The Pfeffer Zelle (Pfeffer Cell Apparatus), invented by Wilhelm Pfeffer [6] in 1877, measured the minimum pressure needed to prevent a pure solvent from passing into a solution across a semi-permeable membrane, called osmotic pressure. The apparatus provided Pfeffer with a way to quantitatively measure osmotic pressure. Pfeffer devised the apparatus in the 1870s at the University of Basel [7] i...

Lab-on-a-chip devices require integrated pumping and fluid control in microchannels. A recently developed mechanism that can produce fluid flow is an integrated ac-electro-osmosis micropump. However, like most electrokinetic pumps, ac-electro-osmotic pumps are incapable of handling backpressure as the pumping force mechanism acts on the surface of the fluid rather than the bulk. This paper pres...

BACKGROUND Aluminium toxicity in dialysis patients is well described. Aluminium has a close chemical affinity with silicon. Silicon may have a role in protection against aluminium toxicity. METHODS We measured serum aluminium and silicon levels from haemodialysis patients from four different centres. RESULTS Though no relationship was seen across all centres combined, in one centre there wa...

At present, many countries in the world are facing serious water crisis, the shortage of water in our country is particularly prominent, especially refining industry, water shortage and water pollution problems in our country have seriously affected the survival of enterprises and sustainable development. In this paper, based on literature research and field investigation, two stage discharging...

Nanofiltration and reverse osmosis are investigated as a possible alternative to the conventional methods of Cr(VI) removal from model water and industrial effluent. The influences of feed concentration, water recovery, pH, and the coexisting anions were studied. The results have shown that retention rates of hexavalent chromium can reach 99.7% using nanofiltration membrane (NF-HL) and vary fro...

Forward (direct) osmosis (FO) using semi-permeable polymeric membranes may be a viable alternative to reverse osmosis as a lower cost and more environmentally friendly desalination technology. The driving force in the described FO process is provided by a draw solution comprising highly soluble gases—ammonia and carbon dioxide. Using a commercially available FO membrane, experiments conducted i...

Enhancement of the performance of a reverse osmosis (RO) unit through periodic control is studied. The periodic control manipulates the feed pressure and flow rate of the RO unit. To ensure the periodic behavior of the inputs, the manipulated variables (MV) are transformed into the form of sinusoidal functions. In this case, the amplitude and period of the sinusoidal functions become the surrog...

? Transport proteins play a critical part in solute movement because membranes constitute a barrier to free diffusion of molecules. If membranes allowed rapid diffusion of both ions and water, gradients of ions would be slight and osmotic pressure could only be achieved with enormous energy consumption. Instead, some molecules, such as water and gases, move rapidly across membranes. Unrestricte...

The game-theoretic view of control system design for multi-loop systems is extended in this work to ensure a closed-loop system with robust stability. The control system design is modeled as a differential cooperative game to incorporate interactions between the multiple loops of the control system. A robust stability indicator is formulated as an additional cost function. The developed approac...