Institution
National Physical Laboratory
Facility•London, United Kingdom•
About: National Physical Laboratory is a facility organization based out in London, United Kingdom. It is known for research contribution in the topics: Dielectric & Thin film. The organization has 7615 authors who have published 13327 publications receiving 319381 citations.
Papers published on a yearly basis
Papers
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TL;DR: The C-MARS as mentioned in this paper is a cantilever microfabricated array of reference springs that can be used to calibrate an atomic force microscope (AFM) cantilevers using a binary code of surface oxide squares (easily visible in light, electron and atomic force microscopy).
Abstract: Calibration of atomic force microscope (AFM) cantilevers is necessary for the measurement of nanonewton and piconewton forces, which are critical to analytical applications of AFM in the analysis of polymer surfaces, biological structures and organic molecules. We have developed a compact and easy-to-use reference artefact for this calibration by bulk micromachining of silicon, which we call a cantilever microfabricated array of reference springs (C-MARS). Two separate reference cantilever structures, each nominally 3 µm thick, are fabricated from a single crystal silicon membrane. A binary code of surface oxide squares (easily visible in light, electron and atomic force microscopy) makes it easy to locate the position of the AFM tip along the length of the cantilevers. Uncertainty in location is the main source of error when calibrating an AFM using reference cantilevers, especially for those having spring constants greater than around 10 N m −1 . This error is effectively eliminated in our new design. The C-MARS device spans the range of spring constants from 25 N m −1 down to 0.03 N m −1 important in AFM, allowing almost any contact-mode AFM cantilever to be calibrated easily and rapidly.
75 citations
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TL;DR: In this paper, the physical bases of Auger electron spectroscopy and X-ray photoelectron spectroscopic analysis are briefly presented in order that their practical applicability and limitations may be understood.
75 citations
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TL;DR: A method is described for comparing the sensitivity of two hydrophones over the frequency range 1-15 MHz, which forms the basis for the dissemination of national ultrasonic standards in the U.K. over this frequency range.
Abstract: A method is described for comparing the sensitivity of two hydrophones over the frequency range 1–15 MHz. This technique forms the basis for the dissemination of national ultrasonic standards in the U.K. over this frequency range. A reference hydrophone is placed in an ultrasonic field and then the device being calibrated is substituted and the two output voltages are compared. This substitution method utilizes a broadband ultrasonic field produced by nonlinear propagation. Thus it is possible to cover the whole frequency range with a single measurement on each hydrophone. The overall uncertainty in the intercomparison of two hydrophones increases from ±4.2% at 1 MHz to ±8.2% at 15 MHz (95% confidence level). The method has been compared with discrete‐frequency substitution, time‐delay spectrometry, and absolute calibrations using the National Physical Laboratory (NPL) primary standard laser interferometer. Various designs and sizes of hydrophones were compared, and agreement was within the combined random uncertainties for all the comparisons.
75 citations
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TL;DR: In this article, the authors explored electrochemically synthesized nanostructured NiCo 2 O 4 spinel thin-film electrode for electrochemical supercapacitors, which exhibited a high specific capacitance value of 580 F g − 1 and an energy density of 32 W − 1 at the power density of 4 W −1, accompanying with good cyclic stability.
75 citations
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TL;DR: The average life of a smoke particle before deposition on land is probably of the order of 1-2 days; that of a molecule of sulphur dioxide is estimated with rather more certainty to be less than 12 hours as mentioned in this paper.
Abstract: Observations of atmospheric pollution throughout Britain are considered in relation to the amounts of pollution emitted through the combustion of coal. The estimated weight of ash emitted into the air and the estimate, from deposit gauges, of the ash deposited, are considered likely to agree fairly well at a figure of rather over one million tons per annum (one million tonnes/yr).
On the assumption that about 1.5 million tons of smoke are blown to sea each year, it is shown that about 1.1 million tons of sulphur dioxide are blown to sea each year; the remaining 0.8 million tons of smoke and 3.9 million tons of sulphur dioxide must be deposited in Britain, irrespective of the quantities measured in deposit gauges.
The average life of a smoke particle before deposition on land is probably of the order of 1–2 days; that of a molecule of sulphur dioxide is estimated with rather more certainty to be less than 12 hours.
Of the chlorides collected in deposit gauges more than half, as a rule, come from the sea, and less than half from the utilization of coal; but the ratio must vary with the position of the deposit gauge relative to the sea and to industries.
75 citations
Authors
Showing all 7655 results
Name | H-index | Papers | Citations |
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Rajesh Kumar | 149 | 4439 | 140830 |
Akhilesh Pandey | 100 | 529 | 53741 |
A. S. Bell | 90 | 305 | 61177 |
David R. Clarke | 90 | 553 | 36039 |
Praveen Kumar | 88 | 1339 | 35718 |
Richard C. Thompson | 87 | 380 | 45702 |
Xin-She Yang | 85 | 444 | 61136 |
Andrew J. Pollard | 79 | 673 | 26295 |
Krishnendu Chakrabarty | 79 | 996 | 27583 |
Vinod Kumar | 77 | 815 | 26882 |
Bansi D. Malhotra | 75 | 375 | 19419 |
Matthew Hall | 75 | 827 | 24352 |
Sanjay K. Srivastava | 73 | 366 | 15587 |
Michael Jones | 72 | 331 | 18889 |
Sanjay Singh | 71 | 1133 | 22099 |