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
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TL;DR: In this article, the Boltzmann constant kB was derived from measurements of the speed of sound in argon gas which can be related directly to the mean molecular kinetic energy.
Abstract: The Comite international des poids et mesures (CIPM) has projected a major revision of the International System of Units (SI) in which all of the base units will be defined by fixing the values of fundamental constants of nature. In preparation for this we have carried out a new, low-uncertainty determination of the Boltzmann constant, kB, in terms of which the SI unit of temperature, the kelvin, can be re-defined. We have evaluated kB from exceptionally accurate measurements of the speed of sound in argon gas which can be related directly to the mean molecular kinetic energy, . Our new estimate is kB = 1.380 651 56 (98) × 10−23 J K−1 with a relative standard uncertainty uR = 0.71 × 10−6.
92 citations
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TL;DR: A comprehensive review is offered to describe the physical and chemical characteristics of microplastics and nanoplastics in relation to their fate, microbial ecology, transport, and ecotoxic behavior.
92 citations
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TL;DR: In this paper, an extensive experimental test on nickel and aluminium has been made of the Bailey-Orowan equation, where the agreement is within a factor of 2, provided that h is measured on creep tested specimens and not on annealed ones; this proviso arises because, as the experiments showed, h increases several times during primary creep, and most of the stress-sensitivity of creep rate is therefore due to the stress sensitivity of recovery rate.
Abstract: An extensive experimental test on nickel and aluminium has been made of the Bailey-Orowan equation $\dot \epsilon$ = r/h, where $\epsilon$ is the steady state creep rate, r is the rate of recovery, and h is the strain hardening coefficient; $\dot \epsilon$ and r were measured, and the value of h calculated from this equation was compared with that measured in a room temperature tensile test; the agreement is within a factor of 2, provided that h is measured on creep tested specimens and not on annealed ones. This proviso arises because, as the experiments showed, h increases several times during primary creep. The experiments also showed that if the stress dependencies are expressed as (stress)$^n$ then for creep rate n is 4$\frac{1}{2}$, for recovery rate 3 to 3$\frac{1}{2}$ and for 1/h 1 to 1$\frac{1}{2}$. Most of the stress-sensitivity of creep rate is therefore due to the stress-sensitivity of recovery rate and is understandable, since dislocation network theory predicts r $\propto$ (stress)$^3$.
92 citations
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TL;DR: In this paper, a generalised model of creep deformation in cubic single crystals is developed that considers the combined effects of viscous glide on two (or more) slip systems and accounts for tertiary creep by the accumulation of mobile dislocations with plastic strain.
Abstract: A generalised model of creep deformation in cubic single crystals is developed that considers the combined effects of viscous glide on two (or more) slip systems and accounts for tertiary creep by the accumulation of mobile dislocations with plastic strain. The model is applied to analyse a database of creep curves for the nickel-base single crystal superalloy SRR99 with the assumption that creep deformation occurs by glide on both the {111}〈 1 01〉 and {001}〈110〉 systems. A procedure for the calculation of creep curves and associated crystal rotations for arbitrary crystal orientations is described. The model predicts changes in the anisotropy of creep behaviour with stress and temperature that is in general agreement with the limited available experimental data. It also includes the contributions of all possible slip vectors to predict crystal rotations that are consistent with observations.
92 citations
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TL;DR: Temperature plays a crucial role in controlling the magnetism as well as the defects in graphene and at 600 °C the self-repair mechanism helps the defects to mend but resulting in the decrement of magnetization and providing a good quality graphene with less defects.
Abstract: The existence of ferromagnetism in the wonder material graphene has opened up the path for many future spintronics and memory applications. But simultaneously it is very important to understand the variation of these properties with temperature in regards to the device applications. Here we observed defect induced ferromagnetism in chemically reduced graphene and the effect of temperature on it. Several theoretical studies have proved that the main cause of ferromagnetism in graphene is due to various defects. The observed results established that these defects can be mended by treating the samples at elevated temperatures but sacrificing the ferromagnetism simultaneously. Hence, temperature plays a crucial role in controlling the magnetism as well as the defects in graphene. In this study we revealed that at 600 °C the self-repair mechanism helps the defects to mend but resulting in the decrement of magnetization and providing a good quality graphene with less defects.
92 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 |