http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Palneedi, Haribabu,Na, Suok-Min,Hwang, Geon-Tae,Peddigari, Mahesh,Shin, Kwang Woo,Kim, Kee Hoon,Ryu, Jungho Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.765 No.-
<P><B>Abstract</B></P> <P>In this study, it is proposed and demonstrated that highly tunable magnetoelectric (ME) response can be achieved from magnetostrictive/piezoelectric laminate composites by integrating the effects of size variation and piezoelectric anisotropy. Tri-layered, rectangular ME composites with different aspect ratios were prepared using a magnetostrictive Fe-Ga alloy and a (011) oriented Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O<SUB>3</SUB>-Pb(Zr,Ti)O<SUB>3</SUB> (PMN-PZT) piezoelectric single crystal. ME coefficients in the range of 0.25–2.2 V/cm·Oe and 2–75 V/cm·Oe in the off-resonance and resonance mode, respectively, were obtained from the composites. Magnetic sensitivity of the ME composites followed a similar trend in variation as that of their ME response with respect to the laminate size and applied magnetic field direction. The tunability of the ME response of the composites was correlated with the size dependent demagnetization and magnetic flux density distribution in the Fe-Ga alloy and direction dependent piezoelectric properties of the (011) PMN-PZT single crystal. In both the off-resonance and resonance modes, an order of magnitude large tunability could be attained in the ME coefficient of the composites. Such a highly tunable ME response will facilitate the development of ME based devices with controllable functionality.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly tunable magnetoelectric response from magnetostrictive/piezoelectric laminate composites. </LI> <LI> Integration of the effects of laminate size variation and piezoelectric anisotropy. </LI> <LI> Size dependent demagnetization and magnetic flux density distribution in the magnetostrictive alloy. </LI> <LI> Direction dependent piezoelectric properties of the oriented single crystal. </LI> </UL> </P>
Palneedi, Haribabu,Maurya, Deepam,Geng, Liwei D.,Song, Hyun-Cheol,Hwang, Geon-Tae,Peddigari, Mahesh,Annapureddy, Venkateswarlu,Song, Kyung,Oh, Yoon Seok,Yang, Su-Chul,Wang, Yu U.,Priya, Shashank,Ryu, American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.13
<P>Enhanced and self-biased magnetoelectric (ME) coupling is demonstrated in a laminate heterostructure comprising 4 μm-thick Pb(Zr,Ti)O<SUB>3</SUB> (PZT) film deposited on 50 μm-thick flexible nickel (Ni) foil. A unique fabrication approach, combining room temperature deposition of PZT film by granule spray in vacuum (GSV) process and localized thermal treatment of the film by laser radiation, is utilized. This approach addresses the challenges in integrating ceramic films on metal substrates, which is often limited by the interfacial chemical reactions occurring at high processing temperatures. Laser-induced crystallinity improvement in the PZT thick film led to enhanced dielectric, ferroelectric, and magnetoelectric properties of the PZT/Ni composite. A high self-biased ME response on the order of 3.15 V/cm·Oe was obtained from the laser-annealed PZT/Ni film heterostructure. This value corresponds to a ∼2000% increment from the ME response (0.16 V/cm·Oe) measured from the as-deposited PZT/Ni sample. This result is also one of the highest reported values among similar ME composite systems. The tunability of self-biased ME coupling in PZT/Ni composite has been found to be related to the demagnetization field in Ni, strain mismatch between PZT and Ni, and flexural moment of the laminate structure. The phase-field model provides quantitative insight into these factors and illustrates their contributions toward the observed self-biased ME response. The results present a viable pathway toward designing and integrating ME components for a new generation of miniaturized tunable electronic devices.</P> [FIG OMISSION]</BR>
Sumisha A,Haribabu K 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.1
Polypyrrole nanoparticle (Ppy-NP) modified carbon cloth (CC) was fabricated as the cathode for single chamber membrane less microbial fuel cell (SCMFC) for bio-energy production and iron removal using Shewanella putrefaciens as a microbial catalyst. The performance of CC coated with Ppy was compared with that of pure platinum (Pt), the conventional cathode catalyst. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel were done to study the electro catalytic activity of modified cathode and showed lower charge transfer resistance and high conductivity. The systems were served with wastewater containing the heavy metal, Iron and the maximum power density and coulombic efficiency obtained with PPy NP was found to be ~190 ± 4 mW/m2 and 10.1 ± 2% respectively, whereas the measured values for Pt catalyst were 278 ± 4 mW/m2 and 13.3 ± 3% respectively. The removal efficiency of both Iron and TOC were found to be greater than 80% for both the electrodes. The results of CC-Ppy show a noticeable comparison with CC-Pt and indicate its possibility of use in MFC as low cost cathode catalyst.
