Quantum Buckling

We study the mechanical buckling of a two dimensional membrane coated with a thin layer of superfluid. It is seen that a singularity (vortex or anti-vortex defect) in the phase of the quantum order parameter, distorts the membrane metric into a negative conical singularity surface, irrespective of the defect sign. The defect-curvature coupling and the observed instability is in striking contrast with classical elasticity where, the in-plane strain induced by positive (negative) disclinations is screened by a corresponding positive (negative) conical singularity surface. Defining a dimensionless ratio between superfluid stiffness and membrane bending modulus, we derive conditions under which the quantum buckling instability occurs. An ansatz for the resulting shape of the buckled membrane is analytically and numerically confirmed

Soliton attenuation and emergent hydrodynamics in fragile matter

Disordered packings of soft grains are fragile mechanical systems that loose rigidity upon lowering the external pressure towards zero. At zero pressure, we find that any infinitesimal strain-impulse propagates initially as a non-linear solitary wave progressively attenuated by disorder. We demonstrate that the particle fluctuations generated by the solitary-wave decay, can be viewed as a granular analogue of temperature. Their presence is manifested by two emergent macroscopic properties absent in the unperturbed granular packing: a finite pressure that scales with the injected energy (akin to a granular temperature) and an anomalous viscosity that arises even when the microscopic mechanisms of energy dissipation are negligible. Consistent with the interpretation of this state as a fluid-like thermalized state, the shear modulus remains zero. Further, we follow in detail the attenuation of the initial solitary wave identifying two distinct regimes : an initial exponential decay, followed by a longer power law decay and suggest simple models to explain these two regimes.Comment: 8 pages, 3 Figure

Strategies for wheat stripe rust pathogenicity identified by transcriptome sequencing

Stripe rust caused by the fungus Puccinia striiformis f.sp. tritici (Pst) is a major constraint to wheat production worldwide. The molecular events that underlie Pst pathogenicity are largely unknown. Like all rusts, Pst creates a specialized cellular structure within host cells called the haustorium to obtain nutrients from wheat, and to secrete pathogenicity factors called effector proteins. We purified Pst haustoria and used next-generation sequencing platforms to assemble the haustorial transcriptome as well as the transcriptome of germinated spores. 12,282 transcripts were assembled from 454-pyrosequencing data and used as reference for digital gene expression analysis to compare the germinated uredinospores and haustoria transcriptomes based on Illumina RNAseq data. More than 400 genes encoding secreted proteins which constitute candidate effectors were identified from the haustorial transcriptome, with two thirds of these up-regulated in this tissue compared to germinated spores. RT-PCR analysis confirmed the expression patterns of 94 effector candidates. The analysis also revealed that spores rely mainly on stored energy reserves for growth and development, while haustoria take up host nutrients for massive energy production for biosynthetic pathways and the ultimate production of spores. Together, these studies substantially increase our knowledge of potential Pst effectors and provide new insights into the pathogenic strategies of this important organism.J.P.R. is an ARC Future Fellow (FT0992129). This project has been supported by Bioplatforms Australia through funding from the Commonwealth Government NCRIS and Education Investment Fund Super Science programs

Solitary Waves and Fluctuations in Fragile Matter

In this thesis, we study energy transport and fluctuations in simple models of fragile matter : a unique state of matter that has a vanishingly small window of linear response since one or both of its elastic moduli (shear and bulk) are nearly zero. As a consequence, even the tiniest perturbations travel as nonlinear waves. In addition, most models of fragile matter have an amorphous structure. It is the interaction of the non-linear waves with the underlying disorder and the resulting fluctuations, that constitutes the unifying theme explored in this thesis. There are at least two seemingly distinct sources of fragility: a local source stemming from the strongly non-linear interaction potential between particles so that one can not expand around a potential minimum to define a spring constant, and a second, global source, whereby the collective response of the sample can be considered weakly linear. As a model of the first kind, we consider a two dimensional packing of soft frictionless elastic disks that are just touching their nearest neighbours. The interaction potential between elastic disks is given by the nonlinear Hertz law that has no harmonic part. Consequently, for a packing in this state, the bulk modulus is vanishingly small and the smallest compressions imparted at the edges leads to nonlinear solitary like waves. As a model of the second kind, we consider a two dimensional random network of harmonic springs where each node has on average around four nearest neighbours. Here, despite the contact interaction being harmonic, the network has a vanishingly small shear modulus. Consequently, even the tiniest shear strains elicit non-linear waves. There are many important similarities and differences between the nature of non-linear waves and the role played by disorder in the two models described above, which we are gradually beginning to understand.This work is part of the research programme of the Foundation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Research (NWO).Biological and Soft Matter Physic

Another Look at Devaluation and the Trade Balance in China

This paper estimates the effect of Chinese Yuan devaluation on the trade balance of China.  For that a regression equation is developed in which domestic income, foreign income, domestic money supply, foreign money supply and real effective exchange rate are used as explanatory variable with trade balance as the dependent variable. In order to test the J-curve phenomenon the lagged values of exchange rata are also included.  Quarterly time series data from 1999 to 2016 are used.  Before estimating the model the time series properties of the data are diagnosed and an error correction model is developed and estimated.  The estimated results show that the contemporaneous effect of devaluation is positive, but the total effect is insignificant.  A J-curve pattern of adjustment of the trade balance is also detected

