表面張力: フローターが静止波で集結する.
G Falkovich1, A Weinberg, P Denissenko
1Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
Nature
|June 24, 2005
まとめ
小さな浮遊粒子は,表面張力によって駆動される,その表面特性に基づいて,静止波に集中する. この現象は,粒子の分布と分離技術の潜在的な応用に関する洞察を提供します.
科学分野:
- 流体力学 流体力学
- 表面科学とは,地表科学のことである.
- 物理化学 物理化学とは
背景:
- 水中の環境における粒子の分布を理解することは極めて重要です.
- アーキメデスの浮力法則は,浮遊物体を典型的に支配する.
- 以前の研究では,粒子による波の集まりが完全に説明できませんでした.
研究 の 目的:
- 静止波が小さな浮遊粒子の分布にどのように影響するか調査する.
- この分布における粒子の表面特性 (水性/水害性) の役割を決定する.
- 波誘発粒子クラスタリングの潜在的応用を探求する.
主な方法:
- 水タンク内の静止波を使った実験装置.
- 視覚追跡を用いた粒子の振る舞いの観察.
- 波のノードと反ノードに関連した粒子の濃度パターンの分析.
主要な成果:
- 水性粒子と水性粒子は,静止波の中で異なる濃度パターンを示した.
- 表面の浸透性に応じて,波のノードまたは反ノードに蓄積された粒子.
- 観測された効果は,表面張力グラデーションに起因し,従来の浮力原理を覆した.
結論:
- 静止波は,表面特性に基づいて選択的粒子の集積を誘導することができます.
- 表面張力は粒子の分布において重要な役割を果たし,単純な浮力モデルに挑戦します.
- この波動による粒子のクラスタリングは,環境科学と粒子の分離技術に影響を及ぼします.
関連する概念動画
02:57Surface Tension, Capillary Action, and Viscosity
28.6K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.6K
01:17Standing Waves
4.3K
Sometimes waves do not seem to move; rather, they just vibrate in place. Unmoving waves can be seen on the surface of a glass of milk kept in a refrigerator, which is one example of standing waves. Vibrations from the refrigerator motor create waves on the milk that oscillate up and down but do not seem to move across the surface. These waves are formed or created by the superposition of two or more identical moving waves in opposite directions. The waves move through each other, with their...
4.3K
01:16Surface Tension and Surface Energy
3.2K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
3.2K
01:04Modes of Standing Waves: II
1.8K
The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions are derived from the physical understanding of how the standing waves are sustained, that is, how the vibrating particles of the medium behave at the boundaries imposed on them.
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
1.8K
01:22Surface Tension of Fluid
1.9K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
1.9K
01:11Buoyancy and Stability for Submerged and Floating Bodies
3.6K
In fluid mechanics, buoyancy and stability are key concepts for understanding the behavior of submerged and floating bodies. When a stationary body is fully or partially submerged in a fluid, the fluid exerts a force on the body known as the buoyant force. This force acts vertically upward through a point called the center of buoyancy, which is the center of the displaced fluid volume. According to Archimedes' principle, the magnitude of the buoyant force is equal to the weight of the fluid...
3.6K