SPECIFIC INFLUENCE OF BIOMASS ON THE DESULPHURISATION PROCESS IN COMBUSTION OF BROWN COAL AND BIOMASS MIXTURE IN FLUIDISED BED BOILER

Thesis is focused on specific aspects of the desulphurisation processes of fluidised- bed boilers. The original goal of the study was to analyse the influence of several kinds of biomass to the quality of the desulphurisation process in combustion of the mixture of brown coal, biomass and limestone in fluidised-bed boilers

The Leading Universities’ Social Responsibility and Regional Development

The paper deals with processes of development of a university's social responsibility in the regional community. The content of ten web-sites of Russia's federal universities and of official sites of regional authorities of their respective locations was taken as the initial empiric material. Theoretical analysis of basic viewpoints on the nature of buildup of universities' social responsibility was conducted. Basing on the socio-cultural approach to analysis of the mission and lines of the universities' activities, the authors generalized modern practices of social responsibility realization and gave insight into prospective lines of the universities' activity in the context of socio-economic development of Russian regions. As a working hypothesis, it has been assumed that it is human and professional experience of regional leaders that has considerable influence on formation of universities' and regions' mutual social responsibility for realization of socio-economic objectives of the regional development. Finally, conclusions about horizons and ways of enhancement of the role of social responsibility within the system of interrelations between universities and regions were formulated

The Leading Universities’ Social Responsibility and Regional Development

The paper deals with processes of development of a university's social responsibility in the regional community. The content of ten web-sites of Russia's federal universities and of official sites of regional authorities of their respective locations was taken as the initial empiric material. Theoretical analysis of basic viewpoints on the nature of buildup of universities' social responsibility was conducted. Basing on the socio-cultural approach to analysis of the mission and lines of the universities' activities, the authors generalized modern practices of social responsibility realization and gave insight into prospective lines of the universities' activity in the context of socio-economic development of Russian regions. As a working hypothesis, it has been assumed that it is human and professional experience of regional leaders that has considerable influence on formation of universities' and regions' mutual social responsibility for realization of socio-economic objectives of the regional development. Finally, conclusions about horizons and ways of enhancement of the role of social responsibility within the system of interrelations between universities and regions were formulated

Physikochemische Eigenschaften von „green solvents“ -Alkylcarbonaten und ionischen Flüssigkeiten

Vielseitige Untersuchungen der thermodynamischen Eigenschaften „green solvents“:organischen Carbonaten und ionischen Flüssigkeiten wurden durchgeführt. Es wurden die Sättigungsdampfdrücke, die Verdampfungs- und die Bildungsenthalpien von Alkyl- und Arylcarbonaten ermittelt und Gruppenbeitragsmethoden entwickelt. Die katalytische und Oberflächenaktivität von ILs wurde nachgewiesen. Die Gleichgewichtsdaten von Transalkylierungsreaktionen wurden gemessen und mit theoretischen Rechnungen unterstützt. Kritische Mizellbildungsparameter und die Aktitvitätskoeffizienten wurden experimentell ermittelt

Influence of optimal conditions of ultrasonic dispersion on the stability of suspensions of finely ground slags

The preparation in the jet mill of finely ground slag (FGS) from the waste of metallurgical production granulated blast-furnace slag, the obtaining of slag suspensions, and the behavior of FGS particles in an aqueous dispersion medium are considered in the paper. It was found that FGS particles in the suspension form micelles of two types with negative (micelle 1) and positive (micelle 2) charges of FGS surface. To increase the aggregative and sedimentation stability of FGS particles in suspensions, studies were carried out using ultrasonic dispersion. The results of investigations on the detection of optimal dispersion parameters for slag suspensions are presented. It was found that in the absence of temperature control, the process of coagulation of slag particles is accelerated and aggregative and sedimentation stability of suspensions of FGS is reduced. The slag particles in the suspension form aggregates that lead to a deterioration of the strength characteristics of the cement stone using suspensions of FGS. Optimal parameters of ultrasonic dispersion of slag suspensions are established: the frequency of ultrasonic vibrations is equal to 44 kHz; the dispersion temperature is 25 ± 2 °C; the dispersion time is 15 min. It was found that the application of ultrasonic dispersion to slag suspensions with the observance of dispersion conditions can increase the aggregative and sedimentation stability of FGS suspension by 2-3 times in comparison with the mechanical mixing of suspensions. The strength of samples with suspensions of FGS prepared using UST under the recommended dispersing conditions increased by 19 to 39% in the first day; for 28 days of hardening - by 19 - 36%, which allows using slag suspensions in the production of cement composite materials and concretes based on them

The Impact of Metal Age® Training Programme on the Well-Being of Latvian Office Workers

