Voltammetric Determination of Manganese on Organo – Modified Electrodes

The researches on the choice of aryldiazonium tosylate salts as a modifier to create an organo-modified electrode were carried out. It is shown that the best organic modifier for surface modification of a mercury-graphite electrode is aryldiazonium tosylate without a substituent. A method for producing an organo-modified electrode and the procedure for measuring the analytical signal of manganese by voltammetry was developed. The method is simple to implement and allows avoiding the use of metal mercury for forming the electrode, and making measurements without aerating of electrolyte by inert gases (nitrogen, argon) with an error (Sr) of not more than 10%

Voltammetric Determination of Manganese on Organo – Modified Electrodes

The researches on the choice of aryldiazonium tosylate salts as a modifier to create an organo-modified electrode were carried out. It is shown that the best organic modifier for surface modification of a mercury-graphite electrode is aryldiazonium tosylate without a substituent. A method for producing an organo-modified electrode and the procedure for measuring the analytical signal of manganese by voltammetry was developed. The method is simple to implement and allows avoiding the use of metal mercury for forming the electrode, and making measurements without aerating of electrolyte by inert gases (nitrogen, argon) with an error (Sr) of not more than 10%

РЕАЛИЗАЦИЯ ПРОЦЕССОВ УЧЕБНО-МЕТОДИЧЕСКОГО ОБЕСПЕЧЕНИЯ В ИНТЕГРИРОВАННОМ ИНФОРМАЦИОННООБРАЗОВАТЕЛЬНОМ ПРОСТРАНСТВЕ НА ОСНОВЕ СЕРВИСНОЙ АРХИТЕКТУРЫ1

The article presents the results of scientific research to develop methods and tools forthe creation and use of information-educational space in the formation and processing, learning objects and software servicesdistributed in the educational network and allows flexibility to implement the processesof training and methodological support ofeducational activities. The article defines the requirements for the meta-descriptionof learning objects and services, and alsopresents a description of technological processes of realization of basic software services training and methodological support.В статье отражены результаты научного исследования по разработке методов и средств создания и использования информационно-образовательного пространства в части формированияиобработкиучебныхобъектов и программных сервисов, распределенных в образовательной сети и позволяющих гибко осуществлятьпроцессыучебно-методического обеспечения образовательной деятельности. В статье определены требования к метаописанию учебных объектов и сервисов, а также представлено описание технологическихпроцессов реализации основных программных сервисовучебно-методическогообеспечения

Clinical, Immunological and Molecular-Genetic Description of Symptoms in Children with Autoimmune Polyglandular Syndrome Type 1: Description of a Case Series

Clinical polymorphism of autoimmune polyglandular syndrome type 1, the presence of atypical forms and a long latent period of the target organ disease determine the difficulties in diagnosing this disease, which leads to late detection of life-threatening conditions and inadequate treatment of such patients. The article presents the results from a retrospective analysis of 7 clinical cases of autoimmune polyglandular syndrome type 1 in children hospitalized between 2006 and 2016. The clinical manifestations of the syndrome included chronic candidiasis (7 patients), hypoparathyroidism (6), chronic adrenal insufficiency (3), and autoimmune hepatitis (3). The atypical clinical signs of the disease (annular erythema, hypoplasia of tooth enamel, sialadenitis) were revealed. All children had high ( 6 norms) antibody titers to interferon , 4 — antibodies to interferon 2. In all cases of chronic adrenal insufficiency and autoimmune hepatitis, the corresponding antibodies were determined in high ( 2 norms) titers. Clinical polymorphism, prolonged monosymptomatic course, prolonged latent period between the debuts of the syndrome manifestations require modern immunological methods of diagnostics and monitoring of the residual function of the target organ for the timely initiation of therapy and prevention of crisis states

Single-Atom Alloy Pd₁Ag₁₀/CeO₂–ZrO₂ as a Promising Catalyst for Selective Alkyne Hydrogenation

The effect of support on the performance of Pd1Ag10/Al2O3 and Pd1Ag10/CeO2–ZrO2 catalysts in the selective hydrogenation of diphenylacetylene (DPA) was studied. Characterization of the catalyst by DRIFTS-CO and HRTEM revealed the formation of a PdAg single-atom alloy (SAA) structure on the surface of PdAg nanoparticles, with Pd1 sites isolated by Ag atoms. It was found that the use of CeO2–ZrO2 as a carrier makes it possible to increase the activity of the Pd1Ag10 catalyst by a factor of three without loss of selectivity compared to the reference Pd1Ag10/Al2O3. According to the HRTEM data, this catalytic behavior can be explained by an increase in the dispersion of Pd1Ag10/CeO2–ZrO2 compared to its Pd1Ag10/Al2O3 counterpart. As evidenced by DRIFTS-CO data, the high selectivity of the Pd1Ag10/CeO2–ZrO2 sample presumably stems from the stability of the structure of isolated Pd1 sites on the surface of SAA Pd1Ag10/CeO2–ZrO2

Liquid-Phase Hydrogenation of 1-Phenyl-1-propyne on the Pd1Ag3/Al2O3 Single-Atom Alloy Catalyst: Kinetic Modeling and the Reaction Mechanism

This research was focused on studying the performance of the Pd1Ag3/Al2O3 single-atom alloy (SAA) in the liquid-phase hydrogenation of di-substituted alkyne (1-phenyl-1-propyne), and development of a kinetic model adequately describing the reaction kinetic being also consistent with the reaction mechanism suggested for alkyne hydrogenation on SAA catalysts. Formation of the SAA structure on the surface of PdAg3 nanoparticles was confirmed by DRIFTS-CO, revealing the presence of single-atom Pd1 sites surrounded by Ag atoms (characteristic symmetrical band at 2046 cm−1) and almost complete absence of multiatomic Pdn surface sites (<0.2%). The catalyst demonstrated excellent selectivity in alkyne formation (95–97%), which is essentially independent of P(H2) and alkyne concentration. It is remarkable that selectivity remains almost constant upon variation of 1-phenyl-1-propyne (1-Ph-1-Pr) conversion from 5 to 95–98%, which indicates that a direct alkyne to alkane hydrogenation is negligible over Pd1Ag3 catalyst. The kinetics of 1-phenyl-1-propyne hydrogenation on Pd1Ag3/Al2O3 was adequately described by the Langmuir-Hinshelwood type of model developed on the basis of the reaction mechanism, which suggests competitive H2 and alkyne/alkene adsorption on single atom Pd1 centers surrounded by inactive Ag atoms. The model is capable to describe kinetic characteristics of 1-phenyl-1-propyne hydrogenation on SAA Pd1Ag3/Al2O3 catalyst with the excellent explanation degree (98.9%)

An Investigation into the Bulk and Surface Phase Transformations of Bimetallic Pd-In/Al2O3 Catalyst during Reductive and Oxidative Treatments In Situ

A series of oxidative treatments of PdIn-supported intermetallic nanoparticles at different temperatures were performed. The bulk and surface structure of catalyst during phase transformation was investigated by bulk- and surface-sensitive techniques (in situ XAFS, DRIFTS of adsorbed CO). It was found that comparison of palladium and indium fractions in bulk and on the surface suggests the formation of a «core-shell» structure. According to obtained results, the core consists of In-depleted intermetallic compound or inhomogeneous bimetallic phase with the inner core of metallic Pd, when a mixture of indium oxide, metallic palladium and small part of PdIn is present on the surface

REALIZATION OF TRAINING AND METHODOLOGICAL SUPPORT IN INTEGRATED INFORMATIONEDUCATIONAL SPACE BASED ON SERVICE ARCHITECTURE

The article presents the results of scientific research to develop methods and tools forthe creation and use of information-educational space in the formation and processing, learning objects and software servicesdistributed in the educational network and allows flexibility to implement the processesof training and methodological support ofeducational activities. The article defines the requirements for the meta-descriptionof learning objects and services, and alsopresents a description of technological processes of realization of basic software services training and methodological support

Reversible Transformations of Palladium–Indium Intermetallic Nanoparticles upon Repetitive Redox Treatments in H₂/O₂

The transformations of chemical states and structures occurring in the PdIn/Al2O3 catalyst upon redox treatments in different gaseous atmospheres at different temperatures are addressed by an assortment of in situ bulk- (XRD) and surface-sensitive (XPS and DRIFTS CO) techniques. Any desired state of the catalyst between two opposite extremes of highly dispersed oxide species and regularly ordered PdIn intermetallic compound could be set in fully controlled and reversible ways by selecting appropriate conditions for the reductive treatment starting from the fully oxidized state. Since mutual conversions of multi-atomic Pdn centers into single-site Pd1 centers are involved in these transformations, the methodology could be used to find an optimum balance between the activity and selectivity of the catalytic system