Nanostructured Bulk Ceramics (Part Ⅰ)

한영환,Amiya K. Mukherjee 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.3

The processing and characterization of ceramic nanocomposites, which produce bulk nanostructures with attractive mechanical properties, have been emphasized and introduced at Prof. Mukherjee’s Lab at UC Davis. The following subjects will be introduced in detail in Part ⅡI, Ⅲ, and Ⅳ. In Part Ⅱ, the paper will describe a three-phase alumina-based nanoceramic composite demonstrating superplasticity at a surprisingly lower temperature and higher strain rate. The next part will show that an alumina-carbon nanotube-niobium nanocomposite produced fracture toughness values that are three times higher than that of pure nanocrystalline alumina. It was possible to take advantage of both fiber-toughening and ductile-metal toughening in this investigation. In the fourth section, discussed will be a silicon-nitride/silicon-carbide nanocomposite, produced by pyrolysis of liquid polymer precursors, demonstrating one of the lowest creep rates reported so far in ceramics at the comparable temperature of 1400℃ This was first achieved by avoiding the oxynitride glass phase at the intergrain boundaries. One important factor in the processing of these nanocomposites was the use of the electrical field assisted sintering method. This allowed the sintering to be completed at significantly lower temperatures and during much shorter times. These improvements in mechanical properties will be discussed in the context of the results from the microstructural investigations. The processing and characterization of ceramic nanocomposites, which produce bulk nanostructures with attractive mechanical properties, have been emphasized and introduced at Prof. Mukherjee’s Lab at UC Davis. The following subjects will be introduced in detail in Part ⅡI, Ⅲ, and Ⅳ. In Part Ⅱ, the paper will describe a three-phase alumina-based nanoceramic composite demonstrating superplasticity at a surprisingly lower temperature and higher strain rate. The next part will show that an alumina-carbon nanotube-niobium nanocomposite produced fracture toughness values that are three times higher than that of pure nanocrystalline alumina. It was possible to take advantage of both fiber-toughening and ductile-metal toughening in this investigation. In the fourth section, discussed will be a silicon-nitride/silicon-carbide nanocomposite, produced by pyrolysis of liquid polymer precursors, demonstrating one of the lowest creep rates reported so far in ceramics at the comparable temperature of 1400℃ This was first achieved by avoiding the oxynitride glass phase at the intergrain boundaries. One important factor in the processing of these nanocomposites was the use of the electrical field assisted sintering method. This allowed the sintering to be completed at significantly lower temperatures and during much shorter times. These improvements in mechanical properties will be discussed in the context of the results from the microstructural investigations.

Nanostructured Bulk Ceramics (Part I)

Han, Young-Hwan,Mukherjee, Amiya K. The Korean Ceramic Society 2009 한국세라믹학회지 Vol.46 No.3

The processing and characterization of ceramic nanocomposites, which produce bulk nanostructures with attractive mechanical properties, have been emphasized and introduced at Prof. Mukherjee's Lab at UC Davis. The following subjects will be introduced in detail in Part II, III, and IV. In Part II, the paper will describe a three-phase alumina-based nanoceramic composite demonstrating superplasticity at a surprisingly lower temperature and higher strain rate. The next part will show that an alumina-carbon nanotube-niobium nanocomposite produced fracture toughness values that are three times higher than that of pure nanocrystalline alumina. It was possible to take advantage of both fiber-toughening and ductile-metal toughening in this investigation. In the fourth section, discussed will be a silicon-nitride/silicon-carbide nanocomposite, produced by pyrolysis of liquid polymer precursors, demonstrating one of the lowest creep rates reported so far in ceramics at the comparable temperature of $1400^{\circ}C$. This was first achieved by avoiding the oxynitride glass phase at the intergrain boundaries. One important factor in the processing of these nanocomposites was the use of the electrical field assisted sintering method. This allowed the sintering to be completed at significantly lower temperatures and during much shorter times. These improvements in mechanical properties will be discussed in the context of the results from the microstructural investigations.

