Microbial Brazil nut effect
Microbial Brazil nut effect
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微生物巴西坚果效应
DOI：
10.1039/d1sm01327k
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Ishikawa Takuji
中科院分区：
文献类型：
--
作者：
Srivastava Atul;Kikuchi Kenji;Ishikawa Takuji
巴西坚果效应 (BNE) 是一种在振动颗粒介质 (GM) 内分离大型物体的反直觉过程，通过使 GM 经受各种剪切和振动，已对该效应进行了广泛研究。在本文中，我们报告了一种新型 BNE，它是由微生物产生的气泡引起的颗粒波动引起的。我们称之为“微生物巴西坚果效应”。该论文展示了微生物 BNE 用于双分散颗粒混合物以及入侵者隔离。此外，该论文利用 X 射线 μCT 和分离速度的简单缩放参数，阐明了气泡颗粒床内入侵者的传输机制。我们认为所报道的现象应该普遍存在于微生物密集的水体潮湿沙质地面中，并且可能对地面附近物质的分布有一定的影响。
The Brazil nut effect (BNE) is a counter-intuitive process of segregation of a large object inside a vibrated granular medium (GM), which has been studied widely by subjecting GMs to various kinds of shears and vibrations. In this article, we report a new kind of BNE which occurs as a consequence of granular fluctuations induced by microbe-generated gas bubbles. We call it the ‘microbial Brazil nut effect’. The paper demonstrates microbial BNE for a bidisperse granular mixture as well as for intruder segregation. Furthermore, using X-ray μCT and a simple scaling argument for segregation velocity, the paper clarifies the transport mechanics of an intruder inside a bubbly granular bed. We think the reported phenomenon should be ubiquitous in the microbe-populated wet sandy floors of waterbodies and may have some implication on the distribution of material near the floors.