Announcing the 2011Measurement Science and TechnologyOutstanding Paper Awards (2012)

Since 1991, Measurement Science and Technology has awarded a Best Paper prize. The Editorial Board of this journal believe that such a prize is an opportunity to thank authors for submitting their work, and serves as an integral part of the on-going quality review of the journal. The current breadth of topical areas that are covered by MST has made it advisable to expand the recognition of excellent publications. Hence, since 2005 the Editorial Board have presented 'Outstanding Paper Awards'. This year awards were presented in the areas of 'Measurement Science', 'Fluid Mechanics' and 'Precision Measurement'. Although the categories mirror subject sections in the journal, the Editorial Board consider articles from all categories in the selection process. 2011 Award Winners—Measurement Science Simultaneous measurement of internal and surrounding flows of a moving droplet using multicolour confocal micro-particle image velocimetry (micro-PIV) M Oishi, H Kinoshita, T Fujii and M Oshima Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo 153-8505, Japan Interfaculty Initiative in Information Studies, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo 153-8505, Japan Whilst the award last year [1] was concerned with the application of microscopy to ultra-high vacuum dynamic force measurements, this year's award [2] goes to another micro-measurement technique, one concerned with measurements related to particle image velocimetry. The technique relates to multiphase flow in microfluidic devices, and offers a non-contact methodology for examining simultaneous dynamic interactions between flows having different phases. There are several features which make this an excellent paper. It introduces its subject with a clear and concise description of previous advances in related measurement methods, before introducing the additional feature of two-colour fluorescent monitoring of flow in two independent optical channels. By adapting a conventional confocal microscope for PIV measurements, the authors describe how to measure multiphase flow having separate phases in a simultaneous way, exploiting fluorescent markers with wavelength separation. The measurement technique required the integration of several optical systems, including two different laser excitation sources. The novelty of the paper resides with the multicolour separation unit and its optical design, with two synchronized camera systems. Alignment and setting of optical components are crucial for efficient monitoring of light from the conjugate focus. All these experimental features are described in detail and with clarity. The technique gives a measurement methodology for velocity measurements in the x–y plane, in a two-phase medium. Additionally, the out-of-plane, z, component of velocity has been estimated analytically using three-dimensional two-component measured velocity data and the continuity equation. This computational method was exploited with experimental data in a post-processing operation to derive full three-dimensional velocity distributions. Examples are then provided of the behaviour of droplets with surrounding flow. Image sizes are typically 800 × 600 pixels with resolution in the x–y plane of 0.284 µm/pixel. For examples discussed within the paper, the recording frame rate was 990 fps with an exposure time of about 1 ms for high quality PIV images. The results section is detailed and convincing, before the paper reaches a set of concise conclusions. There is also a useful list of 22 references at the end of the paper. The paper was rated as excellent by one of the referees in the initial refereeing process, and since publication it has attracted a high number of downloads. It is bound to make an impact within the PIV community. Readers may also like to know that the authors have since published a related paper [3] which uses this technique to measure the microscopic interaction between red blood cells (RBCs) and surrounding flow. 2011 Award Winners—Fluid Mechanics Acoustic tomographic imaging of temperature and flow fields in air Manuela Barth and Armin Raabe University of Leipzig, Institute for Meteorology, Stephanstrase 3, 04103 Leipzig, Germany This paper [4] provides a valuable measurement strategy for volumetric measurements of the velocity and temperature fields in an airflow over large fields. Given that the speed of sound in the medium is influenced by humidity, the recovered temperature is termed 'acoustic virtual temperature' (Tav). The method is demonstrated for a volume of order 1 m3. It can, in principle, be scaled to a much larger domain. The inferred quantities, T(x, y, z, t) and (x, y, z, t), are not intended to replace discrete point measurements (which can be obtained with substantially greater accuracy albeit with intrusive probes or added scattering particles). Rather, the time-resolved measurements will likely be very valuable for HVAC or micro-meteorological, etc measurements. The supporting theory and the respective literature base are succinctly presented. The experimental strategy, in which pairs of counter-propagating acoustic emitters/receivers criss-cross the measurement domain, is supported by the authors' form of an algebraic tomographic reconstruction technique. The demonstration experiment and representative results are clearly presented. The selection committee anticipates a positive response by those investigators whose application problem is compatible with the capabilities offered by this paper. 2011 Award Winner—Precision Measurement Diameter measurements of polystyrene particles with atomic force microscopy J Garnaes Danish Fundamental Metrology, Matematiktorvet 307, DK-2800 Kgs. Lyngby, Denmark This paper [5] describes a geometric diameter measurement of polystyrene spheres with nominal diameters of about 100 nm using atomic force microscopy (AFM). Although electron microscopy has conventionally been used for small diameter measurements, the method can only be used in vacuum, leading to significant changes in deformation as no meniscus of water is formed on the surface of the spheres placed in a vacuum. In this work, AFM is used for the height and distance measurements of the spheres placed on a mica substrate, allowing the measurement in air. Uncertainties in the diameter measurements have been evaluated in detail by taking into account influences of the deformations due to the AFM tip, substrate, surface tension effect of a thin water layer, interaction between the two spheres, and so on. The influence of air gaps introduced by imperfect packing of the spheres has also been evaluated quantitatively from the distribution of the measured diameters. Finally the geometric diameter of the polystyrene spheres has been determined with an uncertainty of 3 nm from the height and packing distance measurements. This paper has been downloaded more than 300 times since its publication. The selection committee members on the Precision Measurement Award, Dr K Fujii, Dr A Yacoot, Dr P Williams, Dr H Bosse, Professor X Chen and Dr T Eom, selected this paper from a strongly competitive list of ten candidates for its sophisticated idea and detailed evaluation of uncertainty in measurement. Considering its impact on accurate evaluation of particles using AFM, the paper was selected as the winner of the MST Precision Measurement Award for 2011. The chairmen would like to thank the authors for choosing to publish their work in Measurement Science and Technology, and hope that other researchers enjoy reading these works and feel encouraged to submit their own best work to the journal. References [1] Lubbe J, Troger L, Torbrugge S, Bechstein R, Richter C, Kuhnle A and Reichling M 2010 Achieving high effective Q-factors in ultra-high vacuum dynamic force microscopy Meas. Sci. Technol. 21 125501 (9pp) [2] Oishi M, Kinoshita H, Fujii T and Oshima M 2011 Simultaneous measurement of internal and surrounding flows of a moving droplet using multicolour confocal micro-particle image velocimetry (micro-PIV) Meas. Sci. Technol. 22 105401 (13pp) [3] Oishi M, Utsubo K, Kinoshita H, Fujii T and Oshima M 2012 Continuous and simultaneous measurement of the tank-treading motion of red blood cells and the surrounding flow using translational confocal micro-particle image velocimetry (micro-PIV) with sub-micron resolution Meas. Sci. Technol. 23 035301 (18pp) [4] Barth M and Raabe A 2011 Acoustic tomographic imaging of temperature and flow fields in air Meas. Sci. Technol. 22 035102 (13pp) [5] Garnaes J 2011 Diameter measurements of polystyrene particles with atomic force microscopy Meas. Sci. Technol. 22 094001 (8pp)