SA, standard

Added NaOH (normality) Number of Determinations Rt (ratio of counting times) Sa (standard deviation)... 

There is still only the early direct measurement of the formal reduction potential for U + -l-e"- U +,-0.63lV (Sa). Standard values are less accurate, because of uncertainties in the necessary activity corrections or extrapolation values of -0.607 and -0.596 V (S6) have been estimated but a larger value of -0.52 V has been proposed as more compatible with data on the enthalpies of formation of the hydrated... 

IEEE Standards documents are developed within the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Association (lEEE-SA) Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Instimte. The standards developed within IEEE represent a consensns of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an interest in participating in the development of the standard. 

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When the lEEE-SA Standards Board approved this standard on 8 December 1998, it had the following membership ... 

SA standard addition. This term refers to the situation in which the method of standard additions has been used, adding the spike in aqueous solution form. 

Wise SA. Standard reference materials (SRMs) for the determination of polycyclic aromatic compounds—twenty years of progress. Polycyd Aromat Comp 2002 22(3—4) 197—230. 

The inspection class SA is based on the requirements of real-time serial inspection that are covered by standard minifocus X-ray tubes. 

Propagation of uncertainty allows us to estimate the uncertainty in a calculated result from the uncertainties of the measurements used to calculate the result. In the equations presented in this section the result is represented by the symbol R and the measurements by the symbols A, B, and C. The corresponding uncertainties are sr, sa, sb) and sq. The uncertainties for A, B, and C can be reported in several ways, including calculated standard deviations or estimated ranges, as long as the same form is used for all measurements. 

Unpaired Data Consider two samples, A and B, for which mean values, Xa and Ab, and standard deviations, sa and sb, have been measured. Confidence intervals for Pa and Pb can be written for both samples... 

It is unclear, however, how many degrees of freedom are associated with f(a, v) since there are two sets of independent measurements. If the variances sa and sb estimate the same O, then the two standard deviations can be factored out of equation 4.19 and replaced by a pooled standard deviation. Spool, which provides a better estimate for the precision of the analysis. Thus, equation 4.19 becomes... 

Since the analyte and internal standard in any sample or standard receive the same treatment, the ratio of their signals will be unaffected by any lack of reproducibility in the procedure. If a solution contains an analyte of concentration Ca, and an internal standard of concentration, Cis, then the signals due to the analyte, Sa, and the internal standard. Sis, are... 

A sixth spectrophotometric method for the quantitative determination of Pb + levels in blood uses CQ+ as an internal standard. A standard containing 1.75 ppb Pb + and 2.25 ppb CQ+ yields a ratio of Sa/Sis of 2.37. A sample of blood is spiked with the same concentration of Cu +, giving a signal ratio of 1.80. Determine the concentration of Pb + in the sample of blood. 

A single-point internal standardization has the same limitations as a singlepoint normal calibration. To construct an internal standard calibration curve, it is necessary to prepare several standards containing different concentrations of analyte. These standards are usually prepared such that the internal standard s concentration is constant. Under these conditions a calibration curve of (SA/Sis)stand versus Ca is linear with a slope of K/Cis-... 

When the internal standard s concentration cannot be held constant the data must be plotted as (SA/Sis)stand versus Ca/Cis, giving a linear calibration curve with a slope of K. 

Methods for improving the precision of absorption measurements (a) high-absorbance method (b) low-absorbance method and (c) maximum precision method. Abbreviations Sa = sample St = standard. 

API Standard 618, Reciprocating Compressors for General Refinery Sa vices. Fourth Edition, Washington, D.C. American Petroleum InstiuiiL... 

Photographic standards and written descriptions of various stages of visual cleanness of steel surfaces after surface preparation by blasting are available in British Standard 7079 Part A1.1989, Series Sa. ... 

All metal surfaces such as mild steel should be grit blasted, normally to SA 2-5 as defined in Swedish Standard SIS 055900. If the surfaces are contaminated with oil, grease or a chemical from previously used items, the contamination is usually removed by sweating in steam prior to grit blasting. Concrete surfaces must be clean and dry and any laitence must be removed as it will affect the bond of the lining. Preferably the surface should be grit blasted. 

The standard deviation from one set of 11 determinations was sA = 0.210, and the standard deviation from another 13 determinations was sB = 0.641. Is there any significant difference between the precision of these two sets of results From equation (3)... 

The errors arising in sampling, particularly in the case of heterogeneous solids, may be the most important source of uncertainty in the subsequent analysis of the material. If we represent the standard deviation of the sampling operation (the sampling error) by ss and the standard deviation of the analytical procedures (the analytical error) by sA, then the overall standard deviation sT (the total error) is given by... 

Notes. (1) Krypton-filled detector. (2) Tungsten content 0.0240 gram of tungsten per gram of solution. (3) Each determination complete and independent except that aliquots of the same solution were used for an entire series. (4) sa is the standard deviation, as usually defined, for a single determination. 

A further aspect that may add to the development work relates to the method of administration. In addition to the standards methods of administration associated with human medicines, veterinary medicines may be introduced to animals through medicated feeds. Such practices have been most commonly associated with the use of antibiotics or other substances to enhance animal performance under intensive farming systems. The use of medicated feeds has been phased out in Europe since the end of 2005, with the exception of coccidiostats and histomonostats intended to kill or inhibit protozoa. In the U SA, however, medicated feeds are still commonplace. Thus, the developer may have to consider the stability and appropriate labelling of the drug when compounded into medicated feeds. 

The difference in rates of release of BCNU from wafers produced by the trituration or solution methods is also seen in vivo (11,14), as is shown in Fig. 6. Wafers of PCPP-SA 20 80 were prepared by either the solution or trituration methods, as described above, and were implanted into the brains of rabbits. The animals were sacrificed at various times after implantation and the brains were removed, fixed, and processed for quantitative autoradiography. To quantitate the percentage of the brain exposed to BCNU released from these wafers, the following calculation was performed. The percentage of the brain in which the radioactivity from the tritiated BCNU released from the wafers exceeded the background counts by at least two standard deviation units was plotted as a function of time following implantation in Fig. 6. A control set of rabbits had a solution of BCNU injected directly into the same location in the... 

Albers GW, Bates VE, Clark WM, Bell R, Verro P, Hamilton SA. Intravenous tissue-type plasminogen activator for treatment of acute stroke The Standard Treatment with Alteplase to Reverse stroke (STARS) study. JAMA. 2000 283 1145-1150. 

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