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Measuring the cosmological bulk flow


 We study large-scale coherent motion in our universe using the existing Type IA supernovae data.If the recently observed bulk ow is real, then some imprint must be left on supernovae motion.We perform a Bayesian Monte Carlo Markov Chain analysis in various redshift bins and nd asharp contrast between the z < 0:05 and z > 0:05 data. The z < 0:05 data are consistent withthe bulk ow in the direction (l; b) = (290+39 ????31; 20+32????32) with a magnitude of vbulk = 188+119????103 km=sat 68% condence. The signicance of detection (compared to the null hypothesis) is 95%. Incontrast, z > 0:05 data (which contains 425 of the 557 supernovae in the Union2 data set) showno evidence for the bulk ow. While the direction of the

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Measuring cosmic bulk flows with Type Ia Supernovae from the Nearby Supernova Factory


  ABSTRACT Context. Our Local Group of galaxies appears to be moving relative to the Cosmic Microwave Background with the source of thepeculiar motion still uncertain. While in the past this has been studied mostly using galaxies as distance indicators, the weight oftype Ia supernovae (SNe Ia) has increased recently with the continuously improving statistics of available low-redshift supernovae.Aims. We measured the bulk flow in the nearby universe (0:015 < z < 0:1) using 117 SNe Ia observed by the Nearby SupernovaFactory, as well as the Union2 compilation of SN Ia data already in the literature.Methods. The bulk flow velocity was determined from SN data binned in

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Cosmic Bulk Flow and the Local Motion from Cosmicflows-2


Full sky surveys of peculiar velocity are arguably the best way to map the large scalestructure (LSS) out to distances of a few100 h????1Mpc. Using the largest and most accurateever catalog of galaxy peculiar velocities Cosmicflows-2, the LSS has been reconstructed bymeans of the Wiener filter (WF) and constrained realizations (CRs) assuming as a Bayesianprior model the CDM model with the WMAP inferred cosmological parameters. The presentpaper focuses on studying the bulk flow of the local flow field, defined as the mean velocityof top-hat spheres with radii ranging out to R = 500 h????1Mpc. The estimated LSS, in general,and the bulk flow, in particular, are determined by the tension between the observational dat

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دانلود تحقیق تحلیل و بررسی FLOW CONDITIONER در یکنواخت کردن جریان گاز در لوله ها


چکیده:در پروژه ای كه پیش رو دارید موارد استفاده Flow Conditioner و نحوه عملكرد آن و استاندارد موجود در مورد ساخت و شكل  Flow Conditioner آورده شده است . چون بیشتر موارد استفاده Flow Conditioner ها در بخش اندازه گیری سیال است در ابتدا به بررسی نحوه كاركرد flow  meter های موجود و مزایا، معایب آنها می پردازیم.در مورد استفاده Flow Conditioner در بحث یكنواخت سازی جریان برای نمونه گیری از آن در صنایع كشاورزی و چگونگی عملكرد آن توضیح داده شده است. آشنایی با بخشهایی از دو نرم افزار گمبیت و فلوئنت كه مربوط به این پروژه می شوند   آورده شده است . تحلیل یك  Flow Conditioner از نوع   tube bundleرا بصورت دو بعدی كه در گمبیت مش بندی شده ودر فلوئنت تحلیل كرده ایم.مقدمه:ب

ادامه مطلب  
دانلود پروژه تحلیل و بررسی FLOW CONDITIONER دریكنواخت كردن جریان گاز در لوله ها


             در پروژه ای كه پیش رو دارید موارد استفاده Flow Conditioner و نحوه عملكرد آن و استاندارد موجود در مورد ساخت و شكل  Flow Conditioner آورده شده است . چون بیشتر موارد استفاده Flow Conditioner ها در بخش اندازه گیری سیال است در ابتدا به بررسی نحوه كاركرد flow  meter های موجود و مزایا، معایب آنها می پردازیم.در مورد استفاده Flow Conditioner در بحث یكنواخت سازی جریان برای نمونه گیری از آن در صنایع كشاورزی و چگونگی عملكرد آن توضیح داده شده است. آشنایی با بخشهایی از دو نرم افزار گمبیت و فلوئنت كه مربوط به این پروژه می شوند   آورده شده است . تحلیل یك  Flow Conditioner از نوع   tube bundleرا بصورت

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Finsler geometric perspective on the bulk flow in the universe


 Astronomical observations showed that there may exist a bulk flow with peculiar velocities in the universe, which contradicts with the CDM model. The bulk flow reveals that the observational universe is anisotropic at large scales. In fact, a more reliable observation on the anisotropy of spacetime comes from the CMB power spectra. The WMAP and Planck satellites both show that there is a hemispherical power asymmetry at large-angular scales. In this paper, we propose a “wind” scenario to the bulk flow (or the anisotropy of spacetime). Under the influence of the “wind”, the spacetime metric could become a Finsler structure. By resolving the null geo

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Using measurements of the cosmic bulk f(R) Gravity


As an alternative explanation for the cosmic acceleration, f(R) theories of gravitycan predict an almost identical expansion history to standard CDM, yet make verydierent predictions for the growth of cosmological structures. Measurements of thecosmic bulk ow provides a method for determining the strength of gravity over thehistory of structure formation. We use the modied gravity N-body code ECOSMOGto simulate dark matter particles and make predictions for the bulk ow magnitudein both CDM and f(R) gravity. With the peculiar velocities output by ECOSMOGwe determine the bulk ow at depths ranging from 20h????1Mpc to 50h????1Mpc, follow-ing the redshift and sky distribution of the 2MASS Tully-Fisher survey (2MTF). Ateach

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Cosmic Flows on 100 Mpc Scales: Standardized Minimum Variance Bulk Flow Shear and Octupole Moments


   The low order moments, such as the bulk flow and shear, of the large scale peculiar velocity field are sensitive probes of the matter density fluctuations on very large scales. In practice, however, peculiar velocity surveys are usually sparse and noisy, which can lead to the aliasing of small scale power into what is meant to be a probe of the largest scales. Previously, we developed an optimal “minimum variance” (MV) weighting scheme, designed to overcome this problem by minimizing the difference between the measured bulk flow (BF) and that which would be measured by an ideal survey. Here we extend this MV

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A new measurement of the bulk flow of X-ray luminous clusters of galaxies


  ABSTRACT We present new measurements of the large-scale bulk flows of galaxy clustersbased on 5-year WMAP data and a significantly expanded X-ray cluster cata-logue. Our method probes the flow via measurements of the kinematic Sunyaev-Zeldovich (SZ) effect produced by the hot gas in moving clusters. It computesthe dipole in the cosmic microwave background (CMB) data at cluster pixels,which preserves the SZ component while integrating down other contributions.Our improved catalog of over 1,000 clusters enables us to further investigate pos-sible systematic effects and, thanks to a higher median cluster redshift, allows usto measure the bulk flow to larger scales. We present a corr

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مجموعه کتابخانه های Hspice


مجموعه کتابخانه های hspiceشامل180nm tsmc180nm bulk180nm cmos130nm bulk90nm bulk65nm bulk65nm cmos45nm bulk45nm finfet32nm bulk32nm finfet22nm bulk22nm finfet20nm finfet16nm finfet14nm finfet10nm finfet7nm finfetHSpice Library

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