Pellet equilibration

For the experiments in type C catalysts, the pellets were overfilled with cyclohexane and initially cooled to 230 K. They were then reheated in steps of 1 K and allowed to equilibrate for 10 min before each measurement. The signal was determined from 32 accumulations with an echo sequence of 20 ms echo time to ensure that the signal from the plastically crystalline phase of cyclohexane had decayed fully. The typical heating curves of cyclohexane in the fresh and coked catalyst are displayed in Figure 3.3.3(a) As the temperature is increased, larger and... 

Anion exchange chromatography The reaction mixture is subjected to phenol/chloroform extraction to remove the T7 RNA polymerase using phenol equilibrated with 50 mM Na acetate (pH 4.5). After isopropanol precipitation, the pellets are resuspended in 20 mM MOPS buffer (pH 6.25) containing 350 mM NaCl. The excess unincorporated NTPs and the smaller abortive transcription products are removed by chromatography on anion exchange FPLC column (MonoQ 5/5 column, Amersham). 

The sample is loaded at a flow-rate of 1 ml/min onto the FPLC column equilibrated with the same MOPS buffer used to resuspend the RNA pellets. The free nucleotides are completely removed with a 5-ml wash with 350 mM NaCl and the RNA is eluted with a 20-ml (350—750 mM NaCl) linear gradient and analyzed by PAGE/urea gel electrophoresis (see later). Up to 2 mg of RNA can be loaded onto and eluted from a 1-ml (of resin) mono Q column without loss of resolution. The homogeneity of RNA in the fractions collected, as seen by gel electrophoresis, should be >90%. The appropriate fractions are pooled and the RNA collected by ethanol precipitation. The RNA pellet is washed twice with 70% ethanol, air-dried, and finally redissolved in DEPC-treated H20. The total recovery after the entire procedure of purification is = 90%. This protocol yields = 800 pmoles of purified 002 mRNA/pmole template DNA. 

Capsules were equilibrated with a tracer solution overnight. A capsule pellet (0.2-0.5 ml) was then placed in 5 ml test buffer (PBS or RPMI-1640 medium, Gib-co/BRL, New York, NY) on a shaker and a 0.2-ml aliquot was immediately sampled by a screen-protected pipette with further samples being taken over the next 700 s. The tracer quantity was assayed using the methods described below. A final sample was taken after the capsules has been in contact with the buffer for several hours (equilibrated tracer quantity) and the increment to the tracer concentration at each time was calculated. From the progress of tracer to equilibrium on a semilog plot a slope denoted as the zero -order rate flux constant was obtained and has been used as a measure of capsule permeability. [3H] -Glucose (580 daltons),insulin (6.2 kDa), and ovalbumin (45 kDa) have been used as tracers. Radioactivity was measured by means of a Packard 2000CA Liquid Scintillation Counter (Packard Instruments,... 

The pellet was redissolved in buffer A, dialysed overnight against the same buffer and loaded on an anion-exchange column (Fractogel EMD DEAE, 10 cm x 2 cm) which was previously equilibrated with buffer A. The enzyme was eluted with a linear gradient from 0 to 0.15 m NaCl for 30 min in the same buffer, at a flow rate of 2 mL... 

The precipitate was collected by centrifugation at 1500 xg for 15 min. at 20 C. Unconjugated Ig was removed by repeated precipitation of the copolymer/Ig conjugate in 14.3% by volume of saturated (NH4)2S04 The final pellet was completely dissolved in 6 ml of 0.01 M phosphate buffer, pH 6.8. This solution was then applied to a column (1.5 x 1.0 cm) of hydroxylapatite (HA) equilibrated with 0.01 M phosphate buffer, pH 6.8 (conditions under which only the... 

Procedure. Partially Hydrated Zeolites. Partially hydrated zeolites are made from samples previously dehydrated by evacuation at 400°C in the conductivity cell, by adsorbing known amounts of water. For comparison, adsorption isotherms were determined independently at the same temperature and pressure. After each adsorption of water, the pellet is allowed to equilibrate for 3 hours. Capacity and conductivity are measured at several frequencies in the range 200-107 Hfc. Regular, checks are made on this equilibrium period with overnight and weekend equilibration times. No appreciable changes of conductivity and capacity were observed after 3 hours. 

