For forthcoming wireless applications, a small and highly decoupled complementary split ring resonators (CSRR)–loaded co-planar waveguide (CPW)–fed antenna for dual-band applications is investigated. The low-profile antenna consists of a CSRR-loaded rectangular radiating element with a truncated bottom, giving a wideband performance over the frequency ranges of 5.28–5.52 GHz and 6–7.2 GHz. The antenna has been printed on a widely used FR4 substrate measuring 7.5 × 10.5 × 1.6 mm3 in volume. This research’s suggested antenna is turned into a 4 × 4 multi input multi output (MIMO) construction using a 25 × 25 mm2 printed circuit board. Individual antennas were isolated by nearly 20 dB without using a decoupling device. The antenna has been built, and the measured and simulated results correspond well. Computing envelope correlation coefficient (ECC), channel capacity (CC), and channel capacity loss (CCL) further validates the antenna’s performance (−). The antenna has an overall gain of around 2.54 dBi and a radiation efficiency of approximately 89% throughout the relevant spectral range, which is much better for wireless applications. The suggested antenna’s omnidirectional emission pattern makes it a potential contender for future wireless and cellular applications.

Scapolite occurrences are widely observed in the metasedimentary rocks exposed around the Khetri Copper Belt and adjoining Nim ka Thana copper mineralized area in western India. Amoeboidal to well-developed and rounded/elliptical-shaped marialitic scapolite (Na-rich end-member) rich zones with variable Cl contents ranging from 1.0 wt % to 2.9 wt % have been identified in proximity to the ore-bearing hydrothermal fluid activity zones. Although scapolite is formed as a product of regional metamorphism in many places, in this study, we propose a strong possibility that scapolite was formed by hydrothermal ore-bearing fluid interaction with metasediments. The evidence of hydrothermal activity and Cl sourcing is attributed to (i) the absence of evaporite beds in the area and no Na-rich plagioclase as inclusions within the scapolite suggesting the formation of marialitic scapolite from sodic plagioclase in the metasediments with the interacting hydrothermal fluid; (ii) an epithermal to mesothermal hydrothermal fluid with moderate salinity responsible for the Cu mineralization that is ascribed to be the source of Cl for the formation of marialitic scapolite; (iii) diffusion of SO2 in the scapolite in close association with the sulfide mineral phase (chalcopyrite) supporting the involvement of ore-bearing fluid in the development of scapolite; (iv) the absence of zoned scapolite, the spatial distribution of scapolite in a particular lithology, the occasional incorporation of sulfur into marialitic scapolite and the texture/geometry in the scapolite suggesting a broad hydrothermal linkage instead of a pure metamorphic origin.

We report a new zircon U–Pb age of 1257 ± 6 Ma for the Punugodu granite (PG) pluton in the Eastern Dharwar Craton (EDC), Southern India. The Mesoproterozoic PG is alkali feldspar hypersolvus granite emplaced at shallow crustal level, as evident from the presence of rhyodacite xenoliths and hornfelsic texture developed in the metavolcanic country rocks of the Neoarchaean Nellore Schist Belt (NSB). Geochemically, the PG is metaluminous, ferroan and alkali-calcic, and is characterized by high SiO2 and Na2O + K2O, Ga/Al ratios >2.6, high-field-strength elements and rare earth element (REE) contents with low CaO, MgO and Sr, indicating its similarity to anorogenic, alkali (A-type) granite. The highly fractionated REE patterns with negative europium anomalies of PG reflect its evolved nature and feldspar fractionation. Mafic (MME) to hybrid (HME) microgranular enclaves represent distinct batches of mantle-derived magmas that interacted, mingled and undercooled within the partly crystalline PG host magma. Felsic microgranular enclaves (FME) having similar mineralogical and geochemical characteristics to the host PG most likely represent fragments of marginal rock facies of the PG pluton. The PG appears to be formed from an oceanic island basalt (OIB)-like source in an anorogenic, within-plate setting. The emplacement of PG (c. 1257 Ma) in the vicinity of Mesoproterozoic Kanigiri Ophiolite (c. 1334 Ma) shows an age gap of nearly 77 Ma, which probably suggests PG emplacement in an extensional environment along a terrain boundary at the western margin of the Neoarchaean NSB in the EDC.

