The Vibrational Spectra and Normal Coordinate Analysis of Semiconducting Y2BaCuO5

Both infrared (FTIR) and Raman spectra have been measured for the green semiconducting Y₂BaCuO₅ (2:1:1) in the Y-Ba-Cu-O system. Factor group analysis and normal-coordinate-analysis calculations have been conducted for this phase in order to determine the symmetries, the wavenumber locations and the eigenvector nature of its first-order modes of vibration along with the appropriate set of modified GVF force constants. The predicted vibrational spectral results are in good agreement with the experimentally observed FTIR and Raman spectral data. The generated force constants are interpreted along with those for related phases on the basis of structure.     

Stochastic nature of earthquake ground motion

In this paper, we analyze the irregular behavior of earthquake ground motion as recorded during the Kraljevo M5.4 earthquake, which occurred on November 3rd, 2010 in Serbia. We perform the analysis for the ground accelerations recorded at 6 seismological stations: Grua, Ruda, Rada, Bara, Zaga and Bdva. The latter were carefully chosen based on their corresponding tectonic zone and the local geological setting. For each station, we analyze the horizontal component of the ground acceleration in the north–south direction, which is the one of primary interest for engineering design. We employ surrogate data testing and methods of nonlinear time series analysis. The obtained results indicate that strong ground accelerations are stochastic, in particular belonging to a class of linear stationary stochastic processes with Gaussian inputs or distorted by a monotonic, instantaneous, time-independent nonlinear function. This type of motion is detected regardless of the corresponding tectonic setting and the local geological conditions. The revealed stochastic nature is in disagreement with the frequently assumed deterministically chaotic nature of earthquake ground motion.     

The Influence of Pressure in Paracetamol Tablet Compaction on 14N Nuclear Quadrupole Resonance Signal

¹⁴N nuclear quadrupole resonance (¹⁴N NQR) of several commercially available paracetamol tablets was measured. The spectra of two polymorphs are presented. The linewidths of the correspondent ¹⁴N NQR lines in all the measured samples containing the room-temperature stable monoclinic polymorph were noticeably different. We proved experimentally that the linewidth differences are the consequence of different compacting pressure in the production of tablets.     

Remote access mössbauer spectrometry

The authors’ design for a Mössbauer spectroscopy unit accessed via the Internet is presented. The spectrometer’s configuration, operational peculiarities, key specifications, and remote access procedures are described. More detailed educational, scientific, and technical information can be found at the project’s official website http://www.efmsb.ru.     

Bismuth titanate thin films prepared by wet-chemical techniques: effect of sol ageing time

In this work, layered perovskite bismuth titanate (Bi₄Ti₃O₁₂) thin films were fabricated on α-alumina substrates by spin coating process. Precursor sol was prepared by sol–gel process from bismuth nitrate and titanium butoxide in concentrated acetic acid, with diethylamine as a stabilizer. Processes occurring in the precursor sol were followed in the ageing period of 20 days. Thin films prepared from the as-synthesized and aged sols are crack-free, with the thickness of ~1 μm, uniform surface texture and rounded grains having grain size in nanometer range. Sintering of thin films was performed at various temperatures, and sintered thin films exhibited dense structure, fully crystallized with typical Aurivillius phase and without any preferred orientation and impurity phase. The influence of ageing of the precursor sol on the microstructure of obtained thin films was also investigated. Direct relation between hydrodynamic diameter of precursor particles and the morphology and the grain size of the obtained films was observed.     

Adamantyl pyran-4-one derivatives and their in vitro antiproliferative activity

Molecular Diversity - Pyran-4-one (maltol, kojic acid and chlorokojic acid 1) esters of adamantan-1-ylacetic acid were prepared through efficient synthetic routes in good yields and evaluated for...     

An algorithm for least squares analysis of spectroscopic data

This paper describes a variant of the Gauss-Newton-Hartley algorithm for nonlinear least squares, in which aQR implementation is used to solve the linear least squares problem. We follow Grey's idea of updating variables at intermediate stages of the orthogonalization. This technique, applied in partitions identified with known or suspected spectral lines, appears to be especially suited to the analysis of spectroscopic data. We suggest that this algorithm is an attractive candidate for the optimization role in Ekenberg's interactive computer graphics curve fitting program.     

On Solutions to Riemann's Functional Equation

In 1921 Hamburger proved that Riemann's functional equation characterizes the Riemann zeta function in the space of functions representable by ordinary Dirichlet series satisfying certain regularity conditions. We consider solutions to a more general functional equation with real weight k. In the case of Hamburger's theorem, k = . We show that, under suitable conditions, the generalized functional equation admits no nontrivial solutions for k > 0 unless k = . Our proof generalizes an elegant proof of Hamburger's theorem given by Siegel, and employs a generalized integral transform.1997 Sunrise Way