Penetration of steam

Other components, is rendered sterile separately, asep-tically weighed, and incorporated in preparing a final product that meets the sterility requirement. This is done because of difficulty in terminal product sterilization, such as lack of penetration of steam into the ointment base and instability of components owing to high dry heating. Antimicrobial preservatives such as methylparaben (0.05%) and propylparaben (0.01%) and its combinations phenylmercuric acetate (0.0008%), chlorobutanol (0.5%),and benzalkonium chloride (0.008%) are used as needed. 

The items to be sterilized, other than products in sealed containers, should be wrapped in a material that allows removal of air and penetration of steam but prevents recontamination after sterilization. All parts of the load should be in contact with water or saturated steam at the required temperature for the required time. 

Production wells started to respond in a relatively short period of time of 15-20 days. The monitoring of production wells indicated the following chants (a) the mineralization of formation water produced with crude oil dropped due to the penetration of steam condensate through macroporosity channels, (b) bottomhole temperatures of the wells went up and (c) their crude oil yields increased. Additionally, measures were taken to make sure that the amount of liquids removed from the reservoir by production wells exceeded the quantity of steam condensate and of encroaching formation water entering into the block. In this manner the production regime of dissolved gas drive could be maintained. 

The packaging of medical devices after cleaning and before sterilisation should protect the content (against contamination) as well as (during sterilisation) allow for removal of air and penetration of steam. The classical and most often used packaging material is sterlisation paper. Instrumentation kits are wrapped in sheets of sterilisation paper or non-woven materials that are subsequently sealed with sterilisation tape, which usually has a sterilisation indicator. 

Decontamination of wastes by autoclaving can be somewhat tricky, since the efficacy of this technique relies on the penetration of steam into every portion of the load (242), and the contact time (the time that the steam contacts all portions of the load) and the autoclave set time (the time set on the autoclave timer) are rarely equal. In fact, for large loads, it has been demonstrated that complete steam contact times can lag autoclave set times by a factor of four or more (254), resulting in incomplete sterility or decontamination. In all cases, the manufacturer s recommendations for the operation of the steam autoclave should be followed. 

Impure quinone may be purified by placing it in a distilling flask attached to a condenser and passing a rapid current of steam into the flask the quinone Sublimes and collects in the receiver. It is separated from the water by filtration and dried the m.p. is 116°. The vapour has a penetrating odour and attacks the eyes. 

Nonstabilized foams are referred to as froths froth-bonded fabrics are similar in properties to some saturation-bonded nonwovens. Typical foams used as nonwoven binder solutions have a consistency similar to shaving cream. AppHcation methods include knife-edge layering onto a horizontal web surface followed by vacuum penetration, and saturation and penetration of a vertical web surface using a horizontal-nip pad. Drying and curing is carried out in ovens, dmm dryers, or steam cans. 

Steam (qv) sterilization specifically means sterilization by moist heat. The process cannot be considered adequate without assurance that complete penetration of saturated steam takes place to all parts and surfaces of the load to be sterilized (Fig. 1). Steam sterilization at 100°C and atmospheric pressure is not considered effective. The process is invariably carried out under higher pressure in autoclaves using saturated steam. The temperature can be as low as 115°C, but is usually 121°C or higher. 

The elimination of air from the chamber and complete steam penetration of the load is of critical importance. This may be accompHshed by gravity displacement or prevacuum techniques. 

Above about 600°C penetration of oxygen and nitrogen occurs. It has already been indicated that the presence of these elements renders the titanium brittle, and this feature must be taken into account in considering the use of titanium at elevated temperatures. Titanium has nevertheless been successfully employed as an autoclave lining in steam atmospheres at a temperature of 400°C and a pressure of lOMPa. 

Heating in an autoclave only Steam-sensitive chemical Usually an organic chemical in a printing ink base impregnated into a carrier material. A combination of moisture and heat produces a darkening of the ink, e.g. autoclave tape. Devices of this sort can be used within dressings packs to confirm adequate removal of air and penetration of saturated steam (Bewie-Dick test) Saturated steam... 

For the case in which the blend components were steamed together, the electron microprobe analyses showed the presence of silica on Additive R. This means that silica was transported from the cracking catalyst particles to the Additive R particles during the steam deactivation. The amount of silica transported and the distance the silica penetrated into the Additive R particles varied from particle to particle. The silica penetration ranged from about 10 microns to complete penetration of an entire particle. The amount of silica transported, expressed as the peak concentration observed in the outer section of the particle, varied from about 0.5% to about 8% SiO (estimates). 

Commercially-aged samples of Additive R, taken from two commercial units, looked like the steamed sample. The silica penetration varied from about 8 microns to complete penetration of the entire particle. The amount of silica transported varied from about 1.5% to about 14% SiO (peak concentration in the particle). 

Pad Processes. In a continuous or semicontinuous processes, the fabric is first padded with the dye solution. The substantive adsorption of dyes during padding is avoided by employing minimum amounts of pad liquor at ambient temperatures. For even penetration of the dye, the material is then steamed without intermediate drying for 1-3 min in saturated steam (pad steam process ). Alternatively, it is heated to 80-85 °C and rolled up in a closed chamber where it is slowly rotated for 2-8 h (pad roll process). 

Continuous dyeing of PAC-cotton plush with cationic and direct dyes by the pad steam process plays an important role. The choice of dyes must take into account liquor stability, reservation of PAC or CEL fiber, and solubility. Precipitation of cationic and anionic dyes present in the pad liquor at relatively high concentrations cannot be avoided solely by dye selection. Suitable auxiliary systems have been developed. Differently charged dyes are kept in solution separated from each other in two phases by the combination of anionic and nonionogenic surfactants. With the help of fixing accelerators, good penetration of PAC fibers can be achieved in 10-15 min with saturated steam at 98-100°C. 

Empty bottles should have their plastic caps only loosely screwed on to allow penetration and escape of steam during the sterilisation cycle. 

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