Thin films of boron carbon nitride (BCN) and boron carbide (BC) were synthesized by plasma enhanced chemical vapor deposition (PECVD) using two different reactant chemistries: (i) N,N’,N” – trimethylborazine (TMB); (ii) dilute diborane (5% in Ar) and hydrocarbon as precursor materials. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Nano-Indentor, Flexus stress instrument and x-ray photoelectron spectroscopy were used to study the deposited films. The BC films are much more stable than BCN films under high humidity (100%) environment. Both BCN and BC films are very stable under atmospheric conditions. A high compressive stress of -4.2 GPA was achieved by conventional PECVD, which show promising applications in high performance ultra large-scale integrated circuit (ULSI) devices.

The population dynamics of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) infesting the coconut fruits was studied during September 1999-May 2000 in Tamil Nadu, India where the mite is a new pest. The densities of active mites and eggs were not significantly correlated with weather factors. Mites were more abundant on the post-fertilisation bunch 3 drupes (fruits) (6.0 mites/7 mm2) than on the other drupes. They were most crowded on the fourth (outer to inner) tepal (bract) of the bunch 3 perianth (2.6 mites/7 mm2). No significant difference was evident between populations of A. guerreronis from the drupe and tepal surfaces. However, eggs were more numerous on the tepal surface (4.9 eggs /tepal) than on the drupe surface (2.5 eggs /drupe). Egg density was highest on bunch 5 drupes (8.6 eggs/tepal) than on the drupes of other bunches. The inner tepals (4–6) carried more eggs (4.6–5.6/tepal) than the outer (1–3) ones (1.2–3.8/tepal). Mite population declined by 62.6 % when the tepal area decreased by 24.3 % due to mealybug (Pseudococcus cocotis Mask.) infestation which caused the tepals to deform. The predatory mites Amblyseius sp. and mealybugs were most abundant on tepals 5 and 6 (2.5–2.6 predatory mites; 4.6–4.7 mealybugs/ tepal). Eggs of A. guerreronis could be stored in the freezer at 3.9 ± 0.3 °C for one month although hatchability decreased from 98 % one day after storage to 54.7 % one month after storage. Loss of the eriophyid mites from sample drupes after five days was minimal (54.7 %) when the drupes were stored in a thermocool box containing ice at 23.7 ± 0.4 CC. Most mites (75.8 %) died when the drupes were stored in the open at room temperature (35.3 ± 0.9 °C).

The deterministic growth of ZnO nanorods using molecular beam epitaxy is reported. The process is catalyst-driven, as single crystal ZnO nanorod growth is realized via nucleation on Ag islands that are distributed on a SiO2-terminated Si substrate surface. Growth occurs at substrate temperatures on the order of 300-500°C. The nanorods exhibit diameters of 15-40 nm and lengths in excess of 1 μm. Nanorod placement can be predefined via location of metal catalyst islands or particles. This, coupled with the relatively low growth temperatures needed, suggests that ZnO nanorods could be integrated on device platforms for numerous applications, including chemical sensors and nanoelectronics.

The main results proved in this note are the following:

(i) Any finitely generated group can be expressed as a quotient of a finitely presented, centreless group which is simultaneously Hopfian and co-Hopfian.

(ii) There is no functorial imbedding of groups (respectively finitely generated groups) into Hopfian groups.

(iii) We prove a result which implies in particular that if the double orientable cover N of a closed non-orientable aspherical manifold M has a co-Hopfian fundamental group then π1(M) itself is co-Hopfian.

The implementation and application of GaAs technology CAD for industrial research and development are described. Existing silicon-oriented software was modified extensively to make it applicable to the simulation of GaAs processes and devices. RF-oriented post-processing capabilities were implemented, and effective applications methodologies were developed. Examples of the practical application of GaAs technology CAD are presented.

Recently A. Gutek, D. Hart, J. Jamison and M. Rajagopalan have obtained many significiant results concerning shift operators on Banach spaces. Using a result of Holsztynski they classify isometric shift operators on C(X) for any compact Hausdorff space X into two (not necessarily disjoint) classes. If there exists an isometric shift operator T: C(X) → C(X) of type II, they show that X is necessarily separable. In case T is of type I, they exhibit a paticular infinite countable set of isolated points in X. Under the additional assumption that the linear functional Γ carrying f ∊ C(X) to Tf(p) ∊ is identically zero, they show that D is dense in X. They raise the question whether D will still be dense in X even when Γ ≠ 0. In this paper we give a negative answer to this question. In fact, given any integer l ≥ 1, we construct an example of an isometric shift operator T: C(X) —> C(X) of type I with X \ having exactly / elements, where is the closure of D in X.

In this paper we show that any (respectively α є Ωm ) can be represented by a closed smooth (respectively closed, oriented smooth) manifold Mm admitting a smooth (Z/2)m (respectively S 1)-action with a finite stationary set. We also completely determine the Grassman manifolds which are oriented boundaries as well as those which represent non-torsion elements in Ω*.

