Pollution from humidifiers: What is the reason, how to measure and to prevent it?

In the beginning of 1998 a three-year European project, AIRLESS, was started to develop strategies, principles and protocols to improve and control the performance of HVAC-systems and its components for incorporation in codes and guidelines. Twelve institutes, universities and companies, from seven European countries are involved in this project...

Improving work load and comfort of operators on modified hydraulic excavators in rail road maintenance

In small-scale projects of mechanized maintenance of rail roads special equipped hydraulic excavators (HE) are used in several maintenance tasks. One task concerns the exchange of the old crossbars and ballast under the rails by new materials (MCE-task). This task requires high precision of the HE-operators. Inaccurate controlling the machine...

Training of troubleshooting: A structured task analysis approach

Maintenance operations - Workstation adjustment, working posture, and workers' perceptions

In the study maintenance workers were involved in pneumatic wrenching, oxy-gas cutting, and grinding at 5 different heights. Working posture and workers' perceptions were measured. Guidelines on working height were formulated in order to minimize the load on the musculoskeletal system. Data trom the present experiment as weIl as from literature...

Preventive measures against concrete damage to ASR in the Netherlands current state-of-affairs

In CUR-Recommendation 38, various vital measures that need to be taken during design of new concrete-mixtures in order to prevent damage due to ASR in the concrete have been outlined. The most important of these measures are: - the use of blast furnace slag cement (with a high slag content: ≥50% by mass of cement as slag); - or the use of...

Alternative short tests for inspection and maintenance of in-use cars with respect to their emissions performance

This paper presents the first results of a project aimed at evaluation of a number of short tests that can be alternatively used for Inspection and Maintenance of in-use cars emissions performance. For this purpose, a large number of in-use cars from four European countries was tested according to a test protocol that included a wide selection...

Hydrophobic treatment of concrete

As part of the maintenance policy of the dutch Ministry of Transport, Civil Engineering Division, hydrophobic treatment of concrete was considered as an additional protective measure against penetration of aggressive substances, for instance deicing salts in bridge decks. A set of tests was designed to determine the performance of commercial...

Identification of high-risk groups among maintenance workers in a steel company with respect to musculoskeletal symptoms and workload

To determine priorities for ergonomic improvements in five maintenance departments of a steel company, a study was carried out to identify groups with a high prevalence of musculoskeletal problems or a high exposure to unfavourable musculoskeletal workload. All workers were asked to complete a standardized questionnaire on musculoskeletal...

Optimum condition-based maintenance policies for deteriorating systems with partial information

Systems are considered which deteriorate as time goes on and whose conditions can be observed. The optimum maintenance policy with respect to cost is determined, based on a continuous deterioration process, by formulating the decision process as a discrete Markov decision problem. Examples from the field of civil engineering are given. The...

Probabilistic maintenance planning for the tubular joints in the steel gates in the eastern Scheldt storm surge barrier

This paper is a summary of a study on the tubular joints in the steel gates of the Eastern Scheldt storm surge barrier in the Netherlands. This study was commissioned by the Directorate-General for Public Works and Water Management (Rijkswaterstaat) and carried out in the period 1985-1992. At a late stage during the fabrication of the Eastern...

A model for determining condition-based maintenance policies for deteriorating multi-component systems

We discuss a method to determine strategies for preventive maintenance of systems consisting of gradually deteriorating components. A model has been developed to compute not only the range of conditions inducing a repair action, but also inspection moments based on the last known condition value so as to minimize expected costs per time unit. ln...