Evaluation of Measurement Uncertainty in Determination of Lead in Glass Materials by a Standard Complexometric Method

MAPAN ◽  
2012 ◽  
Vol 27 (3) ◽  
pp. 175-182 ◽  
Author(s):  
S. Basak ◽  
Dipali Kundu
Talanta ◽  
2021 ◽  
Vol 232 ◽  
pp. 122286
Author(s):  
María Melania Ramírez-Quesada ◽  
Jimmy Venegas-Padilla ◽  
José Pablo Sibaja-Brenes ◽  
Bryan Calderón-Jiménez

The Analyst ◽  
1976 ◽  
Vol 101 (1204) ◽  
pp. 516 ◽  
Author(s):  
Samaresh Banerjee ◽  
R. K. Dutta

2009 ◽  
Vol 52 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Cristiane Soído ◽  
Maurício Carvalho Vasconcellos ◽  
Antônia Gonçalves Diniz ◽  
Jairo Pinheiro

The complexometric method is usually applied to quantitative calcium determination in different materials; however the application of this method to calcium determination in molluscs shells infers significant interferences to the results. The snail Bradybaena similaris, a terrestrial gastropod, was used as experimental model to the improvement of this method. The shells were calcinated and dissolved in nitric acid, the hydrogen peroxide was also used to clarify the medium after the acid addition. The calcination procedure and the use of nitric acid reduced the significantly the interferences, allowing a major degree of destruction of the organic substances of the shell. The improvement of the calcium determination technique usually employed showed calcium content of 874.24 ± 56.617 mg of CaCO3/g of ash in comparison to the conventional technique that allowed the determination of 607.79 ± 67.751 mg of CaCO3/g of shell, wet weight.


Author(s):  
Klaus Brun ◽  
Rainer Kurz

Field testing of gas turbine compressor packages requires the accurate determination of efficiency, capacity, head, power and fuel flow in sometimes less than ideal working environments. Nonetheless, field test results have significant implication for the compressor and gas turbine manufacturers and their customers. Economic considerations demand that the performance and efficiency of an installation are verified to assure a project’s return on investment. Thus, for the compressor and gas turbine manufacturers, as well as for the end-user, an accurate determination of the field performance is of vital interest. This paper describes an analytic method to predict the measurement uncertainty and, thus, the accuracy, of field test results for gas turbine driven compressors. Namely, a method is presented which can be employed to verify the validity of field test performance results. The equations governing the compressor and gas turbine performance uncertainties are rigorously derived and results are numerically compared to actual field test data. Typical field test measurement uncertainties are presented for different sets of instrumentation. Test parameters that correlate to the most significant influence on the performance uncertainties are identified and suggestions are provided on how to minimize their measurement errors. The effect of different equations of state on the calculated performance is also discussed. Results show that compressor efficiency uncertainties can be unacceptably high when some basic rules for accurate testing are violated. However, by following some simple measurement rules and maintaining commonality of the gas equations of state, the overall compressor package performance measurement uncertainty can be limited and meaningful results can be achieved.


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