Spatial planning in subsurface architecture

Achieving a pleasant, safe and orderly atmosphere in an underground building requires careful planning. Special consideration must be given to provisions for access and egress, lighting, and interior decor. The author discusses these topics and many other aspects of underground design, including orientation, passages, uses of interior space, wall and floor surfaces, and creative lighting solutions.     

Regional labor markets in Finland: Adjustment to total versus region-specific shocks

This article analyses regional labor market adjustment in the Finnish provinces during 1976–2000. We investigate the inter-relations of employment, unemployment, labor force participation, and migration to see how a change in region-specific and total labor demand is adjusted. The analysis reveals that region-specific labor demand shocks adjust mainly via participation, whereas total shocks are adjusted by unemployment. The region-specific component of labor demand shock has shorter-lived effects on unemployment and participation, but its effect on employment is permanent. Conversely, total shocks leave no permanent effect. Migration is more important in the region-specific case where, after a few years, it acquires a large role in the adjustment process.     

Effect of biological wastewater treatment on the molecular weight distribution of soluble organic compounds and on the reduction of BOD, COD and P in pulp and paper mill effluent

Pulp and paper mill wastewater was characterizated, before (influent) and after (effluent) biological wastewater treatment based on an activated sludge process, by microfiltration (8, 3, 0.45 and 0.22mum) and ultrafiltration (100, 50, 30 and 3kDa) of the wastewater samples into different size fractions. Various parameters were measured on each fraction: molecular weight distribution (MWD) using high performance size exclusion chromatography (HPSEC), total organic carbon (TOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), phosphate phosphorus (PO(4)-P), electrical conductivity, pH, turbidity, charge quantity and zeta potential. The MWD, TOC and COD(Cr) results indicated that the majority of the material present in both the influent and effluent was in the medium molecular weight (MW) range (i.e. MW<10kDa) with three main MW sub-fractions. There were no significant differences in the range of the MWD between the influent and effluent samples. The magnitude of the MWD in the effluent was about one half that in the influent, the greatest reduction being in the 6kDa fraction. The 3kDa fractions of both the influent and effluent showed a considerable increase in BOD(7), probably due to the removal of compounds harmful to bacteria in 3kDa ultrafiltration. Influent turbidity decreased considerably in microfiltration (8-0.22mum). As the turbidity was removed by 0.22mum filtration, the anionic charge quantity started to decrease. Particles in the influent and effluent contained 19-29% and 14-20% of the total phosphorus, respectively. The major phosphorus fraction was in the form of soluble phosphate.     

Atmospheric circulation patterns influencing variations in organic carbon fluxes in the River Oulujoki,Finland

Atmospheric circulation generally influences regional climate variability and thereby controls catchment hydrology and consequently transport of elements in natural riverine systems. This study examined dependencies between total organic carbon (TOC) variability in the River Oulujoki (Finland) during 1963–2011 and prominent atmospheric circulation patterns (ACPs), which manifest natural climatic conditions over Finland and control hydrological processes in the river catchment. North Atlantic Oscillation, Scandinavia, East Atlantic and East Atlantic/West Russia patterns were statistically significant ACPs affecting variations in TOC export at River Oulujoki lower basin area. In the River Oulujoki, TOC export was largely controlled by changes in TOC fluxes generated from tributaries of river and near areas to its main channel. Besides, runoff from Lake Oulujärvi slightly influenced TOC export variability in the River Oulujoki. Understanding such responses of TOC fluxes to ACPs is a useful tool for sustainable water resources planning and management on regional and local scales.     

Value creation dynamics in a project alliance

Project alliance requires all parties to work together in good faith, share project risks, and make unanimous decisions for the betterment of the project. A key feature of successful implementation of a project alliance is a focus on value creation and value for money. This paper proposes a qualitative system dynamics model to specify and explain dynamics of value creation processes in the context of project alliance. By synthesizing the existing literature and reports on project alliancing, this paper identifies four processes that have a strong influence on the value created in the project alliance context: work progression, rework, redesign and innovation, and rescheduling. In addition, we show how these value creation processes are interrelated and evolve over time. The effectiveness of these processes is influenced by the capability and motivation of the project alliance partners to discover works that do not fully utilize the available resources, and make quick decisions to capture these benefits.     

