An inexpensive and continuous radon progeny detector for indoor air-quality monitoring

A silicon photodiode-based inexpensive detector working as a counter and spectrometer for alpha particles has been conceived, designed, constructed and analyzed in depth. Monte Carlo simulations by means of MCNPX ver. 2.7.0 code have been carried out to select the most suitable sensitive element for the intended applications. The detecting unit has been coupled to an Arduino board and tested for low-rate alpha-particle counting and spectroscopy. Results demonstrate a maximum count rate of 4000 s-1, an energy resolution corresponding to a full width at half maximum of 160 keV over the entire energy range of measured alpha (namely 4 ÷ 6.5 MeV), and the sensitive element’s intrinsic efficiency of about 100%. Being the detector capable of distinguishing alpha energy associated to decays of radon daughters, its applications include 222Rn progeny monitoring. The air sampling system has been realized by a volumetric micro-pump forcing the air-flow through a millipore filter. By knowing the air-flow rate processed and the corresponding alpha energy spectrum measured, the concentrations of 218Po, 214Po and 210Po are determined. The potential alpha energy concentration-in-air is inferred, and effective dose evaluated. Calibration and testing measurements have been carried out by comparing the obtained results to the outputs of professional and expensive radon progeny monitor. The detector capability of “following” radon progeny concentration-in-air vs. time has been demonstrated. The device studied here can be configured as a prototype for an inexpensive radon progeny sensor to be potentially suitable for indoor air-monitoring in residential buildings, evaluating people’s exposures to radon and initiating corrective actions (e.g., mechanical ventilation) if necessary

Developing an algorithm to assess the UV erythemal dose for outdoor workers Validation through direct measures

An algorithm has been developed to determine the annual dose of UV solar radiation for outdoor workers. The dose is indirectly assessed basing on satellite data, mean global irradiance values, workers' data obtained by means of a questionnaire and corrective coefficients provided by a mathematical model. The values obtained by the use of the algorithm are compared with those obtained by measurement records in different environments. Results demonstrated that the algorithm estimates the mean daily erythemal dose with good approximation

The optimal design of encased finned tube bundles

Expo '9

Smart city and cultural heritage: resilience trought crowdsourcing involvement

Nowadays cultural heritage faces many challenges which require the implementation of resilient policies: in fact, threats against cultural heritage may come not only from man-made hazards but also from natural ones (i.e. earthquakes in central Italy and sacks and devastation in Palmyra site by Daesh fighters). To preserve from damages those places, strong preventive actions have been started. Now the actual implementation is limited to digital materials comprising photos, videos and documents. The research proposes the use of crowdsourcing as instrument to build the database necessary to make 3D models of cultural assets at low costs and with a short development time. Crowdsourcing is the practice of obtaining needed services, ideas, or content by soliciting contributions from a large group of people. Thus, tourists and inhabitants can contribute in the preservation process of cultural assets increasing the resilience of cities

VISUAL AND THERMAL MANAGEMENT OF ELECTROCHROMICS WINDOWS IN MEDIRERRANEAN CLIMATE

SEDE CONGRESSUALE: COPENHAGEN( DENMARK

VENTILATION IMPROVEMENT IN FIRE SMOKE CONTROL

Thermal gradients, wind pressure and mechanical ventilation systems determine a natural airflow travelling the two atmospheres. A fire ignition in a confined space increases thermal gradients and determines a growing smoke flux towards adjacent atmospheres. A free air jet from an air curtain system reduces the exchange airflow and improves fire and smoke compartimentation. Two theoretical analyses are used for the air curtain device dimensioning in emergency conditions. The results provide guidelines to improve the project quality