The Experts below are selected from a list of 61821 Experts worldwide ranked by ideXlab platform
H J B Birks - One of the best experts on this subject based on the ideXlab platform.
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chironomid inferred late glacial and early holocene mean july air temperatures for krakenes lake western norway
Journal of Paleolimnology, 2000Co-Authors: Stepehn J Brooks, H J B BirksAbstract:A chironomid data-set calibrated to July air temperatures, based on 44 lakes in western Norway, is used to reconstruct mean July air temperatures from late-glacial and early-Holocene fossil chironomid assemblages at Krakenes Lake. The Calibration Function is based on Weighted Averaging Partial Least Squares regression and has a root mean square error of prediction (RMSEP) of 1.13 °C, a r2 of 0.69, and a maximum bias of 2.66 °C. All these statistics are based on leave-one-out cross-validation. A Calibration Function based on summer surface-water temperatures has a poorer performance (RMSEP = 2.22 °C, r2 = 0.30, maximum bias = 5.29 °C). The reconstructed July air temperatures at Krakenes rise to 10.5 °C soon after deglaciation, are about 11.5 °C in the Allerod, decrease to 9.5-10 °C in the Younger Dryas, and rise rapidly within 15 yrs to 11.5 °C at the onset of the Holocene. There is a two-step rise to 13 °C or more in the early-Holocene. The likely over-estimation of Younger Dryas temperatures and under-estimation of early-Holocene temperatures probably result from the limited temperature range represented by the existing Calibration set. The data set is currently being expanded to include lakes with warmer air temperatures (> 14 °C) and with colder air temperatures (< 8 °C).
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chironomid inferred late glacial and early holocene mean july air temperatures for krakenes lake western norway
Journal of Paleolimnology, 2000Co-Authors: Stepehn J Brooks, H J B BirksAbstract:A chironomid data-set calibrated to July air temperatures, based on 44 lakes in western Norway, is used to reconstruct mean July air temperatures from late-glacial and early-Holocene fossil chironomid assemblages at Krakenes Lake. The Calibration Function is based on Weighted Averaging Partial Least Squares regression and has a root mean square error of prediction (RMSEP) of 1.13 °C, a r2 of 0.69, and a maximum bias of 2.66 °C. All these statistics are based on leave-one-out cross-validation. A Calibration Function based on summer surface-water temperatures has a poorer performance (RMSEP = 2.22 °C, r2 = 0.30, maximum bias = 5.29 °C). The reconstructed July air temperatures at Krakenes rise to 10.5 °C soon after deglaciation, are about 11.5 °C in the Allerod, decrease to 9.5-10 °C in the Younger Dryas, and rise rapidly within 15 yrs to 11.5 °C at the onset of the Holocene. There is a two-step rise to 13 °C or more in the early-Holocene. The likely over-estimation of Younger Dryas temperatures and under-estimation of early-Holocene temperatures probably result from the limited temperature range represented by the existing Calibration set. The data set is currently being expanded to include lakes with warmer air temperatures (> 14 °C) and with colder air temperatures (< 8 °C).
Elio Desimoni - One of the best experts on this subject based on the ideXlab platform.
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Determination of Theophylline at a Cysteic Acid Modified Glassy Carbon Electrode
Electroanalysis, 2009Co-Authors: Barbara Brunetti, Elio DesimoniAbstract:A glassy carbon electrode modified with electrodeposited cysteic acid is proposed for the determination of theophylline. Estimation of the linear range, Calibration Function and limit of detection, as well as determination in real samples such as medication tablets were performed.
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a program for the weighted linear least squares regression of unbalanced response arrays
Analyst, 1999Co-Authors: Elio DesimoniAbstract:A program is described to establish Calibration diagrams by weighted, linear, least-squares regression of unbalanced response arrays. Whatever the confidence level, the number of analysed standard solutions and of their available replicates, the program allows (i) testing for scedasticity, linearity, outliers and normality, (ii) evaluation of slope and intercept of the Calibration Function and their confidence interval and (iii) evaluation of an unknown concentration and its confidence interval by interpolation/extrapolation. For negative results of the linearity test, the program structure allows a rapid evaluation of data to be discarded to attempt entering the linear range. The program was validated by analysing response arrays obtained by adding a Gaussian noise to known response/concentration Functional relationships. The results of validation tests led to the implementation of an empirical but efficient way to correct regression results when certain experimental situations lead to unjustified over-weighting of some responses. The analysis of some real Calibration data sets allows the versatility of the software to be evaluated.
Barbara Brunetti - One of the best experts on this subject based on the ideXlab platform.
