Results 71 to 80 of about 8,346 (279)

Experimenting an optical second with strontium lattice clocks

, 2013
Progress in realizing the SI second had multiple technological impacts and enabled to further constraint theoretical models in fundamental physics. Caesium microwave fountains, realizing best the second according to its current definition with a relative
Abgrall, M., Bize, S., Clairon, A., Coq, Y. Le, Gartman, R., Gurov, M., Guéna, J., Laurent, P., Lemonde, P., Lodewyck, J., Lorini, L., Lours, M., Nagórny, B., Rosenbusch, P., Rovera, D. G., Santarelli, G., Targat, R. Le, Tobar, M. E., Westergaard, P. G., Zawada, M.   +19 more
core   +3 more sources

Thermodynamic Pathways of Nonequilibrium Solidification in Wire‐Arc Additive Manufacturing Fe‐Based Multicomponent Alloy Structures

Advanced Engineering Materials, EarlyView.
Geometry‐driven thermal behavior in wire‐arc additive manufacturing (WAAM) influences microstructural evolution during nonequilibrium solidification of a chemically complex Fe–Cr–Nb–W–Mo–C nanocomposite system. By comparing different deposits configurations, distinct entropy–cooling rate correlations, segregation, and carbide evolution are revealed ...
Blanca Palacios, Anthony Gonzalez, Aleksander Aleman, Tyler Dolmetsch, Tanaji Paul, Arvind Agarwal   +5 more
wiley   +1 more source

Hanle Detection for Optical Clocks

The Scientific World Journal, 2015
Considering the strong inhomogeneous spatial polarization and intensity distribution of spontaneous decay fluorescence due to the Hanle effect, we propose and demonstrate a universe Hanle detection configuration of electron-shelving method for optical ...
Xiaogang Zhang, Shengnan Zhang, Duo Pan, Peipei Chen, Xiaobo Xue, Wei Zhuang, Jingbiao Chen   +6 more
doaj   +1 more source

Controlling dipole-dipole frequency shifts in a lattice-based optical atomic clock

, 2003
Motivated by the ideas of using cold alkaline earth atoms trapped in an optical lattice for realization of optical atomic clocks, we investigate theoretically the perturbative effects of atom-atom interactions on a clock transition frequency.
D. E. Chang, G. Wilpers, I. Courtillot, I.H. Deutsch, J.L. Hall, Jun Ye, M. D. Lukin, M. Fleischhauer, M. Gross, M. Weidemüller, N. Allard, R.J. Rafac, T. Mukaiyama, T. Udem, X. Xu, X. Xu   +15 more
core   +1 more source

Phenomenological and Physically Based Modeling of Flow Stress and Strengthening Mechanism of Inconel 718

Advanced Engineering Materials, EarlyView.
Nickel‐based alloys are widely used in high‐temperature applications due to their excellent mechanical strength and oxidation resistance. However, properties such as high‐temperature strength and pronounced work‐hardening make them difficult to machine.
Soheil Rooein, Oliver Schenk, Christoph Broeckmann   +2 more
wiley   +1 more source

Strontium optical lattice clocks for practical realization of the metre and secondary representation of the second

, 2015
We present a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. The absolute frequency of the clocks can be verified by the use of Er:fiber optical frequency comb with the GPS-disciplined Rb ...
Ablewski, P., Bartoszek-Bober, D., Bielska, K., Bober, M., Ciuryło, R., Cygan, A., Gawlik, W., Lisak, D., Masłowski, P., Morzyński, P., Ozimek, F., Piotrowski, M., Piwiński, M., Prymaczek, M., Radzewicz, C., Trawiński, R., Wcisło, P., Wójtewicz, S., Zachorowski, J., Zawada, M.   +19 more
core   +1 more source

Sol–Gel Derived Polymer Precursors for Stereolithography of ZrC

Advanced Engineering Materials, EarlyView.
ZrC is a critical material target for extreme temperature conditions. This report describes a protocol for preparing ZrC ceramics via stereolithography and examines the impact of the polymer matrix on carbothermal reduction and mechanical stability of 3D printed ZrC.
Charles J. Rafalko, Evelyn Wang, Michael A. Hickner   +2 more
wiley   +1 more source

Frequency stability of optical lattice clocks [PDF]

New Journal of Physics, 2010
In this paper, we review several aspects of the frequency stability of optical lattice clocks. We describe a new ultra-stable cavity design with reduced thermal noise and record frequency stability (below 10 15 ), as well as a non-destructive detection scheme for measuring the clock transition probability. Given the experimental parameters we measured,
Lodewyck, Jérôme, Westergaard, Philip G., Lecallier, Arnaud, Lorini, Luca, Lemonde, Pierre   +4 more
openaire   +4 more sources

Assessing Altered Coating Adhesion on Plasma‐Deoxidized Surfaces Under Oxygen‐Free Conditions

Advanced Engineering Materials, EarlyView.
This study demonstrates the effectiveness of atmospheric pressure plasma pretreatment in modifying silicon and stainless steel surfaces to improve adhesion. Argon‐hydrogen plasma increases surface roughness and improves adhesion strength, whereas pure argon results in smoother surfaces and structural changes.
Selina Raumel, Lara Kuhr, Khemais Barienti, Sebastian Herbst, Florian Nürnberger, Hans Jürgen Maier, Marc C. Wurz   +6 more
wiley   +1 more source

Making optical atomic clocks more stable with $10^{-16}$ level laser stabilization

, 2011
The superb precision of an atomic clock is derived from its stability. Atomic clocks based on optical (rather than microwave) frequencies are attractive because of their potential for high stability, which scales with operational frequency. Nevertheless,
A. D. Ludlow, AD Ludlow, AD Ludlow, B Young, C. W. Oates, CW Chou, CW Chou, G Santarelli, H Katori, J Millo, J Ye, J. A. Sherman, K Numata, L.-S. Ma, LS Ma, M Notcutt, MD Swallows, MM Boyd, N Nakagawa, N. D. Lemke, ND Lemke, PG Westergaard, R. W. Fox, RW Fox, S Bize, S Webster, SA Webster, ST Dawkins, T Legero, T Udem, WM Itano, Y Levin, Y. Y. Jiang   +32 more
core   +1 more source