Resolvent and lattice points on symmetric spaces of strictly negative curvature

We study the asymptotics of the lattice point counting function for a Riemannian symmetric space X obtained from a semisimple Lie group of real rank one and a discontinuous group of motions in X, such that has finite volume. We show that as , for each . The constant corresponds to the sum of the positive roots of the Lie group associated to X, and n = dimX. The sum in the main term runs over a system of orthonormal eigenfunctions of the Laplacian, such that the eigenvalues are less than . Received: 4 January 1999     

Harmonic lifts of modular forms

It is shown that each complex conjugate of a meromorphic modular form for $\mathrm{SL}_{2}(\mathbb{Z})$ of any complex weight p occurs as the image of a harmonic modular form under the operator $2i y^{p} \partial_{\bar{z}}$ . These harmonic lifts occur in holomorphic families with the weight as the parameter.     

Phonologically determined asymmetries in vocabulary structure across languages

Studies of spoken-word recognition have revealed that competition from embedded words differs in strength as a function of where in the carrier word the embedded word is found and have further shown embedding patterns to be skewed such that embeddings in initial position in carriers outnumber embeddings in final position. Lexico-statistical analyses show that this skew is highly attenuated in Japanese, a noninflectional language. Comparison of the extent of the asymmetry in the three Germanic languages English, Dutch, and German allows the source to be traced to a combination of suffixal morphology and vowel reduction in unstressed syllables.     

On the determination of 36Cl and 129I in solid materials from nuclear decommissioning activities

Journal of Radioanalytical and Nuclear Chemistry - Determination of the 36Cl and 129I massic activities using pyrolysis combined with radiochemical separation (using a Cl-resin) in concrete and...     

OH Dynamics in a Nanosecond Pulsed Plasma Filament in Atmospheric Pressure He–H2O upon the Addition of O2

The influence of the addition of O₂ on the OH production in a He + 0.1 % H₂O discharge is investigated using laser induced fluorescence. The plasma properties $(T_{\rm g},\;n_{\rm e})$ are reported and used to explain the observed time and spatially resolved OH density, which is absolutely calibrated using Rayleigh scattering. Compared to the case when only H₂O is added, an increase in the measured OH density is observed in the far afterglow. A zero-dimensional chemical kinetic model is constructed, which allows to determine the reactions responsible for the OH production in the far afterglow. When O₂ is admixed, the key reaction $\hbox{O} + \hbox{OH} \longrightarrow \hbox{O}_{2} + \hbox{H}$ causes quenching of OH and production of increased densities of H, HO₂ and H₂O₂, which subsequently leads to additional OH production in the late afterglow.     

Sum Formula for SL2 over a Number Field and Selberg Type Estimate for Exceptional Eigenvalues

((Without abstract)) Submitted: January 1997     

Reflection of plane waves from the boundary of a pre-stressed compressible elastic half-space

The effect of pre-stress on the propagation and reflection ofplane waves in an incompressible isotropic elastic half-spacehas been examined recently by the authors (Ogden & Sotiropoulos,1997). In the present paper the corresponding analysis for compressiblematerials is detailed. In the two-dimensional context consideredfor incompressible materials the (homogeneous) plane waves werenecessarily shear waves. By contrast, in the compressible contextpure shear waves can propagate only in specific directions inthe considered principal plane and, in a general direction,a quasi-shear wave may be accompanied by a quasi-longitudinalwave, as is the case in the anisotropic linear theory. The dependenceof the (in-plane) slowness section on the pre-stress (and finitedeformation) and on the choice of constitutive law is elucidated.This information is used to determine the reflection coefficientsfor reflection of either a (quasi-) shear wave or a (quasi-)longitudinal wave from the boundary of the half-space and tocharacterize the different cases which arise depending on thegeometry of the slowness section. The theoretical results are illustrated by numerical calculationsfor the range of possible types of behaviour with referenceforms of strain-energy function and different states of finitedeformation and to the question of stability of the half-space.     

Decomposition of Crystal Violet by an Atmospheric Pressure RF Plasma Jet: The Role of Radicals,Ozone, Near-Interfacial Reactions and Convective Transport

Cold atmospheric pressure plasma (CAP) oxidizes organic compounds in water through the generation of a variety of reactive species including O₃ and OH radicals. While the energy efficiency and rate of decomposition of the chemical compound in water is already extensively studied, only few studies focused on the reactive species responsible for the decomposition. We report on an investigation of the chemical reactive species involved in the decomposition of crystal violet (CV), a model organic compound, by an RF driven plasma jet in different gas mixtures. Different gas mixtures lead to different concentrations of reactive species responsible for the decolorization of CV. Moreover, the effect of transport limitations on the efficiency of the plasma treatment is reported. A study of positive control measurements, the effect of scavengers of relevant reactive species and particle imaging velocimetry reveal the dominant role of short-lived species at the plasma–liquid interface in which OH most likely plays an important role. Moreover, the decolorization rate is limited by transport of CV to the near boundary region. The results suggest that for the optimization of water treatment by the short-lived species generated by a plasma, an optimum transport of the to-be-treated compounds to the interface might be more critical than effective reactive species production in the plasma.

     

Enhanced chemiluminescence detection of some dansyl amino acids in liquid chromatography

Summary The dansylated amino acids alanine, glutamic acid, methionine and norleucine were separated by reversedphase HPLC and detected via chemical excitation using the post-column, TCPO-peroxyoxalate reaction system. Enhancement of the chemiluminescence emission was achieved by including the surfactant Triton X-100 in the eluent.