TAPIR — Finnish national geochemical baseline database

In Finland, a Government Decree on the Assessment of Soil Contamination and Remediation Needs has generated a need for reliable and readily accessible data on geochemical baseline concentrations in Finnish soils. According to the Decree, baseline concentrations, referring both to the natural geological background concentrations and the diffuse anthropogenic input of substances, shall be taken into account in the soil contamination assessment process. This baseline information is provided in a national geochemical baseline database, TAPIR, that is publicly available via the Internet.Geochemical provinces with elevated baseline concentrations were delineated to provide regional geochemical baseline values. The nationwide geochemical datasets were used to divide Finland into geochemical provinces. Several metals (Co, Cr, Cu, Ni, V, and Zn) showed anomalous concentrations in seven regions that were defined as metal provinces. Arsenic did not follow a similar distribution to any other elements, and four arsenic provinces were separately determined. Nationwide geochemical datasets were not available for some other important elements such as Cd and Pb. Although these elements are included in the TAPIR system, their distribution does not necessarily follow the ones pre-defined for metal and arsenic provinces.Regional geochemical baseline values, presented as upper limit of geochemical variation within the region, can be used as trigger values to assess potential soil contamination. Baseline values have also been used to determine upper and lower guideline values that must be taken into account as a tool in basic risk assessment. If regional geochemical baseline values are available, the national guideline values prescribed in the Decree based on ecological risks can be modified accordingly.The national geochemical baseline database provides scientifically sound, easily accessible and generally accepted information on the baseline values, and it can be used in various environmental applications.     

Use of nanoparticular and soluble anionic celluloses in coagulation-flocculation treatment of kaolin suspension

In this work, the effectiveness of a novel, combined coagulation-flocculation treatment based on alum and soluble or nanoparticular anionic derivatives of dialdehyde cellulose, ADAC, was evaluated by studying the removal of colloidal material in a model suspension containing kaolin. Four different ADACs with varying degrees of substitution, size and water solubility were synthesized by periodate oxidation and sulfonation of cellulose. The effects of ADAC dosage, solution pH and temperature on flocculation were studied by measuring residual turbidity of the settled suspension. Moreover, the charge densities, sizes, ζ-potentials and stability of the ADACs in aqueous solutions were studied. The combined treatment was effective in the removal of colloidal particles, as demonstrated by reduced residual turbidity with remarkably lower total chemical consumption compared with coagulation with alum alone. Of the ADACs, samples with lower solubility that contained cellulose nanoparticles performed better than the fully water-soluble sample. Due to the restricted pH tolerance of alum, the combined treatment was effective only at acidic conditions (pH < 5), although the ADACs were found to be stable in a much broader pH range (pH of 3 to about 9). ADACs also retained strong activity at higher temperatures (30-60 °C) and after several days of storage in aqueous solution.     

Trends of energy efficiency in Finnish road freight transport 1995–2009 and forecast to 2016

A framework for modeling and analyzing the energy efficiency of road freight transport is presented in this paper. This framework is tested by using the data from the Finnish Goods Transport by Road statistics. The data was enhanced by calculating the fuel consumption for each trip in the data. To calculate this, weight-fuel consumption functions were estimated for each Euro-class vehicles and road type. This is a new method for analyzing the energy efficiency of road freight transport and it could be applied also in other countries gathering freight transport data with continuous company surveys. The analysis show that the energy efficiency of road freight transport in Finland improved during 1995–2002, but has declined since. The major drivers in the development have been the changes in the level of empty running and vehicle fuel efficiency. Extrapolating current statistical trends of factors that influence the energy efficiency show that the target set by the Finnish government for improving energy efficiency by 9% until 2016 will not be achieved. However, the target is possible to be achieved by a combination of small changes to some determinants.     

Estimation of nonstationary EEG with Kalman smoother approach: an application to event-related synchronization (ERS)

An adaptive spectrum estimation method for nonstationary electroencephalogram by means of time-varying autoregressive moving average modeling is presented. The time-varying parameter estimation problem is solved by Kalman filtering along with a fixed-interval smoothing procedure. Kalman filter is an optimal filter in the mean square sense and it is a generalization of other adaptive filters such as recursive least squares or least mean square. Furthermore, by using the smoother the unavoidable tracking lag of adaptive filters can be avoided. Due to the properties of Kalman filter and benefits of the smoothing the time-frequency resolution of the presented Kalman smoother spectra is extremely high. The presented approach is applied to estimation of event-related synchronization/desynchronization (ERS/ERD) dynamics of occipital alpha rhythm measured from three healthy subjects. With the Kalman smoother approach detailed spectral information can be extracted from single ERS/ERD samples.     

