111 research outputs found

    Analyzing capacitance-voltage measurements of vertical wrapped-gated nanowires

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    The capacitance of arrays of vertical wrapped-gate InAs nanowires are analyzed. With the help of a Poisson-Schr"odinger solver, information about the doping density can be obtained directly. Further features in the measured capacitance-voltage characteristics can be attributed to the presence of surface states as well as the coexistence of electrons and holes in the wire. For both scenarios, quantitative estimates are provided. It is furthermore shown that the difference between the actual capacitance and the geometrical limit is quite large, and depends strongly on the nanowire material.Comment: 15 pages, 6 Figures included, to appear in Nanotechnolog

    Foreword Special Issue on Transistors With Steep Subthreshold Swing for Low-Power Electronics

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    The increasing power consumption of integrated circuits is today the main impediment to the density scaling of integrated circuit technology. The reduction of supply voltage is the most effective way to reduce power; however, using modern transistors voltage reduction is traded against reduced speed or limited by a rising off-state leakage, neither of which is desirable. A better tradeoff can be achieved if the fundamental current control mechanism provides a steep turn-on characteristic. Steep means better than 60 mV/decade at room temperature, the limit obtained by barrier lowering in a bipolar transistor or metal oxide semiconductor field effect transistor (MOSFET) when the current is dominated by the thermionic emission of carriers above the energy barrier in the base or channel region

    The MoS2 Nanotubes with Defect-Controlled Electric Properties

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    We describe a two-step synthesis of pure multiwall MoS2 nanotubes with a high degree of homogeneity in size. The Mo6S4I6 nanowires grown directly from elements under temperature gradient conditions in hedgehog-like assemblies were used as precursor material. Transformation in argon-H2S/H2 mixture leads to the MoS2 nanotubes still grouped in hedgehog-like morphology. The described method enables a large-scale production of MoS2 nanotubes and their size control. X-ray diffraction, optical absorption and Raman spectroscopy, scanning electron microscopy with wave dispersive analysis, and transmission electron microscopy were used to characterize the starting Mo6S4I6 nanowires and the MoS2 nanotubes. The unit cell parameters of the Mo6S4I6 phase are proposed. Blue shift in optical absorbance and metallic behavior of MoS2 nanotubes in two-probe measurement are explained by a high defect concentration

    The Vehicle, Fall 1987

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    Table of Contents Sketches in the SunRodger L. Patiencepage 3 Reflecting PoolRob Montgomerypage 5 Grandpa\u27s Porcelain DollRichard E. Hallpage 6 Tintype 1837Catherine Friemannpage 6 PhotographSteven M. Beamerpage 7 Washerwoman\u27s SongBob Zordanipage 8 Scrambled Eggs for D.O.Lynne A. Rafoolpage 8 my mother would sayMonica Grothpage 9 Retired by His ChildrenDan Von Holtenpage 10 I am the oldestMonica Grothpage 11 Ice on WheatRob Montgomerypage 12 The Nature of the RoseTroy Mayfieldpage 12 Past NebraskaDan Hornbostelpage 13 Five Minute Jamaican VacationChristy Dunphypage 14 PhotographSteven M. Beamerpage 14 The Angry PoemChristy Dunphypage 15 Road UnfamiliarChristy Dunphypage 15 raised voicesMonica Grothpage 16 Old Ladies & MiniskirtsKara Shannonpage 17 FreakspeakBob Zordanipage 18 PortraitDan Von Holtenpage 18 Mobile VacuumKathleen L. Fairfieldpage 19 Rev. Fermus DickSteve Hagemannpage 20 PhotographSteven M. Beamerpage 21 What\u27s the Name of That Flower?Richard Jesse Davispage 22 RequestChristy Dunphypage 23 SketchPaul Seabaughpage 24 ExperiencedMarilyn Wilsonpage 26 Leaving: Two ViewsTina Phillipspage 27 AntaeusDan Von Holtenpage 28 Misogyny at 19J. D. Finfrockpage 29 A Mental CrippleSteve Hagemannpage 32 AssociationsRhonda Ealypage 33 Banana BreadGail Bowerpage 34 Bill and JackBradford B. Autenpage 35 After Image No. 2Rob Montgomerypage 35 VrrooomBeth Goodmanpage 36 Mr. Modern LoverMolly Maddenpage 36 TravelogueRodger L. Patiencepage 37 Down the HighwayJoan Sebastianpage 38 A Retread HeavenRob Montgomerypage 41 StuporDan Von Holtenpage 42 Love Poem After a Seizure in Your BedBob Zordanipage 43 PalsyChristy Dunphypage 44 Interview with Mr. MatthewsBob Zordanipage 45 Chasing Down Hot Air Balloons on a Sunday MorningRob Montgomerypage 48https://thekeep.eiu.edu/vehicle/1049/thumbnail.jp

