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41.
Journal of Computer Science and Technology - Contents such as audios, videos, and images, contribute most of the Internet traffic in the current paradigm. Secure content sharing is a tedious issue.... 相似文献
42.
Narayana Thota M. Gurubhaskar A. C. Kasi Reddy G. Hema Chandra B. R. Mehta Ashutosh Tiwari Y. P. Venkata Subbaiah 《Journal of Materials Science: Materials in Electronics》2017,28(16):11702-11711
In this paper, we report the two stage growth of Cu2ZnSnS4 (CZTS) thin films as a function of sulfurization time. First, magnetron sputtered metallic precursors were deposited sequentially (Zn/Cu/Sn/Cu) over rotating glass substrates held at 230?°C. Later, the sputtered precursors were heat treated at 500?°C in the ambiance of sulfur for various time durations in the range, 10–120 min. The sulfur treated samples were examined using various analytical tools to understand the role of sulfurization time on the CZTS growth and properties. From composition and structural analysis, Zn/Cu/Sn/Cu precursors sulfurized for shorter duration (10 and 20 min) revealed severe deficiency of sulfur that resulted in several metallic, bi-metallic and metal sulfide phases. With the increase of sulfurization time to 30 min, sulfur incorporation was enhanced and reached stoichiometric ratio (~50% S) for CZTS growth, however, samples were poorly crystalline in nature and consisted of prominent Cu2?xS phase as well. The Zn/Cu/Sn/Cu precursors sulfurized for 60 min exhibited prominent CZTS phase without Cu2?xS phase. Further, rise in sulfurization time to 120 min enabled drastic improvement in crystallinity of CZTS phase. Raman mapping over 60 µm × 60 µm for these films confirmed the homogeneous phase growth of CZTS. XPS study revealed the oxidation states of Cu1+, Zn2+, Sn4+ and S2? in CZTS films. The optimized films showed high absorption coefficient of 105 cm?1 with an optical band gap of 1.51 eV. These films showed leaf like grain morphology with high mobility and low resistivity of 18.2 cm2/V-s and 0.7 Ω-cm, respectively. 相似文献
43.
Jibin J. Samuel Ashutosh Garudapalli Aiswarya Abhisek Mohapatra Chandrasekhar Gangadharappa Satish Patil Naga Phani B. Aetukuri 《Advanced functional materials》2021,31(45):2102903
Complementary circuits based on organic electrochemical transistors (OECTs) are attractive for the development of inexpensive and disposable point-of-care bioelectronic devices. Ambipolar OECTs, which employ a single channel material, could decrease the fabrication complexity and manufacturing costs of such circuits. An ideal channel material for ambipolar OECTs should be electrochemically stable in aqueous environments, afford facile ion insertion for both cations and anions, and also facilitate high and balanced electron and hole transport. In this study, triethylene glycol functionalized diketopyrrolopyrrole (DPP)-based polymer is proposed for the development of ambipolar OECTs. It is shown that DPP-based OECTs have a high and comparable figure of merit for both n- and p-type operations. Logic NOT, NAND, and NOR operations with corresponding complementary circuits constructed from identical DPP-based OECT devices are demonstrated. This study is an important step toward the development of sophisticated complementary metal–oxide–semiconductor-like logic circuits using single-component OECTs. 相似文献
44.
Kwang Leng Goh Ravi Kumar Patchmuthu Ashutosh Kumar Singh 《Journal of Intelligent Information Systems》2017,49(2):213-235
Web spam uses numerous techniques to misguide Web search engines in exchange of financial profit. A myriad of semi-automatic propagation model has been proposed with the purpose of combating Web spam. In this paper, distrust propagation is used to detect Web spam. An automatic distrust seed set propagation algorithm (DSP), which acts as an extension to the seed set to propagate distrust further to detect more Web spam. Experiments are conducted on WEBSPAM-UK2006 and WEBSPAM-UK2007 dataset; the results have shown that DSP enhanced the baseline algorithms and detected 17.73 % more spam hosts in the former dataset and detected 8.59 % more spam hosts in later dataset. 相似文献
45.
Nithyanantham Thangamani Ashutosh S. Gandhi Vikram Jayaram Atul H. Chokshi 《Journal of the American Ceramic Society》2005,88(10):2696-2701
This study examined pressure consolidation of amorphous Al2 O3 –15 mol% Y2 O3 powders prepared by co-precipitation and spray pyrolysis. The two amorphous powders had similar true densities and crystallization sequences. Uniaxial hot pressing was carried out at 450°–600°C with a moderate pressure of 750 MPa. The co-precipitated powder could be hot pressed to a maximum relative density of 98% and remained amorphous. Pressure adversely affected the densification of the spray-pyrolyzed powder by favoring an early crystallization of γ-Al2 O3 phase at 580°C. Plastic deformation of the amorphous phase is believed to be responsible for the large densification of the amorphous powders. 相似文献
46.
