Question: What is the process that involves energy flow in cells?
About the article "Biology", section "Cell theory".

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Different classes of flow cells (batteries) have been developed, including redox, hybrid and membraneless.
The fundamental difference between conventional batteries and flow cells is that energy is stored as the electrode material in conventional batteries but as the electrolyte in flow cells. 
Active transport is the movement of all types of molecules across a cell membrane.
The movement of these molecules occurs against their concentration gradient, going from a low to high concentration.
In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids.
If the process uses chemical energy, such as from adenosine triphosphate (ATP), it is termed primary active transport.
Secondary active transport involves the use of an electrochemical gradient.
Active transport uses cellular energy, unlike passive transport, which does not use cellular energy.
Active transport is a good example of a process for which cells require energy.
Examples of active transport include the uptake of glucose in the intestines in humans and the uptake of mineral ions into root hair cells of plants.  
Run by Société Générale, the Index tracks the 20 largest stocks involved in: Renewable energy (solar, wind and biomass).
Energy efficiency (better use of energy generation, which involves industries such as energy meters and superconductors).
and Decentralized energy supply (power generation in close proximity to the consumer, involving micro-turbines and fuel cells).
WAEX is an equally weighted benchmark, that is the weight of each member is set at 5% on quarterly basis. 
Cell migration during embryonic development allows for the establishment of body axes, tissue formation, limb induction, and several other processes.
Wnt signaling helps mediate this process, particularly during convergent extension.
Research has shown that signaling from both the Wnt PCP pathway and canonical Wnt pathway is required for proper convergent extension during gastrulation.
Convergent extension is further regulated by the Wnt/calcium pathway, which blocks convergent extension when activated.
Wnt signaling also induces cell migration in later stages of development through the control of the migration behavior of neuroblasts, neural crest cells, myocytes, and tracheal cells.
Wnt signaling is also involved in another key migration process known as the epithelial-mesenchymal transition (EMT).
This process is what allows epithelial cells to transform into mesenchymal cells so that they are no longer held in place at the laminin.
It involves a down-regulation of cadherins so that cells can detach from laminin and migrate.
Wnt signaling is an inducer of EMT, particularly in mammary development. 
Flow assurance is a relatively new term in oil and gas industry.
It refers to ensuring successful and economical flow of hydrocarbon stream from reservoir to the point of sale.
The term was coined by Petrobras in the early 1990s in Portuguese as "Garantia do Escoamento" (:pt::Garantia do Escoamento), meaning literally “Guarantee of Flow”, or Flow Assurance.
Flow assurance is extremely diverse, encompassing many discrete and specialized subjects and bridging across the full gamut of engineering disciplines.
Besides network modeling and transient multiphase simulation, flow assurance involves effectively handling many solid deposits, such as, gas hydrates, asphaltene, wax, scale, and naphthenates.
Flow assurance is the most critical task during deep water energy production because of the high pressures and low temperature (~4 degree Celsius) involved.
The financial loss from production interruption or asset damage due to flow assurance mishap can be astronomical.
What compounds the flow assurance task even further is that "these solid deposits can interact with each other" and can cause catastrophic blockage formation in pipelines and result in flow assurance failure.
Flow assurance includes thermal investigation of pipelines, making sure the temperature is above the hydrate's formation temperature.
Another important aspect of flow assurance is evaluation of erosion due to sand and corrosion in pipelines and equipment.