Improved early bone-implant integration in transgenic mice overexpressing bovine growth hormone

Titanium implants were inserted in transgenic mice overexpressing bovine growth hormone. Four weeks after insertion the implants were cut out en bloc with the surrounding bone. The undecalcified specimens were cut and ground to a thickness of approximately 10 m. Histomorphometry demonstrated significantly more direct bone to metal contact for the transgenic mice than for the non-transgenic littermates. The results indicate that endogenous high levels of bovine growth hormone result in improved early bone-implant integration. This study indicate that it may be possible to systemically administrate growth hormone in man, in the early healing in phase, to improve implant integration.     

Environmental considerations in the Swedish building and construction industry: the role of costs,institutional setting,and information

Despite increasing evidence that being an environment-friendly company not only benefits the environment but also makes long-term economic sense, the transition to a more sustainable society is extremely slow. This is true of the building and construction industry as well. At a strategic level, environmental issues have received more attention with the establishment of roles such as environmental managers and implementation of advanced environmental management systems. However, adoption has been slow in the absence of a holistic approach to environmental challenges, partly reinforced by a perception that giving more than the legally required level of environmental consideration will only add to costs without corresponding financial benefits. This raises the following question that the study aims to answer: What is the most important factor influencing decision makers’ in adopting environmental considerations? To this end, it analysed questionnaire data collected from decision makers in the Swedish construction industry along with an in-depth case study of a specific building and construction company. The results show that decision makers perceive informational and institutional constraints on the adoption of environmental considerations. Lack of information is perceived as the biggest obstacle to environmental considerations. If information and knowledge about clients’ and end users’ financial benefits from adopting environmental considerations need to be exploited, they have to be supported by contractual forms that discard a short-term focus on the investment costs of a building in favour of a focus on long-term operational and maintenance costs and benefits.     

Extensions to “Output prediction under scarce data operation: control applications”

Albertos et al. (Automatica, 35 (1999) 1671–1681), proposed a simple and computationally cheap output estimation algorithm for systems where some output data is missing. In the original paper, a stability analysis of the algorithm is provided for the special case that every Nth sample of the output is observed. We here show how the stability can be analysed for arbitrary periodical missing data patterns.     

Development of decay performance models for outdoor timber structures

Performance based building (PBB) and design is closely connected to various needs and requirements: Performance levels need to be defined, test methods for verification of performance need to be developed, and reliable performance data are needed for materials, products, constructions, and different design solutions. In contrast to other building materials, PBB and thus service life prediction of timber and wood-based products requires particular consideration of wood-degrading organisms and their physiological needs. For the most relevant group of wood-destroying organisms, which are the different decay fungi and bacteria, wood moisture content and temperature need to be considered as key factors. This study aimed on the development of performance models on the basis of hard data obtained in field trials performed under most realistic conditions. Dose–response relationships, which can serve as essential parts of a performance based design model, were derived from material climatic data and corresponding decay development in the field. Different dose–response models are proposed and evaluated for predicting onset (and progress) of decay when wood is exposed to a dynamic and arbitrary climate exposure described in terms of time series of coupled temperature and moisture content. A logistic dose–response model was primarily focused on describing the relation between exposure and decay rating for moisture traps with long periods of high moisture contents. A two-step linear engineering model was more focused on predicting the behavior in a wider, more simplified, sense where periods of high moisture content are interrupted by periods of drier and/or colder climate.     

Analysis on the control principle of the active DC filter in theLindome converter station of the Konti-Skan HVDC link

The control principle of a hybrid passive-active DC filter installed in the Lindome HVDC converter station is analyzed in this paper. The controller of the active filter includes two basic functions: an integrator and a compensator. The main advantage of the Lindome controller is its simple structure for implementation in a digital signal processor (DSP). The drawbacks of this controller are its long response time, low stability margin and the filtering of an unnecessary number of frequencies. An alternative control strategy using a number of notch filters has been investigated. The notch filters can be tuned to those frequencies that need to be damped. This controller gives a much shorter system response time and improved stability margin     

Changing Frames of Mobility through Radical Policy Interventions? The Stockholm Congestion Tax

The introduction of a congestion tax was a significant moment in the management of mobility in Stockholm. This paper critically examines this apparent consensus on confronting car based mobility, by analysing how mobility was framed at key stages in policy making, from the 1970s through to the trial in 2006 and subsequent implementation. Changing transport objectives are compared, and winners and losers are traced in relation to motility and environmental quality. The paper argues that a car-based automobility frame survives, even in the implementation of a radical policy of congestion taxation.     

The rönnskär smelter project: Production, expansion, and start-up

In 1998, the Boliden Limited board of directors voted to modernize the Rönnskär copper smelter and refinery to expand production from 130,000 t/y to 230,000 t/y cathodes. Heavy involvement from operations and management was maintained during the modernization project, enabling the realization of project goals while maintaining full production schedules. Early start-up data indicate a smooth transition from the old to the new units.     

Time-series modeling of moisture exposure on timber structures

This paper presents a methodology with the purpose of modeling and simulating outdoor temperature and relative humidity (vapor concentration) related to moisture exposure on timber structures. The methodology is based on time-series analysis with recorded meteorological data used as input. In situations where recorded data is missing or consists of limited sequences, this methodology offers the possibility to use synthetic data instead. It was found that temperature and vapor concentration could be modeled by a combination of deterministic functions and stochastic processes, which consider the dynamics of the climate, including slow seasonal variations and fast daily changes. Specifically, a model for temperature and vapor concentration in Stockholm, Sweden, is presented together with simulation results. It is shown that the model produces simulated sequences with statistical properties close to the real recorded ones.