Occurrence of drought under rainfed conditions is the foremost factor responsible for yield reduction in soybean. Developing soybean cultivars with an inherent ability to withstand drought would immensely benefit the soybean production in rainfed areas. In the present study, F2 derived mapping populations were developed by crossing drought tolerant (PK 1180, SL 46) and susceptible (UPSL 298, PK 1169) genotypes to investigate the inheritance of seedling survival drought mechanisms and to identify simple-sequence repeat (SSR) markers associated with them, using bulked segregant analysis. Parents as well as a F2 derived mapping population were screened for drought tolerance based on seedling survivability under controlled conditions. Segregation analysis of F2 population derived from a cross between PK 1180 × UPSL 298 was previously shown to have a 3:1 tolerant to susceptible ratio and a probability of 0.61 at a χ2 (3:1) value of 0.258. This was confirmed in another F2 population derived from a cross between PK 1169 × SL 46 with a χ2 (3:1) value of 0.145 obtained at a probability of 0.70. One SSR marker Satt277 showed polymorphism between contracting bulks (tolerant and susceptible) out of 50 polymorphic markers identified during parental polymorphism. Single marker analysis suggested that the marker, Satt277 is linked to seedling survival drought tolerance and is located on chromosome linkage group C2 (chr 6) with a map distance of 3.40 cM. The tolerant genotypes identified could be used as a donor in soybean improvement programs. The marker identified can be used in marker-assisted selection while screening large collection of germplasm.

Experimental investigations were carried out to study the acoustic radiation from a rectangular wall mounted cavity in a confined supersonic flow. The free-stream Mach number was maintained at 1·5 and the cavity length-to-depth ratio was varied from 0·43 to 5·0. Acoustic measurements made on the top wall show jumps in the dominant frequency as the cavity behaviour changes from shallow-to-square-to-deep cavity. Numerical simulations of this unsteady two-dimensional flow using the commercially available software FLUENT have also been carried out. Unsteady pressure data at the same location in the flow field as the pressure transducers in the experiments was collected. FFT analysis of the unsteady pressure data was performed to obtain the dominant acoustic frequencies. The values for these dominant frequencies predicted by the numerical calculations agree well with experimental data. The numerical study also predicts the frequency jump observed in experiments.

In this numerical study, the role of hyper-mixers on supersonic mixing is investigated for six different strut configurations. To this end, 3D, compressible, turbulent, non-reacting flow calculations with air as the secondary injectant have been carried out. A qualitative comparison of the predictions with experimental results is made through Schlieren and Mie scattering images. A quantitative evaluation of the predictions is made by comparison with experimentally measured exit stagnation pressure, wall static pressure and the degree of unmixedness. Based on these results, three strut configurations have been selected for carrying out simulations with hydrogen as the injectant. Results from the hydrogen simulations are compared with the predictions using air and also across the strut configurations. The results clearly demonstrate that castellated strut configurations are very effective in enhancing mixing in such high speed flows.

Results from numerical simulations of the three dimensional flow in the intake-isolator of a dual mode scramjet are presented. The FANS calculations have utilised the SST k -ω turbulence model. The effect of cowl length and cowl convergence angle on the inlet mass capture ratio, flow distortion, shock strength and pressure rise are studied in detail. Three cowl lengths and four or five cowl convergence angles for each cowl length are considered. The predicted values of the dimensionless wall static pressure and inlet mass capture ratio are compared with experimental data reported in the literature. The numerical predictions are shown to agree well with the experimental data. In addition, details of the flow field such as shocks, expansion fans and shock boundary interaction are also captured accurately. Inlet unstart is also demonstrated for one case.

