Terrorist attack in buildings by chemical and biological agents (CBAs) is a reality in our lives. This study applies computational fluid dynamics (CFD) to predict CBA dispersion in an office building in order to find the best locations for CBA sensors and to develop effective ventilation systems to protect building occupants in case of indoor CBA releases. It is found that the CFD is a useful tool for such an application, while some challenges remain.
The behaviour of particles in air flow is important for identifying those in various locations in ventilated space. The main reason for this study is to propose a new modelling concept to determine a realistic distribution of particles of different sizes in a space. The goal for this investigation is to divide particles into groups according to their behaviour in air and to improve the existing settling model. The growth of particle aerodynamic diameter in higher relative humidity is also presented.
This paper examines the performance of a large new multi storey building which relies exclusively on natural ventilation. The building is designed to provide the main library and associated functions for Coventry University. The research outlines the sophisticated control systems necessary for such a building and provides an analysis of the strategies and techniques required for its implementation. A case study of user satisfaction demonstrates that a large naturally ventilated building can provide a pleasant comfortable environment for occupants.
Data exchange is the process by which information is transferred between the engineer and software and between one piece of software and another. Building and plant simulation involves handling large data sets describing constructional details, system components and reference data. The time required to prepare and check the data is significant and is one obstruction to the widespread use of simulation within the design process. Links between drafting systems and analytical tools offer an obvious way to speed up the process and reduce input errors.
This paper present the results of a test programme to validate the Dutch pre-normative protocol NVN 5623 ‘Radioactivity measurements: Determination of the activity of gamma-ray emitting nuclides in a counting sample by means of semi-conductor gamma-spectr
Since the oil crisis of the seventies, the interest given to buildings physics, indoor climate and energy use has strongly increased. The building envelope and HVAC systems in modern buildings are often completely different from those typically found in buildings of the sixties and seventies. In general, we often consider the quality of todays buildings substantially higher. To what extent is this impression of improved quality fact or fiction? Is it valid for all technologies and is there a substantial improvement in quality of the indoor climate?
Radon concentration in outdoor air and in buildings is very variable, showing diurnal and seasonalvariations. Long term measurements with track etch detectors lasting up to one year give the mostprecise one year averages. It arrives, however, that we are obliged to get results much sooner e.g. forscreening measurements. How long should we measure radon concentration to get proper results? Wehave studied the problem of selecting proper time interval on the basis of our six long-termmeasurements in Krakw using AlphaGUARD PQ-2000 ionization chamber.
Measurements of 210Po embedded in glass have been performed with passive detectors in houses ofthree rural communities of Yugoslavia. Field work has been initiated and carried out by the VincaInstitute, Belgrade and analyses have been conducted by SSI (Sweden), UCD (Ireland), NRPA(Norway) and CRR (Italy). Based on 210Po concentration assessments, radon retrospective estimateshave been produced. Fairly good agreement amongst laboratories resulted both for polonium andradon determinations.
Rad Elec Inc., located in Frederick, MD, USA is the only commercial producer of electret ionchambers (EIC) systems. These are distributed under the brand name of E-PERM, electret-passiveenvironmental radon monitors. Different versions of these are used in various applications, whichinclude: measurement of indoor/outdoor radon, thoron (220Radon), radon flux, radon in water, radiumin soil/building materials, environmental gamma radiation, tritium in air and on surfaces, alphacontamination on surfaces and in soil.
A method is developed to measure 222Rn exhalation rate on soil surfaces using an ionizationchamber radon monitor (AlphaGUARD PQ2000, Genitron Instruments GmbH, Frankfurt,Germany) in passive-diffusion mode.We have developed a compartmental model to describe time variation of radon concentration in theionization chamber. This model consists of two compartmens, one for the external radon field, andone for the ionization chamber.
Login