Cylinder-plate procedure

With the organism grown in this manner the sensitivity of the assay is improved. Greely et al2 2 have applied the automated respirometric method to the determination of neomycin in pharmaceutical products and compared these assays with the results obtained by the cylinder-plate procedure on the same samples. Good correlation between the two procedures was demonstrated. 

The Cylinder-Plate Procedure. In this procedure the substance being assayed diffuses from cylinders placed upon a uniform thickness of seeded agar, filled or charged with a fixed volume of the analyte, or reference standards or a series of standard solutions. The petri dishes are incubated at a predetermined temperature and the zones of inhibition measured to the nearest 0.1 mm. 

Utilizing the diffusion assay systems, primarily the cylinder-plate procedure, the following limits of detection and measurement are realistic. 

Metabolite/residue analysis. Milk, urine and plasma samples were first analyzed by a microbiological cylinder/plate procedure against M.luteus which has a limit of detection of 0.02 ppm. A sub-sample of the milk was prepared for this assay by a centrifugation step followed by a pH adjustment to 8.5. In addition, an HPLC/RAM analysis was conducted after treating another sub-sample with FTSH (10% formic acid, 30% trifluoroacetic acid, 2% sodium chloride, 2N hydrochloric acid) followed by centrifugation to precipitate the proteins. The supernatant was basified and concentrated by C-18 solid phase extraction (SPE) techniques. The HPLC conditions were Column - 20 cm x 4.8 mm C-8 Mobile-phase -linear gradient at 5%/minute from 90 10 O.IM pH 7 phosphate buffer methanol to 20 80 Detectors - UV operated at 214 nm and a radioactivity flow detector operated in the DPM mode. 

The microbiological methods used for the determination of CTC potency in body tissues and fluids, bulk products, and pharmaceutical formulations can be separated into two testing procedures (1) agar diffusion plate method (cylinder-plate) and (2) turbidimetric method. 

The Cup-Plate or Well Procedure. This procedure is similar to the cylinder-plate system except that wells are cut into the agar with cutters capable of cutting uniform, completely circular wells. As with the cylinder-plate assays, the wells are filled. Zones are measured after incubation and the concentration determined utilizing a comparison with a standard response line. 

Forced convection heat transfer is probably the most common mode in the process industries. Forced flows may be internal or external. This subsection briefly introduces correlations for estimating heat-transfer coefficients for flows in tubes and ducts flows across plates, cylinders, and spheres flows through tube banks and packed beds heat transfer to nonevaporating falling films and rotating surfaces. Section 11 introduces several types of heat exchangers, design procedures, overall heat-transfer coefficients, and mean temperature differences. 

ASTM standard specimens and procedures were used for flexure (D-690), compression (D 695), Izod impact and torsional pendulum analysis (TPA). For tension, D1822 tensile impact specimens were substituted for D638 specimens to conserve material. Test specimens were machined from the plates and cylinders using a water cooled dlamond wheel. All the specimens were dried in vacuo at 100°C for three weeks before testing or subsequent postcure treatment. Half the specimens were post-cured for 2 hours at 225°C in vacuo before testing. Selected specimens were Immersed in distilled water at 80°C for 6 weeks for moisture uptake determinations. 

Grikshtas and Rao (1993) showed that Kiljanski s method for estimating slip velocities using two concentric cylinder units gave results comparable to that of Mooney. Yoshimura and Pru dhomme (1988) described procedures for estimating slip velocities in a parallel plate geometry. 

Procedure (a) Place a glass bowl half filled with water on an overhead projector. Place a piece of sodium on the surface of the water and observe the path of the metal. Repeat the experiment several times, (b) Repeat the previous experiment using lithium. Place a piece of lithium on the surface of the water and observe, (c) Fill water in an upright cylinder and cover it with a glass plate, turn upside down, place under water and uncover it. Put a piece of lithium in that cylinder (Caution do not use sodium for this experiment). After gas has developed, place the cylinder upright again and light the gas. (d) Take a sample of the solution and test it with indicator solution. Take another sample of the solution, place it in a beaker and boil until dry. 

Procedure (a) Light a candle and place a beaker over it. Repeat this experiment using a cylinder. Extinguish the candle and add limewater to the cylinder cover it with a glass plate and shake, (b) Put a cylinder over a burning... 

Procedure Place a 1-cm layer of sand in the cylinder as a protector for the bottom of the cylinder. Fill the cylinder with carbon dioxide by replacing the air and cover it with a glass plate. Hold a 10-cm piece of magnesium ribbon using crucible tongs, carefully light it and place it deep within the cylinder, taking care not to touch the cylinder. 

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