Measurements of ultrafine bubbles using different types of particle size measuring instruments

Kobayashi, Hideaki; Maeda, Shuhei; Kashiwa, Masakazu; Fujita, Toshihiro

doi:10.1117/12.2064638

Cited by 27 publications

(16 citation statements)

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“…However, accurate prediction of bubble diameters in oceans has been a challenge for the available light-scattering models. More recently, several techniques have been developed to measure or predict the bubble size distribution in water, for example, laser diffraction scattering (LD) [27], static and dynamic light scattering (SLS, DLS), particle tracking analysis (PTA) [28], acoustic sensors [29], video imaging [30], and remote sensing techniques [31]. An inversion method was also developed based on the Critical Angle Refractometry and Sizing technique (CARS) [20], [32]- [33] for the characterization of bubbly flows (size distribution and refractive index of bubbly flow).…”

Section: Introductionmentioning

confidence: 99%

Inversion of Volume Scattering Function for Estimation of Bubble Size Distribution in Ocean Waters

2021

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Angular distribution of the intensity of light scattered by a spherical air bubble in the oceanic medium is distinctive near the critical scattering angle region, when light interacts with a bubble with a refractive index less than its surrounding medium. This study is aimed at presenting theoretical and experimental results for the volume scattering function (VSF) of the bubbles generated under oceanic and laboratory conditions. The effect of bubbles on the VSFs was investigated using Mie calculations for the bubble sizes ranging from 5 to 200 µm and their size distribution slopes ranging from 3.6 to 4.6. Findings revealed that the critical angle scattering patterns (50 0 -80 0 ) produced by bubbles become well-pronounced, enhanced and dependent on the minimum and maximum bubble sizes and their size distribution slopes (rmin, rmax and α). A relationship of the volume scattering phase function (̃( , )) between an inverse power-law and a normally-distributed bubble population was established based on experimental data. Both experimental results and Mie simulations showed that the angular position of the first critical dark fringe (θ1) shifts in the direction of the critical angle as the minimum and mean values of the bubble size increase in accordance with the power law and normally-distributed bubble populations. The new inversion method predicted the light scattering patterns produced by bubbles near the critical angle region in close agreement with results from Mie theory simulations. The inversion method for estimating the bubble size distribution based on the measured VSF data have significant implications for underwater optical communication, imaging and ocean colour remote sensing studies.

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Section: Introductionmentioning

confidence: 99%

Inversion of Volume Scattering Function for Estimation of Bubble Size Distribution in Ocean Waters

2021

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“…The mean sizes measured with these three techniques show that the result from NTA is significantly different from RMM and DLS (Figure 2a). The smaller size obtained from NTA is most likely because of its lower limit of detection (10 nm) compared to RMM, but, unlike the RMM and DLS, it can only measure up to 1 µm [31]. RMM has the advantage of being able to distinguish between bubbles and non-buoyant particles, from which no other instrument is capable of.…”

Section: Resultsmentioning

confidence: 99%

“…The volume is typically calculated based on microbubble size and concentration measurements from the Coulter counter (Beckman Coulter, Indianapolis, IN, USA) [27,30]. Most Coulter counter instruments used have a limit of detection of 600 nm (with the lowest at 200 nm) [31,32] and suffer from documented coincidence errors, which may reduce the accuracy of the measurement, especially for polydisperse bubble populations. For sub-micron bubbles, the size may be measured by dynamic light scattering (DLS), while both size and concentration can be determined by nanoparticle tracking analysis (NTA).…”

Section: Introductionmentioning

confidence: 99%

Theoretical and Experimental Gas Volume Quantification of Micro- and Nanobubble Ultrasound Contrast Agents

et al. 2020

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The amount of gas in ultrasound contrast agents is related to their acoustic activity. Because of this relationship, gas volume has been used as a key variable in normalizing the in vitro and in vivo acoustic behavior of lipid shell-stabilized bubbles with different sizes and shell components. Despite its importance, bubble gas volume has typically only been theoretically calculated based on bubble size and concentration that is typically measured using the Coulter counter for microbubbles and nanoparticle tracking analysis (NTA) for nanoscale bubbles. However, while these methods have been validated for the analysis of liquid or solid particles, their application in bubble analysis has not been rigorously studied. We have previously shown that resonant mass measurement (RMM) may be a better-suited technique for sub-micron bubble analysis, as it can measure both buoyant and non-buoyant particle size and concentration. Here, we provide validation of RMM bubble analysis by using headspace gas chromatography/mass spectrometry (GC/MS) to experimentally measure the gas volume of the bubble samples. This measurement was then used as ground truth to test the accuracy of theoretical gas volume predictions based on RMM, NTA (for nanobubbles), and Coulter counter (for microbubbles) measurements. The results show that the headspace GC/MS gas volume measurements agreed well with the theoretical predictions for the RMM of nanobubbles but not NTA. For nanobubbles, the theoretical gas volume using RMM was 10% lower than the experimental GC/MS measurements; meanwhile, using NTA resulted in an 82% lower predicted gas volume. For microbubbles, the experimental gas volume from the GC/MS measurements was 27% lower compared to RMM and 72% less compared to the Coulter counter results. This study demonstrates that the gas volume of nanobubbles and microbubbles can be reliably measured using headspace GC/MS to validate bubble size measurement techniques. We also conclude that the accuracy of theoretical predictions is highly dependent on proper size and concentration measurements.

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“…Thus, the UFBW appears transparent. Moreover, it has been confirmed that the bubbles remain in the liquid for an extremely long time and carry an electrical charge 27,28) . In our previous in vitro study 29) , we used MBW to clean orthodontic appliances, including a multi-bracket appliance.…”

Section: Introductionmentioning

confidence: 92%

Plaque-removal effect of ultrafine bubble water: Oral application in patients undergoing orthodontic treatment

et al. 2021

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During orthodontic treatment, plaque tends to form around fixed orthodontic appliances, which increases the risk of dental caries. It has been reported that ultarafine bubble with a diameter <1 μm water (UFBW) effectively removes organic matter. In addition, UFBW is harmless and stable for at least one month with refrigeration. The aim of this study was to examine the plaque-removal effect of ultrafine bubble water (UFBW) to establish a new method to prevent dental caries in patients during orthodontic treatment procedures. The in vitro study examined different concentrations of UFBW and compared the cleaning effect to that of existing mouthwashes. High-concentration UFBW (HUFBW) was most effective in cleaning. In the subsequent clinical study, HUFBW showed a significantly higher plaque-removal effect compared to distilled water (p<0.01). Thus, supplementary use of HUFBW could decrease the incidence of dental caries during orthodontic treatment.

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Measurements of ultrafine bubbles using different types of particle size measuring instruments

Cited by 27 publications

References 0 publications

Inversion of Volume Scattering Function for Estimation of Bubble Size Distribution in Ocean Waters

Inversion of Volume Scattering Function for Estimation of Bubble Size Distribution in Ocean Waters

Theoretical and Experimental Gas Volume Quantification of Micro- and Nanobubble Ultrasound Contrast Agents

Plaque-removal effect of ultrafine bubble water: Oral application in patients undergoing orthodontic treatment

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