Asok Aswathy,Haribabu K 한국물리학회 2023 Current Applied Physics Vol.49 No.-
Efficient electron transfer from the counter electrode (CE) to the redox couple electrolyte is the key process in the operation of dye-sensitized solar cells (DSSC). Polythiophene-Iridium oxide (PTh/IrO2) nano composite synthesized by reflux reaction method at different mass ratios (1:4, 1:2 and 1:1) has been explored as an effective electrocatalyst for the triiodide reduction in DSSC. The results of electrochemical impedance spectroscopy (EIS), bode plot studies and Tafel polarization method suggested that the composite synthesized at mass ratio 1:1 exhibited low charge transfer resistance (R ct), faster transport of electrons and excellent electrocatalytic activity. The PTh/IrO 2 composite synthesized at mass ratio 1:1 based DSSC exhibits a conversion efficiency of 3.01%, open-circuit voltage of 0.60 V and a short-circuit current density of 10.1 mA/cm 2. The facile synthesis procedure and attractive electrochemical properties benefit PTh/IrO 2composite to be used as a credible CE in DSSCs.
Peddigari, Mahesh,Palneedi, Haribabu,Hwang, Geon-Tae,Lim, Kyung Won,Kim, Ga-Yeon,Jeong, Dae-Yong,Ryu, Jungho American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.24
<P>Dielectric ceramic film capacitors, which store energy in the form of electric polarization, are promising for miniature pulsed power electronic device applications. For a superior energy storage performance of the capacitors, large recoverable energy density, along with high efficiency, high power density, fast charge/discharge rate, and good thermal/fatigue stability, is desired. Herein, we present highly dense lead-free 0.942[Na<SUB>0.535</SUB>K<SUB>0.480</SUB>NbO<SUB>3</SUB>]-0.058LiNbO<SUB>3</SUB> (KNNLN) ferroelectric ceramic thick films (∼5 μm) demonstrating remarkable energy storage performance. The nanocrystalline KNNLN thick film fabricated by aerosol deposition (AD) process and annealed at 600 °C displayed a quasi-relaxor ferroelectric behavior, which is in contrast to the typical ferroelectric nature of the KNNLN ceramic in its bulk form. The AD film exhibited a large recoverable energy density of 23.4 J/cm<SUP>3</SUP>, with an efficiency of over 70% under the electric field of 1400 kV/cm. Besides, an ultrahigh power density of 38.8 MW/cm<SUP>3</SUP> together with a fast discharge speed of 0.45 μs, good fatigue endurance (up to 10<SUP>6</SUP> cycles), and thermal stability in a wide temperature range of 20-160 °C was also observed. Using the AD process, we could make a highly dense microstructure of the film containing nano-sized grains, which gave rise to the quasi-relaxor ferroelectric characteristics and the remarkable energy storage properties.</P> [FIG OMISSION]</BR>
Mohan, Avvari V.,Ejnavarzala, Haribabu,Lakshmi, C.N. World Technopolis Association 2012 World Technopolis Review Vol.1 No.1
This paper is concerned with the linkages between universities and industry in the information and communications technology (ICT) in Cyberjaya, Malaysia and Cyberabad, India. In the case of the ICT cluster of Cyberjaya, the context can be termed as greenfield cluster development as the whole project is developed from scratch. In the case of Cyberabad, India, the context can be seen as a brownfield development, where the cluster developed based on existing and new organisations in a region. There is extant literature in research, be it from an Innovation systems or a Triple Helix perspective that has given significant attention to the importance of universities as engines of growth and also about the significance of their linkages with industry innovation in regions. But as argued by scholars like Chaminade et al, most of these papers