The catalytic oxidation of volatile organic compounds (VOCs) into mainly CO2 and H2O appears promising in the context of the abatement of atmospheric gaseous pollutants and is the subject of this paper. The catalytic oxidation of toluene and m-xylene was carried out in a tubular reactor on a phenolic resin based activated carbon fiber (ACF) impregnated with nitrates of Co, Cr, Ni, and Cu at the reaction temperatures below 300 °C. The extent of the removal (i.e. conversion) of toluene and m-xylene was examined through the breakthrough curves and was found to strongly depend on the types and loading of the metal precursors. The experimental results showed that the reaction rate was significantly affected by O2 concentration below 3% (v/v). The performance of the ACFs impregnated with 5% (w/w) of Ni oxide was found to be superior to that of other metal oxides at reaction temperature between 170 and 290 °C. A surface kinetic mechanism for the catalytic oxidation of volatile organic compound was proposed and incorporated in a transport model developed to explain the experimental breakthrough data. 相似文献
47.
Structural Characteristics and Electrical Conductivity of Spark Plasma Sintered Ytterbia Co‐doped Scandia Stabilized Zirconia 下载免费PDF全文
Vandana Shukla Ashutosh Kumar Ishamol Labbaveettil Basheer Kantesh Balani Anandh Subramaniam Shobit Omar 《Journal of the American Ceramic Society》2017,100(1):204-214
The effect of replacing Sc2O3 with Yb2O3 on the structural and electrical properties of xYb2O3–(12–x)Sc2O3–88ZrO2 has been investigated. Spark plasma sintering technique is employed to fabricate dense bulk samples from the nano‐sized powders. X‐ray diffraction and transmission electron microscopy performed on pellets indicate the existence of cubic and rhombohedral phases in 12ScSZ, and a single cubic phase in all the co‐doped compositions. However, Raman spectroscopic studies suggest the presence of a metastable tetragonal t″‐phase along with rhombohedral phases in 12ScSZ, whereas a single cubic phase in all the co‐doped compositions. Significant enhancement in the conductivity of grain and grain boundary is observed on replacing Sc2O3 with Yb2O3. In the intermediate temperature range, 1Yb11ScSZ exhibits the highest, while 12ScSZ shows the lowest conductivity values, which is attributed to corresponding phases present in that range. Through co‐doping with >1 mol% Yb2O3 leads to conductivity decrease, but the value remains higher than that of 12ScSZ. A sharp conductivity change is observed in 12ScSZ and 1Yb11ScSZ samples, which is attributed to partial phase transition as well to the formation of cation‐vacancy complexes. In this work, the beneficial effect of Yb2O3 co‐doping in 12ScSZ on the phase and conductivity has been highlighted. 相似文献
48.
Ashutosh G. Bhagurkar Akiyasu Yamamoto Anthony R. Dennis John H. Durrell Talal A. Aljohani Hari B. Nadendla David A. Cardwell 《Journal of the American Ceramic Society》2017,100(6):2451-2460
The study reports phase and microstructural evolution in MgB2 bulk superconductors fabricated by an infiltration and growth (IG) process. Three distinct stages, (1) intermediate boride formation, (2) bulk liquid Mg infiltration, and (3) MgB2 layer formation, were identified in IG process after detailed examination of series of samples prepared with varied heating conditions. The intermediate phase Mg2B25, isomorphous to β‐boron, was detected prior to MgB2 phase formation in stage (1). Due to volume expansion involved in stage 1, cracks formed in the β‐boron particles and propagated radially inwards during stage 3. The growing MgB2 particles sintered simultaneously with formation of grain boundaries during the process, as evidenced by the measured hardness and critical current density in these samples. From our observations, we estimate the total time needed for complete transformation to MgB2. 相似文献
49.
Nikhil Raj Ashutosh Kumar Singh Anil Kumar Gupta 《Circuits, Systems, and Signal Processing》2016,35(8):2683-2703
A low voltage self-biased high-swing cascode current mirror using bulk-driven quasi-floating gate MOSFET is proposed in this paper. The proposed current mirror bandwidth and especially the output impedance show a significant improvement compared to prior arts. The current mirror presented is designed using bulk-driven and bulk-driven quasi-floating gate N-channel MOS transistors, which helped it to operate at very low supply voltage of \({\pm }0.2\,\hbox {V}\). To achieve high output resistance, the current mirror uses regulated cascode stage followed by super cascode architecture. The small-signal analysis carried out proves the improvement achieved by proposed current mirror. The current mirror circuit operates well for input current ranging from 0 to \(250\,{\upmu }\mathrm{A}\) with good linearity and shows the bandwidth of 285 MHz. The input and output resistances are found as \(240\,\Omega \) and \(19.5\,\hbox {G}\Omega \), respectively. Further, the THD analysis and Monte Carlo simulations carried prove the robustness of proposed current mirror. The complete analysis is done using HSpice on UMC \(0.18\,\upmu \mathrm{m}\) technology. 相似文献
50.