Optically sliced measurement of velocity and pH distribution in microchannel

2007 ◽  
Vol 43 (2-3) ◽  
pp. 425-435 ◽  
Author(s):  
Mitsuhisa Ichiyanagi ◽  
Yohei Sato ◽  
Koichi Hishida
Keyword(s):  
2017 ◽  
Vol 78 ◽  
pp. 60-63 ◽  
Author(s):  
J.A. Ramírez-Cano ◽  
L. Veleva ◽  
R.M. Souto ◽  
B.M. Fernández-Pérez

2017 ◽  
Vol 9 (2) ◽  
pp. 74-79 ◽  
Author(s):  
Jin Xiao ◽  
Anderson T Hara ◽  
Dongyeop Kim ◽  
Domenick T Zero ◽  
Hyun Koo ◽  
...  

2005 ◽  
Vol 48 (1) ◽  
pp. 279-285 ◽  
Author(s):  
S. Liu ◽  
V. M. Puri

2014 ◽  
Vol 11 (1) ◽  
pp. 943-974 ◽  
Author(s):  
V. M. C. Rérolle ◽  
M. Ribas-Ribas ◽  
V. Kitidis ◽  
I. Brown ◽  
D. C. E. Bakker ◽  
...  

Abstract. We present here a high resolution surface water pH dataset obtained in the Northwest European shelf seas in summer 2011. This is the first time that pH has been measured at such a high spatial resolution (10 measurements h–1) in this region. The aim of our paper is to investigate the carbonate chemistry dynamics of the surface water using pH and ancillary data. The main processes controlling the pH distribution along the ship's transect, and their relative importance, were determined using a statistical approach. The study highlights the impact of biological activity, temperature and riverine inputs on the carbonate chemistry dynamics of the shelf seas surface water. For this summer cruise, the biological activity formed the main control of the pH distribution along the cruise transect. Variations in chlorophyll and nutrients explained 29% of the pH variance along the full transect and as much as 68% in the northern part of the transect. In contrast, the temperature distribution explained ca. 50% of the pH variation in the Skagerrak region. Riverine inputs were evidenced by high dissolved organic carbon (DOC) levels in the Strait of Moyle (northern Irish Sea) and the southern North Sea with consequent remineralisation processes and a reduction in pH. The DOC distribution described 15% of the pH variance along the full transect. This study highlights the high spatial variability of the surface water pH in shelf seawaters where a range of processes simultaneously impacts the carbonate chemistry.


1994 ◽  
Vol 266 (2) ◽  
pp. R638-R645 ◽  
Author(s):  
R. A. Graham ◽  
A. H. Taylor ◽  
T. R. Brown

The true distribution of the pH in tissues can be determined from the in vivo 31P-nuclear magnetic resonance (NMR) spectrum by converting the parts per million (PPM) axis of the pH responsive resonance to pH using the Henderson-Hasselbalch equation. In addition, the intensity axis of the resonance must be divided by the derivative of the Henderson-Hasselbalch equation to correct for the nonlinear relationship between pH and PPM. This nonlinear relationship causes the apparent center of the resonance in PPM to be dependent not only on the center of the pH distribution but also on its width and distance from the pKa, where Ka is the association constant. Therefore, the pH determined from uncorrected spectra may be in significant error, particularly if the pH distribution is distant from the pKa and is broad. The method was applied to the isolated perfused Morris hepatoma 5123C to determine the distribution of intracellular pH (pHi) using resonances from two intracellular compounds. The two resonances did not report the same pHi unless the spectral data were properly corrected. The method should be of interest to anyone interested in pHi.


Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1724
Author(s):  
Yu Matsuda ◽  
Katsunori Sakai ◽  
Hiroki Yamaguchi ◽  
Tomohide Niimi

The electrophoresis of ampholytes such as amino acids on a paper device is difficult because of the variation of pH distribution in time. On the basis of this observation, we propose a paper-based analytical device (PAD) with origami structure. By folding a filter paper, a low operation voltage of 5 V was achieved, where the power was supplied by a 5 V 1.5 A portable power bank through the USB type A receptacle. As a demonstration, we carried out the electrophoretic separation of pI markers (pI 5.5 and 8.7). The separation was achieved within 4 min before the pH distribution on the paper varied. Though the separation distance was small, it could be increased by expanding the origami structure. This result indicates that our proposed PAD is useful for electrophoretic separation on a paper device.


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