MNDO semi-empirical SCF MO calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

Several acoustic experiments show a surprising degree of stability in wave fronts propagating over multi-megameter ranges through the ocean's sound channel despite the presence of random-like, sound-speed fluctuations. Previous works have pointed out the existence of chaos in simplified ray models incorporating structure inspired by the true ocean environment. A "predictability horizon" has bee...

OBJECTIVE To estimate the costs and health outcomes of C-Leg and non-microprocessor-controlled (NMC) knees using a decision-analytic model. DESIGN Data on costs, rates and duration of problems, knee survival, and health-related quality of life were obtained from interviews with patients and prosthetists with experience of both C-Leg and NMC knees. Interview data were assessed in a decision-an...

AIMS This study was designed to estimate the prevalence of blindness and its main aetiologies in Bioko, an onchocerciasis endemic zone of Equatorial Guinea. METHODS Random sampling was applied, proportionally to population distribution into urban or rural areas. All the subjects underwent a basic eye examination by trained nurses. In the presence of any ocular affection or a visual acuity of ...

Aims: This study was designed to estimate the prevalence of blindness and its main aetiologies in Bioko, an onchocerciasis endemic zone of Equatorial Guinea. Methods: Random sampling was applied, proportionally to population distribution into urban or rural areas. All the subjects underwent a basic eye examination by trained nurses. In the presence of any ocular affection or a visual acuity of ...

let $r$ be a ring‎, ‎and let $n‎, ‎d$ be non-negative integers‎. ‎a right $r$-module $m$ is called $(n‎, ‎d)$-projective if $ext^{d+1}_r(m‎, ‎a)=0$ for every $n$-copresented right $r$-module $a$‎. ‎$r$ is called right $n$-cocoherent if every $n$-copresented right $r$-module is $(n+1)$-coprese-nted‎, ‎it is called a right co-$(n,d)$-ring if every right $r$-module is $(n‎, ‎d)$-projective‎. ‎$r$ ...

mndo semi-empirical scf mo calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

In this article we introduce the notion of n-capable groups. It is shown that every group G admits a uniquely determined subgroup (〖Z^n)〗^* (G) which is a characteristic subgroup and lies in the n-centre subgroup of the group G. This is the smallest subgroup of G whose factor group is n-capable. Moreover, some properties of n-central extension will be studied.

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Let $nin mathbb{N}$. An additive map $h:Ato B$ between algebras $A$ and $B$ is called $n$-Jordan homomorphism if $h(a^n)=(h(a))^n$ for all $ain A$. We show that every $n$-Jordan homomorphism between commutative Banach algebras is a $n$-ring homomorphism when $n < 8$. For these cases, every involutive $n$-Jordan homomorphism between commutative C-algebras is norm continuous.