We present the hyperasymptotic expansions for a certain group of solutions of the heat equation. We extend this result to a more general case of linear PDEs with constant coefficients. The generalisation is based on the method of Borel summability, which allows us to find integral representations of solutions for such PDEs.Comment: 17 page

DESIGN, SYNTHESIS, AND OPTIMIZATION OF NON-FLUOROUS, CO2-PHILIC POLYMERS: A SYSTEMATIC APPROACH

Research done during the last 15 years has proven that one can use CO2 as a solvent in many processes. There have been compounds from surfactants to chelating agents that were shown to be soluble in CO2 to low pressures. By attaching CO2-philic groups to polymer chains, previously insoluble polymers have exhibited miscibility with CO2, allowing for applications such as emulsion polymerization, dispersion polymerization, dissolution of proteins, extraction of heavy metals, and other processes. Unfortunately, the most successful CO2-philes, the fluorinated polymers, have a very unfavorable economic drawback that makes their commercial use impractical. As a result, this work seeks to determine the characteristics that could be built into a carbon based polymer to allow for the polymer to be miscible with CO2 down to low pressures.Several design elements were considered in this work: the cohesive energy density, the free volume, and the Lewis acid/base interactions with CO2 acting as a Lewis acid. Lowering the cohesive energy density and increasing the free volume limited undesirable polymer-polymer interactions, while the addition of Lewis base groups to the polymer in the backbone and as grafted side chains increased the favorable polymer-CO2 interactions. Several side chains containing Lewis base groups were first grafted onto silicon-backbone polymers. The effects of the grafting and degree of substitution were determined, and the best performing side chains were then grafted onto a polyether backbone to investigate their interactions with the carbon/oxygen backbone.This work made clear the importance of adding optimal amounts of a Lewis base group to the polymer, whether in the backbone or as a grafted side chain. While attaining a low cohesive energy density and maintaining a low glass transition temperature are important, polymers with these features alone performed very poorly in CO2. The addition of Lewis base groups in the backbone or as a side chain dramatically improved the solubility of the polymers and showed the importance of favorable polymer-CO2 interactions. A key observation was that an ether functional group may provide the same Lewis acid/base interaction with CO2 that is seen with the acetate group

Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S

In this work the results of physical and numerical modeling of stresses in metal during continuous casting were shown. The numerical research for St3S ingot were realized. Computer program based on Finite Element Method (FEM) was used to simulation. Investigated conditions were based on actual data received from one of polish steel plant. The simulation of continuous casting process was made on GLEEBLE 3800 simulator. The results of thermal load and also stages of bending and straightening of the bloom and stress relaxation phenomenon were shown. Mechanical properties of a solid metal are described by the theory of dislocation that allows taking into account history of changes of stress and strain in the material.Fizikalno modeliranje naprezanja tijekom kontinuiranog lijevanja čelika St3S. U radu su prikazani rezultati fizikalnog i numeričkog modeliranja naprezanja u metalu tijekom kontinuiranog lijevanja. Provedeno je numeričko istraživanje ingota St3S. Za simulaciju je rabljen računalni program utemeljen na Metodi konačnih elemenata (MKE). Istraživani uvjeti temelje se na stvarnim podacima dobijenim u jednoj poljskoj čeličani. Simulacija procesa kontinuiranog lijevanja provedena je na simulatoru GLEEBLE 3800. Prikazani su rezultati toplinskog opterećenja a također stadiji savijanja i izravnavanja bluma te fenomen relaksacije naprezanja. Mehanička svojstva krutog metala opisana su uz pomoć teorije dislokacija koja omogućuje uzimanje u obzir prethodne promjene naprezanja i deformacije u metalu

Synthesis of iso-C-nucleoside analogues from 1-(methyl 2-O-benzyl-4,6-O- benzylidene-3-deoxy-α-D-altropyranosid-3-yl)but-3-yn-2-ones

1-(Methyl 2-O-benzyl-4,6-O-benzylidene-3-deoxy-α-D-altropyranosid-3- yl)but-3-yn-2-one (3a) reacted with 3-amino-1H-1,2,4-triazole and 5-aminopyrazole-4-carboxylic acid derivatives in the presence of base to furnish the triazolo[1,5-a]pyrimidine (5) and the pyrazolo[1,5-a]pyrimidines (8a-d), respectively. Treatment of 1-(methyl 2-O-benzyl-4,6-O-benzylidene-3-deoxy- α-D-altropyranosid-3-yl)-4-phenyl-but-3-yn-2-one (3b) with cyanacetamide, 2-cyano-N-(4-methoxyphenyl)acetamide und N-aryl-3-oxo-butyramides afforded the substituted nicotinonitriles (11a-d). Furthermore, reaction of 3b with 2-benzimidazolyl-acetonitrile yielded the benz[4,5]imidazo[1,2-a]pyridine-4- carbonitrile (13). Deprotection of 8d in two steps afforded the 2-amino-N-benzyl-5-(methyl 3-deoxy-α-D-altropyranosid-3-yl-methyl) pyrazolo[1,5-a]pyrimidine-3-carboxamide (10). Compounds 5 and 11d were treated with AcOH/H2O to furnish the 5-(methyl 2-O-benzyl-3-deoxy-α-D- altropyranosid-3-yl-methyl)[1,2,4]triazolo[1,5-a]pyrimidine (6) and the 3-acetyl-1,2-dihydro-1-(4-methoxyphenyl)-6-(methyl 2-O-benzyl-3-deoxy-α-D- altropyranosid-3-yl-methyl)-4-phenylpyridin-2-one (12), respectively

The Spider Anatomy Ontology (SPD)—A Versatile Tool to Link Anatomy with Cross-Disciplinary Data

Spiders are a diverse group with a high eco-morphological diversity, which complicates anatomical descriptions especially with regard to its terminology. New terms are constantly proposed, and definitions and limits of anatomical concepts are regularly updated. Therefore, it is often challenging to find the correct terms, even for trained scientists, especially when the terminology has obstacles such as synonyms, disputed definitions, ambiguities, or homonyms. Here, we present the Spider Anatomy Ontology (SPD), which we developed combining the functionality of a glossary (a controlled defined vocabulary) with a network of formalized relations between terms that can be used to compute inferences. The SPD follows the guidelines of the Open Biomedical Ontologies and is available through the NCBO BioPortal (ver. 1.1). It constitutes of 757 valid terms and definitions, is rooted with the Common Anatomy Reference Ontology (CARO), and has cross references to other ontologies, especially of arthropods. The SPD offers a wealth of anatomical knowledge that can be used as a resource for any scientific study as, for example, to link images to phylogenetic datasets, compute structural complexity over phylogenies, and produce ancestral ontologies. By using a common reference in a standardized way, the SPD will help bridge diverse disciplines, such as genomics, taxonomy, systematics, evolution, ecology, and behavior.Fil: Ramirez, Martin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Michalik, Peter. Ernst Moritz Arndt Universität Greifswald. Institut fur Geographie und Geologie; Alemani

Simulative Analysis of a New Type Wide Range Estimator of Protection Criterion Values

In the paper a new adaptive estimator of protection criterion values insensitive to wide range power system frequency changes is proposed and analysed. Its operation is based on a coarse calculation of signal frequency and appropriate correction of used orthogonal filters frequency responses as well as adaptation of chosen parameters of the measurement algorithm. The main features of the new method has been compared with standard criterion values estimators both theoretically and by simulations. The proposed estimators assure good accuracy of measurement within the frequency range from 5 to 95 Hz

3D freeform surfaces from planar sketches using neural networks

A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves