Measurement nominal diameter

We note here that the fragment size predicted through the more recent energy-horizon theory ((8.30) or (8.34)) is between a factor of 2 to 3 smaller in nominal diameter than predicted through the earlier kinetic energy theory ((8.26)). This difference is more marked if a measure of fragment mass is... 

Well-measuring strand shall be bright (uncoated) or drawn-galvanized. Well-measuring strand shall be left lay. The lay of the finished strand shall not exceed 10 times the nominal diameter. 

Schiesser and Lapidus (S3), in later studies, measured the liquid residencetime distribution for a column of 4-in. diameter and 4-ft height packed with spherical particles of varying porosity and nominal diameters of in. and in. The liquid medium was water, and as tracers sodium chloride or methyl orange were employed. The specific purposes of this study were to determine radial variations in liquid flow rate and to demonstrate how pore diffusivity and pore structure may be estimated and characterized on the basis of tracer experiments. Significant radial variations in flow rate were observed methods are discussed for separating the hydrodynamic and diffusional contributions to the residence-time curves. 

Particle shapes influence properties such as surface area, bulk density, flow, and so on. A number of methods are available for describing shape from simpler qualitative descriptions, through property ratios, to techniques that employ fast Fourier transformations to describe the projected perimeter of the particle. The measurement of the shape and the relevance of the data obtained are generally the two difficulties associated with particle shape. Fortunately, in the processing of materials physically unlike those in chemical processing, shape is perhaps is less significant and is more often than not inherently accounted for in the nominal diameter. 

Fig. 6 (a) 2-D 7) maps, (b) their 1-D central cross sections, and (c) the 1-D profiles of hexachloroplatinate dianion distributions obtained by electron probe analyzer measurements. S-2 and S-3 identify different porous alumina pellets, both prepared with an egg-shell distribution of hexachloroplatinate dianion the dianion is located towards the external surface of the pellet). S-2 and S-3 differ in terms of their nominal diameter and their pore-size and surface-area characteristics. Reprinted with permission from ref. 24. Copyright (2000) American Chemical Society. 

However, in the typical case of an irregular-shaped particle, it is not easy to calculate its volume and thus dsph is taken equal to the mean nominal diameter measured by sieve analysis dp. In the present book, dp is considered to be equal to the average sieve diameter. 

Sources Hard et al. (80) and Smith and Crosley (103). Smith and Crosley performed calculations for 100-ppbv 03 their results are halved here for comparison. Differing predictions from these two references are due largely to Smith and Crosley s use of 1-mJ nominal laser energy and a 0.4-cm beam diameter compared to Hard et al. s 0.6-mJ measured energy and measured multipass diameters alternating between 0.6 and 0.4 cm. 

The most important property characterizing a microporous membrane is the pore diameter (d). Some of the methods of measuring pore diameters are described in Chapter 7. Although microporous membranes are usually characterized by a single pore diameter value, most membranes actually contain a range of pore sizes. In ultrafiltration, the pore diameter quoted is usually an average value, but to confuse the issue, the pore diameter in microfiltration is usually defined in terms of the largest particle able to penetrate the membrane. This nominal pore diameter can be 5 to 10 times smaller than the apparent pore diameter based on direct microscopic examination of the membrane. 

Nominal Diameter Measured Diameter Input Mass Measured Mass (pm) (pm) Fraction Fraction... 

Nominal Diameter Measured Diameter Input Mass Measured Mass... 

The accuracy obtainable by using this approach can be seen from the results in Figure 5, which were obtained for polystyrene latexes with nominal diameters of 0.804 and 1.09 pm. The diameters calculated from the peak positions were, respectively, 0.789 and 1.093 pm, based on a measured density of 1.048 g/cm3 for these latexes. The small peak at 1.3 pm in Figure 5 is attributed to doublets of the 1.09-pm latex. Although the ratio of the sedimentation times of these two peaks (1.09 and 1.3 pm) is close... 

There are 210,000 particles per cu cm in a packing whose voids by measurement amount to 34.6 percent. Calculate the nominal diameter of the particles in mm units. 

DeMaria and White13 measured the gas holdup in a 10.16-cm diameter column packed with unglazed porcelain Raschig rings of 0.635,0.953, and 1.27 cm nominal diameter. The heights of the column, i.e., 91.44 and 122 cm, were examined. All data were taken under trickle-flow conditiojis. Helium and mixtures of helium and nitrogen were used as tracers in either step or pulse inputs. The gas holdups were calculated from the RTD curves and they were correlated by a dimensionless expression... 

