A global study of resonance production and of exchange processes inK − p interactions at 6.5 GeV/c

A sample of 3414 events of the typeK ^? p →K ^? pπ ⁺ π^? were recorded in the ANL 12-foot hydrogen bubble chamber exposed to aK ^?-meson beam of 6.5 GeV/c momentum. The total cross section for this reaction (1.17±0.07 mb), is compared to data obtained at neighbouring energies. Resonance production is studied using two complementary procedures; an analytical multichannel fit and multidimensional cluster methods. Baryon exchange processes, accounting for approximately 5% of the data, are isolated by the latter method.     

Discretization results for the Huff and Pareto-Huff competitive location models on networks

In this paper we prove that there always exists a finite set that includes an optimal solution for the Huff and the Pareto-Huff competitive models on networks with the assumption of a concave function of the distance. In the Huff model, there is always a vertex of the network that belongs to the solution set. For the Pareto-Huff model, we prove that there is always an optimal solution at, or an ε-optimal solution close to, a vertex or an isodistant point, a new concept introduced in this paper.     

The proton affinities and proton transfer in imine, amidine and guanidine series

The enthalpies of formation of neutral and protonated alkyl imines, amidine and guanidine are obtained by ab initio theoretical means using an isodesmic reaction technique. The corresponding proton affinities are obtained and discussed in terms of thermochemical stabilization energies. Their relation to the proton transfer process is examined and discussed. To this end, the structure and properties of various molecular complexes obtained between these molecules of interest and formic acid are explored. The sensitivity of this process to the presence of a neighbour water molecule is commented.     

Effects of intersubband interaction on multisubband electron transport in single and double quantum wells

The multisubband electron transport properties are studied for doped single quantum well and gated double asymmetric quantum well structures. The effects due to intersubband interaction and screening of the ionized impurity scattering are also investigated. We show that intersubband coupling plays an essential role in describing the screening properties as well as the effect of ionized impurity scattering on the mobility in a doped single quantum well. For coupled double quantum well structures, negative transconductance is found theoretically which is due to resonant tunneling between the two quantum wells.     

Manifestation of internal states in the nonlinear conductivity of Frohlich polarons

A numerical analysis of the Thornber-Feynman (T.F.) theory for the nonlinear polaron conductivity reveals, in the limit low temperature, interesting structure in the electric field versus average velocity curve. This structure is attributed to the internal states of the polaron.     

Optical,magneto-optical and mössbauer spectroscopy on Co3+ substituted cobalt ferrite Co2+Fe2−xCo3+xO4(0 ⩽ x ⩽ 2)

The magneto-optical spectra of Co_1+xFe_2?xO₄ show with increasing Co³⁺ content an increasing intensity of the 4A₂ ? 4T₁(F) and 4A₂ ? 4T₁(P) transition of Co²⁺ at 0.8 and 2.0 eV. A decrease in the Co²⁺-Fe³⁺ charge transfer transitions on octahedral sites is found. In the optical spectra a strong increase in optical absorption is found with dominant transitions at 0.8, 1.6 and 2.6 eV due to Co³⁺ crystal field transitions on octahedral sites and a Co²⁺-Co³⁺ charge transfer. Conversion Electron Mössbauer Spectroscopy has been used to determine the cation distribution in the surface layer of the samples. The results indicate a shift of Co²⁺ from octahedral to tetrahedral sites when Co³⁺ is substituted in CoFe₂O₄. This results in enhanced optical absorption, enhanced magneto-optical effects and a lower Curie temperature.     

Integration of optimization methodology with expert systems

An expert system for ion-pair liquid chromatography of basic drugs is described. Integration of experimental optimization methodology into the expert system is shown to be feasible. The system consists mainly of four modules: an introductory module, and initial guess module, a formal optimization module and an adaptation module. The formal optimization module, based on a simple 2 × 2 factorial design and an overlapping resolution map, is integrated with the expert system. The expert system was validated on 20 basic drugs and their 60 synthetic mixtures combined by using a random method. The rate of succes was satisfactory.     

Analysis of the proteins in sweat and urine by agarose-gel isotachophoresis.

A sensitive and practical method is described for the analysis of the proteins contained in human sweat and urine which does not require pre-concentration of the sample. Technical details are provided of the agarose-gel isotachophoresis and the proteinograms of normal and pathological urine samples, as well as proteinograms of human sweat. The method can also be applied as an electro-concentration system in a field-strength gradient. By means of this electro-concentration system, and in combination with immunodiffusion against monospecific antisera, a detection limit of albumin of 50 ng/ml has been obtained.     

Viskoelastizit?t eines Systems mit orientierbaren K?rpern

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