Prior to 2009 dengue fever had not been reported in the Andaman and Nicobar archipelago. In 2009, a few patients with dengue fever-like illness were reported, some of whom tested positive for dengue antibodies. In 2010, 516 suspected cases were reported, including some with dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS); 80 (15·5%) were positive for dengue antibodies. DENV RNA was detected in five patients and PCR-based typing showed that three of these belonged to serotype 1 and two to serotype 2. This was confirmed by sequence typing. Two clones of dengue virus, one belonging to serotype 1 and the other to serotype 2 appeared to be circulating in Andaman. Emergence of severe diseases such as DHF and DSS might be due to recent introduction of a more virulent strain or because of the enhancing effect of sub-neutralizing levels of antibodies developed due to prior infections. There is a need to revise the vector-borne disease surveillance system in the islands.

Thermal oxide covered silicon wafers were polished with slurries containing (i) only nano-sized particles of ceria, monodispersed colloidal spherical silica, or hematite of different shapes, (ii) a binary mixture of the same nano-sized and uniform colloidal particles, and (iii) the same colloids coated with nano-sized ceria. The procedures for the preparation of the coated particles are described in this article. The polish rates and surface qualities were in all cases higher with mixed slurries, and even more so with coated particles. The performance of composite systems also depended on the shape of the particles, cubic ones being the most and spheres least efficient. Experimental results indicated that ceria in mixtures was responsible for the enhanced polish process, while core materials enhanced a closer contact of nano-sized particles with the wafer. In general, the polish rates were higher with the larger contact area between the abrasives and the wafer. This mechanism was further verified by polishing oxide wafers on 3-M fixed abrasive pads, which have cylindrical structures with flat surfaces.

Several chemical–mechanical planarization characterization test wafers were polished to understand the polishing mechanism of the fixed abrasive process. Oxide thickness removal in the “active” (up) and the “recessed” (down) regions of the wafer was monitored for different times of polish. It was found that there was no significant removal in the recessed areas until the step height was reduced to about 100 Å, and the polish rate in the active area decreased rapidly once this critical step height had been attained. At this critical step height, the polish rate of the down areas started to increase and approached that of the up area, with both eventually reaching the negligibly low removal rate of the blanket wafer. The drop in the polish rate of the up area, after planarity had been attained, was fitted to an exponential model.

CdSexTe1-x nanoparticles (with different stoichiometry ratio x) dispersed in silicon dioxide films have been grown by magnetron sputtering technique followed by thermal annealing. Effect of thermal annealing conditions on the structural, compositional, optical and electronic properties of nanoparticles has been studied using GAXRD, XPS, TEM, and spectroscopic ellipsometry techniques. A structural transformation in the nanoparticle core mediated purely by surface layer effects in the case of CdTe and a spontaneous self-organization of nanoparticles into nanorods in the case of CdSe via fractal growth has been observed. Preliminary observations from the ellipsometry measurements carried out on some of these nanoparticle films shows a blue shift of absorption edge.

Physical properties of a-Si:C:H films, including composition, optical constants, microhardness, and surface energy, were investigated. A factorial experimental design was employed to establish the effects of plasma-assisted chemical vapor deposition parameters on the physical properties of the films. The dynamics of the plasma deposition process are discussed in relation to the interactions observed among the process variables and the effects of the variables on the physical properties of the films.

Thermal oxide covered silicon wafers were polished with slurries containing either nano-sized ceria (CeO2) or newly prepared uniform colloidal silica particles coated with ceria. The polish rate of the latter was significantly higher than that of pure ceria. The experiments were carried out using different concentrations of the abrasives at pH 4 and 10. Little effect on the polishing rates was noted when the conditions of the slurries were varied, which was explained by the compensation of two opposite polishing mechanisms.

The properties of abrasive particles play a key role in chemical mechanical polishing (CMP). This study used well-defined dispersions of uniform particles, including spherical silica of varying diameters to polish Cu films and silica cores coated with nanosized ceria particles to polish oxide films. It was shown that the total surface area of the silica abrasives in the slurry controlled Cu material removal rate. However, pH, solid content, and particle size of ceria coated silica abrasives did not have a strong correlation to the removal rate of oxide films.

