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Displaying 6701 - 6725 of 74137

Characterization of triacontyl (C-30) liquid chromatographic columns

March 15, 2020
Author(s)
Lane C. Sander, Catherine A. Rimmer, Walter B. Wilson
Differences in the performance characteristics of seventeen commercial C30 liquid chromatographic columns were studied for the separation of carotenoid isomers. A mixture consisting of nine xanthophyll and hydrocarbon carotenoids were separated under

Evaluation of Abramowitz functions in the right half of the complex plane

March 15, 2020
Author(s)
Zydrunas Gimbutas, Shidong Jiang, Li-Shi Luo
A numerical scheme is developed for the evaluation of Abramowitz functions J n in the right half of the complex plane. For n = −1, . . . , 2, the scheme utilizes series expansions for |z| R with R determined by the required accuracy, and modified Laurent

NIST Reference Materials: Their Purpose and Their Future

March 15, 2020
Author(s)
Steven J. Choquette, David L. Duewer, Katherine E. Sharpless
The National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards, was established by the U.S. Congress in 1901 and charged with establishing a measurement foundation to facilitate U.S. and international commerce. This

Interleaflet Coupling of n-Alkane Incorporated Bilayers

March 14, 2020
Author(s)
Hatsuho Usuda, Mafumi Hishida, Elizabeth Kelley, Yasuhisa Yamamura, Michihiro Nagao, Kazuya Saito
The relationship between the membrane bending modulus (k) and compressibility modulus (KA) depends on the extent of coupling between the two monolayers (leaflets). Using neutron spin echo (NSE) spectroscopy, we investigate the effects of n-alkanes on the

A framework for assessing 16S rRNA marker-gene survey data analysis methods using mixtures.

March 13, 2020
Author(s)
Nathanael David Olson, Senthil Kumar, Stephanie Hao, Winston Timp, Marc L. Salit, O Colin Stine, Hector Corrada Bravo
Background: There are a variety of bioinformatic pipelines and downstream analysis methods for analyzing 16S rRNA marker-gene surveys. However, appropriate assessment datasets and metrics are needed as there is limited guidance to decide between available

Annual Report 2018: NIST/ITL Cybersecurity Program

March 13, 2020
Author(s)
Patrick D. O'Reilly, Kristina G. Rigopoulos, Larry Feldman, Gregory A. Witte
Title III of the E-Government Act of 2002, entitled the Federal Information Security Management Act (FISMA) of 2002, requires NIST to prepare an annual public report on activities undertaken in the previous year, and planned for the coming year, to carry

Twist Angle-Dependent Atomic Reconstruction and Moire Patterns in Transition Metal Dichalcogenide Heterostructures

March 13, 2020
Author(s)
Matthew R. Rosenberger, Hsun-Jen Chuang, Vladimir Oleshko, Madeleine Phillips, Kathleen M. McCreary, Saujan V. Sivaram, C. Stephen Hellberg, Berend T. Jonker
Van der Waals layered materials, such as the transition metal dichalcogenides (TMDs), are an exciting class of materials with weak interlayer bonding which enables one to create so-called van der Waals heterostructures (vdWH). One promising attribute of

Certified Quantum Measurement of Majorana Fermions

March 12, 2020
Author(s)
Emanuel H. Knill, Abu Ashik Md. Irfan, Karl H. Mayer, Gerardo Ortiz
We present a quantum self-testing protocol to certify measurements of fermion parity involving Majorana fermion modes. We show that observing a set of ideal measurement statistics implies anticommutativity of the implemented Majorana fermion parity

Field Ion Emission in an Atom Probe Microscope Triggered by Femtosecond-Pulsed Coherent Extreme Ultraviolet Light

March 12, 2020
Author(s)
Ann C. Chiaramonti Debay, Luis Miaja Avila, Benjamin W. Caplins, Paul T. Blanchard, Norman A. Sanford, Brian Gorman, David R. Diercks
This paper reports construction of an extreme ultraviolet (EUV) radiation-triggered atom probe tomograph and describes the results from initial experiments on amorphous SiO2. Femtosecond-pulsed coherent EUV radiation of 29.6 nm wavelength (41.85 eV photon

Nanoscale Pattern Decay Monitored via in-situ Heated Atomic Force Microscopy

March 12, 2020
Author(s)
Sonal Bhadauriya, Jianan Zhang, Jaejun Lee, Michael R. Bockstaller, Alamgir Karim, Richard J. Sheridan, Christopher Stafford
We combine in-situ heated atomic force microscopy (AFM) with automated line-by-line spectral analysis to quantify the relaxation or decay of nanopatterned polymer films at temperatures above the glass transition. This approach enables assessment of pattern

The Measurement of the Acceleration Due to Gravity

March 12, 2020
Author(s)
J E. Faller
Instrumental capabilities for both relative and absolute gravity measurements can be made at the parts in 10 9 level of precision. Large but still portable absolute gravimeters have also reached the parts in 10 9 level of accuracy. Present emphasis is on

A MULTIDIMENSIONAL LANDSCAPE MODEL FOR DETERMINING CELLULAR NETWORK THERMODYNAMICS

March 11, 2020
Author(s)
Joseph B. Hubbard, Michael W. Halter, Anne L. Plant
The distribution of phenotypic responses within an isogenic population of cells reflects the thermodynamics of a stationary state that results from coordinated intracellular reactions. The distribution of phenotypes is the result of both deterministic and

Long-Range Magnetic Order in Hydroxide-Layer-Doped (Li 1-x-y Fe x Mn y OD)FeSe

March 11, 2020
Author(s)
Brandon Wilfong, Xiuquan Zhou, Huafei Zheng, Navneeth Babra, Craig Brown, Jeffrey W. Lynn, Keith M. Taddei, Johnpierre Paglione, Efrain E. Rodriguez
The (Li 1-xFe xOH)FeSe superconductor has been suspected to exhibit long-range magnetic ordering due to Fe substitution in the LiOH layer. However, no direct observation such as magnetic reflection from neutron diffraction has be reported. Here, we use a

Large Enhancement of Magnetocaloric and Barocaloric Effects by Hydrostatic Pressure in La(Fe 0.92 Co 0.08 ) 11.9 Si 1.1 with a NaZn 13 -Type Structure

March 10, 2020
Author(s)
Jiazheng Hao, Fengxia Hu, Jian-Tao Wang, Fei-Ran Shen, Zibing Yu, Houbo Zhou, Hui Wu, Qingzhen Huang, Kaiming Qiao, Jing Wang, Jun He, Lunhua He, Ji-Rong Sun, Baogen Shen
Solid state refrigeration based on caloric effect has been regarded as an attractive alternative to conventional gas compression technique. Boosting the caloric effect of a system to its optimum is a long-term pursuit. Here, we report enhanced

Photonic spin-multiplexing metasurface for switchable spiral phase contrast imaging

March 10, 2020
Author(s)
Pengcheng Huo, Cheng Zhang, Wenqi Zhu, Mingze Liu, Song Zhang, Si Zhang, Lu Chen, Henri Lezec, Amit Agrawal, Yanqing Lu, Ting Xu
As the two most representative operation modes in an optical imaging system, bright-field imaging and phase contrast imaging can address different dimensionalities of an object. Developing a miniature and low-cost system capable of switching between these

Quantities and Units for Software Product Measurements

March 10, 2020
Author(s)
David W. Flater
International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 80000, the International System of Quantities, collects and organizes the most important physical quantities into a coherent system. In a similar fashion
Displaying 6701 - 6725 of 74137