Transverse curvature effects in axi-symmetric flow on a circulai cylinder are discussed and it is deduced that for small δ/a, where δ is the boundary layer thickness and a is the cylinder radius, transverse curvature effects are small, for δ/a = 0(1) the effect is felt mainly in the outer region and for δ/a » 1, both the inner and the outer regions are affected. It is argued that the last case can only be achieved experimentally in the laboratory if the radius Reynolds number Ra= U1a/v is small and the streamwise Reynolds number Rx=U1xlv is large, implying x/a large. New experimental data are presented for this case. The data show that both the mean and turbulent flow field scale on outer variables throughout the layer and, for Ra≥455, exhibit Reynolds number independence. No logarithmic region is found in the mean profiles, a result which is echoed by the absence of a shoulder in the streamwise turbulence profiles which clearly evidence that the flow in the layer is fully turbulent. A flow model is suggested, in physical terms, to explain the very high turbulence levels found close to the cylinder at values of Ra which should, according to stability theory, be bordering on laminar flow.

Cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a serious pest of several crops throughout the world, representing millions of United States of America dollars worth of damage. This pest can adapt to various cropping systems in a wide geographical range and has high migratory potential. It features high fecundity and can develop resistance to almost all insecticides used for its management. Several investigations to develop microsatellite markers for H. armigera have not been successful because of the paucity of microsatellites in the lepidopteran genome. As well, collections of H. armigera from cotton fields of southern and western India were not yet studied for molecular genetic diversity. The current study aimed to screen publicly available expressed sequence tag resources for simple sequence repeats and assess their potential as DNA markers for assessment of gene flow between collections of southern and western India. We identified 30 polymorphic microsatellites for potential use in diversity analysis of H. armigera collections. Genetic diversity analysis revealed that the collections were widely diverse with population differentiation index (F st) of 0.17. Furthermore, gene flow analysis revealed a mean frequency of private alleles of 11% within the collections. The microsatellite resources we developed could be widely used for molecular diversity or population genetic research involving this important pest of cotton and food crops.

Conventionally, mean grain size is considered the most critical microstructural parameter in determining the mechanical behavior of pure metals. By systematically controlling the distribution of grain orientations in aluminum films, we show that microstructural heterogeneity alone induces large variation in the mechanical behavior of nanocrystalline metal films. Aluminum films with relatively homogeneous microstructure (all grains with identical out-of-plane orientation) show substantially less early Bauschinger effect compared to films with heterogeneous microstructure, irrespective of film thickness or grain size. On the other hand, the films with homogeneous microstructure show relatively higher yield stresses. A direct correspondence is found between the nonuniformity of plastic deformation and early Bauschinger effect, which confirms the critical role of microstructural heterogeneity.

Investigations of the natural history of the virus of Kyasanur Forest disease since its discovery during 1957 in Shimoga District, Mysore State, south India have concentrated much attention on ticks of the genus Haemaphysalis in the region, as virus has repeatedly been isolated from them.

Keys are provided for larvae, nymphs and adults of both sexes of the 14 species of Haemaphysalis that have been taken in the area, with supplementary comments on six other species of the genus recorded, or likely to occur, elsewhere in south India. Illustrations are given showing the characters of the larvae and nymphs that are used in the keys.

A short term survey to quantify the number of marine mammals incidentally caught, and interviews to gain perceptions of local fishers towards issues of by-catch, were conducted. A total of 44 cetaceans was recorded as incidental catches at Chennai, Kakinada and Mangalore fishing harbours during 80 days of observation. Six species of dolphins and one species of porpoise were recorded. The spinner dolphin Stenella longirostris was the most frequently caught (38.6%), followed by the finless porpoise Neophocaena phocaenoides (31.8%). Gill-nets and purse seines operated from motorized boats accounted for the entire by-catch. It is estimated that 9000–10,000 cetaceans are killed by gill-nets every year along the Indian coast. The intricacies and possibilities of reducing cetacean kills by gill-nets are discussed in this paper.

Investigations have been carried out of some aspects of the fine-scale structure of turbulence in grid flows, in boundary layers in a zero pressure gradient and in a boundary layer in a strong favourable pressure gradient leading to relaminarization. Using a narrow-band filter with suitable mid-band frequencies, the properties of the fine-scale structure (appearing as high frequency pulses in the filtered signal) were analysed using the variable discriminator level technique employed earlier by Rao, Narasimha & Badri Narayanan (1971). It was found that, irrespective of the type of flow, the characteristic pulse frequency (say Np) defined by Rao et al. was about 0·6 times the frequency of the zero crossings.

