Resultanten von Kreisteilungspolynomen

Ohne Zusammenfassung     

Transformation of the Wiener measure under non-invertible shifts

Summary In this paper we consider the transformation of measure induced by a not-necessarily-invertible perturbation of the identity. The Radon-Nikodym density for the image of the Wiener measure and the associated Girsanov-type density are derived. An application of these results yields an extension of the degree theorem.     

Nuclear surface waves in alpha-particle and ion-ion collisions

Our earlier methods of interpretation of the resonances in ion-ion scattering (such as ¹²C + ¹²C, ¹²C + ¹⁶O, or ¹⁶O + ¹⁶O where they appear both experimentally and via optical-model calculations) in terms of nuclear surface waves are applied to the case of α-⁴⁰Ca scattering. The optical-model resonance results of Brink et al. are here extended in order to render them suitable for a surface-wave picture as well. Recent experimental results on ¹²C + ¹²C scattering are used to demonstrate the existence of surface waves of both Rayleigh and whispering gallery type in this system.     

Thermal stability of Ag-exchanged clinoptilolite rich mineral

Thermal stability of clinoptilolite rich mineral from Western Anatolia, Turkey and its Ag-exchange forms was investigated. Parent mineral of different sizes were heated up to 1000°C with heating rate of 2 and 10°C min^-1 using differential thermal analyzer (DTA) and thermogravimetric analyzer (TG). Ag exchange was conducted both in conventional constant temperature waterbath and microwave at 40, 60 and 80°C. The exchanged minerals were then characteized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), DTA and TG. The particle size and heating rate do not have significant effect on the thermal behavior of the parent mineral and no structural changes were observed with Ag exchange, only decomposition temperature was lowered. It was finally concluded that, Ag-exchanged clinoptilolite rich minerals were less thermally stable compared to parent mineral that does not affect their use for possible applications.     

Effects of Heavy Iodine Atoms and π-Expanded Conjugation on Charge Transfer Dynamics in Carboxylic Acid BODIPY Derivatives as Triplet Photosensitizers

Borondipyrromethene (BODIPY) chromophores are composed of a functional-COOH group at meso position with or without a biphenyl ring, and their compounds with heavy iodine atoms at −2, −6 positions of the BODIPY indacene core were synthesized. The photophysical properties of the compounds were studied with steady-state absorption and fluorescence measurements. It was observed that the absorption band is significantly red-shifted, and fluorescence signals are quenched in the presence of iodine atoms. In addition to that, it was indicated that the biphenyl ring does not affect the spectral shifting in the absorption as well as fluorescence spectra. In an attempt to investigate the effect of π-expanded biphenyl moieties and heavy iodine atoms on charge transfer dynamics, femtosecond transient absorption spectroscopy measurements were carried out in the environment of the tetrahydrofuran (THF) solution. Based on the performed ultrafast pump-probe spectroscopy, BODIPY compounds with iodine atoms lead to intersystem crossing (ISC) and ISC rates were determined as 150 ps and 180 ps for iodine BODIPY compounds with and without π-expanded biphenyl moieties, respectively. According to the theoretical results, the charge transfer in the investigated compounds mostly appears to be intrinsic local excitations, corresponding to high photoluminescence efficiency. These experimental findings are useful for the design and study of the fundamental photochemistry of organic triplet photosensitizers.     

Effects of hydrochloric acid treatment on structure characteristics and C<Subscript>2</Subscript>H<Subscript>4</Subscript> adsorption capacities of Ünye bentonite from Turkey: a combined FT-IR,XRD, XRF,TG/DTA and MAS NMR study

In this study, a bentonite sample from Ünye, Turkey was treated with various HCl solutions (0.1, 1.0 and 5.0 M) at 90 °C during 3 and 6 h. X-ray diffraction (XRD), X-ray fluorescence (XRF), differential thermal analysis (DTA), thermogravimetric analysis (TG), Fourier transform infrared (FT-IR), magic angle spinning nuclear magnetic resonance (²⁹Si and ²⁷Al MAS NMR) and surface area measurement methods were employed in order to investigate the structural and thermal changes occurring as a result of the acid activation. The data for the adsorption of C₂H₄ obtained at 273 K and pressures up to 100 kPa correlated with structural properties of the acid treated bentonite samples. With the increase of both concentration of acid solution and treatment time, the specific surface area values and the retentions of C₂H₄ gas of bentonite samples increased. Bentonite treated with 5.0 M HCl for 6 h adsorbed C₂H₄ most effectively.     

Cyclotomic p-adic multi-zeta values in depth two

In this paper we compute the values of the p-adic multiple polylogarithms of depth two at roots of unity. Our method is to solve the fundamental differential equation satisfied by the crystalline frobenius morphism using rigid analytic methods. The main result could be thought of as a computation in the p-adic theory of higher cyclotomy. We expect the result to be useful in proving non-vanishing results since it gives quite explicit formulas.