The ASME Boiler and Pressure Vessel Code, Division VIII, Section 1, Paragraph UG-81 permits an out of roundness maximum of 1% variation of all diameters from the nominal diameter. This is not sufficient to assure a satisfactory CRM lining. A German standard DIN 28050, Section 4 (10.54 issue) specifies that the roundness shall be determined by measuring the radians and that the radians must not vary more than +0.4% from the average value in the cylindrical part of the apparatus to be CRM lined after final erection. 

Sood and Jackson (1970) have measured the collection efficiency for various aerosols by falling ice particles with nominal diameters in the range 1-10 mm. The general behavior of the capture efficiency with the size of aerosol particles was found to be similar to that for water drops. Quantitative differences arise from the different shape of the ice crystals and the corresponding changes in hydrodynamic flow patterns. 

Determining the volumetric probing deviation P and comparing it to MPEp A calibrated test sphere, with a nominal diameter between 10 and 50 mm, is measured using 25 measurement points distributed on its surface, as prescribed by the standard. A Gaussian least squares sphere is calculated based on these 25 coordinate measurements. The value of P is the distance between the maximum and minimum deviation from the calculated sphere. The value describes the deviation of form measurements, e.g., flatness or cylindricity deviation in single-point modus. 

One of the first AFM studies of DLforces was carried out by Hillier and Bard [41]. They measured the interaction force between a gold electrode and a modified AFM probe, as a function of electrode potential, electrolyte concentration, and chemical identity of the anion. A sifica sphere (10-20 p,m nominal diameter) attached to the end of the AFM cantilever functioned as the tip. This probe geometry is often adopted in AFM force measurements, in conjunction with a planar substrate, as the tip-sample geometry is well... 

For a sphere, < >5 = 1.0. For a cylinder where the diameter = length, d>s is calculated to be 0.874 and for a cube, 4>s is calculated as 0.806. For granular materials it is diflScult to measure the actual volume and surface area to obtain the equivalent diameter. Hence, Dp is usually taken to be the nominal size from a screen analysis or visual length measurements. The surface area is determined by adsorption measurements or measurement of the pressure drop in a bed of particles. Then Eq. (3.1—23) is used to calculate (f>s (Table 3.1-1). Typical values for many crushed materials are between 0.6 and 0.7. For convenience for the cylinder and the cube, the nominal diameter is sometimes used (instead of the equivalent diameter) which then gives a shape factor of 1.0. 

We have carried out a series of measurements with water suspensions of PSL spheres seeded with TFA. The spheres were supplied by Duke Scientific as calibrated size standards with nominal diameters as shown in Table I, and with an unknown standard deviation. The table shows also the electrical conductivity of the corresponding solutions as well as the ratio between dmin from equation 3 and the nominal sphere diameter. All the solutions were electrosprayed into CO2 because the high surface tension of water requires large voltages for the cone-jet to set in, which tends to produce electrical breakdown when the gas is air (26, 19), The aerosol is sampled from the spray region and passed through the DMA. This instrument operates in such a way that the exiting aerosol is carried in dry air, and its selected mobility corresponds neaiiy to that in air rather than in CO2. 

Cores cut from outcrops that are quarried for building stone are commonly used in studies of oil recovery. For this study a total of 61 core plugs, each with a nominal length of 0.5 in and a nominal diameter of 1.5 in, were cut from 19 different rocks. Some of them are cunently in use for laboratory studies of oil recovery. 18 of the core plugs were carbonates (lim tones) and 43 were sandstones. The cores were washed, dried at ambient temperature for one day and then oven dried at 110 C for two days. The permeability to nitrogen, kg, was measured in a Hassler-type core holder at a confining pressure of 2.07 MPa (300 psi). Porosity was calculated from the increase in mass after saturation under vacuum with water. Permeability, porosity, BET surface area and cation exchange capacity (CEC) of each rock sample are listed in Table 1. 

Determiimtum of Shrinkage Allowances. The inner bore of the part to be shrunk on is given the nominal diameter. After finish-machining of this bore, the actual dimension, which must be well in the permissible tolerances, is measured and from this value is determined the outside diameter of the inner part which must be larger by the shrinkage allowance s. 

Dimensions and tolerance (A, Do, h, SDR, SIDR) measured in accordance with ASTM D 2122, ISO 3126 or EN 1636-5. The International Standards ISO 11922 with Part 1-metric series and part 2-inch based series specified tolerance grades for outside diameter, out-of roundness, and wall thickness of polyolefin pipes for conveyance of fluids. They are manufactures with nominal diameters and nominal pressure in accordance with ISO 161-1 and nominal wall thickness in accordance with ISO 4065. 

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