Application of average dynamic programming to inventory systems

We show the existence ofaverage cost (AC-) optimal policy for an inventory system withuncountable state space; in fact, the AC-optimal cost and an AC-optimal stationary policy areexplicitly computed. In order to do this, we use a variant of thevanishing discount factor approach, which have been intensively studied in recent years but the available results not cover the inventory problem we are interested in.The work of the first author (OVA) was partially supported by Fondo del Sistema de Investigación del Mar de Cortéz under grant SIMAC/94/CT-005. The work of the second author (RMdO) was partially supported by Consejo Nacional de Ciencia y Tecnologia (CONACyT) under grant 0635P-E9506.     

Surface relaxation of Ni(110) investigated by high energy ion scattering

The surface relaxation of Ni(110) has been investigated with High Energy Ion Scattering (HEIS). The results indicate significant displacements of at least two surface layers, corresponding to a contraction of 4.8 ± 1.7% in the first interlayer distance, followed by an expansion of 2.4 ± 1.2%.     

Nitrat- und Nitritbestimmung in Gerbereiabwässern

Ohne Zusammenfassung     

A theory of inelastic behavior of materials Part I. Ideal inelastic materials

Archive for Rational Mechanics and Analysis -     

Magnetic structure of the canted 1D-antiferromagnet NaBaFe2F9

NaBaFe₂F₉ crystallizes with the Ba₂CoFeF₉ structural type (space group P2₁/n, Z = 4). In this structure, infinite cis double [M₂F₉]^3? chains of corner sharing octahedra are isolated one from each other by sodium and barium ions. At 4.5 K, the cell parameters (Å) are found to be: a = 7.3236(3), b = 17.4525(7), c = 5.4586(2), β = 91.840(3)°. Antiferromagnetic interactions dominate but, below T_N ? 19 K, a parasitic ferromagnetic component appears with σ_r(4.5K) = 0.03(1) μ_B·mole^?.The magnetic structure (C_xF_yC_z mode) was foreseen by the macroscopic theory of Bertaut and established from neutron powder diffraction. Using the Rietveld profile refinement method, the 4.5 K spectrum was analysed at $\text{λ =}\text{1.909}\text{A}\text{?}\text{(R}{}_{\mathrm{<mtext>Profile</mtext>}}\text{=}\text{0.093}\text{, R}{}_{\mathrm{<mtext>Nucl</mtext>}}\text{=}\text{0.053}\text{, R}{}_{\mathrm{<mtext>Mag</mtext>}}\text{=}\text{0.126}\text{)}$ and the 4.5–35K difference spectrum at $\text{λ =}\text{2.518}\text{A}\text{?}\text{(R}{}_{\mathrm{<mtext>Mag</mtext>}}\text{=}\text{0.049}\text{, R}{}_{\mathrm{<mtext>Profile</mtext>}}\text{=}\text{0.092}\text{)}$. The magnetic moments on two Fe³⁺ sites, lie mainly in the (0 1 0) plane, approximately at 45° from the a- and c-axes. They form a pseudo G-type antiferromagnetic arrangement (μ(Fe1) = 3.60(4) μ_B;μ(Fe2) = 3.61(6)μ_B).