610 research outputs found

    Studies on Correlation and Path Analysis in Mutants of Coleus (Coleus forskohlii Briq.) for Yield and forskolin Content in V2M1 Generation

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    The present investigation was carried out during 2003-2007 involving terminal cuttings of coleus ecotype 'Garmai'. Genotypic correlation coefficient between yield and its components in mutants of coleus was studied, viz., plant height, number of branches plant-1, number of leaves plant-1, number of tubers plant-1, tuber length and tuber girth were found to have positive and highly significant correlation with yield. However, forskolin and essential oil content showed negative correlation with yield. Path analysis of component characters on yield of Coleus in V2M1 generation exerted positive direct effect through the characters plant height, number of leaves plant-1 and number of tubers plant-1. Similarly, direct effect was observed to be negative through number of branches plant-1 (-0.930), total amount of alkaloids (-0.066) and forskolin content (-0.026). The current investigation resulted in residual effect of 0.158 indicating the accuracy and appropriate selection of component character for crop improvement programme. Weightage must be given to component characters exhibiting positive attributes towards fresh tuber yield in Coleus. However, some traits with negative attributes are also chosen for getting improved quality, i.e., forskolin content, without much inhibition on fresh tuber yield plant-1

    Towards T.R.I.C.K. 2.0 – A tool for the evaluation of the vehicle performance through the use of an advanced sensors system

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    In the last years, the tire technological development has played a fundamental role in motorsport and in automotive industry. The tire contact patch forces have a great influence on the vehicle behavior, so their correct estimation is a crucial task to understand how to improve the car performance. In order to identify the tire interaction characteristic, it is also necessary to use a procedure that allows the correct evaluation of the slip angles in the different operating conditions. This paper presents an evolution of the T.R.I.C.K. tool developed by the UniNa vehicle dynamics research group. In the first version of this tool an 8 degree of freedom vehicle model has been implemented and, starting from the experimental data acquired, the T.R.I.C.K. calculates the interaction forces and the tire slips using the equilibrium equations. Using more car parameters and further data obtained from track sessions and dedicated tests, in the presented release of the tool, new formulations have been developed for a more accurate calculation of the tire-road forces. The effectiveness of the treatments is assessed using experimental data and the simulator outputs. The new formulations introduced in this paper allows, depending on the availability of additional vehicle data and acquisition sensors, to estimate the interaction forces with different and more accurate methodologies than the equilibrium equations, while retaining very reduced simulation times. In this way it is possible to carry out a more precise study of vehicle dynamics with the possibility of investigating and significantly improving performance

    IMECE2002-32157 GPS-BASED REAL-TIME IDENTIFICATION OF TIRE-ROAD FRICTION COEFFICIENT

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    ABSTRACT Vehicle control systems such as collision avoidance, adaptive cruise control and automated lane-keeping systems as well as ABS and stability control systems can benefit significantly from being made "road-adaptive". The estimation of tire-road friction coefficient at the wheels allows the control algorithm in such systems to adapt to external driving conditions. This paper develops a new tire-road friction coefficient estimation algorithm based on measurements related to the lateral dynamics of the vehicle. A lateral tire force model parameterized as a function of slip angle, friction coefficient, normal force and cornering stiffness is used. A real-time parameter identification algorithm that utilizes measurements from a differential GPS system and a gyroscope is used to identify the tire-road friction coefficient and cornering stiffness parameters of the tire. The advantage of the developed algorithm is that it does not require large longitudinal slip in order to provide reliable friction estimates. Simulation studies indicate that a parameter convergence rate of one second can be obtained. Experiments conducted on both dry and slippery road indicate that the algorithm can work very effectively in identifying a slippery road. Two other new approaches to realtime tire road friction identification system are also discussed in the paper

    Static Safety for an Actor Dedicated Process Calculus by Abstract Interpretation

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    The actor model eases the definition of concurrent programs with non uniform behaviors. Static analysis of such a model was previously done in a data-flow oriented way, with type systems. This approach was based on constraint set resolution and was not able to deal with precise properties for communications of behaviors. We present here a new approach, control-flow oriented, based on the abstract interpretation framework, able to deal with communication of behaviors. Within our new analyses, we are able to verify most of the previous properties we observed as well as new ones, principally based on occurrence counting

