A new approach to the U.V.-spectral quantitative analysis of complex mixtures (petroleum products)

1993 ◽  
Vol 345 (7) ◽  
pp. 521-523 ◽  
Author(s):  
N. Dimov ◽  
N. Dimova ◽  
R. Milina
Keyword(s):  
Quantitative Analysis ◽  
Petroleum Products ◽  
Complex Mixtures ◽  
New Approach

A New Approach for the Analysis of Mixture Toxicity Data

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2345-2348 ◽  
Author(s):  
C. N. Haas
Keyword(s):  
Quantitative Analysis ◽  
Mixture Toxicity ◽  
New Method ◽  
Metal Exposure ◽  
Positive Interactions ◽  
Toxicity Data ◽  
Data Set ◽  
New Approach ◽  
Negative Interactions

A new method for the quantitative analysis of multiple toxicity data is described and illustrated using a data set on metal exposure to copepods. Positive interactions are observed for Ni-Pb and Pb-Cr, with weak negative interactions observed for Ni-Cr.

scholarly journals Nitrogen-containing aromatic compounds: quantitative analysis using gas chromatography with nitrogen phosphorus detector

2021 ◽  
Author(s):  
Yuan Rao ◽  
Arno de Klerk
Keyword(s):  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Aromatic Compounds ◽  
Process Development ◽  
Complex Mixtures ◽  
Response Factors ◽  
Cyanide Anion ◽  
Nitrogen Phosphorus Detector ◽  
Assurance Process ◽  
Nitrogen Containing Compounds

AbstractThe nitrogen-containing aromatic compounds found in the petrochemical industry are varied and extend beyond classes such as the anilines, pyrroles and pyridines. Quantification of these nitrogen-containing compounds that may occur in complex mixtures has practical application for quality assurance, process development and the evaluation of conversion processes. Selective detection of nitrogen-containing species in complex mixtures is possible by making use of gas chromatography coupled with a nitrogen phosphorous detector (GC-NPD), which is also called a thermionic detector. Despite the linearity of the NPD response to individual nitrogen-containing compounds, the response factor is different for different compounds and even isomers of the same species. Quantitative analysis using an NPD requires species-specific calibration. The reason for the sensitivity of the NPD to structure is related to the ease of forming the cyano-radical that is ionized to the cyanide anion, which is detected. The operation of the NPD was related to the processes of pyrolysis and subsequent ionization. It was possible to offer plausible explanations for differences in response factors for isomers based on pyrolysis chemistry. Due to this relationship, the NPD response can in the same way be used to provide information of practical relevance beyond its analytical value and a few possible applications were outlined.

scholarly journals Dynamic changes of the EEG structure during treatment of the ishaemic insult in the frame of the conception of nootropic stimulation

2008 ◽  
Vol 7 (5-1) ◽  
pp. 167-169
Author(s):  
N. S. Kovalyova ◽  
V. A. Balyasin ◽  
Yu. S. Maklyakov
Keyword(s):  
Quantitative Analysis ◽  
Spectral Power ◽  
Dynamic Changes ◽  
New Approach ◽  
Nootropic Agent ◽  
Weight Coefficients ◽  
Endogenous Melatonin

New approach to treatment of the ishaemic insult (IsI) was developed in the frame of the conception of nootropic stimulation, which include carrying out of nootropic agent (piracetam) with melaxen (analog of endogenous melatonin). For complex estimation condition of patient after IsI before treatment and after application of piracetam with melaxen methods of the quantitative analysis of EEG with the using of the multispectral indices, computed as ratio of the changing weight coefficients of spectral power in the different ranges of analysed EEG durig processes of the treatment of the patients with IsI.

Problems and Solutions in Quantitative Analysis of Complex Mixtures by X-Ray Powder Diffraction

1987 ◽  
Vol 31 ◽  
pp. 295-308 ◽  
Author(s):  
David L. Bish ◽  
Steve J. Chipera
Keyword(s):  
Quantitative Analysis ◽  
Amorphous Materials ◽  
Rietveld Method ◽  
Internal Standard ◽  
Preferred Orientation ◽  
Complex Mixtures ◽  
Calibration Data ◽  
Cell Parameters ◽  
Amorphous Phases ◽  
Standard Data