Chemical mechanical polishing of copper and tantalum was performed using fumed amorphous silica abrasive particles dispersed in H2O2, Fe(NO3)3, and glycine solutions. Results showed that in DI water silica did not polish Cu but Ta had a relatively high polish rate. Cu polish rate decreased with increasing particle concentration in Fe(NO3)3-based slurries due to the adsorption of Fe3+ on the silica surface. Addition of H2O2 enhanced Cu polish rate but reduced Ta polish rate. The specific surface area of the particles played an important role in the removal of Ta and Cu, presumably due to some chemical bonding between the materials being polished and the silica particles.

pH has a strong effect on the polish rates of copper (Cu) and tantalum (Ta) [1]. In this paper, removal rates of Cu and Ta using aqueous slurries containing alumina and silica abrasives in H2O2-glycine solution are studied at varying pH values. It is observed that variation in the Cu and Ta removal rates is a direct result of the change in surface characteristics of the films. Surface characteristics such as presence/absence of a passivating layer and hardness of such layer vary with pH and hence result in removal rate variation. It is also shown that a favorable Cu/Ta polish rate selectivity can be obtained by adjusting the pH of the slurry.

This work investigates the retention and transport of chemical species and abrasive particles during chemical-mechanical polishing (CMP) of copper (Cu). “Slurry step-flow” experiments, in which the concentrations of the chemicals and abrasives in the slurry are altered in steps during polishing were conducted with hydrogen peroxide (H2O2)/glycine based slurries. Two different pads, Suba-500 and IC 1400 (with k grooves), were compared in terms of their slurry retention and transport characteristics. With these experiments, it has been shown that both the abrasives and chemicals are constantly replaced during a typical CMP process. Better polishing performance of the IC 1400 over Suba 500 is a result of improved transport of the chemicals and the abrasives between the wafer/pad interface.

The resistance of thin diamondlike carbon (DLC) films to anodic breakdown in aqueous electrolytes was investigated using voltammetry. The films were less than 0.5 μm thick and were deposited on type 301 stainless steel substrates using plasma-assisted chemical vapor deposition (PACVD) from either methane, acetylene, or 1,3-butadiene precursors with argon or hydrogen as diluent. A 10 nm thick polysilicon (PS) film was plasma-deposited prior to DLC film deposition to improve adhesion. The electrolytes used for corrosion testing were mixtures of 0.1 M NaCl and 0.1 M Na2SO4 and 0.1 M HCl and 0.1 M Na2SO4 in de-ionized water. The measured anodic current was lowest for the films deposited from butadiene and highest for those deposited from methane. The anodic current also increased with an increase in the hydrogen content in the feed gas mixture. In addition, the DLC films deposited at higher gas flow rates offered more resistance to anodic dissolution than those deposited at lower gas flow rates. Annealing improved the film performance. There appears to be an optimum DLC film thickness which provides the maximum resistance to anodic dissolution. In the best case, the DLC films reduced the anodic dissolution of bare stainless steel by about 4 orders of magnitude in the passive region. Atomic force microscopy studies of coated and uncoated stainless steel showed that the DLC films conformed to the steel substrate surface and had no effect on surface roughness, while DLC coated silicon substrates showed no evidence of pores.

The corrosion characteristics of a-C:H/fluorocarbon composite films deposited on type 301 stainless steel substrates were investigated using potentiometry and electrochemical impedance spectroscopy. The films were deposited by radio frequency (13.56 MHz) plasma deposition from different mixtures of hexafluoroethane, acetylene, and argon. A 10 nm thick polysilicon film was plasma-deposited prior to a-C:H film deposition to improve adhesion. The anodic current densities recorded with all the coated samples, in an electrolyte consisting of 0.1 M NaCl and 0.1 M Na2SO4 at 1.5 V (Standard Calomel Electrode), were at least three orders of magnitude less than that for a bare steel sample. They were also at least 20 times less than that obtained with diamond-like carbon film-coated substrates. EIS spectra obtained for these samples, while exposed to 0.6 M NaCl solution over an extended period of time (30–40 days), confirm their barrier properties. All the coatings showed near capacitive behavior in the frequency range 10 mHz–4 KHz.