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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Clear-Sky Detection Using Time-Averaged, Tilted-Plane Data

A method is presented to detect clear-sky periods for plane-of-array, time-averaged irradiance data that is based on the algorithm originally described by Reno and Hansen. We show this new method improves the state-of-the-art by providing accurate detection at longer data intervals, and by detecting clear periods in plane-of-array data, which is novel. We illustrate how accurate determination of clear-sky conditions helps to eliminate data noise and bias in the assessment of long-term performance of PV plants.

clear-sky conditions↗
DOE OSTI2024

Performance of plane wavefront Fizeau interferometers in power spectral density measurements with tilted plane optics

Binary pseudo-random array (BPRA) test samples are useful devices for calibrating the instrument transfer function (ITF) of Fizeau interferometers, interferometric microscopes, and other optical and non-optical surface and wavefront metrology instruments. The intrinsic white noise character of the power spectral density (PSD) function of the BPRA pattern simplifies the extraction of the ITF from the measured PSD. The ITF determined in a dedicated calibration experiment can be used to reconstruct the surface height profile from the measured data, effectively enhancing the instrument’s spatial resolution. For a high confidence reconstruction procedure, a reliable analytical model of the IFT is desirable. Usually, the model accounts for the contributions to the ITF related the imperfections of the instrument’s optical and detector systems. Here, we experimentally demonstrate that in the case of surface height metrology with Fizeau interferometers, the PSD measurements and, therefore, the efficacy of the ITF calibration of the tool, are strongly affected by the instrument data acquisition and processing procedures, as well as by the shape of the optic under test and its alignment with respect to the interferometer.

Yashchuk, V V↗
DOE OSTI2023

CSEM, BHP, Salinity, Flow-Rate, Fiber, and Tilt Data Collected in Jan. 2022 for Proj. DE-FE0031785

This dataset consists of four directories: first directory named as EM for the controlled source electromagnetic (CSEM) survey data that are zipped per day for January 18-21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31, 2022; second directory named as "Fiber" for the fiber optic slow-strain and microseismic data that are zipped per well; the third file that contains bottomhole pressure (BHP) and salinity and pump flow rate data during the CSEM surveys; and the fourth file that contained tiltmeter data.

CSEM↗
DOE OSTI2024

Precise micromotion compensation of a tilted ion chain

Excess micromotion can be a substantial source of errors in trapped-ion based quantum processors and clocks due to the sensitivity of the internal states of the ion to external fields and motion. This problem can be fixed by compensating background electric fields in order to position ions at the RF node and minimize their driven micromotion. Here we describe techniques for compensating ion chains in scalable surface ion traps. These traps are capable of cancelling stray electric fields with fine spatial resolution in order to compensate multiple closely spaced ions due to their large number of relatively small control electrodes. We demonstrate a technique that compensates an ion chain to better than 5 V/m and within 0.1 degrees of chain rotation.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Long-period Jovian Tilts the Orbits of Two sub-Neptunes Relative to Stellar Spin Axis in Kepler-129

We present the discovery of Kepler-129 d (P{sub d}=7.2{sub -0.3}{sup +0.4} yr, msini{sub d}=8.3{sub -0.7}{sup +1.1} M{sub Jup}, e{sub d}=0.15{sub -0.05}{sup +0.07}) based on six years of radial-velocity observations from Keck/HIRES. Kepler-129 also hosts two transiting sub-Neptunes: Kepler-129 b (P {sub b} = 15.79 days, r {sub b} = 2.40 ± 0.04 R {sub ⊕}) and Kepler-129 c (P {sub c} = 82.20 days, r {sub c} = 2.52 ± 0.07 R {sub ⊕}) for which we measure masses of m {sub b} < 20 M {sub ⊕} and m{sub c}=43{sub -12}{sup +13} M{sub ⊕}. Kepler-129 is a hierarchical system consisting of two tightly packed inner planets and a massive external companion. In such a system, two inner planets precess around the orbital normal of the outer companion, causing their inclinations to oscillate with time. Based on an asteroseismic analysis of Kepler data, we find tentative evidence that Kepler-129 b and c are misaligned with stellar spin axis by ≳38°, which could be torqued by Kepler-129 d if it is inclined by ≳19° relative to inner planets. Using N-body simulations, we provide additional constraints on the mutual inclination between Kepler-129 d and inner planets by estimating the fraction of time during which two inner planets both transit. The probability that two planets both transit decreases as their misalignment with Kepler-129 d increases. We also find a more massive Kepler-129 c enables the two inner planets to become strongly coupled and more resistant to perturbations from Kepler-129 d. The unusually high mass of Kepler-129 c provides a valuable benchmark for both planetary dynamics and interior structure, since the best-fit mass is consistent with this 2.5 R {sub ⊕} planet having a rocky surface.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Materials Data on Ta36B4C35 by Materials Project