    Antifungal mechanisms by which a novel Pseudomonas aeruginosa phenazine toxin kills Candida albicans in biofilms

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    Pseudomonas aeruginosa produces several phenazines including the recently described 5-methyl-phenazine-1-carboxylic acid (5MPCA), which exhibits a novel antibiotic activity towards pathogenic fungi such as Candida albicans . Here we characterize the unique antifungal mechanisms of 5MPCA using its analogue phenazine methosulphate (PMS). Like 5MPCA, PMS induced fungal red pigmentation and killing. Mass spectrometry analyses demonstrated that PMS can be covalently modified by amino acids, a process that yields red derivatives. Furthermore, soluble proteins from C. albicans grown with either PMS or P. aeruginosa were also red and demonstrated absorbance and fluorescence spectra similar to that of PMS covalently linked to either amino acids or proteins in vitro , suggesting that 5MPCA modification by protein amine groups occurs in vivo . The red-pigmented C. albicans soluble proteins were reduced by NADH and spontaneously oxidized by oxygen, a reaction that likely generates reactive oxygen species (ROS). Additional evidence indicated that ROS generation precedes 5MPCA-induced fungal death. Reducing conditions greatly enhanced PMS uptake by C. albicans and killing. Since 5MPCA was more toxic than other phenazines that are not modified, such as pyocyanin, we propose that the covalent binding of 5MPCA promotes its accumulation in target cells and contributes to its antifungal activity in mixed-species biofilms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79382/1/j.1365-2958.2010.07414.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79382/2/MMI_7414_sm_Figures_Table.pd

    Chiral Fermions on the Lattice

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    An expression for the lattice effective action induced by chiral fermions in any even dimensions in terms of an overlap of two states is shown to have promising properties in two dimensions: The correct abelian anomaly is reproduced and instantons are suppressed.Comment: 9p, Postscript file, RU--93--3

    Quenched divergences in the deconfined phase of SU(2) gauge theory

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    The spectrum of the overlap Dirac operator in the deconfined phase of quenched gauge theory is known to have three parts: exact zeros arising from topology, small nonzero eigenvalues that result in a non-zero chiral condensate, and the dense bulk of the spectrum, which is separated from the small eigenvalues by a gap. In this paper, we focus on the small nonzero eigenvalues in an SU(2) gauge field background at β=2.4\beta=2.4 and NT=4N_T=4. This low-lying spectrum is computed on four different spatial lattices (12312^3, 14314^3, 16316^3, and 18318^3). As the volume increases, the small eigenvalues become increasingly concentrated near zero in such a way as to strongly suggest that the infinite volume condensate diverges.Comment: 12 pages, 3 figures, version to appear in Physical Review

    An alternative to domain wall fermions

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    We define a sparse hermitian lattice Dirac matrix, HH, coupling 2n+12n+1 Dirac fermions. When 2n2n fermions are integrated out the induced action for the last fermion is a rational approximation to the hermitian overlap Dirac operator. We provide rigorous bounds on the condition number of HH and compare them to bounds for the higher dimensional Dirac operator of domain wall fermions. Our main conclusion is that overlap fermions should be taken seriously as a practical alternative to domain wall fermions in the context of numerical QCD.Comment: Revtex Latex, 26 pages, 1 figure, a few minor change

    Universal Scaling of the Chiral Condensate in Finite-Volume Gauge Theories

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    We confront exact analytical predictions for the finite-volume scaling of the chiral condensate with data from quenched lattice gauge theory simulations. Using staggered fermions in both the fundamental and adjoint representations, and gauge groups SU(2) and SU(3), we are able to test simultaneously all of the three chiral universality classes. With overlap fermions we also test the predictions for gauge field sectors of non-zero topological charge. Excellent agreement is found in most cases, and the deviations are understood in the others.Comment: Expanded discussion of overlap fermion results. 17 pages revtex, 7 postscript figure
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