Permanental Mates: Perturbations and Hwang’s conjecture

AbstractLet Ωn denote the set of all n×n doubly stochastic matrices. Two unequal matrices A and B in Ωn are called permanental mates if the permanent function is constant on the line segment tA+(1−t)B,0≤t≤1, connecting A and B. We study the perturbation matrix A+E of a symmetric matrix A in Ωn as a permanental mate of A. Also we show an example to disprove Hwang’s conjecture, which states that, for n≥4, any matrix in the interior of Ωn has no permanental mate

Multiple-input Multiple-output Radar Waveform Design Methodologies

Multiple-input multiple-output (MIMO) radar is currently an active area of research. The MIMO techniques have been well studied for communications applications where they offer benefits in multipath fading environments. Partly inspired by these benefits, MIMO techniques are applied to radar and they offer a number of advantages such as improved resolution and sensitivity. It allows the use of transmitting multiple simultaneous waveforms from different phase centers. The employed radar waveform plays a key role in determining the accuracy, resolution, and ambiguity in performing tasks such as determining the target range, velocity, shape, and so on. The excellent performance promised by MIMO radar can be unleashed only by proper waveform design. In this article, a survey on MIMO radar waveform design is presented. The goal of this paper is to elucidate the key concepts of waveform design to encourage further research on this emerging technology.Defence Science Journal, 2013, 63(4), pp.393-401, DOI:http://dx.doi.org/10.14429/dsj.63.253

Status of red palm weevil damage in East Godavari district and strategies for control with ecofriendly methods

A roving survey conducted during 2003 and 2004 to assess the damage level of red palm weevil in four major coconut growing districts of Andhra Pradesh i.e., East Godavari, West Godavari, Visakhapatnam and Srikakulam revealed East Godavari district as the hot spot area for the pest. Root feeding with Azadirachtin 5 % WSC was found effective in preventing further damage and spread of red palm weevil in the garden. The study confirmed that azadirachtin 5 % WSC can be a suitable botanical substitute for monocrotophos 36 % SL through root feeding against this pest. Aggregation pheromone lures deployed in various infested gardens decreased the damage levels of red palm weevil. A sustainable IPM for red palm weevil was suggested with ecofriendly components

Integrated nutrient management in COD x WCT hybrid coconut under alluvial clay-loam soil of Assam

A field experiment was conducted in alluvial clay-loam soil at the Horticultural Research Station, Kahikuchi of Assam Agricultural University under All India Co-ordinated Research Project on Palms from 2003 to 2007 to study the effect of integrated nutrient management treatments on COD x WCT hybrid coconut taking 27 treatment combinations with three levels each of N (0, 500, 1000 g/palm/year, where 50% N was substituted by vermicompost on N equal nutrient basis), P2O5 (0, 250, 500 g/palm/year) and K2O (0, 1000, 2000 g/palm/year). The results revealed significant influence of the integrated nutrient treatments on number of functional leaves in the crown, number of female flowers, nut setting, nut yield per palm per year and copra content per nut. The highest values for all these characters were obtained under higher level of K application. However, the highest average nut yield of 111nuts/palm/year and benefit cost ratio of 2.02 were recorded in the treatment N1P2K2 (500 g N wherein 50% N substituted by vermicompost, 500 g P2O5 and 2000 g K2O/palm/year), while the lowest nut yield (44 nuts/palm/year) and benefit cost ratio of 0.20 were recorded in the treatment N0P0K0 and N2P2K0, respectively. The integrated nutrient treatments also improved the soil pH, organic carbon content, available N, P and K content of the soil and the leaf NPK contents of the palms under study

Effect of fertigation on the productivity of coconut

An experiment to study the effect of fertigation on the productivity of coconut was laid out at Horticulture Research Station, Arsikere, Karnataka during 2007-08 to 2011-12. Application of 25, 50, 75 and 100 per cent of recommended NPK through drip irrigation system was compared with the soil application of recommended NPK as well as control with no fertilizer application. Fertilizers were given through drip irrigation system throughout the year in ten equal splits at monthly interval excluding peak rainfall months of May and October. Application of 100 per cent NPK through drip irrigation recorded significantly higher number of female flowers and nut setting percentage compared to control and application of 25 per cent NPK through drip irrigation. The mean nut and copra yield per palm over five years was significantly higher with the application of 100 per cent NPK through drip irrigation compared to control and application of 25 and 50 per cent NPK through drip irrigation. However, the copra content was not significantly influenced by the fertigation treatments. Application of 75 per cent NPK through drip irrigation recorded nut and copra yield per palm on par with the application of 100 per cent NPK through drip irrigation and 100 per cent NPK through soil. The net returns and benefit-cost ratio in 75 per cent NPK through drip irrigation were also on par with the application of 100 per cent NPK through drip irrigation, but significantly higher than 100 per cent NPK through soil application. The study indicated the possibility of saving 25 per cent of the recommended fertilizers by adopting fertigation which ensures higher productivity in coconut

Carbon materials as electrocatalysts for oxygen reduction in phosphoric acid medium