Hydrated Zeolites. The zeolitic pellets are hydrated by equilibration at atmospheric moisture content. The cell is immersed in liquid air, and a minimum equilibrium temperature of — 120°C was obtained. At that temperature the conductivity and capacity of the samples are measured over the frequency range 200-107 Hz. After eliminating the cooling liquid, the temperature rises slowly (0.5°C/min). Measurements are performed continuously in the same frequency range during the. temperature rise up to room temperature. The results are near-equilibrium values, and the errors are assumed to be the same over the complete temperature range. The same procedure was applied by Mamy for dielectric measurements on montmorillonite 11). 

The polymer-gas solution to be tested is prepared separately, and is loaded into the rheometer barrel as a well-mixed, equilibrated sample. The loading method depends on whether the polymer itself is a liquid or a solid at room temperature. For liquid polymers such as PDMS, Gerhard (1994) developed a sealed module that attached to the top of the rheometer barrel, with a side valve though which an equilibrated liquid polymer-gas sample is injected. For solid polymers such as polystyrene, Kwag (1998) found that the diffusion of gas from solid pellets at room temperature was sufficiently slow to allow direct loading of the sample as solid pellets pre-... 

Equilibrate column in 100% acetonitrile until pressure stabilizes ( 20 ml acetonitrile). Run a gradient to 100% 100 mMTEAA, pH 7.0 over 5 min and stay at 100% 100 mMTEAA. Wait for pressure to stabilize. Resuspend labeled RNA pellets from previous PAGE purification in 60 fil 100 mM TEAA, pH 7.0. Load sample into a 100 fil loop, and inject. Set a gradient to 100% acetonitrile over 35 column volumes. Begin collecting fractions when... 

Resuspend the ammonium sulphate pellet in 1 ml PBS pH 6.5 and apply to a 20 ml column of QAE Sephadex A-50 (Pharmacia) equilibrated with the same buffer, which is also used to elute the column. Elution of antibodies may be detected by ELISA or by polyacrylamide gel electrophoresis (Campbell, 1984). 

Spatially resolved Raman spectroscopy has provided insights into the physicochemical processes that determine the distribution of the H2PMoOi iCoOV active phase in alumina pellets (Bergwerff et al., 2005). Molybdenum and cobalt complexes were found to diffuse through the pore structure of the alumina pellets at different rates the transport of cobalt complexes was fast, whereas molybdenum complexes required several hours to reach an equilibrated distribution. Spatially resolved Raman monitoring provides information about how preparation conditions affect the distribution of molybdenum ions (Bergwerff et al., 2005). 

Blood is drawn from healthy adult volunteers, who had no medication for the last two weeks. Venous blood (8.4 ml) is collected into 1.4 ml ACD-solution and centrifuged for 10 min at 120 x g. The platelet-rich plasma (PRP) is carefully removed, the pH adjusted to 6.5 with ACD-solution and centrifuged at 285 x g for 20 min. The resulting pellet is resuspended in Tyrode s buffer (approx. 500 xl buffer/10 ml PRP). The platelet suspension is applied immediately to a Sepharose CL 2B column equilibration and elution at 2 ml/min flow rate is done with Tyrode s buffer without hirudin and apyrase. Platelets are recovered in the void volume. Final platelet suspension is adjusted to 4 x 108/ml. Gel-filtered platelets (GFP) are kept at room temperature for 1 h until the test is started. 

Purification of Monoclonal Antibody. Immunoglobulins were precipitated from the pooled ascites by addition of an equal volume of saturated ammonium sulfate [50% (NH4)2S04]. The precipitate was collected by centrifugation (20 min 10,240 X g), dissolved in 0.01 M sodium phosphate (pH 6.8), and reprecipitated. After the second ammonium sulfate precipitation, the pellet was dissolved in a minimum volume of 0.01 M sodium phosphate (pH 6.8) and centrifuged for 10 min at 10,600 X g). The resulting supemate was applied to a P6G, gel filtration polyacrylamid, column (Bio-gel Biorad, Rockville Center, NY 1.5 X 40 cm). Fractions containing protein were pooled and applied to a hydroxyapatite column that had been equilibrated with 0.01 M sodium phosphate (pH 6.8). Proteins were eluted with a linear gradient of 0.01 to 0.3 M sodium phosphate. 

Once the product is adequately frozen, the next step is the removal of ice, i.e., primary drying. During primary drying, the rate of ice sublimation is dependent on the amount of heat supplied to the product. The temperature of the product equilibrates as a function of two opposite effects the transfer of heat from the shelf or from the gaseous atmosphere to the product, and the cooling due to ice sublimation. As the ice-vapor interface (moving front) moves toward the bottom of the containers, the rate of ice sublimation tends to diminish because the nascent porous matrix in the upper part of the pellet offers some resistance to vapor flow. 

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