[en] Silica nanoparticles were successfully extracted from the rice husk ash. The obtained SiO₂ powders had monoclinic crystal system, large specific surface area (258.3 m2/g), and particle size (10 to 15 nm). Nano SiO₂ prepared from rice husk ash increased the chloride resistance of fly ash cement concrete. The ability to resist chloride penetration increases with the content of using nano-SiO₂. When the content of nano-SiO₂ is 2 %, the chloride resistance of concrete is optimized (25 % reduction of charge passed compared to concrete not using nano-SiO₂). (author)

[en] Short communication

[en] Estonian oil shale ash contains chemically active compounds which would undergo different spontaneous transformations in the atmosphere of air. For explaining these processes the system ash-water-air was studied storing moisture samples of ash in laboratory in open-air as well as hermetic conditions. The samples of dry ash formed at pulverized combustion of oil shale at the Baltic Power Plant, and samples obtained from ash storing plateau from different depth of different boreholes were under investigation. Storing conditions as well as the properties of initial samples have a great influence upon the processes taking place at storing of ashes. The results obtained could be used to explain and control the processes taking place at storing of ashes under atmospheric (wet) conditions

[en] The large rapid ashing apparatus consists of a special ashing furnace, oxidation-reduction gas supply system and temperature-programming cabinet. The following advantages have been showed by ashing experiment with apparatus above-mentioned. Because nitrogen and mixed gases of oxygen and nitrogen dioxide were supplied for charring and ashing of samples respectively, the total time of charring and ashing was shortened significantly and electric energy was saved. In comparison with the method of typical muffle furnace, the total time of the rapid ashing method for eight biological samples might be reduced by a factor of 6-53, and electric energy might be saved by a factor of 1.6-13, depending on different properties of biomaterials. This appratus can ash a large amount of samples a batch. For example, it may ash 3.8 kg fresh rabbits muscle a batch and 1.6-2 kg rice or wheat a batch. The fresh sample can also be charred and ashed directly. The apparatus is suitable for rapid ashing of a large amount of environmantal samples containing low level radioactivity and trace elements

[en] Ash from the combustion of powdered Estonian oil shale in power plants has a high chemical reactivity and ability to bind hazardous components in the waste from the Sillamaee plant. This characteristic suggests that the ash should be considered as a component of a barrier system for remediation of the tailings pond. Different types of ash, collected in different parts of a power plant, show different reactivities

[en] Highlights: • Metal and elemental content depends on fish species, proximate composition and size. • Higher levels of most metals were observed in anchovy compared to sardine. • Higher levels of metals and elements can be associated with lower lipid content. • Higher levels of metals and elements can be associated with greater protein content. • Higher levels of metals and elements can be associated with smaller fish size. Species – specific differences in the levels of 26 metals and elements in sardine and anchovy are investigated and the factors of proximate composition (proteins, lipids, ash) and body size (length, weight) that may affect the metal and elemental concentrations in fish are explored. Statistical analysis revealed that levels of metals and elements in fish seem to strongly depend on species. Significantly higher levels of most of the metals and elements studied have been observed in anchovy compared to sardine at each of six different sites. The observed species-specific differences in metal content could be attributed to different proximate composition and size among other factors. The significant (positive or negative) correlations found between lipids, proteins, ash, weight, length and metals or elements, suggest that higher levels of most of the metals and elements studied can be associated with lower lipid content, greater protein and ash content and smaller size.

No abstract available

[en] Peat physical properties (e.g. unit weight, water content, ash and fibre content) are different from mineral soil due to it high water and organic content. Traditional method requires laboratory test which is time consuming and costly. This study attempted to estimate peat physical properties based on its resistivity value. Peat samples were obtained from several locations and various depth using peat sampler in Lukun village at Meranti Distric, Riau Province. The resistivity value measured in the field using 4 pin soil resistance meter along with the determination of moist weight and unit weight. Laboratory tests were conducted on the sample. Statistical analysis was then performed to check whether there is correlation between field resistivity value and peat physical parameters. The result revealed that water content and dry unit weight are correlated to some degree with resistivity value but not for other parameters i.e. wet unnit weight, specific gravity and ash content. (paper)

[en] The coal unburned in flying ashes obtained in the processes of coal combustion is the main disadvantage for its use in the industry of the construction. This material normally has a size of particle greater than the mineral material, therefore it is possible to be separated in a considerable percentage, obtaining double benefit: the reusability of unburned like fuel or precursor for the activated charcoal production and the use of the mineral material in the industry of the construction since the organic matter has retired him that disables its use. In this work it is experienced with a sifted technique of separation by for three obtained flying ash samples with different technology (travelling Grill, pneumatic injection and overturning grill), were made grain sized analyses with meshes of a diameter of particle greater to 0,589 mm, the short analyses were made to them next to the retained material in each mesh and the unburned percentage of removal was determined of. The technique was compared with other developing.

[en] Short communication. 2 refs, 1 fig