New Technology For Preparation Research Articles

Impact of woody biomass in the composition of coal-water suspensions on their transportation and combustion

Relevance. A promising fuel from an environmental point of view is coal-water suspensions. Multiple studies have shown that when they are burned, emissions of anthropogenic gases into the Earth's atmosphere are significantly reduced compared to emissions from coal burning. But the large-scale introduction of coal-water suspensions into the overall balance of energy production is difficult due to a significant delay in their ignition, which can reach several tens of seconds at relatively low oxidizer temperatures (Tg≤1073 K). One of the possible ways to solve this problem is the use of new technologies for preparation for combustion, for example, the use of additional microwave heating of fuel and the introduction of special additives into the composition of coal-water suspensions, which accelerate their ignition. The introduction of such additives into the fuel composition can lead to a significant change in the rheological characteristics. Aim. To determine the degree of impact of the concentration and type of wood additive in the composition of the coal-water suspension on the rheological characteristics of droplets of coal-water fuel, as well as the possibility of reducing the duration of thermal preparation of the latter when exposed to microwave heating. Object. Water-coal suspension based on long-flame thermal coal and on long-flame thermal coal with the addition of sawdust and pine needles (Bio-water-coal suspension). Methods. Experimental studies to determine the time characteristics of water-coal suspension ignition were carried out using a high-speed video camera FASTCAM. Fuel combustion was carried out in a flow-through combustion chamber equipped with magnetrons for additional microwave heating of the fuel. Dynamic viscosity was determined using a Brookfield RVDV-II + Pro viscometer. Results. It has been established that the addition of microwave heating can significantly (up to 15%) reduce the ignition delay of water-coal suspension and Bio-water-coal suspension at relatively low oxidizer temperatures (673 K). Experimental studies shown that the type of biomass affects the time characteristics of fuel ignition at ambient temperatures up to 753 K; with a further increase in the temperature of the oxidizer, the type of additive does not have a significant effect. It is shown that when studying the rheological characteristics of the water-coal suspension, the dynamic viscosity of Bio-water-coal suspension does not go beyond the characteristic value of 1200 Pa s at a shear rate of 100 rpm when no more than 2% of pine sawdust and no more than 6% of pine needles are introduced into the water-coal suspension.

Studies of Conventional and New Technologies for Preparation of Iron Ore Raw Materials at Iron Making Plant of Pao Severstal to Evaluate Prospectives for Reduction of Ecological Load on Environment


 
 
 The experts of Centre for Raw Materials Investigations (CRMI) have conducted research into the usage of recycled materials in the following technological processes: sintering and briquetting. Research shows variation in emissions containing sinter gases and qualitative characteristics of the finished product (cold and hot sinter strength). It is suggested that involvement of recycled waste products of steelmaking and chemical processes shall be increased using the method of vacuum extrusion.
 
 
 
 Keywords: sintering, recycled materials, sinter gas, briquettes
 
 
 
 
 

Environmental-friendly non-sintered permeable bricks: Preparation from wrap-shell lightweight aggregates of dredged sediments and its performance

In this study, a new technology for preparation of permeable bricks from non-sintered wrap-shell lightweight aggregates (WSLAs) of dredged sediments was developed. The volume method was used to calculate the material mix ratio. The effects of water-cement ratio (W/C), forming pressure (Pf), target porosity (P) and size of aggregate particles on the compressive strength and water permeability coefficient of dredged sediment permeable bricks (DSPB) were discussed. Furthermore, the mechanism of water permeability of DSPB was deeply explored. The mass loss rate and strength loss rate of DSPB after 25 freeze–thaw cycles were compared with that of the crushed stone permeable bricks (CSAPB), the commercial sintered clay permeable bricks (SCLPB), and the commercial sintered ceramic permeable bricks (SCEPB) prepared by the same process. The damage mechanism of DSPB caused by the freeze–thaw cycles was analyzed. Results showed that when W/C was 0.34, Pf was 3 MPa, and P was 15%, the comprehensive performance of fine aggregate permeable brick (DSPB-F) was satisfactory. It was found that the water permeability coefficient of DSPB is almost proportional to the connected porosity. After 25 freeze–thaw cycles, interestingly, 0it was found that the freezing resistance of DSPB is closely related to the number, width and development trend of micro-pores and cracks at the junctions of WSLAs.

Molecular information obtained from radiobiological tissue archives: achievements of the past and visions of the future

Radiobiological archives have not been overwhelmed by applications to use their stored tissue materials, in part because of lack of technologies to conduct quantitative analysis of the tissues. Over the last decade, advances in methodology have made it possible to routinely extract both DNA and RNA from archival materials. The quantitative analysis of gene expression by reverse transcription real-time PCR (QRT-PCR), and of gene copy number by array-based CGH (aCGH), are now firmly established methods for the study of tissue samples stored as paraffin blocks. More recent developments in proteomic technology have enabled the extraction of proteins from formalin-fixed paraffin-embedded (FFPE) tissue samples. These protein extracts have been used to produce quantitative data by Western blotting and even to identify proteins through LC/MS analysis. The development of applications using gel-based proteomics (2D/MS) is still a future challenge. This report gives an overview of the methodology already applicable on FFPE tissue, as well as the novel technologies to be used in the future research. Our goal is to collect existing animal and human tissue samples for use by the radiation biology community, to test new technologies for preparation of material from tissue samples, and to actively pursue materials arising from ongoing research.

Preparation of Mg–Li alloys by electrolysis in molten salt at low temperature

A new technology for preparation of low cost Mg–Li alloys was studied. The alloys were prepared by electrolysis in molten LiCl–KCl (weight ratio is 1:1) electrolyte with Mg rod severing as the consumed cathode. Main factors that affect current efficiency were investigated, and optimal electrolysis parameters were obtained. Mg–Li alloys with low lithium content (about 25%) were prepared by the unique method of a higher post-thermal treatment temperature after electrolysis at low temperature. The results showed that the electrolysis can be carried out at low temperature, which resulted in reducing preparation cost due to energy saving. The new technology for the preparation of Mg–Li alloy by electrolysis in molten salt was proved to be feasible.

Whisker probes

A new technology for preparation of AFM probes based on whiskers is proposed. The technology posseses significant advantages to the whisker probes over standard ones as related to the shapes of the probes, as well as to the properties of the cantilevers on which the whiskers are grown.

A new technology for preparation of saturating powder mixtures for diffusion galvanizing

The powder mixtures used for diffusion galvanizing (Zn + inert filler + activator) have the following deficiencies: susceptibility to sintering and fusing under elevated CTT temperatures, complexity of correcting the set of components in repeated use of the mixtures and the related instability of the results obtained, complexity of regeneration of worked-out mixtures, elevated ecological hazard of their use, etc. This explains the need for the present work, which shows that most of the mentioned deficiencies can be eliminated by an appropriate choice of the mixture components and (or) preliminary treatment of them.