Sampling weighted

In 1961, enough einsteinium was produced to separate a macroscopic amount of 253Es. This sample weighted about O.OlMg and was measured using a special magnetic-type balance. 253Es so produced was used to produce mendelevium (Element 101). 

In the presence of oxygen (air), the thermal decomposition of amphiboles is associated with an oxidation of divalent iron to trivalent iron, which may lead to an increase in the sample weight the oxidation process also induces an obvious color alteration, the fibers acquire the characteristic ferric oxide... 

Nonvolatile. A weighed amount of sample is placed ia a dryiag oven maintained at a temperature of 105°C. After three hours, the sample is removed from the oven, placed ia a desiccator to cool, and reweighed. The weight of the residue, consisting of soHds and nonvolatiles, is calculated as a percentage of the total sample weight taken for analysis. 

Example 2 Calculation of Error with Doubled Sample Weight, , , , 19-5... 

Example 3 Calculating Sample Weight for Screen-Size... 

Example 4 Calculation of Sample Weight for Surface Moisture... 

W and V are values for sample weights and variances of parameter measurements at states 1 and 2 respectively. 

Example 2 Calculation of Error with Doubled Sample Weight Repeated measurements from a lot of anhydrous alumina for loss on ignition established test standard error of 0.15 percent for sample weight of 500 grams, noting V is the square of s.e. Calculation of variance V and s.e. for a 1000 gram sample is... 

Example 3 Calculating Sample Weight for Screen-Size Measurement Weight W of bulk sample for screen analysis is calculated by the Gayle model for percent retained on a specified screen with relative standard error s.e. in percent... 

Sample weight estimated in this example is for two standard errors of 2.5 percent (resulting in V of 1.56) for testing iron ore (hematite) retained on a f4-in screen. Estimate of G is 5.5 for 94.5 percent of weight passing. Particle weight... 

Example 4 Calculation of Sample Weight for Surface Moisture Content An example is given with reference to material with minimal internal or pore-retained moisture such as mineral concentrates wherein physically adhering moisture is the sole consideration. With this simphfication, a moisture coefficient K is employed as miiltipher of nominal top-size particle size d taken to the third power to account for surface area. Adapting fundamental sampling theory to moisture sampling, variance is of a minimum sample quantity is expressed as... 

SPh ultramicrodetenuination methods were developed for P, B, Si from sample weights in 1-2 mg. 

When the sample weight is small (0.1-1.0mg), the determination of a trace component at the 0.01 per cent level may be referred to as subtrace analysis. If the trace component is at the microtrace level, the analysis is termed submicrotrace. With a still smaller sample (not larger than 0.1 mg) the determination of a component at the trace level is referred to as ultratrace analysis, whilst with a component at the microtrace level, the analysis is referred to as ultra-microtrace. 

When using a modern thermobalance which incorporates an electronic microbalance requiring small sample weights, the following operating precautions should be noted. 

If a trace is a major constituent, the sample weight is small, absorption and enhancement effects are negligible if the sample has appreciable area, and analytical intensity is at least roughly proportional to the amount present of the element sought. The justification for these statements appears in Sections 6.4, 6.5, and 7.4, where the foundations for this application have been laid. Clearly, this is the simplest of the various applications of x-ray emission spectrography, as von H mos and Engstrom appreciated in 1944.12... 

Head-group functionality of CISi-PaMeSt prepared by this Si-Cl containing functional initiator 1 in conjunction with Et2AlCl was investigated. The amount of Si-Cl head-group was determined by conductometry of the HC1 generated by hydrolysis of CISi-PaMeSt, and the theoretical amount of Si-Cl was calculated from the sample weight and Mn of CISi-PaMeSt. The results are shown in Table 4, where the Effective Functionality E. F. is2... 

DSC Calorimetry was done in a Perkin-Elmer DSC II at a scan rate of 20°C/min. The scale used is 2mcal/sec. full scale. Sample weight was 12" 20 mg. with an empty sample pan as reference. 

Light Source Exposure Time Oclachlorodibenzo-p-dioxin Formed Based on Total Sample Weight... 

Because of the fact that the NO conversion on AljO, increases faster than linearly with sample weight, the contribution of AI2O3 to the observed activity of AU/AI2O3 increases when a larger amount of catalyst is used, and at higher temperatures. When 0.1 g of catalyst is used, the data in Tables 2 and 3 show that A1,0, does not contribute much to the observed NO reduction... 

GPC chromatograms of AOT in benzene obtained with a 500 % + 100 A jjStyragel column set, and over a range of injected sample weights, are shown in Figure 1. The apparent peak molecular weight increases with the amount of sample applied to the columns. At higher sample loads, the value of Mn appears to ap-... 

Plot size should be large enough to apply the test material, to obtain more than twice the required samples (most crops require a total of 12-kg sample weight) and to be able to use appropriate harvesting equipment. 

The collected sample weight must be more than 4 kg in most crops at each sampling time. For light crops such as strawberry, 2 kg or more should be collected. The number of individual units sampled is more than 10 for crops such as watermelon, melon, cabbage, Chinese cabbage, radish, and pumpkin. 

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