A NOVEL DOUBLE GATE FINFET TRANSISTOR: OPTIMIZED POWER AND PERFORMANCE ANALYSIS FOR EMERGING NANOTECHNOLOGIES

Abstract—FinFET technology has been proposed as a promising alternative for deep sub-micron CMOS technology,because of its superior device performance, scalability, lower leakage power consumption and cost-effective fabricationprocess. Fin-type field-effect transistors (FinFETs) are capable substitutes for bulk CMOS at the nano-scale. Previous workshave studied the performance or power advantages of FinFET circuits over bulk CMOS circuits. This paper elucidates thedependability analysis of Average power, Leakage power, Leakage current and Delay of AND gate using double gateFinFET. Our experiments compare FinFET circuits at different voltages at 45 nm technology in virtuoso tool of cadence,showing that DG FinFET circuits have better dependability and scalability.Keywords—double gate FinFET; fin width; low power circuit; device analysi

Spatial Distributions of Multiple Dust Components in the PPN/PN Dust Shells

We investigate spatial distributions of specific dust components in the circumstellar shells of a proto-planetary nebula candidate, HD 179821, and a planetary nebula, BD$+30^{\circ}$3639, by means of spectral imaging. With high-resolution ground-based images and ISO spectra in the mid-infrared, we can derive ``dust feature only'' maps by subtracting synthesized continuum maps from the observed images at the feature wavelength. Such spatially detailed information will help to develop models for the evolution of dust grains around evolved stars.Comment: 4 pages + 7 figures, to appear in the proceedings of the conference, "Post-AGB Objects (proto-planetary nebulae) as a Phase of Stellar Evolution", Torun, Poland, July 5-7, 2000, eds. R. Szczerba, R. Tylenda, and S.K. Gorny. Figures have been degraded to minimize the total file siz

Mid-infrared imaging of the massive young star AFGL 2591: Probing the circumstellar environment of an outflow source

Most, if not all, stars are now believed to produce energetic outflows during their formation. Yet, almost 20 years after the discovery of bipolar outflows from young stars, the origins of this violent phenomenon are not well understood. One of the difficulties of probing the outflow process, particularly in the case of massive embedded stars, is a deficit of high spatial resolution observations. Here, we present sub-arcsecond-resolution mid-infrared images of one massive young stellar object, AFGL 2591, and its immediate surroundings. Our images, at 11.7, 12.5 and 18.0 microns, reveal a knot of emission ~6'' SW of the star, which may be evidence for a recent ejection event or an embedded companion star. This knot is roughly coincident with a previously seen near-infrared reflection nebula and a radio source, and lies within the known large-scale CO outflow. We also find a new faint NW source which may be another embedded lower-luminosity star. The IRAS mid-infrared spectrum of AFGL 2591 shows a large silicate absorption feature at 10 microns, implying that the primary source is surrounded by an optically thick dusty envelope. We discuss the interrelationship of these phenomena and suggest that mid-infrared imaging and spectroscopy provide powerful tools for probing massive star birth.Comment: 14 pages, 3 PostScript figures, accepted for publication in The Astrophysical Journal Letter

Discovery of an Extended Dust Emission around IRAS 18576+0341 (AFGL 2298) at 10.3 and 18.0 microns: a New Luminous Blue Variable Candidate?

We report detection of an extended mid-infrared emission from \iras 18576+0341 (AFGL 2298). The object shows a dusty circumstellar shell that has diameter of \age 7\arcsec at 10.3 and 18.0 \um. The dust nebula shows two emission peaks concentrically elongated and symmetrically oriented on the opposite sides of the third, central peak, which appears to be the central star of the system. The observed mid-infrared morphology indicates that the circumstellar dust shell has an equatorially-enhanced material distribution, which is a common signature of stellar objects that have experienced mass loss. Radiative transfer model calculations suggest that the central star is an extremely bright (\lstar = 10^{6.4} \lsun) star at a distance of about 10 kpc: this object is best described as a new luminous blue variable candidate. The circumstellar dust shell seems to have been generated by an equatorially-enhanced mass loss process with {\dot M} \ge 6.8 \times 10^{-6} \msun yr$^{-1}$ and ${\dot M}_{\rm pole}/{\dot M}_{\rm eq} \sim 0.5$.Comment: 21 pages, 4 figures, to appear in Ap

