4,634 research outputs found

    A comparison of MISiC Schottky-diode hydrogen sensors made by NO, N 2O, or NH 3 nitridations

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    MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N 2O, and NH 3) are fabricated. Steady-state and transien-t-response measurements are carried out at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that these nitrided sensors have high sensitivity and can give a rapid and stable response over a wide range of temperature. This paper also finds that N 2O provides the fastest insulator growth with good insulator quality and hence the highest sensitivity among the three nitrided samples. The N 2O- nitrided sensor can give a significant response even at a low H 2 concentration of 48-ppm H 2 in N 2, indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300°C, the response times of the N 2O, NO, and NH 3-nitrided sample to the 48-ppm H 2 in N 2 are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator. © 2006 IEEE.published_or_final_versio

    Sensing characteristics of a novel NH 3-nitrided schottky-diode hydrogen sensor

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    A novel NHi-nitrided Schottky-diode hydrogen sensor has been successfully fabricated Measurements have been performed to investigate the sensitivity, stability and response speed of the sensor at different temperatures and hydrogen concentrations. It can respond to hydrogen variation very quickly and can give significant response ewn at low hydrogen concentration. The studied device exhibits high sensitivity of 350 % at 300 °C when 800 ppm IJ in N2 gas is introduced. The sensitivity is 15 times greater than that of the Pt-SiC sensor. The excellent hydrogen-sensing characteristics of this novel sensor make it very suitable for detecting hydrogen leakage in high-temperature environment. The effects of hydrogen adsorption on the barrier height and hydrogen reaction kinetics are also investigated. ©2004 IEEE.published_or_final_versio

    Correlation between hot-carrier-induced interface states and GIDL current increase in N-MOSFET's

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    Correlation between created interface states and GIDL current increase in n-MOSFET's during hot-carrier stress is quantitatively discussed. A trap-assisted two-step tunneling model is used to relate the increased interface-state density (ADH) with the shift in GIDL current (ΔI d). Results show that under appropriate drain-gate biases, the two-step tunneling is so dominant that A/d is insensitive to temperatures up to about 50 °C. With the help of 2-D device simulation, the locations of the drain region with significant two-step tunneling and the energy levels of the traps involved can be found, with both depending on the drain voltage. From these insights on ADit,A/d and their relation, A Du near the midgap can be estimated, with an error less than 10% as compared to the results of chargepumping measurement on the same transistors. Devices with nitrided gate oxide, different gate-oxide thicknesses and different channel dimensions are also tested to verify the above correlation. © 1998 IEEE.published_or_final_versio

    A tunable common mode inductor with an auxiliary winding network

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    Paper 1593Track no. 5 - Devices and ComponentsIn conventional switching converter, the parasitic capacitance between switching circuit and ground introduces common mode (CM) noise problem. A CM inductor is inserted in the power feeding paths to produce a high impedance to attenuate the CM noise. However, this parasitic capacitance and the CM inductor create low-frequency resonance near the switching frequency and its harmonics. Thus, the filtering performance is diminished. Increasing the CM inductance to shift the resonant frequency to low-frequency range is one of the methods to tackle this problem. However, this approach leads to increase the power losses (both core and winding losses) of the CM inductor reducing the efficiency of the converter. In this paper, a tunable CM inductor with a small-space auxiliary winding is proposed. The auxiliary winding can be connected to a passive network to alter the frequency response of the CM inductor without affecting the original inductance. As a result, the influence of the low-frequency resonance can be mitigated. A proof-of-concept protytpe is constructed and its performance is experimentally measured. Results show that the proposed tunable CM inductor operates as theoretically anticipated. © IEEE.published_or_final_versio

    Excitation Spectra And Hard-core Thermodynamics Of Bosonic Atoms In Optical Superlattices

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    A generalized double-well-basis coupled representation is proposed to investigate excitation spectra and thermodynamics of bosonic atoms in double-well optical superlattices. In the hard-core limit and with a filling factor of one, excitations describing the creation of pairs of a doubly occupied state and a simultaneous empty state, and those from a symmetric singly occupied state to an antisymmetric state are carefully analyzed and their excitation spectra are calculated within mean-field theory. Based on the hard-core statistics, the equilibrium properties such as heat capacity and particle populations are studied in detail. The cases with other filling factors are also briefly discussed.published_or_final_versio

