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 viscous heating artefact has been characterized by comparison with novel thin-film thermocouples at 1-2 cm focal depths in fresh degassed ex vivo bovine liver and was found to be intensity independent up to 600 W cm(-2) (below the threshold for cavitation and lesion formation) and remained significant at radial distances out to the first side lobe in the focal plane.
Abstract: Accurate temperature measurements in therapeutic ultrasound fields are necessary for understanding damage mechanisms, verification of thermal modelling and calibration of non-invasive clinical thermometry. However, artefactual heating, primarily due to viscous forces which result from motion relative to the surrounding tissue, occurs when metal thermocouples are used in an ultrasound field. The magnitude and time dependence of this artefact has been characterized by comparison with novel thin-film thermocouples (TFTs) at 1-2 cm focal depths in fresh degassed ex vivo bovine liver. High-intensity focused ultrasound exposures (1.7 MHz; free-field spatial-peak temporal-average intensities 40-600 W cm(-2)) were used. Subtraction of the TFT data from that obtained for other thermocouples yielded the time dependence of the viscous heating artefact. This was found to be intensity independent up to 600 W cm(-2) (below the threshold for cavitation and lesion formation) and remained significant at radial distances out to the first side lobe in the focal plane. The contribution of viscous heating to cooling was also found to be significant for at least 5 s after the end of insonation. The ratio of viscous artefact to absorptive heating after 5 s was: 1.76 +/- 0.07 for a fine-wire, 0.45 +/- 0.07 and 1.93 +/- 0.07 for two different sheathed-wires and 0.24 +/- 0.07 for a needle thermocouple.
108 citations
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TL;DR: A monolithic, fixed-barrier single-electron pump made entirely from graphene that performs at frequencies up to several gigahertz is presented, bringing an all-graphene closure of the quantum metrological triangle within reach.
Abstract: A single electron pump made entirely from graphene that performs at frequencies up to several gigahertz is now realized
108 citations
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TL;DR: It is shown that thicknesses derived from XPS data linearly correlated with spectroscopic ellipsometry data on the same samples with a scatter of 10%.
Abstract: Protein adsorption at solid surfaces is central to many phenomena of medical and technological interest. The determination of the amount of protein attached to the surface is a critical measurement performed by using a wide range of methods. X-ray photoelectron spectroscopy (XPS) is able to provide a straightforward quantitative analysis of the amount of protein adsorbed as an overlayer on a material surface. While XPS is commonly employed to assess qualitatively the amount of adsorbed protein, this is usually expressed in terms of the elemental fraction (or at. %) of nitrogen calculated using an assumption of depth homogeneity despite the fact that this does not linearly scale with the amount of protein. In this paper, we have shown that thicknesses derived from XPS data linearly correlated with spectroscopic ellipsometry data on the same samples with a scatter of 10%. A straightforward equation to convert the concentration of nitrogen from XPS into an equivalent thickness of a protein film is presented....
108 citations
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TL;DR: In this article, specific volumes of a series of anionic polystyrenes (M = 2000 to 2 000 000) have been measured dilatometrically over the temperature range −30° to 210°C.
108 citations
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TL;DR: In this paper, a new primary CMM with a target uncertainty of 300 nm (k = 1.96) within a cubic working volume of side 600 mm has been developed to address the industrial requirement for the calibration of 2D and 3D objects.
108 citations
Authors
Showing all 7655 results
Name | H-index | Papers | Citations |
---|---|---|---|
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 |