The individual laboratory method compared with the lecture-demonstration method in teaching general biology

1947 ◽  
Vol 31 (3) ◽  
pp. 175-179 ◽  
Author(s):  
George Greisen Mallinson
2018 ◽  
Vol 8 (11) ◽  
pp. 2275 ◽  
Author(s):  
Barouch Giechaskiel ◽  
Simone Casadei ◽  
Michele Mazzini ◽  
Mario Sammarco ◽  
Gisella Montabone ◽  
...  

The recently introduced Real Driving Emissions (RDE) light-duty vehicle emissions regulation requires testing with Portable Emissions Measurement Systems (PEMS) during type approval and in-service conformity. The studies on the accuracy of PEMS today are limited. An inter-laboratory correlation exercise with PEMS took place in Italy in 2017. Eight laboratories measured exhaust emissions from a Golden Euro 6 gasoline vehicle with a Golden PEMS installed in it, along with the individual lab’s own PEMS, following the regulated laboratory method (bags from the dilution tunnel). The data of the exercise were used to estimate the repeatability and reproducibility of the methodology with PEMS. The statistical analysis estimated reproducibility of 2.9% (bags) to 5.5% (lab PEMS) for CO2, 20–25% for CO (all methods), 23–31% for NOx (all methods), and 29% (tunnel, Golden PEMS) to 39% (lab PEMS) for particle number. The mean differences of the PEMS to the regulated method were ±1.5 g/km (or ±1%) for CO2, <16 mg/km (or <5%) for CO, <4 mg/km (or <11%) for NOx and 1 × 1011 particles/km (40%) for particle number. The results of this study confirm the satisfactory performance of PEMS and the permissible tolerances introduced in RDE regulation.


1998 ◽  
Vol 44 (3) ◽  
pp. 614-621 ◽  
Author(s):  
Paul F H Franck ◽  
Gerard Steen ◽  
Arnold J P F Lombarts ◽  
John H M Souverijn ◽  
Robert K A van Wermeskerken

Abstract A region consisting of 19 clinical laboratories harmonized their calibration of seven common enzymes by using fresh patient-pool sera. One of the laboratories was chosen to act as Regional Reference Laboratory (RRL). This laboratory used internationally accepted (mostly IFCC) methods at 37 °C, with an intralaboratory CV ≤2.5%. First, the reference ranges of the RRL were verified by analysis of a reference population and calculation of the results by a parametric method. Next, all laboratories, including the RRL, received six patient-pool sera and analyzed them at the same time on the same date. Enzyme calibration factors at each laboratory were converted on the basis of the slope, and occasionally the intercept, of regression analysis with the RRL and the individual laboratory. Before harmonization, the interlaboratory CVs varied from 16.9% to 61.6%. After harmonization, CVs decreased to between 5.0% and 9.5%. These results proved to be reproducible over a period of more than a year. Using internationally accepted inaccuracy and imprecision criteria, the achieved interlaboratory CVs permit the use of one set of reference ranges by all participating laboratories. Certified Reference Materials were analyzed, resulting in interlaboratory CVs as low as those achieved with patient-pool sera. These materials can act as commutable reference preparations, except for creatine kinase.


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