Effect of industrial pollution on the distribution of 137Cs in soil and the soil-to-plant transfer in a pine forest in SW Finland

The objective of this study was to evaluate the effect of industrial pollution on the distribution of radiocaesium in soil and on its transfer from soil to plants. The study was started in September 2000 in four Scots pine stands located at distances of 0.5, 2, 4 and 8 km along a transect running SE from the Cu-Ni smelter at Harjavalta in SW Finland. Annual emissions from the smelter in 1990 were 80 t of Cu, 31 t of Ni and 9000 t of SO(2), and in 1999 these were 5.9, 0.8 and 3400 t, respectively. At each site, soil profiles were sampled with a corer, and samples were separated into litter (L), organic soil layer (O) and mineral soil layers (B, E). Mushrooms, lichens (Cladina spp. and Cetraria islandica), lingonberry (Vaccinium vitis-idaea) and crowberry (Empetrum nigrum) plants were collected at each site, except at a distance of 0.5 km, where only mushrooms were available. In the organic soil layer, 137Cs activity decreased from 8000 Bq/m(2) at a distance of 8 km from the smelter to 1500 Bq/m(2) at a distance of 0.5 km; in litter, 137Cs concentration increased from 6300 Bq/m(2) at 8 km to 14000 Bq/m(2) at 0.5 km. 137Cs activity concentration decreased significantly in plants, mushrooms and lichens as the pollution load increased. In lichens, 137Cs activity decreased from 910 Bq/kg at 8 km to 170 Bq/kg at 2 km, while in lingonberry it decreased from 1470 to 20 Bq/kg and in crowberry from 310 to 20 Bq/kg. Aggregated transfer factors for 137Cs decreased in a similar way in lingonberry from 7.6x10(-2) m(2)/kg at 8 km to 7.7x10(-4) m(2)/kg at 2 km and in crowberry from 1.6x10(-2) to 7.9x10(-4) m(2)/kg.     

Effect of Austenite Pancaking on the Microstructure,Texture, and Bendability of an Ultrahigh-Strength Strip Steel

The effect of austenite pancaking in the non-recrystallization regime on microstructure and texture evolution and thereby on bendability was investigated in an ultrahigh-strength strip steel with a martensitic-bainitic microstructure. The results indicate that an increase in rolling reduction (R _tot) below the non-recrystallization temperature, which improves the strength and toughness properties, increases the intensities of the ~{554}〈225〉 _α and ~{112}〈110〉 _α texture components along the strip centerline and of the ~{112}〈111〉 _α component at the surface region. Even with the highest R _tot of 79 pct, the bendability along the rolling direction was good, but the preferred alignment of rod-shaped MA constituents along the rolling direction led to a dramatic decrease in the bendability transverse to the rolling direction, with severe cracking occurring even at small bending angles. The early cracking is attributed to localization of the strain in narrow shear bands. It is concluded that the R_tot value has to be limited to guarantee successful bendability.     

The role of nanocrystalline titania coating on nanostructured austenitic stainless steel in enhancing osteoblasts functions for regeneration of tissue

In the context of osseointegration of metallic implants, while nanostructuring the surface favorably modulates cellular response, the disinfective attributes required during the healing process are not available. Thus, in the present study, we demonstrate that nanocrystalline titania provides cumulative benefit of enhancing osteoblasts functions to promote the efficacy of metal implants together with the disinfective attributes. To this end, the primary objective here is to examine the select functions of bone forming cells (osteoblasts) on electrocrystallized nanonodular titania-coated nanograined/ultrafine grained (NG/UFG) austenitic stainless steel. The accompanying objective is to study the disinfective/antimicrobial activity. To the best of our understanding this is the first study of nanophase titania on a non-titanium substrate. The osteoblasts functions were investigated in terms of cell attachment, proliferation, and quantitative analysis of proteins, actin and vinculin. In comparison to the bare NG/UFG substrate, the nanophase titania-coated substrate exhibited higher degree of cell attachment and proliferation which are regulated via cellular and molecular interactions with proteins, actin and vinculin. The enhanced functions of osteoblasts suggest that nanophase titania adsorbs extracellular matrix proteins, fibronectin and vitronectin from serum enhancing protein, with subsequent binding of integrins and osteoblasts precursor to titania. The antimicrobial attributes assessed in terms of degradation of methyl orange and effectiveness in killing E. coli supports the viewpoint that large surface area of titania would be instrumental in reducing the detrimental effect of biologically reactive oxygen species produced by macrophages in the vicinity of the metal bone/implant interface. In summary, the study provides some new insights concerning nanostructuring of metallic substrates with specific physical and surface properties for medical devices with significantly improved cellular response.     

Crystallographic Analysis of Martensite in 0.2C-2.0Mn-1.5Si-0.6Cr Steel using EBSD

The crystallography of martensite formed in 0.2C-2.0Mn-1.5Si-0.6Cr steel was studied using the electron backscattered diffraction(EBSD) technique.The results showed that the observed orientation relationship(OR) was closer to that of Nishiyama-Wassermann(N-W) than Kurdjumov-Sachs.The martensite consisted of parallel laths forming morphological packets.Typically,there were three different lath orientations in a morphological packet consisting of three specific N-W OR variants sharing the same {111} austenite plane.A packet of martensite laths with a common {111} austenite plane was termed a crystallographic packet.Generally,the crystallographic packet size corresponded to the morphological packet size,but occasionally the morphological packet was found to consist of two or more crystallographic packets.Therefore,the crystallographic packet size appeared to be finer than the morphological packet size.The relative orientation between the variants in crystallographic packets was found to be near 60 /<110>,which explains the strong peak observed near 60 in the grain boundary misorientation distribution.Martensite also contained a high fraction of boundaries with a misorientation in the range 2.5-8.Typically these boundaries were found to be located inside the martensite laths forming sub-laths.     