    Mineralogical and geochemical analysis of Fe-phases in drill-cores from the Triassic Stuttgart Formation at Ketzin CO₂ storage site before CO₂ arrival

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    Reactive iron (Fe) oxides and sheet silicate-bound Fe in reservoir rocks may affect the subsurface storage of CO2 through several processes by changing the capacity to buffer the acidification by CO2 and the permeability of the reservoir rock: (1) the reduction of three-valent Fe in anoxic environments can lead to an increase in pH, (2) under sulphidic conditions, Fe may drive sulphur cycling and lead to the formation of pyrite, and (3) the leaching of Fe from sheet silicates may affect silicate diagenesis. In order to evaluate the importance of Fe-reduction on the CO2 reservoir, we analysed the Fe geochemistry in drill-cores from the Triassic Stuttgart Formation (Schilfsandstein) recovered from the monitoring well at the CO2 test injection site near Ketzin, Germany. The reservoir rock is a porous, poorly to moderately cohesive fluvial sandstone containing up to 2–4 wt% reactive Fe. Based on a sequential extraction, most Fe falls into the dithionite-extractable Fe-fraction and Fe bound to sheet silicates, whereby some Fe in the dithionite-extractable Fe-fraction may have been leached from illite and smectite. Illite and smectite were detected in core samples by X-ray diffraction and confirmed as the main Fe-containing mineral phases by X-ray absorption spectroscopy. Chlorite is also present, but likely does not contribute much to the high amount of Fe in the silicate-bound fraction. The organic carbon content of the reservoir rock is extremely low (<0.3 wt%), thus likely limiting microbial Fe-reduction or sulphate reduction despite relatively high concentrations of reactive Fe-mineral phases in the reservoir rock and sulphate in the reservoir fluid. Both processes could, however, be fuelled by organic matter that is mobilized by the flow of supercritical CO2 or introduced with the drilling fluid. Over long time periods, a potential way of liberating additional reactive Fe could occur through weathering of silicates due to acidification by CO2

    Pathogenicity and virulence of Yersinia

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    ABSTRACTThe genus Yersinia includes human, animal, insect, and plant pathogens as well as many symbionts and harmless bacteria. Within this genus are Yersinia enterocolitica and the Yersinia pseudotuberculosis complex, with four human pathogenic species that are highly related at the genomic level including the causative agent of plague, Yersinia pestis. Extensive laboratory, field work, and clinical research have been conducted to understand the underlying pathogenesis and zoonotic transmission of these pathogens. There are presently more than 500 whole genome sequences from which an evolutionary footprint can be developed that details shared and unique virulence properties. Whereas the virulence of Y. pestis now seems in apparent homoeostasis within its flea transmission cycle, substantial evolutionary changes that affect transmission and disease severity continue to ndergo apparent selective pressure within the other Yersiniae that cause intestinal diseases. In this review, we will summarize the present understanding of the virulence and pathogenesis of Yersinia, highlighting shared mechanisms of virulence and the differences that determine the infection niche and disease severity
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