Determination of Asphaltene Critical Nanoaggregate Concentration Region Using Ultrasound Velocity Measurements

Asphaltenes constitute the heaviest, most polar and aromatic fraction of petroleum crucial to the formation of highlystable water-in-crude oil emulsions. The latter occur during crude oil production as well as spills and cause difficulties to efficient remediation practice. It is thought that in nanoaggregate form, asphaltenes create elastic layers around water droplets enhancing stability of the emulsion matrix. Ultrasonic characterisation is a high-resolution non-invasive tool in colloidal analysis shown to successfully identify asphaltene nanoaggregation in toluene. The high sensitivity of acoustic velocity to molecular rearrangements and ease in implementation renders it an attractive method to study asphaltene phase properties. Currently, aggregation is thought to correspond to an intersection of two concentration-ultrasonic velocity regressions. Our measurements indicate a variation in the proximity of nanoaggregation which is not accounted for by present models. We attribute this uncertainty to physico-chemical heterogeneity of the asphaltene fraction driven by variation in molecular size and propose a critical nanoaggregation region. We treated asphaltenes from North and South American crude oils with ruthenium ion catalysed oxidation to characterise their n-alkyl appendages attached to aromatic cores. Principal component analysis was performed to investigate the coupling between asphaltene structures and velocity measurements and their impact on aggregation

Reading Guide 6: The role of data analytics in decision-making.

Long linear infrastructure, e.g. highways and railways, includes large numbers of dispersed earthwork assets. Depending on their age and history, it can be practically impossible to constantly maintain up-to-date condition information. However, this data, and models using it, play a vital role in predicting earthwork behaviour and guiding intervention decision-making, which must take account of both the likelihood and consequences of asset failures. ACHILLES has developed novel surrogate models to help address uncertainty in earthwork assessment and make the most of limited data

Local Specifics of Vocabulary of Funeral and Memorial Rituals of Russian Prikamye

The relevance of the study is due to the increased interest in displaying the dialectic picture of the world as the most important component of ethnic culture. The issues of local originality of nominations of funeral and memorial ritual realities in Russian dialects of the Middle Prikamye are considered. A review of modern studies of folk funeral and memorial terminology is performed. Attention is paid to the substantive side of ritual terms, their motivation, symbolism, methods of education. The results of a comparative analysis of the semantics of the studied nominations with the data of other Russian dialects are presented. The question of nominative redundancy in the studied ritual sphere is raised, which is associated with the history of the formation of Perm dialects on the basis of North Russian and Volga dialects, with the coexistence of traditional beliefs, Orthodoxy and Old Believers in the folk cultural tradition of the Kama region. It is proved that most of the details and episodes of the funeral-memorial rituals in the Kama region have a specifically local language mapping. Particular attention is paid to the description of semantic groups with pronounced regional specifics (mythologies, names of funeral clothes and shoes, food, temporal nominations, names of ritual objects). It is shown that the terminological composition of the ritual sphere in Prikamye is in many respects correlated with the all-Russian dialect terminological system, while a considerable number of purely Permian nominations related to self-development of the dialect are fixed

Determination of Asphaltene Critical Nanoaggregate Concentration Region Using Ultrasound Velocity Measurements

Asphaltenes constitute the heaviest, most polar and aromatic fraction of petroleum crucial to the formation of highly-stable water-in-crude oil emulsions. The latter occur during crude oil production as well as spills and cause difficulties to efficient remediation practice. It is thought that in nanoaggregate form, asphaltenes create elastic layers around water droplets enhancing stability of the emulsion matrix. Ultrasonic characterisation is a high-resolution non-invasive tool in colloidal analysis shown to successfully identify asphaltene nanoaggregation in toluene. The high sensitivity of acoustic velocity to molecular rearrangements and ease in implementation renders it an attractive method to study asphaltene phase properties. Currently, aggregation is thought to correspond to an intersection of two concentration-ultrasonic velocity regressions. Our measurements indicate a variation in the proximity of nanoaggregation which is not accounted for by present models. We attribute this uncertainty to physico-chemical heterogeneity of the asphaltene fraction driven by variation in molecular size and propose a critical nanoaggregation region. We treated asphaltenes from North and South American crude oils with ruthenium ion catalysed oxidation to characterise their n-alkyl appendages attached to aromatic cores. Principal component analysis was performed to investigate the coupling between asphaltene structures and velocity measurements and their impact on aggregation

