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Managing an oocyte bank
Published in David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham, Textbook of Assisted Reproductive Techniques, 2017
Ana Cobo, Pilar Alamá, José María De Los Santos, María José De Los Santos, José Remohí
With the aim of purifying the LN used during the vitrification process, a specific ceramic filter is coupled to the pressurized tank (Figure 24.5). The Ceralin online filter (Air Liquide Medicinal, Paris, France) consists of a 0.1 pm ceramic membrane in accordance with U.S. Food and Drug Administration Guidelines on Aseptic Processing (1987) (23). The Ceralin online filter consists of two elements of liquid filtration connected in series and inserted into a section of the vacuum transfer line. The ceramic membrane is made from multiple layers formed into a multichannel element. It is housed in a vacuum-insulated pipe, itself installed close to the end-use point. During operation, LN flows through the filter and over the ceramic membrane. The result is high-purity LN with a bacteria count of less than 1 colonyforming unit (CFU)/L gas. Additionally, the large filtration area of the membrane and low level of contamination of LN means it is likely to be several decades before filter saturation. Periodic sampling for microbial assessment is needed.
Modeling the antifouling properties of atomic layer deposition surface-modified ceramic nanofiltration membranes
Published in Biofouling, 2022
Welldone Moyo, Nhamo Chaukura, Machawe M. Motsa, Titus A. M. Msagati, Bhekie B. Mamba, Sebastiaan G. J. Heijman, Thabo T. I. Nkambule
The effectiveness of membrane separation performance is delineated by the physico--chemical properties, composition and microstructure of the active layer (Tylkowski and Tsibranska 2015). Membranes can either be derived from organic/polymeric or inorganic/ceramic materials. Polymeric membranes have been preferred because they are relatively cheaper compared to ceramic membranes. However, they suffer several limitations such as a short life span, limited recyclability and poor chemical, mechanical and thermal stability (Metsämuuronen et al. 2014). In comparison, ceramic membranes derived from metal oxides, typically zirconia, titania, alumina and more recently silicon carbide, have high selectivity and superior mechanical, thermal and chemical stability (Amin 2016). For this reason, ceramic membranes have found applications in food processing, pharmaceutical production, petrochemical refining, chemical manufacturing and water and wastewater treatment, where the conditions can be extreme (Metsämuuronen et al. 2014). The utility of ceramic membranes is further enhanced by modifying the membrane surface and tuning the porosity through the choice of precursors and the fabrication conditions or by post modification treatments following synthesis.