Industrial supply chains and production machinery of forest chips in Finland

Metsäteho Oy surveyed the industrial supply chains used in the production of forest chips in 2006 in Finland. The Metsäteho study also conducted a survey of the production machinery of forest chips used by energy plants in 2007, and provided an estimate of industrial supply chains and future machinery requirements for forest chip production in Finland.The majority of the logging residue chips and chips from small-sized thinning wood were produced using the roadside chipping supply chain in 2006. The chipping at plant supply chain was also significant in the production of logging residue chips. The majority of all stump wood chips consumed were comminuted at the plant, and with only around one fifth comminuted at terminals. The role of the terminal chipping supply chain was also significant in the production of chips from logging residues and small-sized wood chips. It was predicted that the roles of both terminal chipping of logging residues and chipping at the plant will increase by the year 2010. Regarding the production of chips from small-diameter wood, it was estimated that the role of chipping at the plant will also increase in coming years. The proportion of roadside chipping in the production of small-sized wood chips and logging residue chips is expected to decrease.The study estimated that a total of 1100 machine and truck units were employed in the production of forest chips for energy plants in 2007. Increasing forest chip consumption will create considerable demand for additional forest chip production resources in the future.     

Effects of pollution on land snail abundance, size and diversity as resources for pied flycatcher, Ficedula hypoleuca

Passerine birds need extra calcium during their breeding for developing egg shells and proper growth of nestling skeleton. Land snails are an important calcium source for many passerines and human-induced changes in snail populations may pose a severe problem for breeding birds. We studied from the bird's viewpoint how air pollution affects the shell mass, abundance and diversity of land snail communities along a pollution gradient of a copper smelter. We sampled remnant snail shells from the nests of an insectivorous passerine, the pied flycatcher, Ficedula hypoleuca, to find out how the availability of land snails varies along the pollution gradient. The total snail shell mass increased towards the pollution source but declined abruptly in the vicinity of the smelter. This spatial variation in shell mass was evident also within a single snail species and could not be wholly explained by spatially varying snail numbers or species composition. Instead, the total shell mass was related to their shell size, individuals being largest at the moderately polluted areas. Smaller shell size suggests inferior growth of snails in the most heavily polluted area. Our study shows that pollution affects the diversity, abundance (available shell mass) and individual quality of land snails, posing reproductive problems for birds that rely on snails as calcium sources during breeding. There are probably both direct pollution-related (heavy metal and calcium levels) and indirect (habitat change) effects behind the observed changes in snail populations.     

Groupware Environments as Action Constitutive Resources: A Social Action Framework for Analyzing Groupware Technologies

Computer Supported Cooperative Work (CSCW) is a relatively new and dynamic field dealing with the development and use of groupware technologies in organizations. Several frameworks and models have been proposed for studying CSCW, each conveying a different perspective and theoretical basis. Although these frameworks have contributed much to our understanding of the field, they can be criticized for a lack of holistic understanding of the complex social activity that is constitutive of groupwork. This often leads to the failure of otherwise well designed CSCW applications. In this paper we take up this challenge and propose a social action framework for analyzing groupware technologies. The framework is based on Habermas's theory of social action and four action categories, and the idea that groupware applications serve as sets of rules and resources which mediate group interactions. We demonstrate the value of the framework by analyzing a wide range of existing groupware technologies for their appropriateness to specific groupwork situations in terms of their espoused or implicit assumptions of groupwork, and the action constitutive resources they provide. Our analysis points out that a host of current groupware applications can be fairly easily classified and examined by the way they are configured to support different types of social action. It also suggests that, when implementing groupware applications, developers should critically evaluate: (a) the need for supporting a rich variety of action types, (b) the possible role of computer support in the specific groupwork situations, and (c) the underlying assumptions of groupwork embedded in the groupware platform. Finally, we will discuss how the framework can inform future research and development in the field.     

Sharrock and Button ... and Much Ado about Nothing

The paper discusses Sharrock's and Button's criticism of our attempt to use Habermas' communicative action theory to analyze group work platforms. We demonstrate that they misconstrue our goals of the paper, misinterpret our analysis of Habermas' action types, and misunderstand the concept of critical science. At the end we question the usefulness of these types of debates in furthering CSCW research.     

Developing and implementing environmental management systems for small and medium-sized construction enterprises

Environmental aspects are gradually becoming factors of importance for construction businesses, their operations and their management. These factors can be seen as new change makers for construction management itself. New criteria need to be taken into account when structuring construction activities, in decision making, and throughout the production control. Instances of construction management solutions that also encapsulate environmental aspects are likely to appear. A contractor’s environmental management system (EMS) is an example of such an instance. As a management solution an EMS is targeted at minimizing a contractor’s environmental impacts. An experiment has been carried out where an EMS solution was formed and tested for small and medium-sized contractors. Fifteen small and medium-sized construction companies were involved. Along with the action research approach, a set of workshops with company people were arranged for EMS structuring and for its testing. Within these experiments the researcher acted as a developer and inside observer. The proposed EMS solution presents the structuring of environmental aspects for management attention. Moreover, this structuring can be used as a basis for a formal environmentally conscious management system. All companies involved in the research have started to use the EMS solution or its parts.     

