Some characterizations of quasi-symmetric designs with a spread

The designPG ₂ (4,q) of the points and planes ofPG (4,q) forms a quasi-symmetric 2-design with block intersection numbersx=1 andy=q+1. We give some characterizations of quasi-symmetric designs withx=1 which have a spread through a fixed point. For instance, it is proved that if such a designD is also smooth, thenDPG ₂ (4,q).     

Estimation of dissociation energy of alkali diatomics using an extended Linderberg relation

The ground state wave function of a model potential consisting of a zero-range square well joined to a Coulomb tail is used in a two equivalent centre problem to evaluate the overlap integral (S) and the resonance integral (β). It is shown that an extended Linderberg relation of the form β = K/R (dS/dR) is generally well obeyed. The extended relation has been used within a LCAO framework to obtain dissociation energies of the homonuclear diatomic molecules of the alkali atoms.     

Determination of Rosuvastatin Calcium in its Bulk Drug and Pharmaceutical Preparations by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A normal-phase TLC method has been established for the estimation of rosuvastatin calcium in its bulk drug and pharmaceutical...     

A generalization for the distance dependence of the resonance integral

The distance dependence of the resonance integral given by us earlier, has been generalized to cover bonds containing heteroatoms. The validity of the new expression has been checked for molecules containing nitrogen, oxygen, fluorine and chlorine atoms. Systems containing more than one heteroatom have also been studied.     

ENERGY STORAGE STATES OF PHOTOSYNTHETIC MEMBRANES: ACTIVATION ENERGIES AND LIFETIMES OF ELECTRONS IN THE TRAP STATES BY THERMOLUMINESCENCE METHOD

Abstract Several methods discussed by R. Chen (1969) were used for the calculation of the activation energies ( E ), frequency factors ( s ) and mean lifetimes of electrons in trap states at glow peak temperatures ( T _m) and at room temperature ( T _r) from thermoluminescence glow peaks in spinach chloroplasts and Euglena cells. Results are presented for E calculated independently, i.e. without any assumptions regarding the frequency factors which were determined subsequently using the activation energy values thus calculated. The most reliable values for E , s, r( T _m) and ( T _r) for the well-resolved glow peaks Z(118 K), I(236 K), II(261 K), III(283 K), IV(298 K) and V(321 K) are as follows:
The present comprehensive study has been compared with the earlier ones and the significance of the observed high frequency factors is discussed. It is concluded that only peaks I and II, related to photosystem II, follow the Randall–Wilkins (RW) theory, whereas peaks IV and V, related to photosystem I, do not.     

A Proof of the Jungnickel-Tonchev Conjecture on Quasi-Multiple Quasi-Symmetric Designs

A proof of the following conjecture of Jungnickel and Tonchev on quasi-multiple quasi-symmetric designs is given: Let D be a design whose parameter set (v,b,r,k,) equals (v,sv,sk,k, s) for some positive integer s and for some integers v,k, that satisfy (v-1) = k(k-1) (that is, these integers satisfy the parametric feasibility conditions for a symmetric (v,k,)-design). Further assume that D is a quasi-symmetric design, that is D has at most two block intersection numbers. If (k, (s-1)) = 1, then the only way D can be constructed is by taking multiple copies of a symmetric (v,k, )-design.     

THERMOLUMINESCENCE STUDIES ON SPINACH LEAVES AND EUGLENA

Abstract— Spinach leaves and Euglena cells when frozen in light to 77 K emit light during slow warming in the dark to give 6 peaks. The peak appearing at 118 K is observed even after DCMU or heat treatment and also in aged chloroplasts that are inactive in electron transport.
The data indicate that peaks appearing at 261 and 321 K are due to back reactions of primary acceptors of PS II and PS I respectively with oxidized chlorophylls. The DCMU sensitivity of Tl peaks at 283 and 298 K suggests that they are associated with the flow of electrons between PS II and PS I. Evidence has been presented to show that the PS 1 chlorophylls are involved in part of the luminescence observed during the temperature rise.
A mechanism involving the return of the thermally detrapped electrons to the ground state of chlorophylls through their excited states has been proposed to explain some of the Tl peaks.