Publisher Copyright: © 2016 Dagmara Sprudža et al., published by De Gruyter Open 2016. Copyright: Copyright 2016 Elsevier B.V., All rights reserved.There are many factors that affect the well-being and health of employees and the productivity of organisations. The aim of this study was to determine the impact of the Metal Age training programme (MA®) on the well-being of office workers, including investigation of work ability, the stress-causing factors and role of leadership. The study was carried out using questions from four international questionnaires about stress, leadership, and work ability. The intervention group had a training course between the surveys using the ME® method. Several employee stress-causing factors were identified: bad relationship with their workmates was mentioned by 94% of workers; competitive and strenuous atmosphere - by more than 80%; psychological violence or bullying at the workplace by more than 80%, and more than 75% of employee's could not relax after work. Wellness and microclimate in the workplaces were on a relatively high level: the average rating of seven Kiva questions was 7.5. The respondent attitude after ME® did not change significantly. Latvian office workers displayed moderate and good work ability (Work Ability Index, WAI 34.5-38.6). The best work ability was shown in the age group from 20 to 49 (WAI 34.8-39.4); work ability decreased with age. The best correlation was observed between Work Ability Index and "get into situations, that invoke negative feelings" (r = 0.26) and "carrying out ongoing tasks because of other intervening or more urgent matters" (r = -0.24). After ME® the reaction to some stress-causing factors was improved.publishersversionPeer reviewe

Efficiency of stabilization of slag suspensions by polycarboxylate

The paper describes the method of stabilization of slag suspensions prepared on the basis of finely ground slag (FGS) with a predominant particle size of 1-7 μm, a plasticizer based on polycarboxylate (polycarboxylate). In suspension, FGS particles form two types of micelles with negative and positive surface charges. It has been established that stabilization with polycarboxylate, which is an anionic long-chain surfactant, affects slag particles with a positive surface charge. The formation of strong and elastic gel-like films on the surface of FGS leads to an increase in the structural and mechanical factor of aggregative stability of slag suspensions. Thus, the stabilization of slag particles by polycarboxylate is ensured by electrostatic, structural and mechanical factors of aggregative stability. It was established experimentally that the introduction of polycarboxylate into the aqueous dispersion medium increases the aggregative and sedimentation stability of slag suspensions. In the first period of particle sedimentation, on average, stability of slag suspensions is increased by 36 times, in the second period - 19 times, in the third period - 4 times. To ensure stability of slag suspensions, the protective number and the optimal concentration of the polycarboxylate are determined. The protective number of the suspension was 0,016 g/l; the optimal concentration of polycarboxylate - 4 g/l

Exploring the Surface Chemistry for the Stabilization of Bismuth Titanate Fine Particle Suspensions in Cement Systems

ABSTRACT: Introduction. The evolution of the construction industry in its current stage calls for the alteration of traditional building materials through the incorporation of nano- and fine-dispersed additives. These additions confer new, unique attributes to cement-based construction materials, enabling control over structure formation processes. Consequently, this allows for the creation of materials with specifically defined characteristics. Additives can be introduced into the cement composite during the joint grinding with clinker minerals, as a component of dry building mixture, or in the form of a suspension instead of mixing water. Therefore, it is essential to obtain fine particles suspensions resistant to aggregation and sedimentation. Thus, the purpose of this study is to obtain stabilized suspensions of bismuth titanate fine particles for cement systems and to study the properties of modified cement stone. Materials and methods. The purpose of this work was to establish the optimal concentration of polycarboxylate plasticizer in industrial water, necessary for the stabilization of fine bismuth titanate suspensions using surface tension and conductometric determination methods, the sedimentation stability of the obtained suspensions and the effect of ultrasonic exposure, as well as the physical and mechanical characteristics of cement stone modified with the obtained suspensions. Results and discussion. In order to establish the optimal concentration of the plasticizer necessary to obtain stable suspensions of bismuth titanate particles, the critical micelle concentration (CMC) for the plasticizer was determined with tap water as the dispersed medium. The CMC value was 1.3 g/l. If the concentration exceeds CMC, the process of micelle formation begins. In the micellar form, the plasticizer no longer provides stabilizing effect on the additive particles, therefore, the concentration of the plasticizer should be lower than the CMC. It was also found that ultrasound exposure increases the sedimentation stability of suspensions. The resulting stabilized suspensions were used instead of mixing water to obtain modified cement stone samples. There is an increase in the compressive strength of cement stone samples obtained after the introduction of fine bismuth titanate into the cement composite in the form of water suspensions stabilized by ultrasonic treatment with concentrations of 10, 30 and 50 g/l. The increase in compressive strength of modified samples compared to reference sample was from 24 to 33 MPa at first day age (by 13, 25 and 38% respectively), and from 80 to 93 MPa at 28 days age (by 4, 9 and 16%). Compressive strength of samples modified with bismuth titanate suspensions after ultrasonication compared to reference sample with plasticizer increased mostly at the first and third days age: from 29 to 42 MPa (by 31, 38 and 45%) and from 53 to 70 MPa (by 28, 30 and 32%) respectively. Conclusion. As a result of the research carried out in this study, the Critical Micelle Concentration (CMC) of a polycarboxylate plasticizer was determined, optimal for stabilizing fine-dispersed additive of bismuth titanate for cement systems, the effectiveness of ultrasonic treatment to achieve sedimentation stability of the obtained suspensions of the additive was confirmed, an increase in the strength characteristics of modified cement stone samples was established both in the initial hardening periods and at 28 days age. The results allow to consider a cement composite with fine bismuth titanate as a basis for obtaining building materials of new generation