It was also found that, over the small range of Reynolds numbers tested, the ratio of the width of the fine-scale regions to the Kolmogorov scale increased linearly with Reynolds number in grid turbulence as well as in flat-plate boundarylayer flow. Nearly lognormal distributions were exhibited by this ratio as well as by the interval between successive zero crossings.

The values of Np and of the zero-crossing rate were found to be nearly constant across the boundary layer, except towards its outer edge and very near the wall. In the zero-pressure-gradient boundary-layer flow, very near the wall the high frequency pulses were found to occur mostly when the longitudinal velocity fluctuation u was positive (i.e. above the mean), whereas in the outer part of the boundary layer the pulses more often occurred when u was negative. During acceleration this correlation between the fine-scale motion and the sign of u was less marked.

Monolithic wafer-level three-dimensional (3D) ICs based upon bonding of processed wafers and die-to-wafer 3D ICs based upon bonding die to a host wafer require additional planarization considerations compared to conventional planar ICs and wafer-scale packaging. Various planarization issues are described, focusing on the more stringent technology requirements of monolithic wafer-level 3D ICs. The specific 3D IC technology approach considered here consists of wafer bonding with dielectric adhesives, a three-step thinning process of grinding, polishing and etching, and an inter-wafer interconnect process using copper damascene patterning. The use of a bonding adhesive to relax pre-bonding wafer planarization requirements is a key to process compatibility with standard IC processes. Minimizing edge chipping during wafer thinning requires understanding of the relationships between wafer bonding, thinning and pre-bonding IC processes. The advantage of silicon-on-insulator technology in alleviating planarization issues with wafer thinning for 3D ICs is described.

Two first-step copper damascene slurries and one commercial second-step slurry are characterized in terms of their intrinsic properties and CMP performance. A prototype first-step slurry with high static etch rate (∼150 nm/min) yielded higher dishing in the copper lines (∼200 nm in 100 μm lines) compared to a commercial first-step slurry with negligible static etch rate. In both the cases, dishing in copper lines is observed to be a strong function of line width and radial position on the wafer. High static etch rate of the prototype slurry is believed to be responsible for the high dishing. Non-selective second-step polishing removes the liner layer while maintaining planarity.

A locally compact semilattice with open principal filters is a zero-dimensional scattered space. Cardinal invariants of locally compact and compact semilattices with open principal filters are investigated. Structure of topological semilattices on the one-point Alexandroff compactification of an uncountable discrete space and linearly ordered compact semilattices with open principal filters are researched.

Real-valued function spaces CoL lack almost transitive norms. If there is a complex-valued CoL with almost transitive norm then there is also one with transitive norm. We give fairly restrictive topological conditions for the complex-valued CoL to have transitive norm.

The electronic structure and high pressure structural phase transition in thorium antimonide have been investigated using the tight binding LMTO method. We have calculated the total energies by reducing the cell volume for NaCl as well as CsCl structures using TBLMTO method. The total energy calculations reveal that ThSb undergoes a structural transition from NaCl to CsCl structure at 78 kbar. The calculated value of equilibrium cell volume and the cell volume at which phase transition occurs are found to have a good agreement with the experimental results.

One often encounters problems that are difficult as they are, but become manageable when translated to a different category. Thus very often, problems on Boolean algebras are answered by first transferring them to problems on Boolean spaces. (See, for example, [7]). It is with this spirit that we approach in this paper two problems on Boolean algebras. These problems are two decades old, and are considered to be outstanding problems in the field.

A locally convex Hausdorff topological vector space is said to be quasicomplete if closed bounded subsets of the space are complete, and von Neumann complete if closed totally bounded subsets are complete (equivalently, compact). Clearly quasi-completeness implies von Neumann completeness, and the converse holds in, for example, metrizable locally convex spaces. In this note we obtain a class of locally convex spaces for which the converse fails. Specifically, let X be a completely regular Hausdorff space, and let CC(X) denote the space of continuous real-valued functions on X, endowed with the compact-open topology.

In (1) R. G. Douglas says: “For a finite abelian group there exists a unique invariant mean which must be inversion invariant. For an infinite torsion abelian group it is not clear what the situation is.” It is not hard to see that if every element of an abelian group G is of order 2, then every invariant mean on G is also inversion invariant (see 1, remark 4). In this note we prove the following theorem (Theorem 1 below): An abelian torsion group G has an invariant mean which is not inverse invariant if, and only if, 2G is infinite. This result, together with the theorems of Douglas, answers completely the question of the existence (on an arbitrary abelian group) of invariant means which are not inverse invariant.

We propose to study a topological property which is not new, but seems not to have been systematically investigated.