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Plant stress research looks at the response of plants to limitations and excesses of the main abiotic factors (light, temperature, water and nutrients), and of other stress factors that are important in particular situations (e.g. pests, pathogens, or pollutants). Plant stress measurement usually focuses on taking measurements from living plants.
The CO 2 compensation point (Γ) is the CO 2 concentration at which the rate of photosynthesis exactly matches the rate of respiration. There is a significant difference in Γ between C 3 plants and C 4 plants: on land, the typical value for Γ in a C 3 plant ranges from 40–100 μmol/mol, while in C 4 plants the values are lower at 3–10 μmol/mol. Plants with a weaker CCM, such as C2 ...
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
A leaf area index (LAI) expresses the leaf area per unit ground or trunk surface area of a plant and is commonly used as an indicator of the growth rate of a plant. LAI is a complex variable that relates not only to the size of the canopy, but also to its density, and the angle at which leaves are oriented in relation to one another and to ...
The biochemical characteristics of phytoplankton are similar to C3 plants, whereas the gas exchange characteristics more closely resemble the C4 strategy. [37] More specifically, phytoplankton improve the efficiency of their primary carbon-fixing enzyme, RuBisCO, with carbon concentrating mechanisms (CCM), just as C4 plants accumulate CO 2 in ...
Accidental release source terms are the mathematical equations that quantify the flow rate at which accidental releases of liquid or gaseous pollutants into the ambient environment which can occur at industrial facilities such as petroleum refineries, petrochemical plants, natural gas processing plants, oil and gas transportation pipelines, chemical plants, and many other industrial activities.
The respiratory exchange ratio (RER) is the ratio between the metabolic production of carbon dioxide (CO 2) and the uptake of oxygen (O 2). [3] [4] The ratio is determined by comparing exhaled gases to room air. Measuring this ratio is equal to RQ only at rest or during mild to moderate aerobic exercise without the accumulation of lactate.
Here, represents the mass ratio of gas 'x' (meaning mass of gas 'x' relative to the mass of all other non-'x' gas mass) and is the partial pressure of gas 'x'. Using the ideal gas formulation for the mass ratio gives the following definition for the specific mass capacity: