48 research outputs found

    Assessment of Pyrometallurgical Scheme Options of Red Mud and Scale Co-processing

    Get PDF
    The analysis of various options for the use of alumina production wastes (red mud) and oiled scale using various methods of agglomeration to produce conditioned commercial iron is presented. Co-processing utilization of red mud and oiled scale allows to obtain raw materials with an iron content of more than 50%, which meets the modern requirements for charge materials for use in the blast furnace process. The calculation analysis carried out using a mathematical model of blast furnace process, allowed to determine the optimal proportion of the iron-containing material for the partial replacement of charge materials without reducing the technical and economic indicators of blast furnace smelting. Keywords: Bayer process, red mud, oiled scale, mathematical model, blast furnace process, metallurgical properties, complex utilizatio

    Refinement of the process capability index calculation

    Get PDF
    The variability of product performance is the reason for the introduction of special methods to ensure product quality, particularly statistical methods. These include introducing statistical process control (SPC) in production and calculating the process capability index to determine the manufacturing ability to meet the product’s quality requirements. To a large extent, the ability of a process to meet the requirements was determined by the location of the process or the mathematical expectation of the controlled quality characteristic value. Process setup center variability within the boundaries of the Shewhart control chart of the average values was supposed to be the natural state for a statistically controlled process. However, the calculation of the process capability index did not consider the possibility of a shift in the actual value of the process setup center for a controlled characteristic from its mathematical expectation. It was proposed to adjust the process capability index for the setup center’s possible deviation. It demonstrated the possibility of critical errors in determining the ability of a production process to meet requirements without considering the process setup center. The effectiveness of the proposed solutions was also demonstrated by the example of determining the ability of the welding wire manufacturing process to meet the requirements for metal yield strength of the welded joint of metal bridge span constructions

    Imbalance in the oxidative stress system-antioxidant protection in patients with chronic pyelonephritis depending on the course of the diseas

    Get PDF
    Assessment of the imbalance in the system of oxidative stress - antioxidant protection in patients with chronic pyelonephritis depending on the course of the diseas

    Investigation on the association of cardiovascular markers with severity of chronic pyelonephritis

    Get PDF
    Chronic kidney disease (CKD) is an established independent risk factor for cardiovascular disease (CVD) and is caused by chronic pyelonephritis (CP). This study aimed to investigate the effect of the association of cardiovascular markers with the course of CP on the comorbidity of CP with ischemic heart disease. The study participants included 125 patients with CP without symptoms of urinary tract obstruction who were divided into three group

    Mechanisms of Development of Heart Failure in Chronic Kidney Disease

    Get PDF
    The study of scientific data over the past 5 years has shown that cardiorenal syndrome, which has a complex and multifactorial pathophysiology, is a clinical problem. Modern pharmacological methods of treatment are effective, but insufficient to satisfactorily influence or mitigate the progression of cardiorenal syndrome, therefore, the discovery of new drugs and new therapeutic strategies for cardiorenal syndrome is a high priority tas

    ПЛАНАРНЫЕ ФОТОКАТАЛИЗАТОРЫ С ФУНКЦИЕЙ НАКОПЛЕНИЯ ФОТОГЕНЕРИРОВАННОГО ЗАРЯДА

    Get PDF
    It is shown that nanostructured TiO2 : MoO3 films are capable to accumulate the charges induced under UV irradiation due to the generation of reduced forms of molybdenum oxide (hydrogen bronzes). Oxidation of these reduced forms in the air condition is accompanied by the generation of reactive oxygen species, due to which TiO2 : MoO3 films retain the oxidation ability and the pathophysiological activity for a long time after irradiation completion.Показано, что наноструктурированные пленки TiO2 : MoO3 способны под действием УФ-облучения накапливать фотоиндуцированный заряд при облучении за счет генерации восстановленных форм MoO3 (водородных бронз).Окисление указанных восстановленных форм в контакте с воздухом сопровождается генерацией активных форм кислорода, вследствие чего пленки TiO2 : MoO3 сохраняют окислительную способность и патофизиологическую ак­тивность в течение длительного времени (свыше 3 ч) после завершения облучения

    Piezo-Responsive Hydrogen-Bonded Frameworks Based on Vanillin-Barbiturate Conjugates

    Full text link
    A concept of piezo-responsive hydrogen-bonded π-π-stacked organic frameworks made from Knoevenagel-condensed vanillin–barbiturate conjugates was proposed. Replacement of the substituent at the ether oxygen atom of the vanillin moiety from methyl (compound 3a) to ethyl (compound 3b) changed the appearance of the products from rigid rods to porous structures according to optical microscopy and scanning electron microscopy (SEM), and led to a decrease in the degree of crystallinity of corresponding powders according to X-ray diffractometry (XRD). Quantum chemical calculations of possible dimer models of vanillin–barbiturate conjugates using density functional theory (DFT) revealed that π-π stacking between aryl rings of the vanillin moiety stabilized the dimer to a greater extent than hydrogen bonding between carbonyl oxygen atoms and amide hydrogen atoms. According to piezoresponse force microscopy (PFM), there was a notable decrease in the vertical piezo-coefficient upon transition from rigid rods of compound 3a to irregular-shaped aggregates of compound 3b (average values of d33 coefficient corresponded to 2.74 ± 0.54 pm/V and 0.57 ± 0.11 pm/V), which is comparable to that of lithium niobate (d33 coefficient was 7 pm/V). © 2022 by the authors.2.1.06.03, 20211572; Russian Foundation for Basic Research, РФФИ: 20-53-00043-Bel_a; Ministry of Science and Technology, Taiwan, MOST: 19-52-06004 MNTI_a; Ural Federal University, UrFU: 2968; Ministry of Science and Higher Education of the Russian Federation: 075-15-2021-677The work was supported by the Russian Foundation for Basic Research (RFBR, project no. 20-53-00043-Bel_a) and the PFM measurements were done under RFBR and MOST project no. 19-52-06004 MNTI_a. The equipment of the Ural Center for Shared Use “Modern nanotechnology” Ural Federal University (Reg. No. 2968), which is supported by the Ministry of Science and Higher Education RF (project No. 075-15-2021-677), was used. T.V.S. acknowledges the support from the State Program of Scientific Researchers of Belarus (research issue 2.1.06.03, state registration number: 20211572)

    Internal flows and energy circulation in light beams

    Full text link
    We review optical phenomena associated with the internal energy redistribution which accompany propagation and transformations of monochromatic light fields in homogeneous media. The total energy flow (linear-momentum density, Poynting vector) can be divided into spin part associated with the polarization and orbital part associated with the spatial inhomogeneity. We give general description of the internal flows in the coordinate and momentum (angular spectrum) representations for both nonparaxial and paraxial fields. This enables one to determine local densities and integral values of the spin and orbital angular momenta of the field. We analyse patterns of the internal flows in standard beam models (Gaussian, Laguerre-Gaussian, flat-top beam, etc.), which provide an insightful picture of the energy transport. The emphasize is made to the singular points of the flow fields. We describe the spin-orbit and orbit-orbit interactions in the processes of beam focusing and symmetry breakdown. Finally, we consider how the energy flows manifest themselves in the mechanical action on probing particles and in the transformations of a propagating beam subjected to a transverse perturbation.Comment: 50 pages, 21 figures, 173 references. This is the final version of the manuscript (v1) modified in accord to the referee's remarks and with allowance for the recent development. The main changes are: additional discussion of the energy flows in Bessel beams (section 4.1), a lot of new references are added and the Conclusion is shortened and made more accurat

    Remote heart rate monitoring - Assessment of the Facereader rPPg by Noldus

    Get PDF
    Remote photoplethysmography (rPPG) allows contactless monitoring of human cardiac activity through a video camera. In this study, we assessed the accuracy and precision for heart rate measurements of the only consumer product available on the market, namely the Facereader™ rPPG by Noldus, with respect to a gold standard electrocardiograph. Twenty-four healthy participants were asked to sit in front of a computer screen and alternate two periods of rest with two stress tests (i.e. Go/No-Go task), while their heart rate was simultaneously acquired for 20 minutes using the ECG criterion measure and the Facereader™ rPPG. Results show that the Facereader™ rPPG tends to overestimate lower heart rates and underestimate higher heart rates compared to the ECG. The Facereader™ rPPG revealed a mean bias of 9.8 bpm, the 95% limits of agreement (LoA) ranged from almost -30 up to +50 bpm. These results suggest that whilst the rPPG Facereader™ technology has potential for contactless heart rate monitoring, its predictions are inaccurate for higher heart rates, with unacceptable precision across the entire range, rendering its estimates unreliable for monitoring individuals
    corecore