Mid-IR Observations of Mira Circumstellar Environment

This paper presents results from high-angular resolution mid-IR imaging of the Mira AB circumbinary environment using the MIRAC3 camera at the NASA Infrared Telescope Facility (IRTF). We resolved the dusty circumstellar envelope at 9.8, 11.7 and 18 micron around Mira A (o Ceti), and measured the size of the extended emission. Strong deviations from spherical symmetry are detected in the images of Mira AB system, including possible dust clumps in the direction of the companion (Mira B). These observations suggest that Mira B plays an active role in shaping the morphology of the circumstellar environment of Mira A as it evolves toward the Planetary Nebula phase.Comment: 11 pages, 2 PostScript figures, accepted for publication in the Astrophysical Journal Letter

A Mid-Infrared Imaging Survey of Proto-Planetary Nebula Candidates

We present the data from a mid-infrared imaging survey of 66 proto-planetary nebula candidates using two mid-IR cameras (MIRAC2 and Berkcam) at the NASA Infrared Telescope Facility and the United Kingdom Infrared Telescope. The goal of this survey is to determine the size, flux, and morphology of the mid-IR emission regions, which sample the inner regions of the circumstellar dust shells of proto-planetary nebulae. We imaged these proto-planetary nebulae with narrow-band filters ($\Delta\lambda / \lambda \sim 10$) at wavelengths of notable dust features. With our typical angular resolution of 1\arcsec, we resolve 17 sources, find 48 objects unresolved, and do not detect 1 source. For several sources, we checked optical and infrared associations and positions of the sources. In table format, we list the size and flux measurements for all the detected objects and show figures of all the resolved sources. Images for all the detected objects are available on line in FITS format from the Astronomy Digital Image Library at the National Center for Supercomputing Application. The proto-planetary nebula candidate sample includes, in addition to the predominant proto-planetary nebulae, extreme asymptotic giant branch stars, young planetary nebulae, a supergiant, and a luminous blue variable. We find that dust shells which are cooler ($\rm T \sim 150$ K) and brighter in the infrared are more easily resolved. Eleven of the seventeen resolved sources are extended and fall into one of two types of mid-IR morphological classes: core/elliptical or toroidal. Core/elliptical structures show unresolved cores with lower surface brightness elliptical nebulae. Toroidal structures show limb-brightened peaks suggesting equatorial density enhancements. We argue that core/ellipticals have denser dust shells than toroidals.Comment: 32 pages, 5 tables, 2 e/ps figures (fig3 is available through ADIL [see text]), to be published in ApJS May 1999 issu

A thermal-infrared and millimeter-wave study of evolved stars, and proto-planetary and planetary nebulae

The evolution of low- and intermediate-mass stars (1M(⊙) - 8M(⊙)) from the Asymptotic Giant Branch (AGB) to the Planetary Nebula (PN) phase is a poorly understood phase of stellar evolution. We have observed a sample of AGB stars, Proto-Planetary and Planetary Nebulae (PPNe and PNe) at thermal-infrared and millimeter wavelengths. The thermal-infrared emission comes from the warm dust (T(dust) ≈ 100-300 K) circumstellar shells. Images at these wavelengths provide a unique "close-up" look at the morphology of these sources, and therefore allow us to constrain the geometry and/or mass loss rates on short dynamical timescales. The millimeter-wave observations probe the extended circumstellar molecular envelopes; therefore they provide valuable spatial and kinematical information on the larger scales (and over longer dynamical timescales) than the mid-IR images. Our results show that the dust shells of all the planetary and proto-planetary nebulae (PPNe and PNe) in our study are not spherical; those that are well-resolved appear to be bipolar and can be modeled with axially symmetric models. They strongly suggest that the evolution from AGB to PN is often accompanied by higher mass loss rates in the equatorial plane than in the polar regions, as predicted by binary star (common envelope) evolution models, or models involving stellar rotation. At least one bipolar nebula (M 4-18) appears to be a single, low-mass star. From our mid-IR images at feature wavelengths we find that the spatial distribution of the carbonaceous and silicate grains varies over the surface of the nebulae. IC 5117 shows evidence for stratification of carbon- and oxygen-based grains and suggests that some PNe go through temporal changes in circumstellar chemistry (from oxygen-rich to carbon-rich) as they evolve off the AGB. The molecular envelopes of the sources in our study can be modeled with spherically symmetric models though two sources (IRC + 10216 and AFGL 2343) show kinematical and spatial evidence for departures from spherical symmetry. Our millimeter observations of IRC + 10216 also provide confirmation that the interstellar UV photons initiate a variety of photochemical reactions in circumstellar envelopes of AGB stars and PNe