Cellular Mechanisms of Enhanced Osteoblasts Functions via Phase‐Reversion Induced Nano/Submicron‐Grained Structure in a Low‐Ni Austenitic Stainless Steel

We elucidate here the fundamental principles underlying the modulation of osteoblasts functions in stainless steel biomedical devices achieved by nanoscale/submicron grain structure obtained through the novel concept of phase reversion in a low Ni bearing 15Cr–9Mn–1.7Cu steel. Interestingly, a comparative investigation of nano/submicron (N‐SM) and coarse‐grained (CG) structure under identical conditions indicated that cell attachment, proliferation, and viability are favorably enhanced in N‐SM grained structure and significantly different from the CG structure. These observations were further confirmed by expression levels of vinculin and associated actin cytoskeleton. Computational analysis of immunofluorescence micrographs suggested increased vinculin concentration associated with actin stress fibers in the outer regions of the cells and cellular extensions, implying enhanced cell–substrate interactions on the N‐SM grained substrate. The favorable enhancement of osteoblasts functions and cellular attachment on N‐SM grained surface is attributed to ultrafine grain size, i.e., the availability of greater open lattice in the position of high angle grain boundaries, and high hydrophilicity. The integration of cellular and molecular biology with material science and engineering as described here provides a route to modulate cellular and molecular reactions in promoting osteoinductive signaling of surface adherent cells. The end outcome of the study is that stainless steels with low Ni contents in comparison to the conventionally used bioimplant with 10–13 wt%Ni, as specially processed, exhibit desired, enhanced cell functions, and bulk properties.     

Adhesion, spreading and osteogenic differentiation of mesenchymal stem cells cultured on micropatterned amorphous diamond, titanium, tantalum and chromium coatings on silicon

It was hypothesized that human mesenchymal stromal cell (hMSC) can be guided by patterned and plain amorphous diamond (AD), titanium (Ti), tantalum (Ta) and chromium (Cr) coatings, produced on silicon wafer using physical vapour deposition and photolithography. At 7.5 h hMSCs density was 3.0–3.5× higher (P < 0.0003, except Ti) and cells were smaller (68 vs. 102 μm, P 0.000006–0.02) on patterns than on silicon background. HMSC-covered surface of the background silicon was lower on Ti than AD patterns (P = 0.015), but at 5 days this had reversed (P = 0.006). At 7.5 h focal vinculin adhesions and actin cytoskeleton were outgoing from pattern edges so cells assumed geometric square shapes. Patterns allowed induced osteogenesis, but less effectively than plain surfaces, except for AD, which could be used to avoid osseointegration. All these biomaterial patterns exert direct early, intermediate and late guidance on hMSCs and osteogenic differentiation, but indirect interactions exist with cells on silicon background.     

Catalytic Oxidation of Dichloromethane and Perchloroethylene: Laboratory and Industrial Scale Studies

Development of a reliable laboratory scale test for the design of industrial catalysts is crucial. In this article, different laboratory-scale tests were compared with an industrial scale CVOCs treatment. With dichloromethane (DCM) the laboratory scale test results corresponded well to the industrial scale oxidation results. However, the perchloroethylene (PCE) conversions measured in industry were always higher than what was achieved in the laboratory scale indicating that the industrial scale catalytic incinerator operating in transient conditions is highly beneficial in PCE oxidation. It was clearly shown that in order to design high-quality laboratory scale experiments, information on complete composition and total concentration of the emission is needed but also different types of catalytic tests need to be used depending on the industrial reactor. In addition, the catalysts’ performance in an industrial VOC abatement unit was examined as the oxidation efficiencies of DCM, PCE and other hydrocarbons (OHC) were compared after 3, 10 and 23 months of operation. After 23 months and 13,065 operating hours, no significant decrease in the activity of the catalysts was observed showing that the used noble metal catalysts are highly resistant towards these demanding conditions.     

A state machine approach in modelling the heating process of a building

Process models and their applications have gradually become an integral part of the design, maintenance and automation of modern buildings. The following state machine model outlines a new approach in this area. The heating power described by the model is based on the recent inputs as well as on the past inputs and outputs of the process, thus also representing the states of the system. Identifying the model means collecting, assorting and storing observations, but also effectively utilizing their inherent relationships and nearest neighbours. The last aspect enables to create a uniform set of data, which forms the characteristic, dynamic behaviour of the HVAC process. The state machine model is non-parametric and needs no sophisticated algorithm for identification. It is therefore suitable for small microprocessor devices equipped with a larger memory capacity. The first test runs, performed in a simulated environment, were encouraging and showed good prediction capability.     

Thermal comfort and use of thermostats in Finnish homes and offices

Thermal comfort and use of thermostats in homes and office rooms were examined by a quantitative interview survey with a nationally representative sample in Finland. The total number of respondents was 3094. The results show that thermal comfort levels are lower in offices than in homes. People feel cold and hot more often in offices than in homes during both the winter and summer seasons. The perceived control over room temperature is remarkably low in offices. Higher thermal comfort levels and perceived control in homes are supported by greater adaptive opportunities. In offices people have fewer opportunities to control the thermal environment, people deal worse with thermostats, and people have lower opportunities to adapt to different thermal environments.