Fiber columns

Ammonia absorption/ desorption from ammonia water 240 Pilot-plant study in a polypropylene hollow-fiber column ammonia is absorbed in diluted sulfuric acid... 

Kushi, H., Miki, T., Nakahara, J., Okamoto, K., Kawahara, Y., Saito, T., Tanjoh, K. Hemoperfusion with an immobilized polymyxin B fiber column improves tissue oxygen metabolism. Ther Apher Dial 10 (2006a) 430-435. 

Mitaka, C., Tsuchida, N., Kawada, K., Nakajima, Y., Imai, T., Sasaki, S. A longer duration of polymyxin B-immobilizcd fiber column hemoperfusion improves pulmonary oxygenation in patients with septic shock. Shock 32 (2009) 478-483. 

Noma, S., Matsuyama, W., Mitsuyama, H., Suetsugu, T., Koreeda, Y., Mizuno, K., Higashimoto, I., Kakihana, Y., Hashiguchi, T., Maruyama, I., Osame, M., Arimura, K. Two cases of acute exacerbation of interstitial pneumonia treated with polymyxin B-immobilized fiber column hemoperfusion treatment. Intern Med 46 (2007) 1447-1454. 

Oshima, K., Akao, T., Kobayashi, K., Muraoka, M., Matsumoto, K., Takeyoshi, I. The effect of direct hemoperfusion with a polymyxin B-immobilized fiber column (DHP-PMX therapy) on pulmonary ischemia-reperfusion injury in a canine model. J Invest Surg 21 (2008) 127-132. 

Shimizu, T., Hanasawa, K., Sato, K., Umeki, M., Koga, N., Naganuma, T., Sato, S., Shimonishi, T., Ikeda, T., Matsuno, N., Ono, S., Saitoh, H., Satoh, K., Otani, Y., Endo, Y., Eguchi, Y., Tani, T. Direct hemoperfusion with polymyxin-B-immobilized fiber columns improves septic hypotension and reduces inflammatory mediators in septic patients with colorectal perforation. Langenbecks Arch Surg 394 (2009) 303-311. 

Carbon fiber column cleanup has been successfully used for separation of PCDEs from PCDDs and PCDFs in a HPLC system [129]. The separation can be achieved using three solvent system, in which dichloromethanexyclohexane (1 1 v/v) is the first eluent, ethyl acetate benzene (1 1 v/v) the second, and toluene the third. PCDEs are eluted in the first fraction and PCDDs and PCDFs in the third, which is collected using reversed elution. 

It should be obvious that the packed fiber column can be regarded as a chemical reactor for fiber surface modification, involving either gas or liquid phase chemistries. Thus, a powerful and convenient system for exploring surface properties is created by careful construction of the initial column. 

Respiratoiy A 53-year-old man with chronic pulmonary aspergillosis developed near-fatal diffuse alveolar hemorrhage after receiving intravenous itraconazole a lymphocyte stimulation test was positive he did not respond to methylprednisolone but responded dramatically to hemoperfusion using a poly-m) in B-immobiUzed fiber column P6 ]. 

The cellulose specific surface deirends on the treatment applied to tin fiber, column loading and exposure to moisture. The study of surface properties of polymeric fibres by GSC Avas carried out fairly recently [100]. 

Figure 27 Comparison of volatiles extracted from a soft drink with SPME (upper curve) and SBSE (lower curve) the SPME fiber used was PDMS/DVB. (A) 5 ml soft drink sample. Immersion SPME at room temperature using a 65 xm PDMS/DVB fiber, column 30 m DB-WAX, 0.25 mm l.D. 0.25 xm film thickness. (B) 5 ml soft drink sample. SBSE at room temperature. Column 20 m DB-WAX, 0.18 mm l.D. 0.18 Xm film thickness.

Caffeine in coffee, tea, and soda is determined by a solid-phase microextraction using an uncoated silica fiber, followed by a GC analysis using a capillary SPB-5 column with an MS detector. Standard solutions are spiked with G3 caffeine as an internal standard. 

Caprolactam Extraction. A high degree of purification is necessary for fiber-grade caprolactam, the monomer for nylon-6 (see Polyamides). Cmde aqueous caprolactam is purified by solvent extractions using aromatic hydrocarbons such as toluene as the solvent (233). Many of the well-known types of column contactors have been used a detailed description of the process is available (234). 

The heated polymer solution emerges as filaments from the spinneret into a column of warm air. Instantaneous loss of solvent from the surface of the filament causes a soHd skin to form over the stiU-Hquid interior. As the filament is heated by the warm air, more solvent evaporates. More than 80% of the solvent can be removed during a brief residence time of less than 1 s in the hot air column. The air column or cabinet height is 2—8 m, depending on the extent of drying required and the extmsion speed. The air flow may be concurrent or countercurrent to the direction of fiber movement. The fiber properties are contingent on the solvent-removal rate, and precise air flow and temperature control are necessary. 

The principal uses of PCTFE plastics remain in the areas of aeronautical and space, electrical/electronics, cryogenic, chemical, and medical instmmentation industries. AppHcations include chemically resistant electrical insulation and components cryogenic seals, gaskets, valve seats (56,57) and liners instmment parts for medical and chemical equipment (58), and medical packaging fiber optic appHcations (see Fiber optics) seals for the petrochemical /oil industry and electrodes, sample containers, and column packing in analytical chemistry and equipment (59). 

Technologies to purify cells from white cell concentrates are in the research stage. Principles used include antibodies covalently bound to a surface, antibody-coated microbeads in a column, magnetic microparticles that have been coated with antibodies, and hoUow fibers that have been coated with antibodies. 

Fibers spun by this method may be isotropic or asymmetric, with dense or porous walls, depending on the dope composition. An isotropic porous membrane results from spinning solutions at the point of incipient gelation. The dope mixture comprises a polymer, a solvent, and a nonsolvent, which are spun into an evaporative column. Because of the rapid evaporation of the solvent component, the spinning dope solidifies almost immediately upon emergence from the spinneret in contact with the gas phase. The amount of time between the solution s exit from the spinneret and its entrance into the coagulation bath has been found to be a critical variable. Asymmetric fibers result from an inherently more compatible solvent/nonsolvent composition, ie, a composition containing lower nonsolvent concentrations. The nature of the exterior skin (dense or porous) of the fiber is also controlled by the dope composition. 

Cellulose acetate [9004-35-7], prepared by reaction of cellulose with acetic anhydride, acetic acid, and sulfuric acid, is spun into acetate rayon fibers by dissolving it in acetone and spinning the solution into a column of warm air that evaporates the acetone. Cellulose acetate is also shaped into a variety of plastic products, and its solutions are used as coating dopes. Cellulose acetate butyrate [9004-36-8], made from cellulose, acetic anhydride, and butyric anhydride in the presence of sulfuric acid, is a shock-resistant plastic. 

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