Ambiguous Configurations for the 1D Structure and Motion Problem

In this paper we investigate, determine and classify the critical configurations for solving structure and motion problems for 1D retina vision. We give a complete categorization of all ambiguous configurations for a 1D (calibrated or uncalibrated) perspective camera irrespective of the number of points and views. It is well-known that the calibrated and uncalibrated case are linked through the circular points. This link enables us to solve for both cases simultaneously. Another important tool is the duality in exchanging points and cameras and its corresponding Cremona transformation. These concepts are generalized to the 1D case and used for the investigation of ambiguous configurations. Several examples and illustrations are also provided to explain the results and to provide geometrical insight.     

Multi-radio coexistence and collaboration on an SDR platform

In order to support the simultaneous use of both legacy and new radios in a multi-radio handset, a Software Defined Radio (SDR) platform needs to offer coexistence mechanisms and services for radios. This paper proposes an SDR control framework to provide the coexistence services and common interfaces for them. The multi-radio control in proposed platform is divided into two parts, the light-weight dynamic scheduling with tight real-time constraints to solve the temporal interoperability issues between radios, and the semi-dynamic admission control to perform the resource allocation when a radio changes its behavioral pattern. The control framework was implemented on a SDR technology demonstrator, to show how multiple simultaneously active radios are controlled, and how the coexistence mechanism can be used to provide tangible benefits to the SDR modem user, like the ability to utilize fine-grained spectral holes.     

Untersuchungen zur Wiederverwendung von Spundwänden

Insbesondere in den letzten Jahren wird das Thema Nachhaltigkeit und ressourcenschonender Umgang mit der Umwelt immer stärker in Politik und Gesellschaft diskutiert. Auch in der Geotechnik ist viel Potential vorhanden, nachhaltig mit den Rohstoffen umzugehen. In diesem Beitrag wird hierzu auf die Möglichkeiten der Wiederverwendung von Stahlspundwänden eingegangen. Dabei wird ein wesentliches Augenmerk auf die Möglichkeiten des Recyclings des Spundwandstahls gelegt. Weiterhin erfolgt eine ausführliche Diskussion bezüglich des Ziehens von Spundwänden und den hierbei auftretenden Problemen. So ist häufig ein Anstieg des Herausziehwiderstands über die Zeit feststellbar. Anhand verschiedener Finite‐Elemente‐Untersuchungen wird dieser Zuwachs des Herausziehwiderstands numerisch untersucht, und es können verschiedene Faktoren herausgearbeitet werden, die dem zugrunde liegen. Investigations regarding the re‐use of sheet‐piles. Especially in recent years the topic sustainability and careful handling of environment are discussed more and more in politics and society. In geotechnical engineering there is great potential to deal more sustainable with the used resources. In this contribution, the possibilities of re‐using steel sheet‐piles are discussed. A main scope is set on the possibilities of recycling of the steel. Furthermore, the pull‐out process of sheet‐piles is discussed and problems during the pull‐out process are described. In‐situ often an increase of pull‐out forces over time can be noticed. Several numerical investigations using finite element method are presented to investigate the possible factors which influence the increase in pull‐out forces.     

Kinetic behaviour of HC-SCR over Ag/alumina catalyst using a model paraffinic second generation biodiesel compound

The effect of longer paraffins on the mechanism of the HC-SCR reaction over a 1.91 wt.% Ag/alumina catalyst was investigated by kinetic studies. Hexadecane (C₁₆H₃₄) was chosen as a model compound as it is also a representative molecule for a second generation biodiesel consisting of only long-chain paraffins. The kinetic behaviour of the catalytic reduction of NO_x was examined at steady-state conditions in the temperature range 250–550 °C (50 °C ramping) and by using the following gas concentrations: P_NO = 100, 250, 500, 750 or 1000 ppm, P_hexadecane = 31, 94, 188, 281 or 375 ppm and P_O2=1.5, 3, 4.5, 6 or 9 vol.%. Results showed that in the temperature range 250–425 °C high hexadecane concentration had an inhibiting effect on the NO reduction. At temperatures above 350 °C the apparent reaction orders for hexadecane with respect to hexadecane increased to close or above 1. Reaction orders towards NO were close to 0.55 indicating that NO adsorption on the catalyst surface is stronger than hexadecane adsorption. Based on the experimental data it is proposed that small clusters alone cannot be the active sites for HC-SCR over Ag/Al₂O₃ but the important requirement for high activity over the catalyst is the local concentrations of hydrocarbon and NO on the interface of silver and the support.