Interactions between tungsten carbide (WC) particulates and metal matrix in WC-reinforced composites

A variety of experimental techniques have been used to investigate the interactions between tungsten carbide (WC–Co 88/12) particulates and the matrix in some new wear resistant cobalt-based superalloy and steel matrix composites produced by hot isostatic pressing. The results show that the chemical composition of the matrix has a strong influence on the interface reaction between WC and matrix and the structural stability of the WC particulates in the composite. Some characteristics of the interaction between matrix and reinforcement are explained by the calculation of diffusion kinetics. The three-body abrasion wear resistance of the composites has been examined based on the ASTM G65-91 standard procedure. The wear behavior of the best composites of this study shows great potential for wear protection applications.     

Sustainable virtual communities: suggestions from the colonial model

While virtual community research has contributed to the understanding of the virtual community sustainability, a need for a systematic model exists. In this paper, we propose a model of sustainable virtual communities based on the sustainability properties of animal colonies in nature. The premise of our model is that if we manage to replicate the sustainability properties of colonial systems in virtual communities, they can become longer lasting. We also present the results of an exploratory case study. The study shows that colonial properties form a construct that predicts member perceptions of their community being sustainable. While our primary objective is the conceptual introduction of the colonial principles of sustainability, the case study provides some early indications that these principles may help design systems that can bind virtual communities more permanently.

Physical, chemical and microbiological water characteristics associated with the occurrence of Legionella in cooling tower systems

The occurrence of Legionella in water of 30 cooling tower systems was studied, as well as the relationship of its occurrence with the physical, chemical and microbiological characteristics of the waters. The samples were concentrated by membrane filtration and one part of the concentrate was acid washed. Three types of culture media, MWY, CCVC and BCYEα were used. Fourteen (47%) of the cooling systems were Legionella-positive. Numbers of Legionella in the positive systems varied between 50 and 490,000 cfu/l. Legionella pneumophila was the dominant isolate, and the serogroups 6 and 1 were the commonest ones. There was no statistically significant difference in mean water temperature between the Legionella-positive (27°C) and -negative (24°C) systems. The total number of bacteria (AODC) was lower in the Legionella-positive than in the negative systems. Also the nutrient concentrations were generally lower in the Legionella-positive cooling systems. The results suggest that different factors regulate the occurrence of Legionella than that of overall bacterial populations in the cooling tower systems.     

Bioactive glass induced in vitro apatite formation on composite GBR membranes

The aim of this study was to investigate in vitro bioactivity of different thermoplastic biodegradable barrier membranes. Three experimental GBR membranes were fabricated using Poly(epsilon-caprolactone-co-D: ,L-lactide) P(CL/DL-LA) and particulate bioactive glass S53P4 (BAG; granule size 90-315 microm): (A) composite membrane with 60-wt.% of BAG, (B) membrane coated with BAG; and (C) copolymer membrane without BAG. Membranes were immersed in simulated body fluid (SBF), and their surfaces were characterized with SEM, XRD and EDS after 6 and 12 h and after 1, 3, 5, 7, and 14 days. Calcium phosphate (Ca-P) surface formation was observed on both composite membranes (A and B) but not on the copolymer membrane without bioactive glass (C). The Ca-P precipitation appeared to be initiated on the bioactive glass followed by growth of the layer along the polymer surface. In 6-12 h ion dissolution of the bioactive glass led to formation of the silica rich layer on the surface of the exposed glass granules on composite membrane B whereas only small amounts of silica was observed on the polymer surface of the composite membrane A. At 24 h nucleation of Ca-P precipitation was observed, and by 3-5 days membrane surface was covered with a uniform Ca-P layer transforming from amorphous to low crystalline structure. At 7 days composition and structure of the apatite surface resembled the apatite in bone. Once nucleated, the surface topography seemed to have significant effect on the growth of the apatite layer.     

Modelling of transport properties and state of water of polyelectrolytes containing various amounts of water

Atomistic molecular modelling is used to construct sulfonated PVF-based polyelectrolyte materials containing 0, 10 or 40 wt% of water. The systems contain hydronium ions, with which the classical diffusion of the hydronium ions can be simulated, and particles called protons, with which the proton hopping mechanism can be simulated. System containing 40 wt% of water is conducting. Both the proton hopping and the classical diffusion mechanisms occur in the system and neither of them is dominating. The interactions between ions are calculated and they are found to be relatively small. Diffusion coefficients of the protons, hydronium ions and the water molecules are reported and the movement of ions is studied. The location of the protons, the hydronium ions and the water molecules is studied at the atomistic level. In system containing 40 wt% of water, water clusters are seen. There are no remarkable differences between the results that are measured for similar materials or calculated in this study.