Fast Implementation of Transmit Beamforming for Colocated MIMO Radar

Multiple-input Multiple-output (MIMO) radars benefit from spatial and waveform diversities to improve the performance potential. Phased array radars transmit scaled versions of a single waveform thereby limiting the transmit degrees of freedom to one. However MIMO radars transmit diverse waveforms from different transmit array elements thereby increasing the degrees of freedom to form flexible transmit beampatterns. The transmit beampattern of a colocated MIMO radar depends on the zero-lag correlation matrix of different transmit waveforms. Many solutions have been developed for designing the signal correlation matrix to achieve a desired transmit beampattern based on optimization algorithms in the literature. In this paper, a fast algorithm for designing the correlation matrix of the transmit waveforms is developed that allows the next generation radars to form flexible beampatterns in real-time. An efficient method for sidelobe control with negligible increase in mainlobe width is also presented

Occultation of compact radio sources by the ion tail of Halley's Comet

Enhancements of scintillations of the compact radio sources PKS 2314+03 and 1827-360 were observed at 103 MHz and 408 MHz during 18-21 December 1985 and on 29 March 1986, respectively, when the plasma tail of Halley's Comet swept across them. At 103 MHz the RMS plasma density variation along the tail was 10 and 3.3/cu cm at 0.12 AU and 0.18 AU, respectively, as measured from the comet's position. At 408 MHz it was 1.9/cu cm at 0.036 AU. Comparison of results of these two sets of observations is presented

Kinetics and mechanistic study of cetyltrimethylammonium bromide catalyzed oxidation of tetraethylene glycol by N-chlorosaccharin in acidic medium

The kinetics and mechanism of cetyltrimethylammonium bromide catalyzed oxidation of tetraethylene glycol [2,2'-(oxibis(ethylenoxy)diethanol)] by N-chlorosaccharin in aqueous acetic acid medium in presence of perchloric acid have been investigated at 323K. The reaction is first order dependence on Nchlorosaccharin. The reaction rate follows first order kinetics with respect to [tetraethylene glycol] with excess concentration of other reactants. The miceller effect due to cetyltrimethylammonium bromide, a cationic surfactant has been studied. The change in ionic strength shows negligible salt effect. The dielectric effect is found to be positive. Addition of one of the products (saccharin) retards the reaction rate. Activation parameters are calculated from the Arrhenious plot. A possible mechanism consistent with the experimental results has been proposed

Groundwater externalities of surface irrigation transfers under National River Linking Project: Polavaram – Vijayawada link

River basin managementRiver basin developmentDevelopment projectsWater transferIrrigation canalsGroundwater irrigationTube well irrigationRiceSurface irrigationCrop managementSoil salinityWaterlogging

Mineral content of red skinned potatoes of Eastern India

Potato tuber colour is an important factor that influences consumer preferences. Eastern plain region of India contributes about 50% of total potato acreage and production. Consumers in this region generally prefer red skinned varieties. Growing awareness for nutrient rich food can create a niche market for nutritious potatoes. Potato is crop of choice for mineral biofortification owing to better mineral bioavailability due to its high ascorbic acid and minimal phytate content. Iron and zinc are the essentially required minerals for good health. Considering the nutritional importance of these elements and wider prevalence of their deficiency in Indian sub-continent, thirteen Eastern regions red skinned advanced hybrids and varieties were evaluated to find the genetic diversity for iron and zinc content. A significant wide range of contents was observed for both the elements. High heritability of both mineral suggests feasibility of selecting genotypes for breeding nutrient rich varieties. Identified genotypes can be utilised as parental lines for future breeding programme and can be released as nutrient rich potato variety