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Determination of Theophylline at a Cysteic Acid Modified Glassy Carbon Electrode
Electroanalysis, 2009Co-Authors: Barbara Brunetti, Elio DesimoniAbstract:A glassy carbon electrode modified with electrodeposited cysteic acid is proposed for the determination of theophylline. Estimation of the linear range, Calibration Function and limit of detection, as well as determination in real samples such as medication tablets were performed.
Carlos A Martinezhuitle - One of the best experts on this subject based on the ideXlab platform.
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cysteic acid modified glassy carbon electrode for monitoring oxalic acid oa concentration during its electrochemical oxidation at ti pt anode
Electroanalysis, 2014Co-Authors: Eliane Goncalves De Araujo, Alexsandro Jhones Dos Santos, Djalma Ribeiro Da Silva, Ricardo Salazar, Carlos A MartinezhuitleAbstract:The aim of this manuscript is to develop a combined method for the detection and elimination of oxalic acid (OA) in aqueous environment. For that, the surface of glassy carbon (GC) electrode has been modified by oxidation of L-cysteine using cyclic voltammetric (CV) technique. After modification, the formation of a compact and uniform cysteic acid layer film was achieved and it was confirmed by surface analysis (scanning electron microscopy (SEM) and atomic force microscopy (AFM)). Estimation of the linear range, Calibration Function and limit of detection for OA were performed by differential pulse voltammetry using Cysteine-modified electrode (Cysteine-MGC). Due to its stability and sensitive response to OA, it was used for monitoring OA during its electrochemical oxidation at Ti/Pt anode. DPV analyses have been compared with classic titration method and HPLC achieving a good fit, confidence intervals and limits. The results are described and discussed in the light of the existing literature.
Stepehn J Brooks - One of the best experts on this subject based on the ideXlab platform.
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chironomid inferred late glacial and early holocene mean july air temperatures for krakenes lake western norway
Journal of Paleolimnology, 2000Co-Authors: Stepehn J Brooks, H J B BirksAbstract:A chironomid data-set calibrated to July air temperatures, based on 44 lakes in western Norway, is used to reconstruct mean July air temperatures from late-glacial and early-Holocene fossil chironomid assemblages at Krakenes Lake. The Calibration Function is based on Weighted Averaging Partial Least Squares regression and has a root mean square error of prediction (RMSEP) of 1.13 °C, a r2 of 0.69, and a maximum bias of 2.66 °C. All these statistics are based on leave-one-out cross-validation. A Calibration Function based on summer surface-water temperatures has a poorer performance (RMSEP = 2.22 °C, r2 = 0.30, maximum bias = 5.29 °C). The reconstructed July air temperatures at Krakenes rise to 10.5 °C soon after deglaciation, are about 11.5 °C in the Allerod, decrease to 9.5-10 °C in the Younger Dryas, and rise rapidly within 15 yrs to 11.5 °C at the onset of the Holocene. There is a two-step rise to 13 °C or more in the early-Holocene. The likely over-estimation of Younger Dryas temperatures and under-estimation of early-Holocene temperatures probably result from the limited temperature range represented by the existing Calibration set. The data set is currently being expanded to include lakes with warmer air temperatures (> 14 °C) and with colder air temperatures (< 8 °C).
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chironomid inferred late glacial and early holocene mean july air temperatures for krakenes lake western norway
Journal of Paleolimnology, 2000Co-Authors: Stepehn J Brooks, H J B BirksAbstract:A chironomid data-set calibrated to July air temperatures, based on 44 lakes in western Norway, is used to reconstruct mean July air temperatures from late-glacial and early-Holocene fossil chironomid assemblages at Krakenes Lake. The Calibration Function is based on Weighted Averaging Partial Least Squares regression and has a root mean square error of prediction (RMSEP) of 1.13 °C, a r2 of 0.69, and a maximum bias of 2.66 °C. All these statistics are based on leave-one-out cross-validation. A Calibration Function based on summer surface-water temperatures has a poorer performance (RMSEP = 2.22 °C, r2 = 0.30, maximum bias = 5.29 °C). The reconstructed July air temperatures at Krakenes rise to 10.5 °C soon after deglaciation, are about 11.5 °C in the Allerod, decrease to 9.5-10 °C in the Younger Dryas, and rise rapidly within 15 yrs to 11.5 °C at the onset of the Holocene. There is a two-step rise to 13 °C or more in the early-Holocene. The likely over-estimation of Younger Dryas temperatures and under-estimation of early-Holocene temperatures probably result from the limited temperature range represented by the existing Calibration set. The data set is currently being expanded to include lakes with warmer air temperatures (> 14 °C) and with colder air temperatures (< 8 °C).
