Studies of an infinite element method for acoustical radiation

Infinite element computations are very efficient for predicting the vibro-acoustic response and sensitivities of a vibrating structure for an exterior acoustic domain. In addition, domain decomposition methods are very powerful algorithms for solving large linear systems in parallel. In this paper, an infinite element method is proposed and analyzed for parallel computations purpose. An original formulation of this method with Lagrange multipliers defined on (semi-)infinite space is presented. The implementation aspects of this method in an industrial acoustic software (SYSNOISE) are discussed. New numerical results illustrate the efficiency of the proposed method for realistic acoustical radiation problems.     

Algebraic expressions for vibration-rotation line intensities of near prolate asymmetric molecules: Application to SO2 molecule

A treatment of the intensities of vibration-rotation lines of near prolate asymmetric molecules is given, leading to explicit expressions relating the observed to the appropriate coefficients in the expansions of the potential energy and the dipole moment. The theoretical results are compared with experimental determinations of line intensities in the υ₁-band of sulfur dioxide.     

Reactions of collman complex with tin(IV) and germanium(IV) porphyris,formation of [tin(II) and germanium(II) porphyrins] tetracarbonyliron and crystal structure of [2,3,7,8,12,13,17,18-octaethylporphinato tin(II)] tetracarbonyliron

The action of Na₂Fe(CO)₄ with tin(IV) and germanium(IV) porphyrins affords metal(II) porphyrin complexes [(por)M(II)Fe(CO)₄] (por = porphyrinate, M - Sn(II) or Ge(II)). The molecular structure of [(oep)Sn(II)Fe(CO)₄] was solved by X-ray diffraction techniques. The molecular structure of [(oep)Sn(II)Fe(CO)₄] was solved by X-ray diffraction techniques : the Sn coordination is square pyramidal with the iron in axial position (Sn-Fe = 2.492(1)Å) whereas the Fe coordination is trigonal bipyramidal. Mössbauer parameters provide convincing evidence for the formal zero oxidation state of the iron atom.     

Representation matricielle du moment dipolaire dans la base des fonctions propres de l'Hamiltonien; intensites infrarouges et moments dipolaires des etats vibrationnellement excites

The molecular dipole moment matrix is obtained in the Hamiltonian representation by a contact transformation. Infrared intensities and dipole moments of polyatomic molecules have been obtained for vibrationally-excited states. The results have been applied to the SO₂ molecule.     

X-ray crystallographic structure of the 9,10-dihydro-11,12bis[(1,3,3-trimethylureido)methyl]-9,10ethanoanthracene dihydrate

As a part of studies on MDR reversal agents, structure of the 9,10-dihydro-11,12-bis[(1,3,3-trimethylureido)methyl]-9,10-ethanoanthracene dihydrate is reported. Crystal data: C₂₆H₃₄N₄O₂ × 2 H₂O; mol. mass 470.60; monoclinic; space group: C2/c, a = 15.7492(6) Å; b = 7.2245(3) Å; c = 24.3442(10) Å; β = 106.795(2)^∘; V = 2651.73(22) ų; z = 4; dx = 1.179 mg/m³; μ = 0.64 mm⁻¹; F(000) = 1016; final R = 0.061 for 2501 reflections [I > 4 σ (I)]. Only half of the molecule is unique. The two nonplanar rings from the independent part of 9,10-dihydro-9,10-ethanoanthracene adopt a boat conformation. Crystallographic data demonstrate the “syn-syn” conformation of urea substituents in the molecule. In the crystal, water molecules are linked to the main species by H-bonds: O3′⋅sH12w—O1—H11w⋅sO3′(1.5 − x, 0.5 − y, 1 − z).     

Absolute Continuity of Joint Laws of Multiple Stable Stochastic Integrals

We are interested in the laws of multiple stable stochastic integrals defined by LePage series representation in references(3,10,11). We continue the study started in Ref. 3 and give conditions ensuring absolute continuity of joint laws of stable integrals. To this end, we apply a stratification method on the Skorohod space on which we first take back the problem.     

Approaches toward the synthesis of 2,5-disubstituted-1,3-thiazolidines

Synthetic approaches for new 2,5-disubstituted-1,3-thiazolidines are described. Steric and electronic effects of the N-substituent of the thiazolidine ring represent the major parameter in the rearrangement process. The nmr studies demonstrate that N-unsubstituted 2,5-disubstituted-1,3-thiazolidines exist as epimeric mixture, while the corresponding N-acetylated analogues exist as a conformer mixture.