Simultaneous separation of alkali and alkaline-earth cations on polybutadiene-maleic acid-coated stationary phase by mineral acid eluents

The simultaneous separation of alkali and alkaline-earth cations on polybutadiene-maleic acid-coated silica columns can be achieved with mineral acid eluents. Simple ion-exchange retention mechanisms and the high selectivity of eluent hydronium ions towards the carboxylate group are the basis for the separation. Use of mineral acid eluents allows using this column in both single column and suppressor-based IC systems. Both types of ion chromatography systems provide detection limits in the low-ng/ml range with excellent linearity.     

Stark effect measurements in high temperature molecules: Hyperfine structure and stark effect in the rotational spectrum of the silver iodide molecule

In the region of 8 GHz the rotational transition of J = 3 → 2 of both isotopic species of AgI has been investigated. The analysis of the quadrupole hyperfine structure in the vibrational states up to v = 4 resulted in the v-dependent coupling constant

$\text{eq}{}_{\mathrm{v}}\text{Q}\text{(}{}^{127}\text{I}\text{) = { ? 1061.37(40) ? 2.13(20)(v +}\text{1}\text{2}\text{) }}\text{MHz}$

. From observations of the Stark pattern of ¹⁰⁷AgI in its ground vibrational state we derived the electric dipole moment

$\text{|μ}{}_{\mathrm{O}}\text{| = 5.10 (15)}\text{D}$

.     

Suboptimal control of nonlinear time-delay systems

An interative method for the suboptimal control of nonlinear time-delay systems is presented. Polynomial forms are assumed for the state in cases with delay in the state only and for the control in other cases. The coefficients in the approximating polynomial are chosen by a direct search method.Many discussions with Dr. S. Narayana Iyer, Professor of Electrical Engineering, College of Engineering, Trivandrum, India, are gratefully acknowledged.     

Neutron-proton interaction and nuclear deformations

In Hartree-Fock-Bogoliubov calculations with and without the neutron-proton (n-p) interaction for a few nuclei in the s-d shell and in the rare-earth region it is found that the n-p interaction is the major source of nuclear deformation.     

Parameter representation of average potential energy of zero point vibrations

The variation of contributions to the average vibrational potential energy with a parameter characterizing the force field has been mapped for some twenty-three bent symmetrical XY₂ systems. Simple and physically significant criteria for the calculation of extremely reliable harmonic force fields are found to emerge from this study. For nonhydrides minimization of the main average bending energy contribution f_ασ_α and for hydrides minimization of the quantity f_ασ_α + 2f_rασ_rα yield excellent force fields in agreement with standard force fields fixed with the help of additional experimental data.     

Polynomial Algorithms for a Class of Discrete Minmax Linear Programming Problems

We consider the problem of obtaining integer solutions to a minmax linear programming problem. Although this general problem is NP-complete, it is shown that a restricted version of this problem can be solved in polynomial time. For this restricted class of problems two polynomial time algorithms are suggested, one of which is strongly polynomial whenever its continuous analogue and an associated linear programming problem can be solved by a strongly polynomial algorithm. Our algorithms can also be used to obtain integer solutions for the minmax transportation problem with an inequality budget constraint. The equality constrained version of this problem is shown to be NP-complete. We also provide some new insights into the solution procedures for the continuous minmax linear programming problem.     

Oxidative cyclisation of cinnamyl ethers mediated by CAN: a stereoselective synthesis of 3,4-trans disubstituted tetrahydrofuran derivatives

The oxidative cyclisation of cinnamyl ethers mediated by cerium(IV) ammonium nitrate results in the stereospecific formation of 3,4-trans disubstituted tetrahydrofuran derivatives in moderate to good yields.     

On Strong Uniform Distribution II

 Let ? be a class of real valued integrable functions on [0,1). We will call a strictly increasing sequence of natural numbers an sequence if for every f in ? we have