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Eliminating seawater matrix effects in ATP measurement using a filtration process
Published in Almotasembellah Mustafa Jawdat Abushaban, Assessing Bacterial Growth Potential in Seawater Reverse Osmosis Pretreatment: Method Development and Applications, 2019
Almotasembellah Mustafa Jawdat Abushaban
Artificial seawater containing all ions (ASWall ions) in seawater was prepared using Milli-Q water (Milli-Q® water Optimized purification, 18.2 MΩ.cm at 25°C, Millipore, USA) and analytical or reagent-grade inorganic salts (Merck, USA) with similar ion concentrations as the average global seawater (Villacorte 2014) (23.668 g/L NaCl, 10.873 g/L MgCl2.6H2O, 3.993 g/L Na2SO4, 1.54 g/L CaCl2.2H2O, 0.739 g/L KCl, 0.213 g/L NaHCO3, and 0.002 g/L Na2CO3). Similarly, ASW NaOH + NaHCO3 was prepared using 33.2 g/L NaCl and 0.213 g/L NaHCO3. All salts except sodium bicarbonate were mixed (150 rpm) with Milli-Q water for 24 hours and autoclaved at 100 °C for 20 minutes. Sodium bicarbonate was added after autoclaving because its melting point is 50 °C.
Microbial Sulfate-Reducing Activities in Anoxic Sediment from Marine Lake Grevelingen: Screening of Electron Donors and Acceptors
Published in Chiara Cassarini, Anaerobic Oxidation of Methane Coupled to the Reduction of Different Sulfur Compounds as Electron Acceptors in Bioreactors, 2019
The wet sediment was homogenized separately in a N2-purged anaerobic chamber from PLAS LABS INCTM and diluted with artificial seawater medium in a ratio of 1:3, and then aliquoted in 250 ml sterile serum bottles with 40 % headspace. The artificial seawater medium composed of (per liter of demineralized water): NaCl (26 g), KCl (0.5 g) MgCl2·6H2O (5 g), NH4Cl (0.3 g), CaCl2°2H2O (1.4 g), KH2PO4 (0.1 g), trace element solution (1 ml), 1 M NaHCO3 (30 ml), vitamin solution (1 ml), thiamin solution (1 ml), vitamin B12 solution (1 ml), 0.5 g L-1 resazurin solution (1 ml) and 0.5 M Na2S solution (1 ml) (Zhang et al. 2010). The vitamins and trace element mixture was prepared according to Widdel and Bak (1992). pH was adjusted to 7.0 with sterile 1 M Na2CO3 or 1 M H2SO4 solution, which was stored under nitrogen atmosphere. The medium was kept anoxic through N2 purging until the incubation with the sediment. The prepared serum bottles were incubated in the dark with gentle shaking at room temperature (~ 20 ± 2°C).
Pinus wallichiana-synthesized silver nanoparticles as biomedical agents: in-vitro and in-vivo approach
Published in Green Chemistry Letters and Reviews, 2020
Nazish Khan, Ibrar Khan, Akhtar Nadhman, Sadiq Azam, Inam Ullah, Farhan Ahmad, Hamid Ali Khan
Brine shrimp lethality bioassay (19) was used to determine the cytotoxic potential of AgNPs. Artificial seawater was prepared by mixing commercial salt with double-distilled (38 g/l) under constant aeration for 48 h. Cone-shaped vessels (1 l) filled with sterile artificial seawater were used for brine shrimp egg hatching. Active nauplii, after hatching, were collected for the assay. The stock solution of AgNPs (10 mg/ml of distilled water) was serially diluted (10, 100, and 1000 μg/ml) and 1 ml solution from each concentration was added into the test tubes containing 30 nauplii and 1 ml of seawater. The mortality rate was determined by counting the number of dead nauplii after 24 h. Standard drug (Etoposide) was used as a positive control. The mean mortality in the test and control tubes were compared to evaluate the percentage lethality. The LC50 values were determined from the best-fit line plotted concentration versus percentage.
Finite element modelling of load-carrying capacity of concrete-filled unplasticised polyvinyl chloride (UPVC) tubes exposed to marine environment
Published in Ships and Offshore Structures, 2021
Water supply UPVC pipes of 160, 200 and 225 mm diameters and Class 3, 4 and 5 (IS: 4985-2000) (2005) of were filled with Reinforced concrete of M30 and M40 grades. M30 and M40 grade concrete were designed and prepared as per (IS: 10262-2009). The cylinder strength of these mixes was found out to be 35.08 and 30.05 MPa after 28 days as well as 37.54 and 41.69 MPa after putting them in sea water for 6 months. Artificial sea water was prepared by mixing Sodium chloride 78.21% (29.0 gm/l), Magnesium chloride 10.60% (3.93 gm/l), Magnesium sulphate 5.04% (1.87 gm/l), Calcium sulphate 3.15% (1.17 gm/l), Potassium sulphate 2.43% (0.9 gm/l), Calcium carbonate 0.30% (0.11 gm/l) and Magnesium bromide 0.27% (0.10 gm/l). These amounts of chemicals were dissolved in plain water to prepare 1.0 l of sea water of 1N concentration (Jain 2007). To prepare sea water of 20 N concentration, chemicals were taken 20 times as used for 1N concentration. The Elastic modulus was obtained as 880 MPa in normal condition and 1016 MPa after submergence in sea water for 6 months. Moreover, the Ultimate tensile strength of UPVC material was found out to be 22.5 MPa in normal condition and 24.64 MPa after submergence in sea water for 6 months. All three types (Class 3, Class 4 and Class 5) of UPVC pipes were tested for pressure test. In each Class pipes of diameter 160, 200 mm and 225 mm were used. The tensile test as per (ASTM-D638-10) and internal hydrostatic pressure test as per IS: 12235 (part 8)-1986 (IS: 12235(Part 8)-2009) of UPVC pipes were conducted in the laboratory to obtain stress–strain curve as well as ultimate tensile strength (fu) and internal hydrostatic pressure (p) (Figures 1 and 2). Six bars of 12 mm diameter and Fe500 grade were used as longitudinal reinforcement and 8 mm dia. bars at spacing of 150 mm c/c were used for lateral ties.
Parametric study of aluminium alloy fouling in marine environment using RSM technique
Published in Tribology - Materials, Surfaces & Interfaces, 2020
M. Lavanya, Padmalatha Rao, V. Ramachandra Murthy, Subbalaxmi Selvaraj
The suspended solids in the slurry were sea sand of size 300 μ. Sand selection was based on the fact that since the industrial processes involving sea water for cooling is contaminated with sand. Throughout the experiments 0.3% sand concentration was maintained. The optimum conditions to obtain minimum fouling rate through weight gain method were deduced with the statistical design of experiments technique. The pH of the artificial sea water is around 8–8.5.