Transition from anticipatory to lag synchronization via complete synchronization in time-delay systems

The existence of anticipatory, complete and lag synchronization in a single system having two different time-delays, that is feedback delay $\tau_1$ and coupling delay $\tau_2$, is identified. The transition from anticipatory to complete synchronization and from complete to lag synchronization as a function of coupling delay $\tau_2$ with suitable stability condition is discussed. The existence of anticipatory and lag synchronization is characterized both by the minimum of similarity function and the transition from on-off intermittency to periodic structure in laminar phase distribution.Comment: 14 Pages and 12 Figure

Change in the room temperature magnetic property of ZnO upon Mn doping

We present in this paper the changes in the room temperature magnetic property of ZnO on Mn doping prepared using solvo-thermal process. The zero field cooled (ZFC) and field cooled (FC) magnetisation of undoped ZnO showed bifurcation and magnetic hysteresis at room temperature. Upon Mn doping the magnetic hysteresis at room temperature and the bifurcation in ZFC-FC magnetization vanishes. The results seem to indicate that undoped ZnO is ferromagnetic while on the other hand the Mn doped ZnO is not a ferromagnetic system. We observe that on addition of Mn atoms the system shows antiferromagnetism with very giant magnetic moments.Comment: 5 figure

Scaling and synchronization in a ring of diffusively coupled nonlinear oscillators

Chaos synchronization in a ring of diffusively coupled nonlinear oscillators driven by an external identical oscillator is studied. Based on numerical simulations we show that by introducing additional couplings at $(mN_c+1)$-th oscillators in the ring, where $m$ is an integer and $N_c$ is the maximum number of synchronized oscillators in the ring with a single coupling, the maximum number of oscillators that can be synchronized can be increased considerably beyond the limit restricted by size instability. We also demonstrate that there exists an exponential relation between the number of oscillators that can support stable synchronization in the ring with the external drive and the critical coupling strength $\epsilon_c$ with a scaling exponent $\gamma$. The critical coupling strength is calculated by numerically estimating the synchronization error and is also confirmed from the conditional Lyapunov exponents (CLEs) of the coupled systems. We find that the same scaling relation exists for $m$ couplings between the drive and the ring. Further, we have examined the robustness of the synchronous states against Gaussian white noise and found that the synchronization error exhibits a power-law decay as a function of the noise intensity indicating the existence of both noise-enhanced and noise-induced synchronizations depending on the value of the coupling strength $\epsilon$. In addition, we have found that $\epsilon_c$ shows an exponential decay as a function of the number of additional couplings. These results are demonstrated using the paradigmatic models of R\"ossler and Lorenz oscillators.Comment: Accepted for Publication in Physical Review

Farmers Perception on the Communication Behaviour and Usefulness of Farmer Producer Organizations in Namakkal District of Tamil Nadu

Agriculture is the main occupation of the vast majority of the population of India. Producers companies can help smallholder farmers participate in emerging high-value markets, such as the export market and the unfolding modern retail sector in India. Farmer producer organizations (FPO) need to strengthen support service for small farmers developing a link between farmers and purchasers of agricultural produce. The study was conducted among four assisting FPOs with 45 respondents in Namakkal district of Tamil Nadu. Data were collected through a well-structured interview schedule among the respondents of four farmer producers companies select randomly. The data collected were coded, tabulated, ranked and the result was interpreted worked out. Overall the respondent's member perception score was ranged between “good†to “excellentâ€

Approaches of material selection, alignment and methods of fabrication for natural fiber polymer composites: A review

The recent superiority of the composite materials is cautiously focusing on environmental adoption of natural fiber composites. The major source of the natural fiber materials covered in the globe, especially natural fibers, is plant-based, animal-based and mineral-based. Eco friendly based material can save the environment and recycling of the material is possible, as well as important criteria. Hence engineers ultimately focused on natural fiber polymer matrix materials to save the environment, pollution control, plastic manipulation, etc. The literature work was studied to identify natural fiber material possession. The major goal of the present review was to identify material characterization and appropriate application, mainly offering to enhance mechanical properties, flexural strength, electrical properties, thermal properties etc. The major consequence of the natural fiber is hydrophilic treatment. There is poor interfacial adhesion between the addition/filling substances and poor mechanical characteristics. All of these shortcomings constitute a critical issue. This review presents numerous sorts of  natural and synthetic polymers, natural fibres such as jute, ramie, banana, pineapple leaf fibre, and kenaf, etc.; short and long fibre loading methods, fibre fillers in micro and nanoparticle, American society of testing and materials (ASTM) standard plate dimensions, fabrication methods such as hand lay-up process, spray lay-up process, vacuumed-bag, continuous pultrusion, and pulforming process, etc.; industries and home appliances such as automotive parts, building construction, sports kits, domestic goods, and electronic devices. The review lists various material combinations, fibre loading, fillers, and matrix that can aid in the improvement of material properties and the reduction of failures during mechanical testing of composites.                

