Carbon storage change and δ13C transitions of peat columns in a partially forestry-drained boreal bog

Background and aims In forestry-drained peatlands, drying leads to changes in C cycling which could affect peat δ13C. Furthermore, the δ13C profile of the entire peat column may reveal effects of earlier climatic periods. Methods We measured peat δ13C and C inventories in adjacent peat profiles, two collected from undrained and two from the drained side of a bog that was partially ditch-drained 37 years earlier. The cores were sliced into 10-cm subsamples for analyses; matching of the profiles based on surface levelling, peat stratigraphic correlation and a horizontal ash layer found in both profiles. Results Surface subsidence of 30 cm was observed in the dried site and the uppermost 160 cm in the undrained site contained an excess of 5.9 kg m−2 of C compared with the corresponding strata of the ditch-drained site. The δ13C values increased but markedly only in the thin surface layer of the drained site, indicating low δ13C of the missing C (ca. –30‰). In the deeper strata, dating to Mid-Holocene, high dry bulk density, C%, N%, humification index and low C/N ratio were connected to low δ13C of peat. Conclusions Drainage of 37 years increased δ13C values in the upper peat profile of the drained bog and led to the selective loss of 13C depleted C. Results indicate that C balance studies can be aided by C isotope analyses. Low δ13C values in the peat profile indicate the existence of a wet fen stage during the moist and warm period during Mid-Holocene.

STRUCTURE FORMATION OF α-Fe THIN SURFACE LAYER WITH GLOW DISCHARGE PLASMA

A theory explaining a structure formation in a thin surface layer of material after a low-energy impact of glow discharge plasma with the purpose of the development of new methods, technologies and automated devices for the formation of automated technological environment is developed. An impact of lowenergy processing in a glow discharge upon dislocation structure changes in a thin surface layer by the example of annealed α-Fe is investigated.

Methodology and Installation of the Etching of the Surface Layer from Pipes, Rods and Profiles for the Aim of the Analysis of Residual Stresses

The paper presents the design of the etching unit, the experiment procedure to remove a thin surface layer of metal and fixing the elastic discharge of the pipe along its length. The value of elastic discharge is necessary to calculate the residual stresses of a thin surface layer, as well as the distribution of residual stresses of the pipe wall.

Fire-protection of wooden structures by modification in a thin surface layer

The mechanism of fire protection of wood by the modification of a thin surface layer with organophosphorus compounds has been studied. The properties of the modified thin surface layer were studied by X-ray spectral analysis, IR spectroscopy and differential thermal analysis. Promising wood modifiers have been identified and the conditions for effective fire protection of wooden structures with organophosphorus compounds in a thin surface layer have been determined.