68 research outputs found
A note on absolute summability factors
In this paper, by using an almost increasing and -quasi-monotone
sequence, a general theorem on summability
factors, which generalizes a result of Bor \cite{3} on
summability factors, has been proved under weaker and more general conditions.Comment: 4 page
Studying neuroanatomy using MRI
The study of neuroanatomy using imaging enables key insights into how our brains function, are shaped by genes and environment, and change with development, aging, and disease. Developments in MRI acquisition, image processing, and data modelling have been key to these advances. However, MRI provides an indirect measurement of the biological signals we aim to investigate. Thus, artifacts and key questions of correct interpretation can confound the readouts provided by anatomical MRI. In this review we provide an overview of the methods for measuring macro- and mesoscopic structure and inferring microstructural properties; we also describe key artefacts and confounds that can lead to incorrect conclusions. Ultimately, we believe that, though methods need to improve and caution is required in its interpretation, structural MRI continues to have great promise in furthering our understanding of how the brain works
Influence of CaO on the nanohardness behaviour of AZ63 magnesium alloys produced by mechanical alloying method
In this study we aimed to produce AZ63 magnesium alloys containing different amounts of CaO, to investigate the nanohardness behaviour of the resulting alloys. These alloys were produced by mechanical alloying under argon atmosphere. Magnesium based alloys with the initial CaO content of 0.1%, 0.3%, and 0.5% were produced by high-energy ball milling, followed by process that involved cold pressing and sintering. These alloys were characterized using scanning electron microscopy, scanning probe microscopy, X-ray diffraction, and nanoindentation methods. Unloading segments of nanoindentation curves were analyzed using Oliver-Pharr method. Experimental results show that measured nanohardness exhibits a peak load dependence. As a result, in these alloys the microstructure and nanohardness depend on the content of CaO
Influence of rare earth element on the mechanical properties of ZE41 magnesium alloys produced by mechanical alloying
In this work, we have intended to synthesize ZE41 Magnesium alloys having varying content of Ce of 0.3, 0.6 and 0.9 wt.% and to investigate mechanical properties of these alloys. Alloys were produced by mechanical alloying under argon atmosphere. Structural, and mechanical properties of these alloys were investigated by means of XRD, SEM and nanoindenter analysis. From the XRD data it is found that as the Ce content increases, the crystallite size also increases. On the other hand, the hardness of the alloys decreases with the increasing Ce content. Indentation results show that the measured hardness displays a peak load dependence. Load-independent hardness was calculated by Hays-Kendall approach. As a results, it was found that Ce-doping modifies the microstructure and hardness of the alloy
Influence of Rare Earth Element on the Mechanical Properties of ZE41 Magnesium Alloys Produced by Mechanical Alloying
In this work, we have intended to synthesize ZE41 Magnesium alloys having varying content of Ce of 0.3, 0.6 and 0.9 wt.% and to investigate mechanical properties of these alloys. Alloys were produced by mechanical alloying under argon atmosphere. Structural, and mechanical properties of these alloys were investigated by means of XRD, SEM and nanoindenter analysis. From the XRD data it is found that as the Ce content increases, the crystallite size also increases. On the other hand, the hardness of the alloys decreases with the increasing Ce content. Indentation results show that the measured hardness displays a peak load dependence. Load-independent hardness was calculated by Hays-Kendall approach. As a results, it was found that Ce-doping modifies the microstructure and hardness of the alloy
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