    Improved performance for OTFT with HfTiO2 as gate dielectric by N2O annealing

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    OTFTs with HfTiO 2 as gate dielectric have been successfully fabricated. The devices show small threshold voltage and subthreshold slope, and thus are suitable for low-voltage and low-power applications. This work also finds that OTFT with gate dielectric annealed in N 2O has larger dielectric constant, smaller threshold voltage, smaller subthreshold slope and larger on/off ratio than the N 2-annealed sample. This demonstrates that the N 2O annealing is an important surface treatment for preparing a high-quality insulator/organic interface. © 2007 IEEE.published_or_final_versio

    Pentacene thin-film transistors with HfO2 gate dielectric annealed in NH3 or N2O

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    Pentacene-based Organic Thin-Film Transistor (OTFT) with HfO 2 as gate dielectric is studied in this work. The HfO2 dielectric was prepared by RF sputtering at room temperature, and subsequently annealed in N 2O or NH 3 at 200 °C. The OTFTs were characterized by IV measurement and 1/f noise measurement. The OTFTs show small threshold voltage and can operate at as low as 3 V. Results indicate that the OTFT annealed in NH 3 shows higher carrier mobility, larger on/off current ratio, smaller sub-threshold swing and smaller Hooge parameter than the OTFT annealed in N 2O. Therefore, NH 3-annealed HfO 2 is a promising gate dielectric for the fabrication of high-performance OTFTs. © 2008 IEEE.published_or_final_versio

    The Embryotrophic Activity of Oviductal Cell-derived Complement C3b and iC3b, a Novel Function of Complement Protein in Reproduction

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    The oviduct-derived embryotrophic factor, ETF-3, enhances the development of trophectoderm and the hatching process of treated embryos. Monoclonal anti-ETF-3 antibody that abolishes the embryotrophic activity of ETF-3 recognized a 115-kDa protein from the conditioned medium of immortalized human oviductal cells. Mass spectrometry analysis showed that the protein was complement C3. Western blot analysis using an antibody against C3 confirmed the cross-reactivities between anti-C3 antibody with ETF-3 and anti-ETF-3 antibody with C3 and its derivatives, C3b and iC3b. Both derivatives, but not C3, were embryotrophic. iC3b was most efficient in enhancing the development of blastocysts with larger size and higher hatching rate, consistent with the previous reported embryotrophic activity of ETF-3. Embryos treated with iC3b contained iC3b immunoreactivity. The oviductal epithelium produced C3 as evidenced by the presence of C3 immunoreactivity and mRNA in the human oviduct and cultured oviductal cells. Cyclical changes in the expression of C3 immunoreactivity and mRNA were also found in the mouse oviduct with the highest expression at the estrus stage. Molecules involving in the conversion of C3b to iC3b and binding of iC3b were present in the human oviduct (factor I) and mouse preimplantation embryo (Crry and CR3), respectively. In conclusion, the present data showed that the oviduct produced C3/C3b, which was converted to iC3b to stimulate embryo development.postprin

    Resilience Analysis of Service Oriented Collaboration Process Management systems

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    Collaborative business process management allows for the automated coordination of processes involving human and computer actors. In modern economies it is increasingly needed for this coordination to be not only within organizations but also to cross organizational boundaries. The dependence on the performance of other organizations should however be limited, and the control over the own processes is required from a competitiveness perspective. The main objective of this work is to propose an evaluation model for measuring a resilience of a Service Oriented Architecture (SOA) collaborative process management system. In this paper, we have proposed resilience analysis perspectives of SOA collaborative process systems, i.e. overall system perspective, individual process model perspective, individual process instance perspective, service perspective, and resource perspective. A collaborative incident and maintenance notification process system is reviewed for illustrating our resilience analysis. This research contributes to extend SOA collaborative business process management systems with resilience support, not only looking at quantification and identification of resilience factors, but also considering ways of improving the resilience of SOA collaborative process systems through measures at design and run-time
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