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1.
Sumantra Mandal A. K. Bhaduri V. Subramanya Sarma 《Metallurgical and Materials Transactions A》2011,42(4):1062-1072
Dynamic recrystallization (DRX) behavior in hot deformed (by uniaxial compression in a thermomechanical simulator in the temperatures
range 1173 K to 1373 K [900 °C to 1100 °C]) Ti-modified austenitic stainless steel was studied using electron back scatter
diffraction. Grain orientation spread with a “cut off” of 1 deg was a suitable criterion to partition dynamically recrystallized
grains from the deformed matrix. The extent of DRX increased with strain and temperature, and a completely DRX microstructure
with a fine grain size ~4 μm (considering twins as grain boundaries) was obtained in the sample deformed to a strain of 0.8 at 1373 K (1100 °C). The
nucleation of new DRX grains occurred by the bulging of the parent grain boundary. The DRX grains were twinned, and a linear
relationship was observed between the area fraction of DRX grains and the number fraction of Σ3 boundaries. The deviation
from the ideal misorientation of Σ3 boundaries decreased with an increase in the fraction of Σ3 boundaries (as well as the
area fraction of DRX) signifying that most Σ3 boundaries are newly nucleated during DRX. The generation of these Σ3 boundaries
could account for the formation of annealing twins during DRX. The role of Σ3 twin boundaries on DRX is discussed. 相似文献
2.
Kundu Sumantra R. Pal Sourav Basu Kalyan Das Sajal K. 《Parallel and Distributed Systems, IEEE Transactions on》2009,20(1):111-123
In networks carrying large volume of traffic, accurate traffic characterization is necessary for understanding the dynamics and patterns of network resource usage. Previous approaches to flow characterization are based on random sampling of the packets (e.g., Cisco's NetFlow) or inferring characteristics solely based on long lived flows (LLFs) or on lossy data structures (e.g., bloom filters, hash tables). However, none of these approaches takes into account the heavy-tailed nature of the Internet traffic and separates the estimation algorithm from the flow measurement architecture.In this paper, we propose an alternate approach to traffic characterization by closely linking the flow measurement architecture with the estimation algorithm. Our measurement framework stores complete information related to short lived flows (SLFs) while collecting partial information related to LLFs. For real-time separation of LLFs and SLFs, we propose a novel algorithm based on typical sequences from Information theory. The distribution (pdf) and sample space of the underlying traffic is estimated using the non-parametric Parzen window technique and likelihood function defined over the Coupon collector problem. We validate the accuracy and performance of our estimation technique using traffic traces from the internal LAN in our laboratory and from National Library for Applied Network Research (NLANR). 相似文献
3.
Sumantra Dutta Roy Santanu Chaudhury Subhashis Banerjee 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2005,35(2):282-292
Most model-based three-dimensional (3-D) object recognition systems use information from a single view of an object. However, a single view may not contain sufficient features to recognize it unambiguously. Further, two objects may have all views in common with respect to a given feature set, and may be distinguished only through a sequence of views. A further complication arises when in an image, we do not have a complete view of an object. This paper presents a new online scheme for the recognition and pose estimation of a large isolated 3-D object, which may not entirely fit in a camera's field of view. We consider an uncalibrated projective camera, and consider the case when the internal parameters of the camera may be varied either unintentionally, or on purpose. The scheme uses a probabilistic reasoning framework for recognition and next-view planning. We show results of successful recognition and pose estimation even in cases of a high degree of interpretation ambiguity associated with the initial view. 相似文献
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A comprehensive meta‐analysis on dietary flavonoid and lignan intake and cancer risk: Level of evidence and limitations 下载免费PDF全文
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Darothi Bairagi Venkataramana Munukuti Pallabi Bhuyan Rajib Saha Sumantra Mandal 《工业材料与腐蚀》2021,72(5):829-838
The influence of cementite spheroidization on the impact toughness and electrochemical properties of a high-carbon steel has been thoroughly investigated in this study. Heavy warm rolling, followed by 2 h of annealing, has resulted in near-complete spheroidization, leading to a microstructure consisting of nano-cementite globules dispersed in the ultrafine-grained ferritic matrix. The Charpy impact test exhibited superior impact toughness with increased spheroidization. It is validated by the presence of abundant dimples in the fractographs of spheroidized specimens, in contrast to the as-received one that experienced a brittle failure due to its lamellar pearlitic structure. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) carried out in a 3.5% NaCl solution revealed that the corrosion resistance of the alloy gets improved with the increase in the degree of spheroidization. This is attributed to the lower susceptibility of the spheroidized specimen to microgalvanic corrosion owing to the minimum area of contact between nano-spheroidized cementite and ferrite, as elucidated with the help of EIS results aided by equivalent electrical circuit model. 相似文献
8.
International Journal of Coal Science & Technology - An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of... 相似文献
9.
Aluminum nitride‐single walled carbon nanotube nanocomposite with superior electrical and thermal conductivities 下载免费PDF全文
Amrita Chakravarty Ravindra Singh Sudakshina Roy Ujjal Chowdhury Sumantra Basu Sampad Kumar Biswas 《Journal of the American Ceramic Society》2017,100(8):3360-3364
Development of aluminum nitride (AlN)‐single walled carbon nanotube (SWCNT) ceramic‐matrix composite containing 1‐6 vol% SWCNT by hot pressing has been reported in this article. The composites containing 6 vol% SWCNT are dense (~99% relative density) and show high dc electrical conductivity (200 Sm?1) and thermal conductivity (62 Wm?1K?1) at room temperature. SWCNTs contain mostly metallic variety tubes obtained by controlled processing of the pristine tubes before incorporation into the ceramic matrix. Raman spectroscopy and field emission scanning electron microscopy (FESEM) of the fracture surface of the samples show the excellent survivability of the SWCNTs even after high‐temperature hot pressing. The results indicate the possibility of preparation of AlN nanocomposite for use in plasma devices and electromagnetic shielding. 相似文献
10.
Subha Ranjan Paul Sumantra Bhattacharya 《Transactions of the Indian Institute of Metals》2018,71(6):1439-1444
Jigging is essentially a cleaning process to separate particles of different relative densities. Usually the jig feed is narrowly sized, however the definition of settling velocity indicates that particle size possibly plays certain role in the process of separation. Limited work is available in published literature on the separation characteristics of constituent size fractions of the feed that has been subjected to jigging. The present communication examines size by size separation characteristics of a Batac jig cleaning metallurgical coal. The characteristics have been measured by Probable Error in Separation, Imperfection and Organic Efficiency. Effect of NGM on the separation characteristics, if any, has also been investigated. 相似文献