Filter port sizes

A typical bioprocess system will include a bag, tubing, fittings to connect them, filters, valves, clamps, vents, and sampling ports. Sizes range from about 250 ml to 10,000 liters, currently the largest standard size. 

Instead, membrane filtration may be used to sterilise the nutrient in this experiment. This can be accomplished by drawing the nutrient from a mixing jar and forcing it through an in-line filter (0.2 p,m pore size) either by gravity or with a peristaltic pump. The sterilised medium is fed into an autoclaved nutrient jar with a rubber stopper fitted with a filtered vent and a hooded sampling port. 

The prototype shell-and-tube type cross-flow filtration modules (Pall Corp.) used for filtration tests are welded into a stainless steel shell enclosure. The modules have an inlet (filtrate) and outlet (retentate) port (both at tube sides) with Vi-inch tubing ends, and a permeate port, located near the midpoint of the shell side of the unit. The stainless steel filter membranes have a nominal pore size of 0.1 pm. The surface of the filter media is coated with a proprietary submicron layer of zirconia. 

The positive lead of the single-fiber electrode (see Figure 25.6) is the end cap of a 25-/xm wire exposed through a side port on the cannula of a steel needle. Due to the small size of the positive lead, bioelectric sources, which are located more than about 300 /xm from the side port, will appear as common-mode signals and be suppressed by the differential amplifier. To further enhance the selectivity, the recorded signal is high-pass filtered at 500 Hz to remove low-frequency background activity from distant fibers. 

The sterilization begins when the sterilization temperature is reached in the coldest spots, e.g., drain ports and gas inlet filters. The entire process in production plants is normally carried out automatically, controlled, and documented. Depending on the design and size of the plant the time for CIP and SIP can be expected to lie between 8 and 12 h. 

Fig. XI/4.2-1A and D) Internet and other digital network data travel in packets of limited sizes. Consists of the Data, Ack, Request or Command, Protocol Information, Source and Destination IP Address, Port Error Checking Code, etc. Filtering consists of examining incoming and outgoing packets compared with a set of rules for allowing and disallowing transmission or acceptance. Rather fast because it really does not check any data in the packet except IP header. Works in the network layer (internet) of the Open Systems Interconnection (OSI) model. Fast but not foolproof. IP address can be spoofed.

Syringe filters of different diameters and pore sizes. The most common filter pore diameters are 0.45 and 0.2 pm. Note that the top filter is 0.02 pm. Construction of the housing is typically polypropylene or polyethylene, and all these are connected to a syringe via a Luer port. 

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