Correction method for quantitative area determination of overlapping chromatographic peaks based on the exponentially modified Gaussian (EMG) model

1987 ◽  
Vol 10 (8) ◽  
pp. 449-454 ◽  
Author(s):  
Lin Binsheng ◽  
Lu Peichang
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karine Arrhenius ◽  
Oliver Büker

AbstractThe study presents an optimised method to correct flow rates measured with a LFE flowmeter pre-set on methane while used for gas mixtures of unknown composition at the time of the measurement. The method requires the correction of the flow rate using a factor based on the viscosity of the gas mixtures once the composition is accurately known. The method has several different possible applications inclusive for the sampling of biogas and biomethane onto sorbent tubes for conformity assessment for the determination of siloxanes, terpenes and VOC in general. Five models for the calculation of the viscosity of the gas mixtures were compared and the models were used for ten binary mixtures and four multi-component mixtures. The results of the evaluation of the different models showed that the correction method using the viscosity of the mixtures calculated with the model of Reichenberg and Carr showed the smallest biases for binary mixtures. For multi-component mixtures, the best results were obtained when using the models of Lucas and Carr.


2012 ◽  
Vol 463-464 ◽  
pp. 1277-1280 ◽  
Author(s):  
Constantin Bucşan ◽  
Mihai Avram

This paper presents a method for increasing the speed and the positioning accuracy of the positioning systems with mechanical position feedback. The method consists in using a position transducer for real time determination of the position of the load and correcting this position using an adequate algorithm. It is preferable not to modify the construction of the positioning unit, allowing the user to decide when to use this correction method according to the practical application. An interesting solution to this problem is to use an external space-position finding sensing system, as presented in the paper.


1975 ◽  
Vol 97 (1) ◽  
pp. 45-51 ◽  
Author(s):  
M. Jolles ◽  
J. J. McGowan ◽  
C. W. Smith

A technique consisting of stress-freezing photoelasticity coupled with a Taylor Series Expansion of the maximum local in-plane shearing stress known as the Taylor Series Correction Method (TSCM) is applied to the determination of stress intensity factors (SIF’s) in flat bottomed surface flaws of flaw depth/length ratios of approximately 0.033. Flaw depth/thickness ratios of approximately 0.20 and 0.40 were studied as were plate width/crack length ratios of approximately 2.33 and 1.25, the former of which corresponded to a nearly infinite width. Agreement to well within 10 percent was found with the Rice-Levy and Newman theories using a depth-modified secant correction and equivalent flaw depth/length ratios. The Shah-Kobayashi Theory, when compared on the same basis, was lower than the experimental results. Using a modified net section stress correction suggested by Shah, agreement with the Shah-Kobayashi Theory was greatly improved but agreement with the other theories was poorer. On the basis of the experiments alone, it was found that the SIF was intensified by about 10 percent by decreasing the plate width/crack length from 2.33 to 1.25.


2018 ◽  
Vol 73 ◽  
pp. 03004
Author(s):  
Lidya Ernawati ◽  
Sutrisno Anggoro

Population increased has consequences for the economic development of land demands for agriculture, settlement and other infrastructure. This resulted the change of area land cover which impact on the climate change and decline the environmental quality. Therefore, it is necessary to improve the environment through the land rehabilitation activities. The analysis of land cover change is needed as the first step to identify areas targeted by the land rehabilitation. Geographic information system is used as a spatial based on the appropriate determination of rehabilitation activities


2015 ◽  
Vol 1 (3) ◽  
pp. 151
Author(s):  
Sojitra Rajanit ◽  
Paras Virani ◽  
Hashumati Raj

A new simple, economical, precise and accurate method are described for the simultaneous determination of Nifedipine (NIF) and Metoprolol Succinate (MET) in combined tablet dosage form. The proposed method was applied for the determination of Nifedipine and Metoprolol Succinate in synthetic mixture, for determination of sampling wavelength, 10?g/ml of each of NIF and MET were scanned in 200-400 nm range and sampling wavelengths were 313nm for NIF and 275.40nm for MET are selected for development and validation of absorption correction method. For this method linearity observed in the range of 5-25?g/ml for NIF and 25-125?g/ml for MET, and in their pharmaceutical formulation with mean percentage recoveries 100.68 and 100.33, respectively. The method was validated according to ICH guidelines and can be applied for routine quality control testing.


1965 ◽  
Vol 48 (5) ◽  
pp. 952-954
Author(s):  
Alfred D Thruston

Abstract The qualitative and quantitative determination of chlordane residues on raw agricultural products has been best achieved by gas chromatography techniques. While good recoveries (90–100% at the 0.1 ppm level) have been obtained from plant extracts with added standard chlordane, weathered chlordane residues show changes in number and size of gas chromatographic peaks. Chlordane at the 50 µg level, when exposed to the air at room temperature over a period of time, showed progressive decomposition and loss of the many components that make up chlordane.


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