RESPONSE OF PEARL MILLET TO INTEGRATED USE OF ORGANICS AND FERTILIZERS

In the present study, the integrated organic fertilizers were used to estimate the growth and yield of pearl millet. The treatments consisted of application of increased levels of recommended dose of fertilizer with organic manures for pearl millet. The treatments were; T1-100% RDF,T2-125%RDF,T3-75%RDF, T4-100% RDF + FYM @ 12.5 t ha-1, T5-100% RDF+Poultrymanure@5tha-1,T6-100 % RDF + Vermicompost @ 5 t ha-1, T7-100 % RDF + Pressmud@5tha-1, T8-125% RDF + Poultry manure @ 5 t ha-1, T9-125 % RDF + Vermicompost @ 5 t ha-1, T10-125 % RDF + Pressmud  @ 5 t ha-1, T11-75% RDF + Poultry manure @ 5 t ha-1, T12-75 % RDF + Vermicompost @ 5 t ha-1 and T13-75 % RDF + Pressmud @ 5 t ha-1. The experiments were laid out in randomized block design (RBD) and replicated thrice. The result of the experiment revealed that the application of 125% recommended dose of fertilizer + vermicompost@5tha-1(T9), significantly increased the growth, yield, quality and nutrient uptake of pearl millet followed by, T10 (125% recommended dose of fertilizer + Pressmud @ 5 t ha-1) respectively

Sucrose and Maltose as Carbon Sources for Fermentative Production of Polysaccharide by Aspergillus niger van tiegh.

Two carbon sources viz., sucrose and maltose were used to induce extracellular polysaccharide production in Aspergillus niger. Maximum production of polysaccharide 513 mg/100ml of culture filtrate was observed at pH 7, 10% sucrose concentration, 15 days of incubation.  Polysaccharide production was increased with increase in growth of mycelium of A. niger in both the substrates.  The optimum pH and incubation periods for the maximum production of polysaccharide were pH 7 and 15 days respectively.  The polysaccharide produced by A. niger was the polyol of 3,4,6 tri-o-methyl D glucose with b-1-3 glycosidic linkage commonly known as glucan.  The polysaccharide produced by this species may be composed of glucose and little amount of galactose and other oligosaccharides.  Polarimetric studies revealed that the fractions containing glucose gave laevorotatory values of the optical rotation.ÂÂ

Entomopathogenic Fungi for the Management of Calopepla leayana on Gmelina arborea

Entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae were isolated and identified as natural pathogens of Calopepla leayana. Both the species of fungi were effective against the larval and adult stages of C. leayana causing white and green muscardine diseases respectively. It was also found that B. bassiana was more pathogenic to the pest as compared to M. anisopliae.  The susceptibility of larvae and adults was negatively associated with the age and positively associated with the fungal spore concentration. In all the stages from I instar to adult, the highest mortality was observed in 10% of 1x109 spores/ml concentration of B. bassiana among 1, 2.5, 5 & 10% of 1x109 spores/ml concentration.  It was also reflected in probit analysis that the concentration of spores required to kill fifty percent of the population was ranges from 0.09% to 5.98% of 1x109 spores/ml concentration of B. bassiana and 1.02% to 9.72% of 1x109 spores/ml concentration of M. anisopliae. The larvae of I instar have shown highest mortality, which gradually decreased with the increase in age or decrease in the concentration of fungal spores. Mass production of B. bassiana using different substrates was attempted to harvest ample amount of spores. This study revealed that spore production was directly proportional to the mycelial weight and incubation period. From the seven substrates tested, wheat flour was identified as one of the suitable substrates for the mass production of B. bassiana.  A field trial was conducted to test their efficacy under field conditions. 72-93% mortality was observed in field conditions.-----------------------------------------------------------------------------------------------------Division of Bioprospecting, Institute of Forest Genetics and Tree Breeding, Coimbatore-641002, Tamilnadu, India*Corresponding author, Email: [email protected] This Article As: N. Senthilkumar and S. Murugesan. 2010. Entomopathogenic Fungi for the Management of Calopepla leayana on Gmelina arborea. J. Ecobiotechnol. 2(3): 01-0