Electrochemical behavior of chloramphenicol on carbon electrodes in a microelectrochemical cell

Express determination of antibiotics is an extremely important task today. Portable electrochemical microdevices are a viable alternative to traditional methods of analysis. The development of such devices requires the study of redox processes in detail. This article is devoted to the comparative study of the electrochemical behavior of chloramphenicol in water solvents in standard laboratory and portable microelectrochemical cells. It was found that the electrochemical reduction of chloramphenicol proceeds via a 3-electron mechanism to the formation of a dimer. In the transition from the macrocell to the microcell, a decrease in the electrochemical reduction current and a shift of the peak potential to the cathode region are observed, which is apparently associated mainly with the type of the electrode material. The best characteristics of the direct electrochemical response were obtained in the differential pulse voltammetry mode. Under the selected operating parameters, the peak current of the electrochemical reduction of chloramphenicol is linearly dependent on the concentration of the antibiotic in the range of 2∙10–3–1∙10–5 M with a detection limit of 3∙10–5 M. Obtained characteristics are sufficient for the quality control of pharmaceuticals and can be improved through the use of organic and hybrid modifiers of the working electrode surface

A LABEL-FREE VOLTAMPEROMETRIC SENSOR BASED ON ELECTRIC CONDUCTIVE POLYMER COATINGS OF 3,4-ETHYLENEDIOXYTHIOPHENE / 3-ETHYNYLTHIOPHENE FOR DETERMINATION OF E.COLI AND S.AUREUS

This work was supported by a grant from the President of the Russian Federation for young scientists - candidates of sciences MK-567.2020.3

SMALL ORGANIC MOLECULES FOR SELECTIVE ELECTROCHEMICAL DETERMINATION OF NITROAROMATIC COMPOUNDS

The work was carried out with the financial support of the Russian Science Foundation grant No. 20-13-00142

Emulating long-term weather-driven transportation earthworks deterioration models to support asset management

The deterioration of transport infrastructure earthworks is a global problem, with negative impacts for infrastructure resilience, becoming of increasing significance as existing infrastructure ages. Key mechanisms which affect this deterioration include seasonal pore pressure cycling driven by changing weather and climate, and the long-term dissipation of construction induced excess pore pressures. These complex processes lead to significant uncertainty in rates of deterioration and the current state of existing earthworks assets. The objective in this work was to establish a framework to emulate deterministic numerical models of slope deterioration over time using statistical (Gaussian process) emulation. A validated, physically based, deterministic modeling capability has been developed that can replicate the hydro-mechanically coupled behavior of cut and embankment slopes and their deterioration as driven by weather and climate. In parallel, a statistical (Gaussian process) emulator model was developed, and then trained with data from a deterministic modeling parametric study, using a formal experimental design approach, making use of Latin hypercube sampling. Exemplar forecasting outputs are presented to demonstrate application of the approach for use in decision-making. This information can be used in the design of new earthworks and the management of existing earthwork portfolio

Determination of E. Coli in Water Using the Enzyme Free Electrochemical Impedimetric Immunosensors

In this article, we have shown the results of E. coli bacteria determination in water using the enzyme free electrochemical immunosensor with covalent via click chemistry immobilized receptor layer in comparison with dropwise immobilized antibodies. Covalent immobilization was realized by creating precursors on the surface of the working electrode with the reaction of azide-alkyne copper-catalysed cycloaddition approach. The detection limit of the immunosensor with covalent and dropwise immobilization of antibodies was estimated as 6.6 CFU/ml and 11.2 CFU/ml, respectively, a linear range was 103-106 CFU/ml. Moreover, the sensor with "click"immobilized antibodies showed good stability for 30 days when stored in a phosphate buffer, while the sensor with dropwise immobilized receptor layer was stable for 3 days. © Published under licence by IOP Publishing Ltd.This work was supported by the Presidential Grants Fund of the Russian Federation (grant MK-567.2020.3)