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Prevention of Microbial Contamination during Manufacturing
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Deep-bed filtration or multimedia/sand filters are used to remove suspended material such as particulate matter, colloidal matter, and heavy molecular weight matter such as naturally occurring organic matter. The installation of an activated carbon bed is used to absorb chlorine, chloramines and organic material from a potable or drinking water source. Water softeners are used to remove calcium, magnesium and other cations that can cause water hardness. A reverse osmosis unit is a purification technology in which a semi-permeable membrane is used to remove both multivalent and monovalent ions from water. Depending upon the water quality, reverse osmosis units be either a single or a double pass. In a double-pass reverse osmosis unit, two individual reverse osmosis units are operated in a series in which one unit will provide the feedwater to the second unit. Cation/anion/mixed bed ion exchange columns or electrodeionization unit (EDI) unit is used to remove cations and anions from water that had not been removed by the reverse osmosis unit.
Sample Protocols for Carcinogenesis and Photocarcinogenesis
Published in Francis N. Marzulli, Howard I. Maibach, Dermatotoxicology Methods: The Laboratory Worker’s Vade Mecum, 2019
P. Donald Forbes, Christopher P. Sambuco, George E. Dearlove, Robert M. Parker, Anthony L. Kiorpes, John H. Wedig
Water will be available ad libitum from an automatic watering access system. All water will be from a local source and passed through a reverse osmosis membrane before use. Chlorine will be added to the processed water as a bacteriostat; processed water is expected to contain no more than 1.2 ppm chlorine at the time of analysis. Water is analyzed monthly for possible bacterial contamination and twice annually for possible chemical contamination.
Aircrew equipment – Thermal protection and survival
Published in Nicholas Green, Steven Gaydos, Hutchison Ewan, Edward Nicol, Handbook of Aviation and Space Medicine, 2019
Nicholas Green, Steven Gaydos, Hutchison Ewan, Edward Nicol
Priorities of survivor (in order) are: Protection – principally clothing and shelter (see below for protection from water immersion).Location – includes filing a flight plan, use of personal locator beacons, pyrotechnic and other visual aids such as strobes and brightly coloured clothing.Water – intake can be reduced to 110–220 mL per day under ideal conditions for short period; reverse osmosis pumps, desalination kits and solar still may be used to source water.Food – intake can be reduced to 600–1,400 calories for a short period; use of survival rations (primarily carbohydrate) and survival skills enhances preservation of function.
Development of taste-masking microcapsules containing azithromycin by fluid bed coating for powder for suspension and in vivo evaluation
Published in Journal of Microencapsulation, 2023
Pham-Thi-Phuong Dung, Thanh-Dat Trinh, Quoc-Hoai Nguyen, Huu-Manh Nguyen, Ngoc-Chien Nguyen, Ngoc-Bao Tran, Cao-Son Tran, Thi-Hong-Ngoc Nguyen, Nguyen-Thach Tung
Azithromycin was obtained from Hebei Dongfeng Pharmaceutical Co., Ltd. (Handan, China). Poly(meth)acrylates (E100, L100, and RL100) and hydrophilic fumed silica (Aerosil® 200) were supported by Evonik Co., Ltd. (Essen, Germany). Precirol® ATO 5 (glyceryl distearate) was purchased from Gattefossé (Saint-Priest, France). Ethyl cellulose N10 (EC) and hydroxy propyl methyl cellulose (HPMC E6) were purchased from Colorcon (Harleysville, PA). Microcrystalline cellulose (Avicel PH 101), natri phosphate, magnesium hydroxide, dicalcium phosphate, and dibutyl phthalate were purchased from Mingtai Chemical Co., Ltd. (Taoyuan, Taiwan). Zithromax® powder for suspension 200 mg/5 ml was obtained from Pfizer, Inc. (New York, NY). Quinine hydrochloride and roxithromycin were purchased from Sigma-Aldrich (St. Louis, MO). HPLC-grade methanol was purchased from J.T. Baker (Phillipsburg, NJ). Water was purified by reverse osmosis. All other reagents were of analytical grade commercial products and purchased from Beijing Chemical Reagent Factory (Beijing, China).
Anti-biofouling efficacy of three home and personal care product preservatives: Pseudomonas aeruginosa biofilm inhibition and prevention
Published in Biofouling, 2021
A. M. Curtin, M. C. Thibodeau, H. L. Buckley
Desalination via reverse osmosis (RO) is a promising technology for helping to mitigate water scarcity. However, it is limited by energy requirements to pump water across the semipermeable membrane (Qasim et al. 2019). Although the energy demand of the RO process has been decreased by improvements such as switching to hybrid RO systems that utilize low flow, high rejection membranes followed by high flow, low rejection membranes, future design changes are projected to only provide about 0.5 kWh m−3 of improvements due to the impacts of flux and pressure drop (Bartels and Andes 2013). A complementary and critical improvement that remains for increasing RO energy efficiency, which will make the technology available for widespread application, lies in preventing fouling ( i.e. Saffarimiandoab et al. 2019; Choi et al. 2020; Hamdy and Taher 2020; Karabelas et al. 2020; Liu et al. 2020).
Non-destructive approaches for assessing biofouling of household reverse osmosis membranes
Published in Biofouling, 2018
Stephen D. Markwardt, Nirmala Ronnie, Anne K. Camper
A significant problem with reverse osmosis (RO) water treatment is membrane fouling. Fouling is the accumulation of foreign materials from the feed water on the active membrane surface and/or on the feed channel spacer to the point of causing operational problems (Pandey et al. 2012). Fouling of membranes results in increased power consumption and a reduction of membrane lifespan, which are major operational and economic issues for the feasibility of membrane treatment (Kavanagh et al. 2009). Inorganic fouling can occur from the precipitation of dissolved solids on the membrane surface (inorganic fouling) or the accumulation of inert particles (colloidal fouling) (Pandey et al. 2012). Organic fouling is the deposition of non-viable organic matter on the membrane surface (Al-Juboori and Yusaf 2012), and includes humic substances, amino acids, sugars and aromatic acids (Pandey et al. 2012). Biofouling is the attachment and growth of microorganisms to form a biofilm on the membrane surface and/or feed channel spacer to the point where economic operation is impacted (Flemming 1997; Vrouwenvelder and van der Kooij 2001; Pandey et al. 2012). Of all the fouling types, biofouling is the most detrimental to long term operation (Pandey et al. 2012), contributing to >45% of all membrane fouling (Komlenic 2010).