Optimization of the metakaolin geopolymer preparation for maximized ammonium adsorption capacity

Geopolymers are functional materials that can be used in various environmental applications such as adsorbents in pollutant removal from wastewaters. Metakaolin geopolymer (MK-GP) has been proven to be especially suitable for ammonium (NH₄ ⁺) removal. In this research, the optimal reagent and raw material ratios in the preparation of MK-GP in terms of NH₄ ⁺ adsorption capacity were investigated. The response surface methodology based on the face-centered central composite design was used to optimize the levels of three factors: the amounts of hydroxide, silicate, and metakaolin. In addition, the effect of Na or K as the charge-balancing cation was studied. Empirical models were fitted to the experimental data using multiple linear regression. The significance of the models was confirmed by means of analysis of variance. Optimal NH₄ ⁺ removal efficiency was achieved when the amounts of hydroxide and silicate were maximized, the amount of metakaolin was minimized, and Na-based reagents were used. These trends are most likely a result of optimized conversion of metakaolin into MK-GP.     

Changes in soil carbon stock after cropland conversion to grassland in Russian temperate zone: measurements versus model simulation

The collapse of Soviet Union in early 1990s led to abandonment of large area of arable land which is assumed to act as a carbon (C) sink. We studied the ability of two dynamic soil C models (Yasso07 and RothC) to predict changes in soil C content after cropland abandonment. The performance of the models was compared using the results of a long-term experiment in Pushchino, Moscow region (54°50′N, 37°35′E) in Russia. The experiment was divided in four combinations of fertilizer or mowing treatments on former cropland soil. The soil C content was determined in the year of establishment (1980) and thereafter in 1999 and 2004. The soil C stocks increased by about 1.5- to 1.8-fold during the study period. Both models predicted the overall change in soil C relatively well (modelling efficiency of Yasso07 and RothC were 0.60 and 0.73, respectively). According to the models, the soil gained on average 140–150 g C m^?2 year^?1 during the first 5 years after conversion of cropland to grassland. The C sequestration rate decreased to 40–50 g C m^?2 year^?1 after 20 years of land use change. The sequestration rates estimated in this study are comparable to the rates observed in other studies.     

Quadrature ���� Modulators for Cognitive Radio��I/Q Imbalance Analysis and Complex Multiband Principle

This article discusses the applicability of quadrature ΣΔ modulator (QΣΔM) based analog-to-digital (A/D) conversion in cognitive radio (CR) receivers. First, unavoidable in-phase/quadrature (I/Q) mismatch effects, limiting the dynamic range, are analyzed in closed-form in the case of a first-order modulator. In addition, using the derived analytical converter model, it is shown that notching the signal transfer function (STF) of the modulator at the mirror frequencies of the desired signals will effectively cancel the I/Q imbalance induced mirror-frequency interference in case of the modulator feedback mismatch. In practice, such STF design is easy to implement within the existing converter circuitry, as will be demonstrated in this article. The latter part of the article proposes a novel complex multiband QΣΔM scheme, particularly aimed for the CR receivers. This multiband scheme allows parallel reception of scattered frequency chunks in the CR context and is stemming from the additional degrees of freedom in noise transfer function (NTF) design, provided by the QΣΔM principle. Here multiple noise shaping notches on distinct frequencies are effectively realized through proper design of complex NTF. The modulator structure also allows flexible reconfigurability of the notches with straightforward parameterization of the modulator transfer functions. When combined with the above mirror-frequency rejecting STF design, the concept is demonstrated and proved effective and robust against I/Q imbalances using practical radio signal simulations in realistic received signal conditions.     

Two practical methods for unionized energy grid construction in continuous-energy Monte Carlo neutron transport calculation

A considerable speed-up in continuous-energy Monte Carlo neutron transport calculation can be achieved by using the same unionized energy grid for all point-wise reaction cross sections. This speed-up results from the fact that time-consuming grid iteration is reduced to minimum, and if the unionized grid is constructed by combining the grids of all nuclides, there is no loss of data or accuracy in the calculation. The drawback of this approach is that computer memory is wasted for storing a large number of redundant data points. Memory usage may become a problem, especially in burnup calculation, in which the irradiated materials consist of several hundred actinide and fission product nuclides. The grid size easily increases to over 1 million points, requiring tens of gigabytes of memory for storing the cross section data. This paper presents two practical methods for reducing the memory demand, while trying preserve the accuracy of the original data. The calculation routines are included in the PSG2/Serpent Monte Carlo reactor physics burnup calculation code and the methods are tested in a BWR assembly burnup calculation.