The concept of a ‘concentration town’

The Netherlands Habitat Commission was founded to coordinate all activities during the International Year of Shelter for the Homeless (1987). Over the years in the Netherlands, both on the governmental and nongovernmental level, attention to and support for the urban problems in the Third World has significantly increased. The Commission had taken the initiative of developing a so called concentration town project, based on the concept that targeting aid to one city will strengthen the impact of each individual project. A pilot project is being established in the Indian city of Bangalore. The results so far are promising. Through this project the NHC would like to show how use can be made of the growing interest in the plight of the urban poor in the Third World.     

Wind turbine drives — Test results from the ‘falcon’

A wind turbine drive has been designed and built for full scale trials in order to assess the use of this type of propulsion for commercial craft. This wind turbine rig is fitted to the 5.6m long Blackwater sloop ‘Falcon’.

Test results from this boat are presented over a range of operating wind conditions up to Beaufort force 6 (11.5m/s) for two different wind turbine rotors. Maximum boatspeeds reached were 3.5 knots upwind (in 7.2m/s wind), 5.0 knots across the wind (9.8m/s wind) and 5.2 knots downwind (8m/s wind). The ‘hull speed’ of this boat is around 5.0 knots.     

The application of ‘least-cost’ modelling as a functional landscape model

The growing awareness of the adverse effects of habitat fragmentation on natural systems has resulted in a rapidly increasing number of actions to reduce current fragmentation of natural systems as well as a growing demand for tools to predict and evaluate the effect of changes in the landscape on connectivity in the natural world. Recent studies used ‘least-cost’ modelling (available as a toolbox in GIS-systems) to calculate ‘effective distance’, a measure for distance modified with the cost to move between habitat patches based on detailed geographical information on the landscape as well as behavioural aspects of the organisms studied. We applied the method to a virtual landscape and a small scaled agricultural system subject to different scenarios in a land re-allotment project. We discuss the importance of technical aspects and ecological assumption underlying this modelling method. The model is shown to be a flexible tool to model functional connectivity in the study of the relation between landscape and mobility of organisms as well as in scenario building and evaluation in wild life protection projects and applied land management projects. Since ‘effective distance’ has the same units as Euclidean distance (m), this effective distance may be a straightforward way to include landscape and behavioural aspects in other models which include distance as a measure for isolation. We show the importance of the ‘ecological’ quality of the input maps and the choice of relevant landscape features and resistance values.     

Performance evaluation of the Walnut Creek ‘soft armor’ lining system

As both cities and erosion control legislation continue to grow, the need for cost effective, high performance channel lining systems is becoming even more important than ever. When the City of Austin, Texas (USA) faced this challenge, lenge, sought to use a soft armor lining in lieu of the specified concrete lining along Walnut Creek Tributary #7, Phase 1. Located in a largely residential neighborhood, the need to provide good aesthetics at a reasonable price was important to the city. Installed in March 1991, roughly up to 11 meters (36 feet) wide and 350 meters (1150 feet) long, the channel lining system has remained in good condition and continues to provide the benefits of a turf reinforced waterway.

This paper provides the background, selection, and long-term performance evaluation of a soft armor channel as an alternative to traditional hard armor. Data from rainfall events is used to estimate velocity and shear stress exerted on the system over the first five years of performance. Included are also photographs, vegetation progression, chronological data, and field observations from the time of installation in 1991 to the present.     

Improving the interpretation of ‘less than’ values in environmental monitoring

This paper reviews the approaches used to deal with the interpretation of measurements reported as ‘less than’ a stated reporting limit. The principal current methodologies are examined and their shortcomings discussed. Recent key papers on the subject are summarised. It is concluded that lack of easy‐to‐use alternative methods have led to the continued use of substitution methods that are acknowledged to be biased. With the aim of promoting a more technically sound approach to dealing with ‘less than’ data, a supplementary spreadsheet tool is supplied to provide the reader with ready introductory access to a simple way to apply maximum likelihood methods. Recommendations and simple guidelines for better practice are provided.     

‘Management by projects’: the management approach for the future

The trend toward the project-oriented company, performing simultaneously a network of internal and external projects, creates the demand for the management approach ‘Management by Projects’. The specific feature of ‘management by projects’ is that the management of single projects, the management of the network of projects and the management of the relationships between the company and the single projects are considered. For the successful management of the project-oriented company, instruments of ‘Management by Projects’ are presented.     

Material-specific effects of hydrated lime on the properties and performance behavior of asphalt mixtures and asphaltic pavements

This study evaluates hydrated lime-treated hot-mix asphalt (HMA) mixtures through various laboratory tests, including the dynamic modulus test and performance tests to characterize permanent deformation and fatigue damage resistance both in displacement-controlled and force-controlled modes. Two different asphalt mixtures — the asphalt concrete mixture and the fine aggregate asphalt matrix mixture — which differ only in the amount of additional hydrated lime (0.5–3.0%), are tested. Test results demonstrate material-specific damage characteristics of hydrated lime and the existence of a more appropriate amount of hydrated lime to be added to the HMA mixtures than the current typical application rate such as the addition of 1.0% lime to dry or pre-moistened aggregates. In addition, the newly released Mechanistic-Empirical Pavement Design Guide (MEPDG) is used for predicting pavement performance related to hydrated lime content. The MEPDG analysis results show that damage prediction models implemented in the current MEPDG are limited to accurately predicting material-specific damage characteristics. Mechanistic models that consider material-specific crack phenomenon and fracture behavior should be pursued.     

