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Interval Dependence Structures of Two Bivariate Distributions in Risk and Reliability
No full textWe follow the ideas of measuring strength of dependence between random events, presented at two previous MMR conferences in South Africa and Tokyo. In our work here we apply it for analyzing local dependence structure of some popular bivariate distributions. At the Grenoble conference presentation we focus on the Bivariate Normal distributions with various correlation coefficients, and on the Marshal-Olkin distribution with various parameter’s combinations. We draw the surface z = gii(x,y), i=1,2 of dependence of i-th component on the other component j≠i within the squares [x, x +1]x[y,y+1], and [x, x +.5]x[y,y+.5]. The points (x,y) run within the square [-3.5, 3.5]x[-3.5, 3.5] for Bivariate Normal distribution, and in [0.10]x[0,10] for the Marshal-Olkin distribution
Supplemetrary information for Sample preparation procedure using extraction and derivatization of carboxylic acids from aqueous samples by means of deep eutectic solvents for gas chromatographic-mass spectrometric analysis
No full textThe paper presents a new procedure for the determination of organic acids in a complex aqueous matrix using ultrasound-assisted dispersive liquid-liquid microextraction followed by injection port derivatization and GC-MS analysis. A deep eutectic solvent (choline chloride: 4-methylphenol in a 1:2 mol ratio) was used both as an extracting solvent and as a derivatizing agent to yield ion pairs which were next converted to methyl esters of organic acids in a hot GC injection port. The procedure was optimized in terms of selection of a deep eutectic solvent, disperser solvent, and the ratio of their volumes, pH, salting out effect, extraction time, injection port temperature and time of opening the split valve. The developed procedure is characterized by low LOD (1.7-8.3 μg/L) and LOQ (5.1-25 μg/L) values, good repeatability (RSD ranging from 4.0 to 6.7%), good recoveries for most of the studied analyte (81,5-106%) and a wide linear range. The procedure was used for the determination of carboxylic acids in real effluents from the production of petroleum bitumens. A total of ten analytes at concentrations ranging from 0.33 to 43.3 μg/mL were identified and determined in the effluents before and after chemical treatment. The study revealed that in effluents treated by hydrodynamic cavitation an increase in concentration of benzoic acid and related compounds was observed
The Multi-Mode Modulator: A Versatile Fluidic Device for Two-Dimensional Gas Chromatography
No full textA fluidic device called the multi-mode modulator (MMM) has been developed for use as a comprehensive two-dimensional gas chromatography (GC x GC) modulator. The MMM can be employed in a wide range of capacities including as a traditional heart-cutting device, a low duty cycle GC x GC modulator, and a full transfer GC x GC modulator. The MMM is capable of producing narrow component pulses (widths \u3c50 ms) while operating at flows compatible with high resolution chromatography. The sample path of modulated components is confined to the interior of a joining capillary. The joining capillary dimensions and the position of the columns within the joining capillary can be optimized for the selected modulation mode. Furthermore, the joining capillary can be replaced easily and inexpensively if it becomes fouled due to sample matrix components or column bleed. The principles of operation of the MMM are described and its efficacy is demonstrated as a heart-cutting device and as a GC x GC modulator
11/14/2018: Course Change Form Math 427
No full textThe name change from generic “Mathematical Statistics II” to specific “Probability and Stochastic Modeling” reflects the contents of this course