The behaviour of acstylene black (Indian grade) as catalyst support material is reported. The acetylene black is heat treated (activated) at variour temperatures in nitrogen atmosphere. The surface area of the various heat treated samples is obtained. Platinum is deporited into the carbon bye reported technique. The of platinum agglomeration on the carbon in identified through scanning electron microscope. The above catalyst is applied to glassy carbon disc. The electrochemical surface area of the catalyst ie determined by the hydrogen absorption and oxidation in alkaline medium. Similar electrodes (disc, dia 6 mm) are used in H3PO4 medium. Cyclic vottammograms are obtained in the oxygen evolution region and oxygen reduction region. The exchange current density of the catalyst for oxygen evolution and reduction ir reported for different catalyst loadings

Intercropping of medicinal and aromatic plants in coconut gardens

A field study was conducted at Horticulture Research Station, Arsikere, Karnataka during 2006-07 to 2008-09 to identify suitable medicinal and aromatic plants for intercropping in coconut gardens of maidan tract of Karnataka. The experiment consisted of 14 medicinal and aromatic crops viz., Kalmegh (Andrographis paniculata), Makoi (Solanum nigrum), Coleus (Coleus forskohlii), Garden rue (Ruta graveolens), Lepidium (Lepidium sativum), Tulsi (Ocimum sanctum), Arrow root (Maranta arundinaceae), Kacholam (Kaemferia galanga), Cowhage (Mucuna pruriens), Roselle (Hibiscus sabdariffa), Ambrette (Abelmoschus moschatus), Citronella (Cymbopogon winteranus), Lemon grass (Cymbopogon flexuosus) and Vetiver grass (Vetiveria zizanoides). The yield of all the medicinal and aromatic crops grown as intercrop in coconut garden were reduced compared to their sole crop yields. The reduction in yield was less in lemon grass (6.4 %), tulsi (23.5 %), arrow root (23.9 %), vetiver grass (25.1 %), kalmegh (25.7 %), makoi (29.1 %), citronella (30.2 %) and garden rue (30.5 %). The nut yield of coconut was improved with intercropping of medicinal and aromatic crops. The andrographolide content in kalmegh (4.40 to 3.20 %), rutin alkaloids in garden rue (1.68 to 1.40 %) and oil content in lepidium (19.60 to 17.23 %) were significantly reduced when grown as intercrops in coconut garden as compared to sole crop. However, the forskohlin content in coleus (0.43 to 0.61 %) and essential oil content in ambrette (0.24 to 0.29 %) were significantly increased by intercropping. In other medicinal and aromatic crops, the quality parameters were not significantly influenced by intercropping. The intercropping system of growing lemon grass under coconut recorded the highest net income (Rs. 91,561/ha) and B:C ratio (2.89) followed by garden rue (Rs. 81,865/ha and 2.79), tulsi (Rs. 77,472/ha and 2.71), kalmegh (Rs. 75,163/ha and 2.56), arrow root (Rs. 72,211/ha and 2.28) and makoi (Rs. 67,058/ha and 2.68). Hence, intercropping of lemon grass, garden rue, tulsi, kalmegh, arrow root and makoi with coconut can be recommended for maidan tract of Karnataka

Performance of medicinal and aromatic plants as intercrops in coconut plantations in Konkan region of Maharashtra

A field experiment was conducted at Regional Coconut Research Station, Bhatye, Ratnagiri (AICRP on Palms) during 2006-2011 to develop appropriate cropping system with medicinal and aromatic plants as intercrops compatible with coconut. The experiment consisted ‘shatavari’ (Asparagus racemosus), ‘adulasa’ (Adhatoda vasica), arrowroot (Maranta arundincea), lemon grass (Cymbopogum citratus) and citronella (Cymbopogum winterianus) replicated four times in randomized block design. The yield of different medicinal/aromatic plants was maximum in lemon grass (31 t ha-1) followed by citronella (22 t ha-1), arrowroot (16 t ha-1), adulsa (2.1 t ha-1) and shatavari (0.8 t ha-1). The yield of intercrops in terms of coconut equivalent yield was higher with lemongrass (7750 nuts ha-1) followed by arrowroot (6000 nuts ha-1), adulasa (4725 nuts ha-1), citronella (4125 nuts ha-1) and shatavari (3500 nuts ha-1). The yield of coconut increased from 12 to 21 per cent after planting the intercrops. The net return was maximum in coconut + lemongrass (Rs. 96,200/ - per ha) followed by coconut + arrowroot (Rs. 93,200/- per ha), coconut + shatavari (Rs. 83,300/- per ha), coconut + adulasa (Rs. 78,300/- per ha) and coconut + citronella (Rs. 73,800/- per ha). Further, it was observed that shatavarin and saponins in shatavari, alkaloid in adulasa, citranol in citronella and sugar in arrowroot were higher with intercropping whereas citral in lemon grass slightly reduced with intercropping. Considering the performance of different medicinal crops as intercrop and market demand, arrowroot, lemongrass, adulasa, citronella and shatavari have been recommended as intercrops in coconut plantation for Konkan region of Maharashtra