AbstractIn spite of the wide availability of automated diffractometers and advanced data reduction software, numerous traditional problems still exist that make highly precise and accurate quantitative analyses of complex mixtures difficult. The problems include particle statistics, primary extinction, microabsorption, preferred orientation, overlapping and broad reflections, variation in standard data with composition, availability of pure standards, and detection of amorphous and trace phases. Our analyses of rocks use the matrix flushing method on < 5μm particle-size material mixed with a 1.0-μm corundum internal standard to minimize the first four effects. Integrated intensities are used, and we employ several peaks from each phase whenever possible. We overcame overlap problems through iterative calculations using integral, multiple peaks or with profile refinement. Use of observed and calculated diffraction patterns for every phase enables us to predict the effects of composition and preferred orientation on RIRs. This allows us to correct for these effects if reference intensity ratios (RIRs) are known as a function of composition and orientation. Detection of amorphous phases is a significant problem, and standard mixtures reveal that amounts of amorphous components below 30% are difficult to detect. The poor detection limit and the nature of the diffraction band from amorphous phases make internal standard or spiking methods the best approach for analyzing samples containing amorphous materials. The Rietveld method of quantitative analysis has the potential to minimize all of the above problems. This method requires a knowledge of the crystal structures of all component crystalline phases, but no calibration data are necessary, structural and cell parameters can be varied during the refinement process, so that compositional effects can be accommodated and precise cell parameters can be obtained for every phase. Since this method fits the entire diffraction pattern and explicitly uses all reflections from every phase, complex, overlapped patterns can be easily analysed. In addition, this method presents the opportunity to correct for preferred orientation and microabsorption during data analysis.

scholarly journals A proposed approach to study the toxicology of complex mixtures of petroleum products: the integrated use of QSAR, lumping analysis and PBPK/PD modeling.

1997 ◽  
Vol 105 (suppl 1) ◽  
pp. 179-195 ◽  
Author(s):  
H J Verhaar ◽  
J R Morroni ◽  
K F Reardon ◽  
S M Hays ◽  
D P Gaver ◽  
...  
Keyword(s):  
Petroleum Products ◽  
Complex Mixtures ◽  
Lumping Analysis

Epitaxial hard magnetic SmCo5 MFM tips – a new approach to advanced magnetic force microscopy imaging

Nanoscale ◽  
2018 ◽  
Vol 10 (35) ◽  
pp. 16881-16886 ◽  
Author(s):  
Volker Neu ◽  
Silvia Vock ◽  
Tina Sturm ◽  
Ludwig Schultz
Keyword(s):  
Quantitative Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
External Fields ◽  
Microscopy Imaging ◽  
New Approach ◽  
Force Microscopy ◽  
Improved Performance ◽  
Magnetic Hardness

MFM tips nanofabricated from epitaxial SmCo5 films possess unprecedented magnetic hardness for improved performance in external fields and quantitative analysis.

An Approach to Analyse the Volume Flexibility of Production Systems

2014 ◽  
Vol 1018 ◽  
pp. 605-612
Author(s):  
Jan Busch ◽  
Matthias Görke ◽  
Dietmar Krämer
Keyword(s):  
Quantitative Analysis ◽  
Specific Volume ◽  
Production Systems ◽  
Research Work ◽  
Uncertain Demand ◽  
Future Research ◽  
Research Projects ◽  
New Approach ◽  
Volume Flexibility ◽  
Competitive Factor

Modern enterprises face the challenge of volatile markets. The multifarious influencing factors particularly include uncertain demand quantities. This means that it is increasingly important for production systems to be able to react quickly. At the same time, it is becoming more and more difficult to adequately depict this specific volume flexibility due to the complexity of the systems involved. Although existing research work has recognised flexibility as a decisive competitive factor for production systems, the focus until now has only been on qualitative investigations. Quantitative approaches are only found for specific problems. This paper presents a new approach to depict and analyse the volume flexibility of production systems in consideration of existing definitions and approaches. The resulting paths of investigation serve as approaches for future research projects for a quantitative analysis and optimisation of the volume flexibility of production systems.

A new approach to quantitative analysis of bainitic transformation in a superbainite steel

2013 ◽  
Vol 68 (11) ◽  
pp. 833-836 ◽  
Author(s):  
Guang Xu ◽  
Feng Liu ◽  
Li Wang ◽  
Haijiang Hu
Keyword(s):  
Quantitative Analysis ◽  
Bainitic Transformation ◽  
New Approach
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