WHATMAN FILTER PAPERS

About 5 ml of sample is withdrawn for every 4-6 hours. The absorbance reading of the sample at 580 nm was measured using a Hitachi U-2000 spectrophotometer. The sample is filtered in a vacuum through Whatman filter paper with a pore size of 2.5 pin and diameter of 47 mm. The dry weight of cells is measured to monitoring microbial cell population and cell density. A plot of optical density reading from the spectrophotometer against cell dry... 

Procedure Purslane seeds were collected from crop fields near Naples. Five hundred seeds were sown in 10 Petri dishes (0 =90 mm), containing 5 layers of Whatman filter paper impregnated with 7 ml of water (control) or 7 ml rue infusion/chromatographic fractions or isolated compounds as per treatment. Thereafter, daily 3 ml water was added to each Petri plate. Germination conditions were 30 1°C with a continuous light of 25 4,E/m2/... 

The PVA solutions were prepared by dispersing the powdered polymer in water using sufficient agitation to wet all particles and then increasing the temperature to 95°C (fully hydrolyzed PVA) or 80°C (88%-hydrolyzed PVA) until the PVA was competely dissolved, as recommended by the supplier. The clear solutions were filtered hot through Whatman filter paper and cooled. The PVA contents were determined gravimetrically. Freshly prepared solutions were used for all experiments the solutions were discarded after 36 hours. 

Early separators used in NiCd cells for space applications consisted of materials as ordinary as Whatman filter paper and eventually nonwoven nylon felt (Pellon 2505). Pellon 2505 was more stable than cellulosic separators, but it too had stability limitations. In the late 1960s and early 1970s, nonwoven polypropylene saw limited use in NiCd cells. The PP separators were quite useful where sterilization (heating the cell to 135 °C) was required.The major difficulty with nonwoven polypropylene was that it was only marginally wet-table. and the amount of electrolyte that can be placed in the cell was limited. 

Whatman filter paper 4 were examined for the distribution of lignin fractions (oligolignols), produced during the pretreatment. The results given in Table 4 at 0 time (uninoculated) indicated that the solubilized lignin just after pretreatment and prior to its fermentation with P. sajor-caju contained oligolignols of different MW. 

Supersaturated sodium aluminate solutions were prepared using an autoclave which was operated at 150 C and about 600 kPA. The hot caustic solution was filtered through three Whatman filter papers of 4 pm pore size under positive pressure. Three litres of the filtered solution was transferred to the crystallizer, maintained at a constant temperature, which was set for a particular run. 

A. 3-Methyl-3-(toluenesulfonyloxymethyl)oxetane [Oxetane tosylate, ( )]. A dry, 1-L, round-bottomed flask is charged with a-toluenesulfonyl chloride (57.20 g, 0.30 mol) (Note 1) to which pyridine (250 mL) (Note 2) is added while stirring is carried out under nitrogen with a magnetic stir bar (Note 3). The reaction flask is placed inside a container to which an ice/water mixture may be added in the event that the reaction becomes too exothermic. 3-Methyl-3-oxetanemethanol (20.4 g, 0.2 mol) (Note 4) is added slowly and stirred for 1.5 hr. The mixture is slowly added to a vigorously (Note 3) stirred mixture of deionized water (700 mL) and crushed ice (700 g) in a 2-L Erlenmeyer flask and allowed to stir for ein additional 0.5 hr. The white precipitate is collected on Whatman filter paper 1 and washed with cold water (HjO, Note 5). The product is dried under high vacuum and/or phosphorus pentoxide (P2O5) to obtain the white powder of oxetane tosylate 1 (39.8-44.60 g, 78-87%) (Note 6). 

Mineral Jelly (Ref l),Evaporate most of the ether from the extract on a water bath. Remove the remainder with a stream of air. Dry the residue in an oven at 60° C for 1 hour. Then add 20 ml of 80% methyl alcohol (by volume) and heat to gentle boiling on a water bath. Decant the hot solvent thru a small funnel fitted with a 7 cm No 41 Whatman filter paper and collect the filtrate in an iodine flask. Retain as much mineral jelly in the extraction flask as possible. Repeat the extraction twice, using 10 ml of 80% methyl alcohol making 40 ml in all. Finally wash the filter paper six times with hot 80% methyl alcohol... 

The paper chromatograms were developed on Whatman filter paper No. 1, chromatography grade, using sheets 6" x 22 " in size, with development of the chromatograms in the machine direction of the paper. 

For example, strongly alkaline or strongly acidic reaction mixtures weaken cellulose filter papers. Acid-hardened grades which are more chemically resistant are commercially available (e.g. Whatman filter papers) but for maximum resistance to chemical attack, glass-fibre paper (e.g. Whatman) or a glass funnel fitted with a fixed sintered glass plate (Section 2.11) may be used. 

Neither silica nor Whatman filter paper, so exposed, develops fluorescence. As we have indicated, polyunsaturated lipids produce the same fluorescence on polyamide, but not on silica or filter paper. 

The two genes encoding ECB deacylase subunits from A. utahensis were cloned and overexpressed by S. lividans as soluble extracellular proteins [25], The recombinant S. lividans was grown in a 10-liter fermenter under conditions described previously [30], After 2 days of growth, the culture was filtered through 1 Whatman filter paper. The recombinant ECB deacylase from the culture filtrate... 

Lipase was immobilized by ADS on the support following the methodology of Pereira et al. (10) with slight modifications. Pure silica (1 g dry wt) was soaked previously in hexane under agitation (100 rpm) for 1 h. Excess hexane was then removed with a 10 mLpipet, and 0.3 g of powdered lipase dissolved in 10 mL of distilled water was added. The fixation of lipase onto the support was performed under agitation for 3 h at room temperature and followed by an additional period of 18 h under static conditions at 4°C. The derivative was filtered (Whatman filter paper no. 41) and thoroughly rinsed with hexane. 

Initial work used Whatmans filter paper (cotton based) as a control and Figure 2 shows that as the X polymer deposited within the paper structure increases the fold endurance also Increases. Figure 3 shows a similar relationship for a lignin containing (wood based) paper, although the strength increases are usually less dramatic. 

Figure 2. Dependence of fold endurance on percentage weight gain for Whatmans filter paper using EA MMA 5 1.

The chloroform extracts are combined and shaken with a small amount of activated charcoal for decolorization and then filtered through Whatman filter paper. The charcoal on the filter paper is washed with twenty milliliters of chloroform, and the washings are collected together with the chloroform extract. The combined chloroform extract is dried by passing it through a column of... 

A 2% solution of natural orcein (Gurr s) in 60% glacial acetic acid is prepared by dissolving the orcein in boiling glacial acetic acid with stirring. Cool to 55 °C. Add distilled water to make the acid 60%. Cool to room temperature. Filter twice through Whatman filter paper No. 1. 

Soil is placed into the clean dry cell. A 90-mm diameter Whatman filter paper is then placed on to the shoulder of the sample chamber and a clean steel filter placed on top of the filter paper. The top plate is screwed into the cell to contact the metal filter the temperature control unit cooler is then switched on. A small nominal stress (<1 MPa) needs to be applied to remove most of the air from the cell and to allow the sample and the components to bed in. When the selected temperature ( 2 C) is attained, the pressure can be increased and water collected. 

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