21,566 research outputs found

    Gate-capacitance extraction from RF C-V measurements

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    In this work, a full two-port analysis of an RF C-V measurement set-up is given. This two-port analysis gives insight on the limitations of the commonly used gate capacitance extraction, based on the Y/sub 11/ parameter of the device. It is shown that the parasitics of the device can disturb the extracted gate capacitance and a new extraction scheme, based on the Z-matrix, is introduced that eliminates the effect of these parasitics. Measurement results prove the validity of this new extraction scheme, under different conditions

    Complex Scalar DM in a B-L Model

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    In this work, we implement a complex scalar Dark Matter (DM) candidate in a U(1)B−LU(1)_{B-L} gauge extension of the Standard Model. The model contains three right handed neutrinos with different quantum numbers and a rich scalar sector, with extra doublets and singlets. In principle, these extra scalars can have VEVs (VΊV_{\Phi} and VϕV_{\phi} for the extra doublets and singlets, respectively) belonging to different energy scales. In the context of ζ≥VΊVϕâ‰Ș1\zeta\equiv\frac{V_{\Phi}}{V_{\phi}}\ll1, which allows to obtain naturally light active neutrino masses and mixing compatible with neutrino experiments, the DM candidate arises by imposing a Z2Z_{2} symmetry on a given complex singlet, ϕ2\phi_{2}, in order to make it stable. After doing a study of the scalar potential and the gauge sector, we obtain all the DM dominant processes concerning the relic abundance and direct detection. Then, for a representative set of parameters, we found that a complex DM with mass around 200200 GeV, for example, is compatible with the current experimental constraints without resorting to resonances. However, additional compatible solutions with heavier masses can be found in vicinities of resonances. Finally, we address the issue of having a light CP-odd scalar in the model showing that it is safe concerning the Higgs and the ZÎŒZ_{\mu} boson invisible decay widths, and also the energy loss in stars astrophysical constraints.Comment: 20 pages, 3 figure

    Kinetic Vlasov Simulations of collisionless magnetic Reconnection

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    A fully kinetic Vlasov simulation of the Geospace Environment Modeling (GEM) Magnetic Reconnection Challenge is presented. Good agreement is found with previous kinetic simulations using particle in cell (PIC) codes, confirming both the PIC and the Vlasov code. In the latter the complete distribution functions fkf_k (k=i,ek=i,e) are discretised on a numerical grid in phase space. In contrast to PIC simulations, the Vlasov code does not suffer from numerical noise and allows a more detailed investigation of the distribution functions. The role of the different contributions of Ohm's law are compared by calculating each of the terms from the moments of the fkf_k. The important role of the off--diagonal elements of the electron pressure tensor could be confirmed. The inductive electric field at the X--Line is found to be dominated by the non--gyrotropic electron pressure, while the bulk electron inertia is of minor importance. Detailed analysis of the electron distribution function within the diffusion region reveals the kinetic origin of the non--gyrotropic terms

    Gate Oxide Reliability and Deuterated CMOS Processing

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    In recent literature, a controversy has arisen over the question whether deuterium improves the stability of the MOS gate dielectric. It appears as if this controversy finds its origin in the different stages (e.g. oxidation or post metal anneal) deuterium is introduced in the CMOS process. This paper investigates this in detail. The obtained results show that the hot carrier degradation only benefits from an isotope effect when deuterium is introduced in the post metal anneal. At the same time, charge to breakdown for high quality oxides does not benefit from an isotope effect, regardless of the processing stage deuterium is introduced, or the gate oxide thickness used. This is verified on two different sets of wafers fabricated in two different laboratories

    Targeted genome modifications in soybean with CRISPR/Cas9

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    Background: The ability to selectively alter genomic DNA sequences in vivo is a powerful tool for basic and applied research. The CRISPR/Cas9 system precisely mutates DNA sequences in a number of organisms. Here, the CRISPR/Cas9 system is shown to be effective in soybean by knocking-out a green fluorescent protein (GFP) transgene and modifying nine endogenous loci. Results: Targeted DNA mutations were detected in 95% of 88 hairy-root transgenic events analyzed. Bi-allelic mutations were detected in events transformed with eight of the nine targeting vectors. Small deletions were the most common type of mutation produced, although SNPs and short insertions were also observed. Homoeologous genes were successfully targeted singly and together, demonstrating that CRISPR/Cas9 can both selectively, and generally, target members of gene families. Somatic embryo cultures were also modified to enable the production of plants with heritable mutations, with the frequency of DNA modifications increasing with culture time. A novel cloning strategy and vector system based on In-Fusion (R) cloning was developed to simplify the production of CRISPR/Cas9 targeting vectors, which should be applicable for targeting any gene in any organism. Conclusions: The CRISPR/Cas9 is a simple, efficient, and highly specific genome editing tool in soybean. Although some vectors are more efficient than others, it is possible to edit duplicated genes relatively easily. The vectors and methods developed here will be useful for the application of CRISPR/Cas9 to soybean and other plant species

    Operational benefits from the terminal configured vehicle

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    The NASA Terminal Configured Vehicle is a flying laboratory used to conduct research and development on improved airborne systems (including avionics) and operational flight procedures, with particular emphasis on utilization in the terminal area environment. The objectives of this technology development activity, focused on conventional transport aircraft, are to develop and demonstrate improvements which can lead to increased airport and runway capacity, increased air traffic controller productivity, energy efficient terminal area operations, reduced weather minima with safety, and reduced community noise by use of appropriate procedures. This paper discusses some early results of this activity in addition to defining present efforts and future research plans

    The Impact of Deuterated CMOS processing on Gate Oxide Reliability

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    In recent literature, a controversy has arisen over the question whether deuterium improves the stability of the MOS gate dielectric. In particular, the influence of deuterium incorporation on the bulk oxide quality is not clear. In this letter, deuterium or hydrogen is introduced during either the gate oxidation, postoxidation anneal, and/or the postmetal anneal (PMA). The oxide bulk degradation was evaluated using charge-to-breakdown and stress-induced leakage current; and the oxide interface degradation using hot-carrier degradation and low-frequency noise. The obtained results show that the oxide bulk does not benefit from the presence of deuterium, regardless of the stage of deuterium introduction, or the gate oxide thickness. The oxide interface is more stable only when deuterium is introduced in the PMA

    The NASA CSTI high capacity power project

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    The SP-100 Space Nuclear Power Program was established in 1983 by DOD, DOE, and NASA as a joint program to develop technology for military and civil applications. Starting in 1986, NASA has funded a technology program to maintain the momentum of promising aerospace technology advancement started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for a wide range of future space applications. The elements of the Civilian Space Technology Initiative (CSTI) High Capacity Power Project include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timelines recently developed
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