Search results
Results from the WOW.Com Content Network
Critical unit stream power is the amount of stream power needed to displace a grain of a specific size, it is given by the equation: ω 0 = τ 0 ν 0 {\displaystyle \omega _{0}=\tau _{0}\nu _{0}} where τ 0 is the critical shear stress of the grain size that will be moved which can be found in the literature or experimentally determined while v ...
The Evans–Polanyi model is a linear energy relationship that serves as an efficient way to calculate activation energy of many reactions within a distinct family. The activation energy may be used to characterize the kinetic rate parameter of a given reaction through application of the Arrhenius equation .
We can consider as an example a positively charged ion, such as K +, and a negatively charged membrane, as it is commonly the case in most organisms. [4] [5] The membrane voltage opposes the flow of the potassium ions out of the cell and the ions can leave the interior of the cell only if they have sufficient thermal energy to overcome the energy barrier produced by the negative membrane ...
The term stream power law describes a semi-empirical family of equations used to predict the rate of erosion of a river into its bed. These combine equations describing conservation of water mass and momentum in streams with relations for channel hydraulic geometry (width-discharge scaling) and basin hydrology (discharge-area scaling) and an assumed dependency of erosion rate on either unit ...
An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H +) across a membrane during cellular respiration or photosynthesis. An ion gradient has potential energy and can be used to power chemical reactions when the ions pass through a channel (red).
In hydrology, discharge is the volumetric flow rate (volume per time, in units of m 3 /h or ft 3 /h) of a stream.It equals the product of average flow velocity (with dimension of length per time, in m/h or ft/h) and the cross-sectional area (in m 2 or ft 2). [1]
A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, [1] which are a type of calcium channel regulated by changes in membrane potential. Some calcium channels are regulated by the binding of a ligand.
Voltage-gated ion channel. When the membrane is polarized, the voltage sensing domain of the channel shifts, opening the channel to ion flow (ions represented by yellow circles). Voltage-gated ion channels open and close in response to the electrical potential across the cell membrane. Portions of the channel domain act as voltage sensors.