Accuracy Of Calibration Models Research Articles

Adaptive calibration scheme for quantification of nutrients and byproducts in insect cell bioreactors by near-infrared spectroscopy.

Spectroscopic methods are gaining in popularity in biotechnology because of their ability to deliver rapid, noninvasive measurements of the concentrations of multiple chemical species. Such measurements are particularly necessary for the implementation of control schemes for cell culture bioreactors. One of the major challenges to the development of spectroscopic methods for bioreactor monitoring is the generation of accurate and robust calibration models, particularly because of the inherent variability of biological processes. We have evaluated several methods of building calibration models, including synthetic calibrations and medium spiking methods. The approach that consistently produced reliable models incorporated samples removed from a bioreactor that were subsequently altered so as to increase the sample variation. Several large volume samples were removed from a bioreactor at varying time points and divided into multiple aliquots to which were added random, known amounts of the analytes of interest. Near-infrared spectra of these samples were collected and used to build calibration models. Such models were used to quantify analyte concentrations from independent samples removed from a second bioreactor. Prediction errors for alanine, glucose, glutamine, and leucine were 1.4, 1.0, 1.1, and 0.31 mM, respectively. This adaptive calibration method produces models with less error and less bias than observed with other calibration methods. Somewhat more accurate measurements could be attained with calibrations consisting of a combination of synthetic samples and spiked medium samples, but with an increase in calibration development time.

Calibration of an integrated hydrogen gas-sensing system

Calibration of an integrated hydrogen gas-sensing system

Numerical simulation of SiGe HBT's at cryogenic temperatures

This paper describes SCORPIO, a new one-dimensional, drift-diffusion simulator for modeling silicon-germanium heterojunction bipolar transistors (SiGe HBT's) over a wide temperature range (77-400K). SCORPIO will be used to investigate fundamental low-temperature device physics problems and key device design issues. Comparisons of simulation results with experimental measurements are being used to ensure accurate model calibration

Assuring Accurate Model Calibration

Water distribution system models are only as good as the data with which they are calibrated. Simply comparing predicted and observed pressures during normal use cannot ensure accuracy. Some tips for calibration are presented.

Simple and accurate calibration model for hydrogen-content, .beta.-particle backscatter gauges

Simple and accurate calibration model for hydrogen-content, .beta.-particle backscatter gauges

A Simple and Accurate Calibration Model for Hydrogen-Content, Beta-Particle Transmission Gauges.

A Simple and Accurate Calibration Model for Hydrogen-Content, Beta-Particle Transmission Gauges.