A comparative study of dragonfly inspired flapping wings actuated by single crystal piezoceramic

Mukherjee, Sujoy,Ganguli, Ranjan Techno-Press 2012 Smart Structures and Systems, An International Jou Vol.10 No.1

A dragonfly inspired flapping wing is investigated in this paper. The flapping wing is actuated from the root by a PZT-5H and PZN-7%PT single crystal unimorph in the piezofan configuration. The non-linear governing equations of motion of the smart flapping wing are obtained using the Hamilton's principle. These equations are then discretized using the Galerkin method and solved using the method of multiple scales. Dynamic characteristics of smart flapping wings having the same size as the actual wings of three different dragonfly species Aeshna Multicolor, Anax Parthenope Julius and Sympetrum Frequens are analyzed using numerical simulations. An unsteady aerodynamic model is used to obtain the aerodynamic forces. Finally, a comparative study of performances of three piezoelectrically actuated flapping wings is performed. The numerical results in this paper show that use of PZN-7%PT single crystal piezoceramic can lead to considerable amount of wing weight reduction and increase of lift and thrust force compared to PZT-5H material. It is also shown that dragonfly inspired smart flapping wings actuated by single crystal piezoceramic are a viable contender for insect scale flapping wing micro air vehicles.

Magnon bistability in a hybrid cavity–magnon system

Mukherjee Kousik,Jana Paresh Chandra 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.4

We have explored the magnon bistability in cavity–magnon system. The stationary solution of the Heisenberg–Langevin equation is obtained numerically and magnon profle is studied as function of diferent experimentally feasible system parameters. The magnon profle shows an anticlockwise hysteresis loop and the loop area increases with input power. The mean magnon number shows bistable nature. The Kittel mode can transit from one stable state to another stable state near two transition points. The threshold powers of transition and bistable region strongly depend on magnon dissipation rate, photon-magnon coupling strength, and Kerr nonlinear strength. This study confrms that bistable quantum states may supply a platform to describe bistability at macroscopic regime in nonlinear systems. This study may also be used in potential applications in magnetic spintronics.

Quercetin Down-regulates IL-6/STAT-3 Signals to Induce Mitochondrial-mediated Apoptosis in a Non-small-cell Lung-cancer Cell Line, A549

Mukherjee, Avinaba,Khuda-Bukhsh, Anisur Rahman KOREAN PHARMACOPUNCTURE INSTITUTE 2015 Journal of pharmacopuncture Vol.18 No.1

Objectives: Quercetin, a flavonoid compound, has been reported to induce apoptosis in cancer cells, but its anti-inflammatory effects, which are also closely linked with apoptosis, if any, on non-small-cell lung cancer (NSCLC) have not so far been critically examined. In this study, we tried to determine if quercetin had any demonstrable anti-inflammatory potential, which also could significantly contribute to inducing apoptosis in a NSCLC cell line, A549. Methods: In this context, several assays, including cytotoxicity, flow cytometry and fluorimetry, were done. Gene expression was analyzed by using a western blot analysis. Results: Results revealed that quercetin could induce apoptosis in A549 cells through mitochondrial depolarization by causing an imbalance in B-cell lymphoma 2/Bcl2 Antagonist X (Bcl2/Bax) ratio and by down-regulating the interleukine-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling pathway. An analysis of the data revealed that quercetin could block nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$) activity at early hours, which might cause a down-regulation of the IL-6 titer, and the IL-6 expression, in turn, could inhibit p-STAT3 expression. Down-regulation of both the STAT3 and the NF-${\kappa}B$ expressions might, therefore, cause down-regulation of Bcl2 activity because both are major upstream effectors of Bcl2. Alteration in Bcl2 responses might result in an imbalance in the Bcl2/Bax ratio, which could ultimately bring about mitochondria mediated apoptosis in A549 cells. Conclusion: Overall, the finding of this study indicates that a quercetin induced anti-inflammatory pathway in A549 cells appeared to make a significant contribution towards induction of apoptosis in NSCLC and, thus, may have a therapeutic use such as a strong apoptosis inducer in cancer cells.

