[en] The uncertainties on the calculation of the temperature coefficient in thermal reactors are estimated. A table gives some numerical examples of these uncertainties for ²³⁵U, ²³⁸U, ²³⁹Pu, ²⁴⁰Pu and ²⁴¹Pu

[en] Small silica colloidal particles suspended in a binary solvent, such as water and 2,6-lutidine, have attracted increasing attention in the past several decades as model systems to study critical adsorption, critical Casimir force, and colloidal glass transitions because the preferential solvent adsorption and the effective interaction between these colloidal particles can be tuned by controlling the temperature and solvent concentrations. In these early studies, the aggregation or clustering of particles driven by the solvent fluctuation is believed to be stable and thermally reversible. However, we demonstrate here conclusively that irreversible aggregates and gels can occur for silica nanoparticles in the binary solvent 2,6-lutidine and water when either the lutidine concentration or particle volume fraction is high enough. Hence, the interpretation of the experiment results needs to be taken into consideration when using such systems as model thermally reversible colloidal systems.

No abstract available

[en] We report magnetoresistivity measurements on strongly underdoped YBa₂Cu₃O_x (x=6.25 and 6.36) single crystals in applied magnetic fields H parallel c axis. We identify two different contributions to both in-plane Δρ_ab/ρ_ab and out-of-plane Δρ_c/ρ_c magnetoresistivities. The first contribution has the same sign as the temperature coefficient of the resistivity ∂ ln ρ_i/∂T (i={c,ab}). This contribution reflects the incoherent nature of the out-of-plane transport. The second contribution is positive, quadratic in field, with an onset temperature that correlates to the antiferromagnetic ordering

[en] An attempt is made to construct sufficient conditions for xenon and temperature-controlled nuclear reactors to be stable against power excursions or inadvertent shutdowns. Region of asymptotic stability in the large in the plane of equilibrium flux versus temperature coefficient is determined. Two different criteria for the region asymptotic stability are compared. (author)

[en] An extremely low power voltage reference without resistors is presented for power-aware ASICs. In order to reduce the power dissipation, an Oguey current reference source is used to reduce the static current; a cascode current mirror is used to increase the power supply rejection ratio (PSRR) and reduce the line sensitivity of the circuit. The voltage reference is fabricated in SMIC 0.18-μm CMOS process. The measured results for the voltage reference demonstrate that the temperature coefficient of the voltage is 66 ppm/°C in a range from 25 to 100 °C. The line sensitivity is 0.9% in a supply voltage range of 1.8 to 3.3 V, and PSRR is −49 dB at 100 Hz. The power dissipation is 200 nW. The chip area is 0.01 mm"2. The circuit can be used as an elementary circuit block for power-aware ASICs. (paper)

[en] Temperature coefficients for the 5 Kwe reactor are calculated and compared to previous experiments and reactors. The recommended isothermal temperature coefficient is -0.18 cents/⁰F. (U.S.)

[en] Temperatures, radii, and luminosities have been derived for 74 solar neighborhood stars by using visual spectrophotometry and trigonometric parallaxes. Mass and surface gravity, as derived from evolutionary tracks, have been estimated

No abstract available

[en] Small-angle X-ray scattering (SAXS) measurements were carried out for two cellulose tris(phenylcarbamate) (CTPC) samples in tricresyl phosphate (TCP) at 25 °C to determine the particle scattering function P(q) and the z-average mean-square radius of gyration ${⟨S^2⟩}_z$. The obtained data were analyzed in terms of the wormlike chain model to estimate the Kuhn segment length λ⁻¹ (the stiffness parameter, equivalent to twice the persistence length) and the helix pitch (or helix rise) per residue h. The resultant λ⁻¹ and h were 11.5 ± 0.5 and 0.51 nm, respectively. While the latter value (h) is consistent with the previously reported values both for cellulose and cellulose derivatives, appreciably higher chain flexibility was found for CTPC in TCP than that in tetrahydrofuran at 25 °C (19–24 nm). The value is fairly close to that in anisol, cyclohexanol, and benzophenone, assuming an appropriate temperature coefficient. We may thus conclude that CTPC behaves as a semiflexible chain in TCP.