Flow visualization and PIV measurement of a water exchange process in a biosensor container

2004 ◽  
Vol 24 (Supplement1) ◽  
pp. 331-332
Author(s):  
Takashi MIKAMI ◽  
Masaru ISHIZUKA ◽  
Shinji NAKAGAWA ◽  
Koichiro KAWANO ◽  
Yoshio ISHIMORI ◽  
...  
2005 ◽  
Vol 2005.42 (0) ◽  
pp. 383-384
Author(s):  
Takashi MIKAMI ◽  
Masaru ISHIZUKA ◽  
Shinji NAKAGAWA ◽  
Koichiro KAWANO ◽  
Yoshio ISHIMORI ◽  
...  

2011 ◽  
Vol 8 (3) ◽  
pp. 5537-5562 ◽  
Author(s):  
Z. Xie ◽  
B. P. Koch ◽  
A. Möller ◽  
R. Sturm ◽  
R. Ebinghaus

Abstract. Hexachlorocyclohexanes (HCHs) are ubiquitous organic pollutants derived from pesticide application. They are subject to long-range transport, persistent in the environment, and capable of accumulation in biota. Shipboard measurements of HCH isomers (α-, γ- and β-HCH) in surface seawater and boundary layer atmospheric samples were conducted in the Atlantic and the Southern Ocean in October to December of 2008. ΣHCHs concentrations (the sum of α-, γ- and β-HCH) in the lower atmosphere ranged from 11.8 to 36.9 pg m−3 (mean: 26.6 ± 11.0 pg m−3) in the Northern Hemisphere (NH), and from 1.5 to 4.0 pg m−3 (mean: 2.8 ± 1.1 pg m−3) in the Southern Hemisphere (SH), respectively. Water concentrations were: α-HCH 0.33–46.8 pg l−1, γ-HCH 0.02–33.2 pg l−1 and β-HCH 0.11–2 pg l−1. HCH concentrations decreased from the North Atlantic to the Southern Ocean, indicating historical use of HCHs in the NH. Spatial distribution showed increasing concentrations from the equator towards North and South latitudes illustrating the concept of cold condensation and less interhemispheric mixing process. In comparison to concentrations measured in 1987–1999/2000, gaseous HCHs were slightly lower, while dissolved HCHs decreased by factor of 2–3 orders of magnitude. Air-water exchange gradients suggested net deposition for α-HCH (mean: 3759 pg m−2 day−1) and γ-HCH (mean: 1987 pg m−2 day−1), whereas β-HCH varied between equilibrium (volatilization: <0–12 pg m−2 day−1) and net deposition (range: 6–687 pg m−2 day−1), indicating a multi-hopper transport behavior. Climate change may significantly accelerate the releasing process of "old" HCHs from continental storage (e.g. soil, vegetation and high mountains) and drive long-range transport from sources to deposition in the open oceans. Biological productivities may interfere with the air-water exchange process as well. Consequently, further investigation is necessary to elucidate the long term trends and the biogeochemical turnover of HCHs in the oceanic environment.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Abhijit Banerjee ◽  
Saurav K. Ghosh ◽  
Debopam Das

Flow field of a butterfly mimicking flapping model with plan form of various shapes and butterfly-shaped wings is studied. The nature of the unsteady flow and embedded vortical structures are obtained at chord cross-sectional plane of the scaled wings to understand the dynamics of insect flapping flight. Flow visualization and PIV experiments are carried out for the better understanding of the flow field. The model being studied has a single degree of freedom of flapping. The wing flexibility adds another degree to a certain extent introducing feathering effect in the kinematics. The mechanisms that produce high lift and considerable thrust during the flapping motion are identified. The effect of the Reynolds number on the flapping flight is studied by varying the wing size and the flapping frequency. Force measurements are carried out to study the variations of lift forces in the Reynolds number (Re) range of 3000 to 7000. Force experiments are conducted both at zero and finite forward velocity in a wind tunnel. Flow visualization as well as PIV measurement is conducted only at zero forward velocity in a stagnant water tank and in air, respectively. The aim here is to measure the aerodynamic lift force and visualize the flow field and notice the difference with different Reynolds number (Re), and flapping frequency (f), and advance ratios (J=U∞/2ϕfR).


2020 ◽  
Author(s):  
Yongyong Zhang ◽  
Wenzhi Zhao ◽  
Chun Zhao

&lt;p&gt;Soil water and groundwater convert frequently under cropland in a desert-oasis transition area, Northwest China. Crops variedly utilize soil water and groundwater during different growth periods under the cropland with shallow groundwater. The study of water exchange process under irrigated cropland has important significance for regulating the contradiction between water saving and groundwater recharge in the desert-oasis transition area. Soil moisture and soil matric potential at depths ranging from 0 to 70 cm were measured using HydraProbe II and TEROS-21 soil sensors in maize (Zea mays L.) fields in 2019. Stable isotope (&amp;#948;&lt;sup&gt;2&lt;/sup&gt;H&amp;#12289;&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O) in different water sources (precipitation, irrigation water, soil water, crop stem, and groundwater) was also measured. The results showed that the groundwater depth varied between 0.57-1.07 m during the maize growth periods. The groundwater depth increased in summer due to the influence of pumped well, while the depth decreased in autumn resulting from the irrigation return water. In the maize growing season, soil moisture and water potential at depths from 10 cm to 30 cm responded to three irrigation times, while soil moisture and water potential below the depth of 50 cm were greater and kept a steady state, which were affected by upward capillary rise of groundwater. The relationship of soil water stable isotope values &amp;#8203;&amp;#8203;was &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H=2.45&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O-31.41, which was lower than the slope of the local atmospheric precipitation line due to the evaporation effect. The soil water stable isotope values at depth of 10 cm varied, while the variation of soil water stable isotope values decreased with the increase of soil depth. The soil water stable isotope values at the depths from 70 to 90cm were close to the groundwater isotope values, which were affected by the groundwater. The stable isotope values in crop stem water were relatively scattered, indicating that the maize used multiple water sources and the water use strategy changed during the growth periods.&lt;/p&gt;


2006 ◽  
Vol 2006.2 (0) ◽  
pp. 421-422
Author(s):  
Miho KATO ◽  
Hiroyuki FURUKAWA ◽  
Yorinobu TOYA ◽  
Takasi WATANABE ◽  
Ikuo NAKAMURA

2011 ◽  
Vol 9 (4) ◽  
Author(s):  
Chie Imagawa ◽  
Junichiro Takeuchi ◽  
Toshihiko Kawachi ◽  
Kei Ishida ◽  
Shunsuke Chono ◽  
...  

2016 ◽  
Vol 2016.53 (0) ◽  
pp. _1614-1_-_1614-5_
Author(s):  
Shuuto MATSUMURA ◽  
Yuuta MICHISITA ◽  
Tatsuya YONEMURA ◽  
Fumiya TAKAHASHI ◽  
Katsushi FUJITA ◽  
...  

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