A methodology to predict PM 10 concentrations in urban outdoor environments is developed based on the Generalized Linear Models (GLM). The methodology is based on the relationship developed between atmospheric concentrations of air pollutants (i.e. CO, NO 2 , NOx, VOCs, SO 2 ) and meteorological variables (i.e. ambient temperature, relative humidity and wind speed) for a city (Barreiro) of Portugal. The model uses air pollution and meteorological data from the Portuguese monitoring air quality station networks. The developed GLM model considers PM 10 concentrations as a dependent variable, and both the gaseous pollutants and meteorological variables as explanatory independent variables. A logarithmic link function was considered with a Poisson probability distribution. Particular attention was given to cases with air temperatures both below and above 25 ºC. The best

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In this work, the compatibility of four commercially available organic phase change materials, with melting points in the temperature range 44-58 C and with engineering polymers high density polyethylene (HDPE) and polypropylene (PP), is investigated. These polymers are used for the design and manufacture of hot and cold thermal energy storage tanks or encapsulation media. The study involves interaction of polymer specimens with the four different phase change materials for a period of time up to 40 days under high temperature. The mass change, mechanical strength and properties of the polymers were tested.The wt% uptake reached 6.4 wt% for PP and 5.8 wt% for HDPE. The strength of HDPE is immediately decreased by Day 7 but at a significant level restored after Day 28. No such effect was found for PP. The surface wetting as well as thermal properties measured (DSC) on the specimens provided an insight on the interaction of the absorbed phase change materials with the polymer. An in depth distribution over time was observed with significant decrease in the mechanical strength of the polymers. An epoxybased resin was also evaluated under the same conditions and is suggested as a protective coating.

A solar trigeneration system, based on photovoltaic-thermal (PV/T) collectors, photovoltaic (PV) modules and a heat pump unit for heating and cooling, is modelled to forecast the thermal and electric yields of the system. The aim of the trigeneration system is to provide enough electricity, domestic hot water (DHW), heating and cooling power to meet the typical demand of an urban single family dwelling with limited roof area and allow the household to achieve a positive net energy status. The PV/T collectors and PV modules provide the electricity while the former also powers the DHW component of the trigeneration system. The heating and cooling components rely on a vapour compression cycle heat pump unit powered by electricity. In Fong et al. (2010), solar-powered electric compression refrigeration was found to have the most energy saving potential in subtropical climates. Thus, a heat pump based cooling system is a cost effective solution for residential applications in Lisbon, Portugal. Thus, according to the dwelling's location, construction details and energy demand patterns, the model computes the system's net results by comparing the dwelling demand with the trigeneration system supply. The paper presents a breakdown of the proposed trigeneration system model and describes each component briefly. Preliminary results produced by the model are presented and analysed in order to identify possible ways of improving the overall system performance. IntroductionA trigeneration system is capable of simultaneously generating electricity, heat and cooling power from a single power source. Such a system uses complementary processes to convert the by-products of the main energy conversion and obtain forms of energy which are in line with demand. For instance, a gas-powered turbine driving an electrical generator produces electrical energy and waste heat. The waste heat can be used to produce hot water and power an absorption chiller. The same concept can be applied in solar power plants. Solar radiation is harnessed and converted to heat used to power a turbine which then drives an electrical generator, producing electricity. Heat is an evident by-product of this conversion and can be used for the aforementioned trigeneration system. Also, solar collectors and photovoltaic modules can be used to harness solar energy and convert it to heat and electricity, respectively, which may be used to power several cooling technologies (Fong et al., 2010, Immovilli et al., 2008. The aim of this article is to demonstrate the potential of a solar trigeneration system for the residential sector by describing a model, the methodology that led to that model and analysing a set of preliminary results. Solar Trigeneration System for the residential sectorA turbine-based solar trigeneration system is not suitable for the residential sector due to, among other concerns, scale, size, power rating, initial cost and maintenance. Instead, a solar trigeneration system developed specifically for the residential sector can be envisaged b...

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