Black hole Attack Prevention in VANET

The past decade has witnessed the emergence of Vehicular Ad-hoc Networks (VANETs), from the well-known Mobile Ad Hoc Networks (MANETs) in wireless communications. VANETs are self-organizing networks established among vehicles equipped with communication facilities. In VANETs vehicles are equipped with On Board Unit (OBU) through which they are capable of organizing themselves, by discovering their neighbor vehicles and capable to communicate with Infrastructure nodes equipped with Road Side Unit (RSU) for finding optimal path, Service based Information as well as other sensible Information for safe Transportation over the wireless medium. Recently, VANETs have been getting greater attention as more applications are depending on them. Researchers have tried to propose various Protocols, Approaches and methodologies that will improve the Quality, Efficiency, Authenticity and Integrity of different services of VANETs. Many of the applications require a high level of security. Thus, the main challenge is to protect VANETs from different security attacks. VANETs use the open wireless medium to communicate which makes it easy for an attacker to impose his attacks by Manipulating, Sniffing, and blocking the different packets. In VANETs all the nodes can act as routers for the data packets and there is no clear line of defence where it is possible to place a firewall. The main concern is how to provide best security in VANET without any negotiating with performance & reliability.The objective of this work is to check feasibility of using infrastructure based vehicular communication for detecting and preventing Blackhole Attacks. In this paper we proposed three different approaches for Blackhole attack prevention. We analyze performance of the proposed approaches for different scenario by generating heterogeneous traffic environment. With the proposed approaches we get the reduction in Packet Loss of up to 79.6971%

(2E)-1-(5-Chloro­thio­phen-2-yl)-3-(2,4,5-trimeth­oxy­phen­yl)prop-2-en-1-one

In the title mol­ecule, C16H15ClO4S, the chloro­thio­phene and trimeth­oxy­phenyl rings make a dihedral angle of 31.12 (5)°. The C=C double bond exhibits an E conformation. In the crystal, C—H⋯O inter­actions generate bifurcated bonds, linking the mol­ecules into chains along the b axis

Geotechnical Problems Encountered During the Excavation of Underground Cavities for Varahi Hydro Electric Project

Varahi river in Karnataka State, India originates on the Western Ghats and is harnessed for power generation by constructing three dams. The water is conveyed through two inclined pressure shaft to the underground power house below the Ghats. The underground power house of the Varahi Hydro Electric Project executed by the Karnataka Power Corporation has 2 units of 135 MW each in the first stage with a provision to add two more identical units. Three underground cavities are excavated parallel to one another for housing the rotary valves, generators and the transformers respectively and are at a gee-static head of about 230 m. The paper deals with a case history of the excavation practice and the stabilisation measures adopted during the excavation of the cavities for housing the underground power house complex of the Varahi Hydro Electric Project in Karnataka, India

Plant species composition and product utility pattern of Garo homegardens in Meghalaya, India

Home garden is a traditional landuse system practiced by many rural households in the tropical region. The composition and management practices within homegardens are largely driven by cultural setup and ecological conditions. The present study characterized the plant species composition, utility patterns and management of  Garo homegardens in Dadenggre block, West Garo Hill district of Meghalaya, India. Fifty households from 5 villages were randomly selected and interviewed using a semi-structured questionnaire. The homegardens size ranged between 0.07 and 1.29ha, harbouring 132 plant species, out of which 74 species were trees, 19 shrubs and 39 herbs. Among the perennials, Areca catechu (areca nut) was the most common contributor to household earnings. When species were grouped into 9 utility classes (timber, medicinal, fruit, fuelwood, fodder, vegetables, ornamental, spice, and others), highest number was for fuelwood, followed by vegetables and fruits. The average household income was Rs. 318/100m2, the highest contribution from the sale of vegetables. Various home garden management activities were conducted, engaging family members and generating employment for others. Animal rearing is common in many households and the application of animal manure and household waste has helped maintain soil fertility of homegardens’ soils. Homegardens are integral to the Garo society, contributing significantly to household needs and activities.

High mobility titanium-doped indium oxide for use in tandem solar cells deposited via pulsed DC magnetron sputtering

© 2014 The Authors. The effects of pulsed DC (PDC) magnetron sputtering on the crystalline structure of the high mobility transparent conducting oxide (TCO), titanium-doped indium oxide (ITiO), are investigated. High mobility (μ >100 V-1s-1cm2) ITiO films are deposited by PDC magnetron sputtering and compared to RF deposited films using optimized conditions. These high mobility ITiO films have shown to extend the transmission in the NIR region compared to typical TCOs, such as ITO, exhibiting their potential in a tandem or multiple junction solar cell application. ITiO films deposited by PDC magnetron sputtering offer an increased deposition rate without a significant reduction in mobility when compared to RF sputtering, thus potentially offering PDC as a preferred industrial choice over RF sputtering. Structural characterization of the ITiO films prepared by PDC show a change in crystalline orientation and crystallite shape when compared to RF films, measured by XRD and SEM, which have been linked with the electrical parameters of the TCO