Hammett constants (σ) can be important factor to understanding substitution and position effects on benzoic acid. This report describes a computational study of ∆G◦ and σ for six substituted benzoic acid (X= F,Cl ,OH ,NH2 ,CN,NO2 )and phenylacetic acid substituted (X=OH ,NH2 ) at para and meta positions ingas and aqueousphases by DFT method and comparesit to available experimental and theoretic...

In this Note, we consider traveling waves in a reaction-diffusion equation dimension one. Motivated by the motion of dislocations crystals, introduce an additive parameter σ reaction term, which may be interpreted as exterior force applied on crystal. Under certain natural assumptions and for every value σ∈[σ - ,σ + ], show existence ϕ velocity c. The range σ∈(σ ) corresponds to bistable cases ...

In this article, semi-ring and semi-algebra of sets are formalized so as to construct a measure of a given set in the next step. Although a semi-ring of sets has already been formalized in [12], that is, strictly speaking, a definition of a quasi semi-ring of sets suggested in the last few decades [14]. We adopt a classical definition of a semi-ring of sets here to avoid such a confusion. Ring ...

We prove several dichotomy theorems which extend some known results on σ -bounded and σ -compactpointsets. In particular we show that, given a finite number of Δ1 equivalence relations F1 , . . . , Fn , any Σ1 set A of the Baire space either is covered by compact Δ1 sets and lightface Δ1 equivalence classes of the relations Fi , or A contains a superperfect subset which is pairwise Fi -inequiva...