Influence of the Composition of Solid Fuel on the Equilibrium Characteristics of a Gasification Process in the Mixtures of Oxygen and Carbon Dioxide

The gasification of solid fuels of different elemental compositions in O2/N2 and O2/CO2 mixtures was studied using equilibrium thermodynamic modeling. The dependences of process characteristics (temperature and the yield of carbon residue) on the composition of gasification agent and the stoichiometric ratio were calculated. The addition of carbon dioxide, on the one hand, promoted the conversion of carbon due to an increase in the concentration of gasifying agents and, on the other hand, decreased the process temperature due to an increase in heat capacity and an endothermic effect of the gasification reaction. The efficiency of using O2/CO2 mixtures for the gasification of fuels increased with the carbon content. The highest chemical efficiency of coke and coal gasification was achieved at an initial CO2 concentration of about 40–60 vol %.

Analysis of the physico-chemical efficiency of the bioceramic silers application in endodontic practice

The purpose of this systematic review of the literature is to detail the main physical, chemical, biological, operational, and other significant properties of bioceramic materials used in endodontic practice ю Фccording to the studied literature, we can say that bioceramic endodontic materials have satisfactory performance properties, are characterized by antimicrobial action and alkaline pH, have optimal biocompatibility and bioactivity, which indicates the feasibility of their use in the clinical practice of a dentist-endodontist.

Optimization of 210Po determination in soil

In recent years, naturally occurring radioactive materials (NORM) have become an important topic from the perspective of environmental protection. The list of isotopes that should be monitored in the environment is constantly growing as new amendments to international legislation are introduced. One of the often studied NORM elements is 210Po. In this study, a process of elaborating of a new method of 210Po determination in soil was presented. In the proposed method, several analytical aspects, like the influence of silica decomposition or optimization of an electrode material, were revised. The obtained procedure allows performance of complete radiochemical analysis in a single day, with the chemical efficiency of over 85% and great reduction of costs. Further, the influence of the use of phosphate fertilizers on polonium concentration in soil was also confirmed.

Effectiveness Of Chemicals Against Cotton Scoop Of A Suitable Crop

The article achieved the chemical efficiency of Entovant 15% em.k., 0,5 l per hectare, Vertimek, 1,8% em.k., 0,5 l, biological efficiency 89,0-90,0%. It is r ecommended to use these preparations at least 25-30 days before harvest.

Effects of Calcination Temperature and Time on the Physical-Chemical Efficiency of Thermally Activated Clays in Cement Systems

Introduction of finely disperse mineral additives of natural and man-made origin to Portland cement in order to improve the indicators of its physical-mechanical properties and partially replace clinker is one of the urgent directions for solving the resource and energy saving problems, as well as environmental protection problems in the production and application of building materials. The expansion of the raw material base of mineral additives can be achieved by using calcined polymineral clays, which are common in many regions of the Russian Federation, including the Republic of Mordovia. The article presents the results of research on the effects of calcination temperature and time of thermally activated polymineral clays of the Republic of Mordovia on their physical-chemical efficiency in cement systems. According to the study results of dehydration processes of clay minerals using the synchronous thermal analysis, it is established that the optimum calcination temperature for clays of Nikitsky and Staroshaigovsky deposits located in the area of 500–800 °C. This temperature range corresponds to the processes of the initial crystal structure restructuring of clay minerals of the kaolinite and illite groups, associated with their dehydroxylation, which contributes to the transition of these phases to the active form. The optimization of calcination parameters of polymineral clays based on the study results of influence of their additives on the mixed cement binder activity confirmed the thermal analysis data. It was found that the production of mineral additives with the highest values of the activity index is facilitated by 2-hour heat treatment of clays at 700 °C. At the specified calcination parameters, the replacement of 10% of Portland cement with the additive of thermally activated Nikitsky clay allows achieving the mixed binder activity that exceeds by 3 % the same indicator of mixed binder based on Portland cement and high-quality metakaolin.

A high-pressure artificial photosynthetic device: pumping carbon dioxide as well as achieving selectivity

By leveraging a distinct operational strategy, a high-pressure artificial-photosynthetic device achieved CO2R selectivity over 80% and solar-to-chemical efficiency exceeding 0.9%.

Characterization of Activated Carbon Paper Electrodes Prepared by Rice Husk-Isolated Cellulose Fibers for Supercapacitor Applications

For the preparation of activated carbon papers (APCs) as supercapacitor electrodes, impurity substances were removed from rice husks, before carbonization and various activation temperature treatments, to optimize electro chemical efficiency. The porosities and electrochemical performances of the ACPs depended strongly on activation temperature: The specific surface area increased from 202.92 (500 °C) to 2158.48 m2 g−1 (1100 °C). XRD and Raman analyses revealed that ACP graphitization also increased with the activation temperature. For activation at 1100 °C, the maximum specific capacitance was 255 F g−1, and over 92% of its capacitance was retained after 2000 cycles.

Optimization and Characterization of Bio-oil Produced from Rice Husk Using Surface Response Methodology

The study depicts the production, optimization and characterization of bio-oil from pyrolyzed rice husk using a fabricated fixed bed reactor. The pyrolysis process was conducted with bio-oil response, bio-char response and non-condensable gases response as products. The effect of pyrolysis variables were observed by the production of the bio-oil as the response. Sixty runs of pyrolysis experiments were suggested by Box Benkhen design indicated optimum pyrolysis conditions at particle size of 2.03mm mesh, reaction time of 81.80 mins and temperature of 650oC for rice husk. The maximum bio-oil yield was obtained with 38.39% at optimum condition of the variables. The bio-oil sample obtained had better performance compared with ASTM standard. Such a determination would contribute so immensely to a significant comprehension of the chemical efficiency of the pyrolysis reaction.