Fire detector systems with ‘distributed intelligence’ the pulse polling system

Well over a million fire detectors are currently in use in the Federal Republic of Germany. Provided they are correctly installed and efficiently maintained, they detect fires reliably at a very early stage. At the present time, the false alarm rate equals about 1% of the number of installed detectors per annum. This false alarm rate must be at least proportionately reduced as further detectors are installed.

Since it is scarcely possible to improve tried-and-tested detector designs, the employment of higher-grade detector signal processing methods suggests itself.

However, ‘more intelligent’ detector signal processing using microprocessors calls for an entirely new fire detection system structure: detectors which independently ‘decide’ whether an alarm criterion is met and then initiate an alarm are replaced by sensors which continuously transmit their measured values to the ‘intelligence’ panel for evaluation. Passive panels which simply receive alarm signals from activated detectors and indicate these or transmit them to the fire brigade are replaced by active processors using permanently improved algorithms for the detection of real fires.

A structural change of this type is possible provided the positive — and the customary — characteristics of the conventional technique are not lost, viz. two-wire lines between detector and panel, simple installation and handling, easy detector replaceability, low cost, etc.

The pulse detector technology is described in detail; it combines the simplicity of conventional fire detection systems with new characteristics, e.g. identification of individual detectors, permanent functional check of all connected detectors, automatic notification of maintenance requirement prior to a slowly developing fault (e.g. such as that caused by corrosion or contamination), uniform response sensitivity unaffected by drifting from the operating points of the detectors and, above all, greater protection against false alarms.     

Evaluation of the engineering properties of some Egyptian limestones as construction materials for highway pavements

Several hundred limestone samples representing eight different deposits within Egypt have been evaluated and results indicate that some of the deposits are adequate for use as highway pavement construction materials. The evaluation included tests on index properties, strength, chemical, petrographic and resistance-to-abrasion. The suitability or adverse features of the eight limestone deposits have been evaluated and the various engineering characteristics are discussed, based on a rating scheme, recommendations are made for the use of selected limestones as pavement materials in Egypt.     

Improvement of engineering properties of expansive soil using liming leather waste ash

Bulletin of Engineering Geology and the Environment - The expansive soils have always presented various challenges for geotechnical and civil engineers due to their low bearing capacity and high...     

Public policy for a multiproduct firm : Tearing down the ‘Berlin Wall’ in telecommunications

United States telecommunications policy contains ‘Berlin Walls’ that due to technology advances are being breached. Policies that encourage competitors are unnecessarily constraining traditional providers, the local exchange carriers. These constraints are causing market distortions, harmful to consumers. We propose four specific policy changes that should be adopted in order to bring down the walls while providing protections against any residual market power held by the exchange carriers. Specifically: use of incremental cost test to deter/detect cross-subsidies, price imputation for intrafirm transfers, generalized open network architecture, and removal of prohibitions on exchange carrier provision of video programming.     

Seismic analysis of the ‘South Gate’ tall building according to Eurocode 8

The tallest building designed in Poznań (western part of Poland) is the case study. The analysed building is a multifunctional office centre with the heliport on the top, called the ‘South Gate’. The main structure is the RC slab and column system with shear walls and cores. After many static analyses the seismic analysis, based on damage limitation state according to Eurocode 8, was made. The analysis, in which a continuous–discrete approach and the response spectrum technique were applied, was carried out by means of the DAMB program as part of an integrated system. The allowable design ground acceleration was evaluated. Copyright © 2004 John Wiley & Sons, Ltd.     

Deculverting: reviewing the evidence on the ‘daylighting’ and restoration of culverted rivers

We review published references on ‘deculverting’ (also known as ‘daylighting’) projects in the United Kingdom and internationally. The aim of the review was to assess the objectives of implemented projects and to establish where evidence exists for the purported social, economic and environmental benefits of deculverting. The outcomes highlight the need for collaboration to collate detailed information on such projects, to support the further development of evidence‐based policy. It is clear that deculverting schemes can indeed exert considerable positive impacts, including ecological benefits, reduced flood risks, recreation for local communities and a stimulus for regeneration, but that the evidence for these impacts is sparse. We conclude that improvements in policy will help to maximise these opportunities, by encouraging the implementation of good practices.     

Implementation of improved wetland systems as a ‘zero‐discharge‐technology’ in Poland

This paper discusses results from the implementation of a ‘zero‐discharge‐ technology’ primarily for single households, as well as hotels and small residential urban and rural areas. During a 15‐year span, 5600 improved wetland systems (IWS) were built, and approximately 50% of treatment wetlands in Europe are located in Poland. The first section of this paper discusses water and wastewater management and its development trends. Particular attention is paid to creating sustainable water management in rural areas due to increased necessity in these regions. The second section presents the principle of the IWS, which consists of two options. The third section discusses the current requirements regarding the quality of treated wastewater in Poland. The fourth section presents the effectiveness of the implementation of this system by the Institute for Applied Ecology and the further prospects of ‘zero‐discharge‐technology’ development. The last section discusses the obtained results in the reduction of pollution.