The concept of a mitotic group was introduced in [3] by Baumslag, Dyer and Heller who showed that mitotic groups were acyclic. In [8] one of the authors introduced the concept of a pseudo-mitotic group, a concept weaker than that of a mitotic group, and showed that pseudo-mitotic groups were acyclic and that the group Gn of homeomorphisms of Rn with compact support is pseudo-mitotic. In our present paper we develop techniques to prove pseudomitoticity of certain other homeomorphism groups. In [5] Kan and Thurston observed that the group of set theoretic bijections of Q with bounded support is acyclic. A natural question is to decide whether the group of homeomorphisms of Q (resp. the irrationals I ) with bounded support is acyclic or not. In the present paper we develop techniques to answer this question in the affirmative.

Let C be a cochain complex satisfying the condition that inj.dim. Hq(C) < ∞. Then we prove that C admits an injective approximation.

V-rings and their generalisations have been studied extensively in recent years [2], [3], [5],[6], [7]. All the rings we consider will be associative rings with 1 ≠ 0 and all the modules considered will be unitary left R-modules. All the concepts will be left-sided unless otherwise mentioned. Thus by an ideal in R we mean a left ideal of R. A ring R is called a V-ring (respectively a GV-ring) if every simple (resp. simple, singular) module is injective. An R-module M is called p-injective if any homomorphism f: I → M with I a principal left ideal of R can be extended to a homomorphism g: R → M. A ring R is called a p-V-ring (resp. a p-V'-ring) if every simple (resp. simple, singular) module over R is p-injective. The object of the present paper is to introduce torsion theoretic generalizations of p-V-rings and prove results similar to those obtained by Yue Chi Ming about p-V-rings and p-V'-rings [6], [7]. For any M ∈ R-mod, J(M) will denote the Jacobson radical of M and Z(M) the singular submodule of M. For any λ ∈ R, we denote the left annihilator { r ∈ R| rλ =0 } of λ in R by l(λ).

Let R be an associative ring with 1 ≠ 0. Throughout we will be considering unitary left R-modules. Given a chain complex C over R, a free approximation of C is defined to be a free chain complex F over R together with an epimorphism τ:F → C of chain complexes with the property that H(τ):H(F) ≃ H(C). In Chapter 5, Section 2 of [3] it is proved that any chain complex C over Z has a free approximation τ:F → C. Moreover given a free approximation τ:F→ C of C and any chain map f:F’ → C with F’ a free chain complex over Z, there exists a chain map φ:F’→ F with T O φ = f . Any two chain maps φ, ψ of F’ in F with T O φ = T O ψ are chain homotopic.

Given a hereditary torsion theory on the category Mod R of right R-modules we obtain in this paper necessary and sufficient conditions for the direct sum of a given family of R-modules to be divisible for the torsion theory . Using this criterion we show that if is a family of R-modules having the property that is divisible for every countable subset K ol J then is itself divisible.

Evaluation subgroups of the homotopy groups have been objects of extensive study recently by Gottlieb, Haslam, Jerrold Siegel, G. E. Lang (Jr), etc. In [8] one of the authors has introduced the notions of ‘cyclic' and ‘cocyclic’ maps and studied generalizations of evaluation subgroups and their duals in the set up of Eckmann-Hilton duality. This paper continues the study of these generalized Gottlieb and dual Gottlieb subsets. All the spaces, except the function spaces, will be arc connected locally compact CW-complexes with base point at a vertex. For any X, Y the set of base point preserving homotopy classes of maps of X to Y is denoted by [X, Y].

Classically CW-complexes were found to be the best suited objects for studying problems in homotopy theory. Certain numerical invariants associated to a CW-complex X such as the Lusternik-Schnirelmann Category of X, the index of nilpotency of ᘯ(X), the cocategory of X, the index of conilpotency of ∑ (X) have been studied by Eckmann, Hilton, Berstein and Ganea, etc. Recently D. G. Quillen [6] has developed homotopy theory for categories satisfying certain axioms. In the axiomatic set up of Quillen the duality observed in classical homotopy theory becomes a self-evident phenomenon, the axioms being so formulated.

This paper deals with some applications in the results obtained in “Numerical Invariants in Homotopical Algebra” [7]. The applications are mainly concerned with the homotopy theory of modules developed by P. J. Hilton [4]. However we have to restrict the class of rings because we want to obtain a situation where the axioms of Quillen [6] hold good. This paper is organised as follows.

Borsuk has asked whether there exists for each compact metric absolute neighbourhood retract X an integer l (depending only on X) with the property that if X is homotopy equivalent to a cartesian product of more than l spaces than at least one of these spaces is contractible. The answer to this question is still not known. The following theorem has been proved by Ganea and Hilton [Theorem 1.3 of [1]].

The main result proved in this paper can be stated as follows:

Theorem. Let Mnbe a closed l-connected topological manifold of dimension n ≥ 5. Then M × R carries a differentiable (respectively aPL) structure if and only if M × S1carries a differentiable (respectively aPL) structure.