Viscosity Behaviour of Aqueous Solutions of Sodium Chloroacetate & ɑ-Chloropropionate

1097-109

Restricted Wiedemann-Franz law and vanishing thermoelectric power in one-dimensional conductors

In one-dimensional (1D) conductors with linear E-k dispersion (Dirac systems) intrabranch thermalization is favored by elastic electron-electron interaction in contrast to electron systems with a nonlinear (parabolic) dispersion. We show that under external electric fields or thermal gradients the carrier populations of different branches, treated as Fermi gases, have different temperatures as a consequence of self-consistent carrier-heat transport. Specifically, in the presence of elastic phonon scattering, the Wiedemann-Franz law is restricted to each branch with its specific temperature and is characterized by twice the Lorenz number. In addition thermoelectric power vanishes due to electron-hole symmetry, which is validated by experiment.Comment: 10 pages, 2 figure

Synthesis of biologically active compounds of agricultural interest

A practical approach for the chiral synthesis of propargyl alcohols and hydroxyvinyl chlorides, making use of base induced elimination of chiral 2,3-epoxy chlorides is described and their utility in the synthesis of octadecenoids, viz., (S)-coriolic acid (I) and (S)-l5,16-didehydrocoriolic acid (V) the self-defensive substances in rice plant against rice blast disease, is discussed

Universalization of any adversarial attack using very few test examples

Deep learning models are known to be vulnerable not only to input-dependent adversarial attacks but also to input-agnostic or universal adversarial attacks. Dezfooli et al. \cite{Dezfooli17,Dezfooli17anal} construct universal adversarial attack on a given model by looking at a large number of training data points and the geometry of the decision boundary near them. Subsequent work \cite{Khrulkov18} constructs universal attack by looking only at test examples and intermediate layers of the given model. In this paper, we propose a simple universalization technique to take any input-dependent adversarial attack and construct a universal attack by only looking at very few adversarial test examples. We do not require details of the given model and have negligible computational overhead for universalization. We theoretically justify our universalization technique by a spectral property common to many input-dependent adversarial perturbations, e.g., gradients, Fast Gradient Sign Method (FGSM) and DeepFool. Using matrix concentration inequalities and spectral perturbation bounds, we show that the top singular vector of input-dependent adversarial directions on a small test sample gives an effective and simple universal adversarial attack. For VGG16 and VGG19 models trained on ImageNet, our simple universalization of Gradient, FGSM, and DeepFool perturbations using a test sample of 64 images gives fooling rates comparable to state-of-the-art universal attacks \cite{Dezfooli17,Khrulkov18} for reasonable norms of perturbation

Deep penetration of ultra-high molecular weight polyethylene composites by a sharp-tipped punch

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The penetration of unidirectional (UD) and [0o/90o] cross-ply ultra-high molecular weight polyethylene fibre composites by sharp-tipped cylindrical punches has been investigated. While the measured penetration pressure for both composite types increased with decreasing punch diameter, the pressure was significantly higher for the cross-ply composites and increased with decreasing ply thickness. A combination of optical microscopy and X-ray tomography revealed that in both composites, the sharp-tipped punch penetrated without fibre fracture by the formation of mode-I cracks along the fibre directions, followed by the wedging open of the crack by the advancing punch. In the cross-ply composites, delamination between adjacent 0o and 90o plies also occurred to accommodate the incompatible deformation between plies containing orthogonal mode-I cracks. Micromechanical models for the steady-state penetration pressure were developed for both composites. To account for material anisotropy as well as the large shear strains and fibre rotations, the deformation of the composites was modelled via a pressure-dependent crystal plasticity framework. Intra and inter-ply fracture were accounted for via mode-I and delamination toughnesses respectively. These models account for the competition between deformation and fracture of the plies and accurately predict the measured steady-state penetration pressures over the wide range of punch diameters and ply thicknesses investigated here. Design maps for the penetration resistance of cross-ply composites were constructed using these models and subsequently used to infer composite designs that maximise the penetration resistance for a user prescribed value of fibre strength

Texture of fermion mass matrices in partially unified theories

We investigate the texture of fermion mass matrices in theories with partial unification (for example $SU(2)_L\times SU(2)_R\times SU(4)_c$) at a scale $\sim 10^{12}$ GeV. Starting with the low energy values of the masses and the mixing angles, we find only two viable textures with atmost four texture zeros. One of these corresponds to a somewhat modified Fritzsch textures. A theoretical derivataion of these textures leads to new interesting relations among the masses and the mixing angles.Comment: 10 pages(Latex

Nondestructive Evaluation of Weld seam Failures in Tubes and Other Structures for Thermal, Wind and Nuclear Power Applications

The paper gives inspection and maintenance practices being followed in an important Tube manufacturing plant (Bundy India Limited, Baroda) where the first author (R.M Joshi) worked. Advances in the eddy current technique of on line surface and subsurface inspection along with some unconventional modern methods and their scope of appli-cation have been highlighted. The inspection techniques contribute to improved customer confidence