A note on chance constrained programming with fuzzy coefficients

This paper deals with nonlinear chance constrained programming as well as multiobjective case and goal programming with fuzzy coefficients occurring in not only constraints but also objectives. We also present a fuzzy simulation technique for handling fuzzy objective constraints and fuzzy goal constraints. Finally, a fuzzy simulation based genetic algorithm is employed to solve a numerical example.     

Facile synthesis of 8-benzoylthio-2,6-methano-3-benzazocines and 3-benzoylthiomorphinans having small-ring substituents

Synthesis of 3-cyclopropylmethyl-, 3-cyclobutylmethyl-, and 3-methyl-8-benzoylthio-2,6-methano-3-benzazocines (1j-l) was performed by regio-selective chlorosulfonation of non-narcotic 8-deoxy derivatives (1a-c) followed by reduction and benzoylation. 3-Benzoylthiomorphinans (2h-j) were also obtained by the same method. Compounds having small-ring substituents (1k, 1l, 2i, 2j) were found to be weak but pure mu- and delta-opioid antagonists. The analgetic activity of 1k was almost equal to that of pentazocine.     

Synthesis and analgetic activity of sulfur-containing morphinans and related compounds

3-Acylthiomorphinans, 3-carbamoylthio-3-deoxydihydromorphine and 3-benzoylthio-9-aza-17-carbamorphinan were synthesized by Newman-Kwart rearrangement of the corresponding O-thiocarbamates. The analgetic activities were lower than that of pentazocine, and the opioid receptor binding affinities were very weak. These acylthiomorphinans showed low antinociceptive activity compared with corresponding sulfur-containing benzomorphans. 3-Carbamoylthio-deoxydihydromorphine had no significant analgetic activity.     

Expressions for the perfect matching numbers of cubicl x m x n lattices and their asymptotic values

A general expression of the perfect matching number for thel x m x n cubic lattice was conjectured and examined for infinitely large systems. The asymptotic value of the square of the perfect matching number was calculated by numerical integration. The present treatment will give a key to obtain the true analytic solution of the perfect matching numbers for the 3-dimensional lattices.     

Preconcentration of phthalic acid esters in water samples by Saccharomyces cerevisiae immobilized on silica gel

A sensitive and selective column adsorption method is proposed for the off-line preconcentration and determination of phthalic acid esters (PAEs), namely benzyl-butyl phthalate (BBP), di-n-butyl phthalate (DBP) and di-cyclohexyl phthalate (DCHP). The PAEs was preconcentrated on Saccharomyces cerevisiae immobilized on silica gel and then determined by high performance liquid chromatography (HPLC). Several parameters on the recovery of the analytes were investigated. Recoveries of BBP, DBP and DCHP were 100±2, 98±2 and 98±3%, respectively, at 95% confidence level under optimum conditions. The detection limits (3S/N) of BBP, DBP and DCHP were 3.2, 6.3 and 3.1 μg l⁻¹, respectively. The capacity of the adsorbent was also examined and found to be 1.4 mg g⁻¹ for BBP and DBP, and 3.6 mg g⁻¹ for DCHP. S. cerevisiae immobilized on silica gel is suitable for repeated use without decreasing recovery up to about 25 adsorption-elution cycles. The proposed method was successfully applied to the determination of PAEs in river water with high precision and accuracy.     

Noncovalent Bond Lengths and Their Cooperative Shortening: Dimers of Vancomycin Group Antibiotics in Crystals and in Solution

A wide range of dimerisation constants (K_dim ca. 10¹–10⁶ M ^?1) for various glycopeptide antibiotics have been determined. We consider these dimerisation constants in the light of the published X‐ray structures of the antibiotics, in particular, the relationship between K _dim and the length of a specified distance at the dimer interface. In the crystals, we find that this distance is smaller for strongly dimerising antibiotics and larger for weakly dimerising antibiotics. Thus, the dimerisation constant is correlated with tightness at the dimer interface. Despite the crystal‐packing forces exerted between adjacent dimer molecules in the crystals, the noncovalent bond distances at the dimer interface are correlated with the distances in solution (inferred from solution NMR data). These observations can account for the benefits in enthalpy, and costs in entropy, associated with positively cooperative binding.     

pH-induced reversible permeability control of the 4-carboxy acrylanilide-methyl methacrylate copolymer membrane

To develop a polymer membrane whose permeability of water-soluble compounds could be controlled in response to a pH change of the medium, a polyelectrolyte membrane containing an aromatic carboxyl group, i.e., 4-carboxyacrylanilide (CAAn)-methyl methacrylate(MMA) copolymer membrane, was prepared. The water content of the CAAn-MMA copolymer membrane increased with increasing pH owing to ionization change in the CAAn moiety. This increase was particularly remarkable in the pH range from 5 to 7. The change in water content was reversible and could be controlled by the CAAn composition in the copolymer. Permeation of 1,4-bis(2-hydroxyethoxy)benzene(DHEB) through the CAAn-MMA copolymer membrane was investigated in solutions of various pH. Change in the permeability of DHEB in function of the pH was similar to the change in membrane water content. This was explained by an increase in the permeation pathway of DHEB in the membrane, in proportion to that in the water content. Moreover, when a pH-sensitive membrane was placed in a solution in which an enzymatic reaction occurred, substrate-induced permeation control of DHEB through the CAAn-MMA copolymer membrane was possible.     

Synthesis and characterization of polyester dendrimers from acetoacetate and acrylate

New aliphatic polyester-type dendrimers were synthesized using a new AB2-type building block 3, prepared from benzyl acetoacetate and 2 equiv of tert-butyl acrylate by acetoacetic acid ester synthesis. The reiterative [deprotection by HCO2H, then EDCI/DMAP coupling] sequence using divergent growth method gave [G1]-4tBu-[G5]-64tBu dendrimers. 13C NMR relaxation time (T1) measurements on the carboxy carbons show that the extended chain conformations are predominant in CDCl3. [structure: see text]     

Inclined N2 desorption in a steady-state NO + CO reaction on Pt(100)

The angular and velocity distributions of desorbing products N2 and CO2 were studied in a steady-state NO + CO reaction on Pt(100). From the observation of the inclined N2 desorption, a contribution of the intermediate N2O decomposition pathway was first proposed on this surface. On the other hand, CO2 desorption collimated along the surface normal.     

Addition of chlorodisilanes to 1,3-butadienes in the presence of tetrakis(triphenylphosphine)palladium(0). A facile route to (Z)-1,4-bis(chlorosilyl)but-2-enes

In the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0), chlorodisilanes of type Me_nSi₂Cl_6-n (n  0, 2, 3 and 4) add to 1,3-butadienes to give (Z)-1,4-bis(chlorosilyl)but-2-enes.