UPPER GREAT LAKES TRANSPORTATION IMPACT FORECASTING SYSTEM

Community/Rural/Urban Development,

Detecting z > 10 objects through carbon, nitrogen and oxygen emission lines

By redshift of 10, star formation in the first objects should have produced considerable amounts of Carbon, Nitrogen and Oxygen. The submillimeter lines of C, N and O redshift into the millimeter and centimeter bands (0.5 mm -- 1.2 cm), where they may be detectable. High spectral resolution observations could potentially detect inhomogeneities in C, N and O emission, and see the first objects forming at high redshift. We calculate expected intensity fluctuations and discuss frequency and angular resolution required to detect them. For CII emission, we estimate the intensity using two independent methods: the line emission coefficient argument and the luminosity density argument. We find they are in good agreement. At 1+z \sim 10, the typical protogalaxy has a velocity dispersion of 30 km s^{-1} and angular size of 1 arcsecond. If CII is the dominant coolant, then we estimate a characteristic line strength of \sim 0.1 K km s^{-1}. We also discuss other atomic lines and estimate their signal. Observations with angular resolution of 10^{-3} can detect moderately nonlinear fluctuations of amplitude 2 \cdot 10^{-5} times the microwave background. If the intensity fluctuations are detected, they will probe matter density inhomogeneity, chemical evolution and ionization history at high redshifts.Comment: 15 pages, 1 postscript figures included; Uses aaspp4.sty (AASTeX v4.0); Submitted to The Astrophysical Journa

IMPLAN MODELING APPLICATIONS IN STATE AND REGIONAL DEVELOPMENT

Community/Rural/Urban Development,

Small T1−1T_1^{-1} coherence peak near TcT_c in unconventional superconductors

It is usually believed that a coherence peak just below T$_{c}$ in the nuclear spin lattice relaxation rate T$_{1}^{-1}$ in superconducting materials is a signature of conventional s-wave pairing. In this paper we demonstrate that any unconventional superconductor obeying BCS pure-case weak-coupling theory should show a small T$_{1}^{-1}$ coherence peak near T$_{c}$, generally with a height between 3 and 15 percent greater than the normal state T$_{1}^{-1}$ at T$_{c}$. It is largely due to impurity effects that this peak has not commonly been observed.Comment: 4 pages, 5 figure

Existence Theory for the Radically Symmetric Contact Lens Equation

In this paper we present a variational formulation of the problem of determining the elastic stresses in a contact lens on an eye and the induced suction pressure distribution in the tear film between the eye and the lens. This complements the force-balance derivation that we used in earlier work [K. L. Maki and D. S. Ross, J. Bio. Sys., 22 (2014), pp. 235–248]. We investigate the existence of solutions of the relevant boundary value problem for the singular, second-order Euler–Lagrange equation. We prove that, for lenses of constant thickness, solutions exist. We present an example to show that in some cases in which the lens thickness increases with distance from the lens center no solution exists

Cross-Correlating Cosmic Microwave Background Radiation Fluctuations with Redshift Surveys: Detecting the Signature of Gravitational Lensing

Density inhomogeneities along the line-of-sight distort fluctuations in the cosmic microwave background. Usually, this effect is thought of as a small second-order effect that mildly alters the statistics of the microwave background fluctuations. We show that there is a first-order effect that is potentially observable if we combine microwave background maps with large redshift surveys. We introduce a new quantity that measures this lensing effect, $$, where T is the microwave background temperature and $\delta \theta$ is the lensing due to matter in the region probed by the redshift survey. We show that the expected signal is first order in the gravitational lensing bending angle, $< (\delta \theta)^2 >^{1/2}$, and find that it should be easily detectable, (S/N) $\sim$ 15-35, if we combine the Microwave Anisotropy Probe satellite and Sloan Digital Sky Survey data. Measurements of this cross-correlation will directly probe the ``bias'' factor, the relationship between fluctuations in mass and fluctuations in galaxy counts.Comment: 13 pages, 4 postscript figures included; Uses aaspp4.sty (AASTeX v4.0); Accepted for publication in Astrophysical Journal, Part

The Challenges Associated with High Burnup and High Temperature for UO2 TRISO-Coated Particle Fuel

The fuel service conditions for the DOE Next Generation Nuclear Plant (NGNP) will be challenging. All major fuel related design parameters (burnup, temperature, fast neutron fluence, power density, particle packing fraction) exceed the values that were qualified in the successful German UO2 TRISO-coated particle fuel development program in the 1980s. While TRISO-coated particle fuel has been irradiated at NGNP relevant levels for two or three of the design parameters, no data exist for TRISO-coated particle fuel for all five parameters simultaneously. Of particular concern are the high burnup and high temperatures expected in the NGNP. In this paper, where possible, we evaluate the challenges associated with high burnup and high temperature quantitatively by examining the performance of the fuel in terms of different known failure mechanisms. Potential design solutions to ameliorate the negative effects of high burnup and high temperature are also discussed