Physical screen

Fara D.C. Oprea T. Prossnitz E.R. Bologa C.G. Edwards B.S. Sklar L.A. Integration of virtual and physical screening. Drug Discovery Today, 2006, 3, 337-385. 

Filters can be divided into two types membrane (screen) filters and depth filters. Membrane filters, such as silver membrane filters, physically screen and retain particles on their surfaces. These filters have uniform pore sizes and are rated for absolute retention all particles larger than the pore size are retained. Depth filters, such as glass-fiber filters, consist of a matrix of fibers that form a tortuous maze of flow channels. The particulate fraction becomes entrapped by this matrix. These filters do not have a uniform pore size, and it is not possible to rate them for absolute retention. They are rated according to nominal pore size, which is determined by the particle size that is retained by the filter to a predetermined percentage. This percentage is usually given as 98 retention however, it can be as low as 90. ... 

Fara DC, Oprea TI, Prossnitz ER, Bologa CG, Edwards BS, Sklar LA. Integration of virtual and physical screening. Drug Disc. Today Technol. 2006 3 377-385. 

When the wastewater arrives at the treatment plant, it moves through a series of processes which remove the waste from the water and reduce its threat to public health. Treatment at the plant consists of p re-treatment, primary treatment, and secondary treatment. Pre-treatment physically screens out large debris, and removes sand, gravel, and oil. Primary treatment removes settled and floating materials. Secondary treatment involves biological, chemical, and physical processes which remove suspended and dissolved solids secondary treatment also kills pathogenic organisms. 

Some microbes tolerate oxygen in their surroundings by physically screening themselves from the worst atrocities. The simplest screen is a pile of dead cells. In the same way, the riddled body of a dead comrade may protect a soldier from the bullets of an execution squad. Anaerobic cells living in stromatolites (Chapter 3) have relied heavily on this device, sheltering behind successive layers of dead cells. They have been doing this for 3.5 billion years. 

Physical screen arrangement Does your system have Would more screens help is satisfactory a large display ... 

While there are apparent temperature dependent efiects on the LAD screen itself (pores may shrink at reduced temperatures) due to apparent higher FTS pressure drop with reduced temperatures, recent comprehensive analysis conducted by Darr et al. (2015) show that the screen pores do not appreciably shrink at cryogenic temperatures, and that screen properties vary hy less than 1% at LH2 temperatures. For example, the coefficient of thermal contraction can be used to show physical screen property variation with temperature ... 

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