tend to ignore the specific context in which this interaction between the university and the industry takes place - this study aims to fill this gap through an exploratory study from emerging economies and in a greenfield and brownfield contexts. The findings from the two cases point towards (1) the role of intermediary organisations in developing the linkages, (2) the issue of capabilities of universities for supporting industry development and (3) university-industry linkages are different in greenfield and brown field developments. The paper presents the cases and discusses the findings and provides insights to cluster development officials and policy makers and implications to researchers for developing studies of university-industry from a capabilities and context perspectives.
Hwang, Geon-Tae,Palneedi, Haribabu,Jung, Byung Mun,Kwon, Suk Jin,Peddigari, Mahesh,Min, Yuho,Kim, Jong-Woo,Ahn, Cheol-Woo,Choi, Jong-Jin,Hahn, Byung-Dong,Choi, Joon-Hwan,Yoon, Woon-Ha,Park, Dong-Soo,L American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.38
<P>We report the effect of epoxy adhesion layers with different mechanical or physical property on a magnetoelectric (ME) composite laminate composed of FeBSi alloy (Metglas)/single-crystal Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O<SUB>3</SUB>-Pb(Zr,Ti)O<SUB>3</SUB>/Metglas to achieve an improved ME conversion performance. Through theoretical simulation, it was revealed that the Young’s modulus and the thickness of interfacial adhesives were major parameters that influence the conversion efficiency in ME composites. In the experimental evaluation, we utilized three epoxy materials with a distinct Young’s modulus and adjusted the average thickness of the adhesion layers to optimize the ME conversion. The experimental results show that a thin epoxy layer with a high Young’s modulus provided the best performance in the inorganic-based ME conversion process. By tailoring the interfacial adhesion property, the ME laminate generated a high conversion coefficient of 328.8 V/(cm Oe), with a mechanical quality factor of 132.0 at the resonance mode. Moreover, we demonstrated a highly sensitive alternating current magnetic field sensor that had a detection resolution below 10 pT. The optimization of the epoxy layers in the ME laminate composite provided significant enhancement of the ME response in a simple manner.</P> [FIG OMISSION]</BR>
Linear and Nonlinear Dielectric Ceramics for High-Power Energy Storage Capacitor Applications
Peddigari, Mahesh,Palneedi, Haribabu,Hwang, Geon-Tae,Ryu, Jungho The Korean Ceramic Society 2019 한국세라믹학회지 Vol.56 No.1
Dielectric materials with inherently high power densities and fast discharge rates are particularly suitable for pulsed power capacitors. The ongoing multifaceted efforts on developing these capacitors are focused on improving their energy density and storage efficiency, as well as ensuring their reliable operation over long periods, including under harsh environments. This review article summarizes the studies that have been conducted to date on the development of high-performance dielectric ceramics for employment in pulsed power capacitors. The energy storage characteristics of various lead-based and lead-free ceramics belonging to linear and nonlinear dielectrics are discussed. Various strategies such as mechanical confinement, self-confinement, core-shell structuring, glass incorporation, chemical modifications, and special sintering routes have been adopted to tailor the electrical properties and energy storage performances of dielectric ceramics. In addition, this review article highlights the challenges and opportunities associated with the development of pulsed power capacitors.