Search results

Filter

Filetype

Your search for "*" yielded 529962 hits

The knowledge problem of public transport policy

The overall aim of the thesis is to investigate the knowledge problem in regional public transport planning. The knowledge problem is twofold. How do transport policy arrive at the desirable actions they take and how do they assess the alternatives, and what can we say about the contributions of already implemented transport schemes. Paper 1 explores how policy objectives in regional public transp

Movement of knowledge : Medical humanities perspectives on medicine, science, and experience

Medical knowledge is always in motion. It moves from the lab to the office, from a press release to a patient, from an academic journal to a civil servant s desk and then on to a policymaker. These movements matter: value judgements on the validity of certain forms of know­ledge determine the direction of clinical research, and policy decisions are taken in relation to existing knowledge.The compl

Characterisation of microbial communities for improved management of anaerobic digestion of food waste

Anaerobic digestion of food waste is an attractive and increasingly popular technology within waste management and energy recovery. A better understanding of the microbiology associated with anaerobic digestion of food waste will provide new insight into the operational conditions required for optimizing this process, as well as its potential for utilisation in co-digestion systems. Eighteen full-

Vibration-based structural health monitoring of a wind turbine system Part II : Environmental/operational effects on dynamic properties

The second part of these companion papers mainly researches environmental/operational influences on structural dynamic properties under normal operational conditions during two years, in order to extract a statistical based damage-sensitive indicator for health monitoring of a wind turbine system. The correlation analyses between experimental identified frequencies, damping values as well as mode

Condition monitoring benefit for operation support of offshore wind turbines

As more offshore wind parks are commissioned, the focus will inevitably shift from a planning, construction, and warranty focus to an operation, maintenance, and investment payback focus. In this latter case, both short-term risks associated with wind turbine component assemblies, and long-term risks related to integrity of the support structure, are highly important. This research focuses on the

Resonance phenomenon in a wind turbine system under operational conditions

A prototype of wind turbines in 5 megawatt class was built and tested at the first German offshore wind energy test field in the North Sea. In order to investigate dynamic behaviors under a complex state of loads, a continuous dynamic monitoring system was implemented by Federal Institute for Material Research and Testing (BAM). It recorded structural responses and environmental/operational variab

On the value of structural health monitoring

Health monitoring has, over the last 2-3 decades, become a topic of significant interest within the structural engineering research community, but also in the broader areas of civil and mechanical engineering. Whereas the merits of Structural Health Monitoring (SHM) are generally appreciated in qualitative terms there has, as of yet, not been reported much fundamental research on the quantificatio

Assessing the value of structural health monitoring

Structural Health Monitoring (SHM) systems are designed for assisting owners and operators with information and forecasts concerning the fitness for purpose of structures and building systems. The benefit associated with the implementation of SHM may in some cases be intuitively anticipated or proven by past experiences but in general there appears to be no rational or systematic approach for asse

Effect of different inspection strategies on the reliability of daniels systems subjected to fatigue

Inspections are an efficient means of enhancing the reliability of redundant structural systems subjected to fatigue.To investigate the effect of such inspections, we represent the deterioration state of a Daniels system by means of a probabilistic fatigue crack growth model of all elements, which considers stochastic dependence among element fatigue behavior. We include inspection results in the

Risk and operation optimized damage detection and inspection systems

Damage detection systems are usually developed and optimized based on the methods of damage detection system reliability. This implies that the later purpose of a damage detection system namely e.g. the employment of the structural integrity management is not directly accounted for. This paper addresses thus the issue of optimizing a damage detection system in the perspective its utilization for t

SHM strategies, application and measurements on tripod offshore wind energy converters within the German offshore park Alpha Ventus

Prototypes of wind turbines of the megawatt class are to be built and tested until 2008 within a German offshore wind energy test field in the North Sea (ALPHA VENTUS). To ensure a high operational reliability of offshore wind turbines with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring systems will be an

Ultimate limit state model basis for assessment of offshore wind energy converters

This paper establishes the model basis regarding the ultimate limit state consisting of structural, loading, and probabilistic models of the support structure of offshore wind energy converters together with a sensitivity study. The model basis is part of a risk based assessment and monitoring framework and will be applied for establishing the "as designed and constructed" reliability as prior inf