Novel mesoporous microspheres of Al and Ni doped LMO spinels and their performance as cathodes in secondary lithium ion batteries

Mukherjee, Santanu,Schuppert, Nicholas,Bates, Alex,Lee, Sang C.,Park, Sam Taylor and Francis 2017 INTERNATIONAL JOURNAL OF GREEN ENERGY Vol.14 No.7

Freshness Assessment of Indian Gooseberry (Phyllanthus emblica) Using Probabilistic Neural Network

Mukherjee Alok,Sarkar Tanmay,Chatterjee Kingshuk 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.4

Purpose In this paper, a probabilistic neural network (PNN)-based simple model for the detection of freshness in Indian gooseberry or amla (Phyllanthus emblica) samples has been developed. Methods The amla images have been analyzed using two features: hue histogram, which is a kind of color representative of the image, and entropy analysis, which corresponds to texture analysis of the sample images. Three freshness classes have been assigned depending on the freshness of the samples and governed by the Hedonic scale. Results The proposed PNN model is also tested with five different activation functions; out of which, radial and triangular basis functions are found to yield the most accurate results. Moreover, the hue-PNN model is found to possess marginal superiority over the entropy-PNN model, thus signifying the higher effectiveness of the former in the proposed work. The proposed work is computationally lighter as it contains PNN as the single analysis tool, aided by the image histograms. Moreover, the experiments have been conducted with the images captured using smartphones only, which establishes the portability of capturing images. Conclusions High freshness classification accuracy of 97.5%, ease of implementation, and use of smartphone captured images widen its practical applicability of developing into a smartphone application-based module.

A supervised-learning-based spatial performance prediction framework for heterogeneous communication networks

Mukherjee, Shubhabrata,Choi, Taesang,Islam, Md Tajul,Choi, Baek-Young,Beard, Cory,Won, Seuck Ho,Song, Sejun Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.5

In this paper, we propose a supervised-learning-based spatial performance prediction (SLPP) framework for next-generation heterogeneous communication networks (HCNs). Adaptive asset placement, dynamic resource allocation, and load balancing are critical network functions in an HCN to ensure seamless network management and enhance service quality. Although many existing systems use measurement data to react to network performance changes, it is highly beneficial to perform accurate performance prediction for different systems to support various network functions. Recent advancements in complex statistical algorithms and computational efficiency have made machine-learning ubiquitous for accurate data-based prediction. A robust network performance prediction framework for optimizing performance and resource utilization through a linear discriminant analysis-based prediction approach has been proposed in this paper. Comparison results with different machine-learning techniques on real-world data demonstrate that SLPP provides superior accuracy and computational efficiency for both stationary and mobile user conditions.

Emergence of a novel optically isotropic transient state with low frequency in a blue phase liquid crystal mixture

Mukherjee, A.,Yang, G. H.,Jeong, H.,Nayek, P.,Kang, S. W.,Lee, S. H.,Hong, S. H.,Lee, H. J.,Shin, S. T. Taylor Francis 2012 Liquid crystals Vol.39 No.2

Jatropha curcas: a review on biotechnological status and challenges

Mukherjee, Priyanka,Varshney, Alok,Johnson, T. Sudhakar,Jha, Timir Baran The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.3

Plant tissue culture and molecular biology techniques are powerful tools of biotechnology that can complement conventional breeding, expedite crop improvement and meet the demand for availability of uniform clones in large numbers. Jatropha curcas Linn., a non-edible, eco-friendly, non-toxic, biodegradable fuel-producing plant has attracted worldwide attention as an alternate sustainable energy source for the future. This review presents a consolidated account of biotechnological interventions made in J. curcas over the decades and focuses on contemporary information and trends of future research.