scholarly journals Dimensionless Numbers to Analyze Expansive Growth Processes

Plants ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Joseph Ortega

Cells of algae, fungi, and plants have walls and exhibit expansive growth which can increase their volume by as much as 10,000 times. Expansive growth is central to their morphogenesis, development, and sensory responses to environmental stimuli. Equations describing the biophysical processes of the water uptake rate and the wall deformation rate have been derived, validated, and established. A significant amount of research provides insight into the molecular underpinnings of these processes. What is less well known are the relative magnitudes of these processes and how they compare during expansive growth and with walled cells from other species. Here, dimensionless numbers (Π parameters) are used to determine the magnitudes of the biophysical processes involved in the expansive growth rate of cells from algae (Chara corallina), fungi (Phycomyces blakesleeanus), and plants (Pisum satinis L.). It is found for all three species that the cell’s capability for the water uptake rate is larger than the wall plastic deformation rate and much larger than the wall elastic deformation rate. Also, the wall plastic deformation rates of all three species are of similar magnitude as their expansive growth rate even though the stress relaxation rates of their walls are very different. It is envisioned that dimensionless numbers can assist in determining how these biophysical processes change during development, morphogenesis, sensory responses, environmental stress, climate change, and after genetic modification.

1993 ◽  
Vol 18 ◽  
pp. 208-210
Author(s):  
Hitoshi Shoji ◽  
Atau Mitani ◽  
Kohji Horita ◽  
Chester C. Langway

Continuous crystal-size measurements made on the G6 Antarctic ice core (100m deep) show enhanced growth rates above a depth of 30 m (Zone 1) and in the interval between 70 and 80 m (Zone 2). Crystal growth in Zone 1 most probably takes place by a process of sublimation and condensation. The higher growth rate in Zone 2 is most probably related to the pore close-off transformation process in which a non-uniform strain field is created to form air bubbles by plastic deformation and “cannibalization” of individual ice crystals.


2012 ◽  
Vol 268-270 ◽  
pp. 127-133
Author(s):  
Chen Zheng ◽  
Yan Yan Xu ◽  
Takahiko Kawai ◽  
Shin-ichi Kuroda

In order to improve the properties and the processability of kenaf fiber (KF) / polystyrene (PS) composites, the newly synthesized polymeric silane coupling agent (CA) was utilized and evaluated. KFs were reacted with CA in the melt system and in the solvent system. The composites reinforced by the modified KF showed enhanced mechanical properties compared with those reinforced by the unmodified KF. The effect was especially remarkable when the KF was modified with CA in the solvent system. As the CA content increases, the surface of KF recovered from the composites showed the higher Si / C ratio indicating the good reaction between KF and CA. The modified composites also showed a remarkable reduction in water uptake rate.


2013 ◽  
Vol 12 (4) ◽  
pp. vzj2013.02.0042 ◽  
Author(s):  
Mathieu Javaux ◽  
Valentin Couvreur ◽  
Jan Vanderborght ◽  
Harry Vereecken

1983 ◽  
Vol 32 (1) ◽  
pp. 83-90
Author(s):  
Gilda Schmidt

The phytoplankton Ks anã Vmax as a function of ammonium and nitrate concentrations were determined. The growth rate was estimated from measurements on synthesized chlorophyll-α and the cell number in the. culture media. The uptake rate was determined as to the consumption of ammonium and nitrate after the nutrients depletion from culture media.


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