Ta26C25Ta9C8TaBC(B)2BC1 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of two boron molecules; one BC1 sheet oriented in the (0, 0, 1) direction; one Ta26C25 sheet oriented in the (0, 0, 1) direction; one Ta9C8 sheet oriented in the (0, 0, 1) direction; and one TaBC sheet oriented in the (0, 0, 1) direction. In the BC1 sheet, B3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All B–C bond lengths are 1.83 Å. C4- is bonded in a distorted trigonal planar geometry to three equivalent B3+ atoms. In the Ta26C25 sheet, there are eighteen inequivalent Ta+3.56+ sites. In the first Ta+3.56+ site, Ta+3.56+ is bonded in a 3-coordinate geometry to three equivalent C4- atoms. There are one shorter (2.14 Å) and two longer (2.15 Å) Ta–C bond lengths. In the second Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Ta–C bond lengths are 2.23 Å. In the third Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are five shorter (2.25 Å) and one longer (2.26 Å) Ta–C bond lengths. In the fourth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Ta–C bond lengths are 2.25 Å. In the fifth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.24 Å) and three longer (2.26 Å) Ta–C bond lengths. In the sixth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.24 Å) and three longer (2.25 Å) Ta–C bond lengths. In the seventh Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.24 Å. In the eighth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.24 Å. In the ninth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.24 Å. In the tenth Ta+3.56+ site, Ta+3.56+ is bonded to six equivalent C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.24 Å. In the eleventh Ta+3.56+ site, Ta+3.56+ is bonded to six equivalent C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.23 Å) and three longer (2.24 Å) Ta–C bond lengths. In the twelfth Ta+3.56+ site, Ta+3.56+ is bonded to six equivalent C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.23 Å. In the thirteenth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.23 Å. In the fourteenth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.23 Å. In the fifteenth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.23 Å) and three longer (2.24 Å) Ta–C bond lengths. In the sixteenth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.23 Å. In the seventeenth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.23 Å) and two longer (2.24 Å) Ta–C bond lengths. In the eighteenth Ta+3.56+ site, Ta+3.56+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All Ta–C bond lengths are 2.25 Å. There are fifteen inequivalent C4- sites. In the first C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fifth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the sixth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the ninth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the tenth C4- site, C4- is bonded to six equivalent Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.23 Å) and three longer (2.24 Å) C–Ta bond lengths. In the eleventh C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the twelfth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the thirteenth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourteenth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifteenth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. All C–Ta bond lengths are 2.25 Å. In the Ta9C8 sheet, there are nine inequivalent Ta+3.56+ sites. In the first Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are five shorter (2.24 Å) and one longer (2.25 Å) Ta–C bond lengths. In the second Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ta–C bond distances ranging from 2.23–2.26 Å. In the third Ta+3.56+ site, Ta+3.56+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All Ta–C bond lengths are 2.26 Å. In the fourth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth Ta+3.56+ site, Ta+3.56+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. In the sixth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.23 Å) and three longer (2.24 Å) Ta–C bond lengths. In the seventh Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.23 Å) and four longer (2.24 Å) Ta–C bond lengths. In the eighth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.24 Å) and two longer (2.25 Å) Ta–C bond lengths. In the ninth Ta+3.56+ site, Ta+3.56+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing TaC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ta–C bond lengths are 2.24 Å. There are eight inequivalent C4- sites. In the first C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. All C–Ta bond lengths are 2.24 Å. In the fourth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. All C–Ta bond lengths are 2.24 Å. In the fifth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the eighth C4- site, C4- is bonded to six Ta+3.56+ atoms to form a mixture of corner and edge-sharing CTa6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the TaBC sheet, Ta+3.56+ is bonded in a single-bond geometry to one C4- atom. The Ta–C bond length is 2.08 Å. B3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. There are a spread of B–C bond distances ranging from 1.81–1.85 Å. C4- is bonded to one Ta+3.56+ and three equivalent B3+ atoms to form corner-sharing CTaB3 trigonal pyramids.

36 MATERIALS SCIENCE↗