Oscillation criteria for fourth-order functional differential equations

Some new criteria for the oscillation of all solutions of certain fourth-order functional differential equations are established.     

Generalized Krull Semigroup Rings

In this article, we give a complete characterization of when the (composite) semigroup ring is a generalized Krull domain.     

Coupling of mixed finite elements and boundary elements

The symmetric coupling of mixed finite element and boundaryelement methods is analysed for a model interface problem withthe Laplacian. The coupling involves a further continuous ansatzfunction on the interface to link the discontinuous displacementfield to the necessarily continuous boundary ansatz function.Quasi-optimal a priori error estimates and sharp a posteriorierror estimates are established which justify adaptive mesh-refiningalgorithms. Numerical experiments prove the adaptive couplingas an efficient tool for the numerical treatment of transmissionproblems.     

Automorphisms of one-rooted trees: Growth, circuit structure, and acyclicity

A natural interpretation of automorphisms of one-rooted trees as output automata permits the application of notions of growth and circuit structure in their study. New classes of groups are introduced corresponding to diverse growth functions and circuit structure. In the context of automorphisms of the binary tree, we discuss the structure of maximal 2-subgroups and the question of existence of free subgroups. Moreover, we construct Burnside 2-groups generated by automorphisms of the binary tree which are finite state, bounded, and acyclic. Translated from Itogi Nauki i Tekhniki, Seriya Sovremennaya Matematika i Ee Prilozheniya. Tematicheskie Obzory. Vol. 58, Algebra-12, 1998.     

Tetra-tert-butyl-s-indacene is a Bond-Localized C2h Structure and a Challenge for Computational Chemistry

Whether tetra-tert-butyl-s-indacene is a symmetric D_2h structure or a bond-alternating C_2h structure remains a standing puzzle. Close agreement between experimental and computed proton chemical shifts based on minima structures optimized at the M06-2X, ωB97X-D, and M11 levels confirm a bond-localized C_2h symmetry, which is consistent with the expected strong antiaromaticity of TtB-s-indacene.     

Thermal properties of clay containing polymeric reinforcement as an eco-friendly bio-insulation composite for buildings

Journal of Thermal Analysis and Calorimetry - Polymer/clay-based composites were prepared via solution intercalation method using natural clay and poly (ethylene) glycol (PEG4000) as organic...     

An investigation of pine needles fluidization,combustion performance,and fly ash behavior in fluidized bed combustor

Journal of Thermal Analysis and Calorimetry - Coniferous forest residue, such as pine needles, has enormous potential in Himalayan territories and could play a significant role in energy supply....     

Synthesis,characterization, and antioxidant and anticholinesterase activities of pyrazolo derivatives

Twenty-four pyrazolo derivatives (1–4)(a-f) were synthesized and characterized by FTIR, ¹H, and ¹³C NMR (Nuclear Magnetic Resonance), and elemental analysis. The synthesized compounds were also investigated for their antioxidant and anticholinesterase activities. The compounds (3–4)(a-f) carrying morpholine ring were more active than the piperidinyl containing compounds (1–2)(a-f) in both activities. The compound 4f showed higher activity in both assays as compared with the others. Additionally, the anticholinesterase activity test provided higher values than the galantamine in the BChE assay. Therefore, compound 4f can be used as anticholinesterase agent and/or anticholinesterase assay standard.     

Preparation of produced water reference material for analyzing 226Ra by gamma spectrometry

Journal of Radioanalytical and Nuclear Chemistry - Produced water reference material containing high concentration of 226Ra activity was prepared in 2009 and used for ALMERA worldwide proficiency...