1,203 research outputs found
Role of Ni-Mn hybridization in magnetism of martensitic state of Ni-Mn-In shape memory alloys
Extended X-ray Absorption Fine Structure (EXAFS) studies on
NiMnIn have been carried out at Ni and Mn K edge as a
function of temperature. Thermal evolution of nearest neighbor Ni-Mn and Mn-Mn
bond distances in the martensitic phase give a clear evidence of a close
relation between structural and magnetic degrees of freedom in these alloys. In
particular, the study highlights the role of Ni 3d - Mn 3d hybridization in the
magnetism of martensitic phase of these alloys.Comment: Accepted for publication in EP
Anomalous Magnetic Properties in Ni50Mn35In15
We present here a comprehensive investigation of the magnetic ordering in
Ni50Mn35In15 composition. A concomitant first order martensitic transition and
the magnetic ordering occurring in this off-stoichiometric Heusler compound at
room temperature signifies the multifunctional character of this magnetic shape
memory alloy. Unusual features are observed in the dependence of the
magnetization on temperature that can be ascribed to a frustrated magnetic
order. It is compelling to ascribe these features to the cluster type
description that may arise due to inhomogeneity in the distribution of magnetic
atoms. However, evidences are presented from our ac susceptibility, electrical
resistivity and dc magnetization studies that there exists a competing
ferromagnetic and antiferromagnetic order within crystal structure of this
system. We show that excess Mn atoms that substitute the In atoms have a
crucial bearing on the magnetic order of this compound. These excess Mn atoms
are antiferromagnetically aligned to the other Mn, which explains the peculiar
dependence of magnetization on temperature.Comment: Accepted in J. Phys. D.:Appl. Physic
REGENERATION AND ABNORMALITY IN BENTHIC FORAMINIFER ROSALINA LEEI: IMPLICATIONS IN RECONSTRUCTING PAST SALINITY CHANGES
A laboratory culture experiment has been conducted to assess the response of marginal marine benthic foraminifer Rosalina leei to salinity and associated pH changes. Live specimens of Rosalina leei were subjected to a range (10-35 psu) of salinity. It was observed that hyposaline condition leads to dissolution of the calcareous tests. However, if the hyposaline condition persists only for a short period, then even after considerable dissolution, specimens were able to regenerate the dissolved part of the test. Additionally, in all the specimens subjected to lower than normal salinity, the regenerated chambers were abnormal. The abnormalities included smaller or larger chambers and addition of new chambers in planes different than the normal plane of the tests. The regenerated specimens, however, attained a final size almost equal to that of control specimens that were not subjected to hyposaline conditions. The differential response of R. leei was attributed to decreased seawater pH under hyposaline condition. The findings can help understand the increased abundance of abnormal specimens under ecologically stressed environments.
Evaluation and Analysis of Different Type of Edge Detection Techniques on Cartridge Case Image
The forensic identification of ballistics specimens relies on the detection, recognition and ultimate matching of markings on the surfaces of cartridges and projectiles made by the firearms. The feature extraction from the images is always a very important step in automated examination system. The edge detection refers to the process of identifying and locating sharp discontinuities in an image which helps in pattern recognition. The edge detection of ballistics specimens like, the firing pin mark, head stamp mark and striation on cartridge case the positive identification is based mainly on the image segmentation and feature extraction of the proposed area. Thus, applying an edge detection algorithm to an image may significantly reduce the amount of data to be processed and may therefore filter out information that may be regarded as less relevant, while preserving the important structural properties of an image. If the edge detection step is successful, the subsequent task of interpreting the information contents in the original image may therefore be substantially simplifiedIn this paper we have compared different techniques of Gradient-based and Laplacian based edge detection on the cartridge case image with MATLAB tool
Critical exponents and the correlation length in the charge exchange manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3}
The critical regime of the charge exchange (CE) manganite spin glass
Eu_{0.5}Ba_{0.5}MnO_{3} is investigated using linear and non linear magnetic
susceptibility and the divergence of the third ordered susceptibility (chi{_3})
signifying the onset of a conventional freezing transition is experimentally
demonstrated. The divergence in chi{_3}, dynamical scaling of the linear
susceptibility and relevant scaling equations are used to determine the
critical exponents associated with this freezing transition, the values of
which match well with the 3D Ising universality class. Magnetic field
dependence of the spin glass response function is used to estimate the spin
correlation length which is seen to be larger than the charge/orbital
correlation length reported in this system.Comment: 4 pages, 4 Figure
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