Paul B. MacCready has a knack for knowing the difference between the impossible and that which is merely extremely difficult. In the late 1980s, MacCready, founder and CEO of AeroVironment, a company that consults on pollution management and wind energy, figured that a battery-powered automobile could be practical , provided the entire machine was optimized for efficiency. It would have to be e...

Plant cell vacuoles occupy up to 90% of the cell volume and, beyond their physiological function, are constantly subjected to water and solute exchange. The osmotic flow and vacuole volume dynamics relies on the vacuole membrane -the tonoplast- and its capacity to regulate its permeability to both water and solutes. The osmotic permeability coefficient (Pf ) is the parameter that better charact...

the “driving force - pressure - state - impact – response” modeling framework isadopted to consider the formation mechanisms of environmental risks and the requirements ofecological environment protection. moreover, a systematical index system and evaluation model forthe measurement of the coastal ecological security level is put forward in this paper to assess thestate of coastal ecological en...

Pollen tube growth is central to the sexual reproduction of plants and is a longstanding model for cellular tip growth. For rapid tip growth, cell wall deposition and hardening must balance the rate of osmotic water uptake, and this involves the control of turgor pressure. Pressure contributes directly to both the driving force for water entry and tip expansion causing thinning of wall material...

Based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. Expressions for the supersaturation are obtained in isothermal and isobaric regimes. The results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to ...

We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping efficiency of these flows is limited by the presence of "unstirred" concentration boundary layers nea...

A study was carried out to elucidate the physiological mechanisms responsible for the intestinal secretion produced by venous pressure elevation. In dogs, measurements were made of the rate and composition of small intestinal secretion, rate of flow and composition of intestinal lymph, plasma composition, and mucosal water content, all in response to elevations of intestinal venous pressure. Ve...

Mitochondrial volume homeostasis is a housekeeping cellular function essential for maintaining the structural integrity of the organelle. Changes in mitochondrial volume have been associated with a wide range of important biological functions and pathologies. Mitochondrial matrix volume is controlled by osmotic balance between cytosol and mitochondria. Any dysbalance in the fluxes of the main i...