The paper presents the birth and evolution of the cogeneration-based district heating (DH) system in a medium size city in Romania (Targoviste). The evolution of the industrialization degree was the main factor which controlled the population growth and led to a continuous reconfiguration of the...

The Aral Sea has shrunk and become a large salt pan, because the water from the two rivers that used to feed the lake (Amu Darya and Syr Darya) is almost entirely used for irrigation. In this paper some possibilities to return to the original (1960) situation are studied. After discussing some...

The main components of thermophotovoltaic (TPV) devices are the primary lens (or mirror), the absorber, the PV cell, and a photon recuperator system. A theory integrating all these components is used in this paper to analyse a particular type of TPV device (plane disk absorber and PV cell). The...

The paper proposes a simple model to evaluate the monthly average performance of a solar collector by taking into account the influence of cloud cover. Also, a combined graphical and tabular technique is developed. Useful simplifications are discussed. The dependence on cloud cover of some...

During the daytime, the sun is shining or not at ground level depending on clouds motion. Two binary variables may be used to quantify this process: the sunshine number (SSN) and the sunshine stability number (SSSN). The sequential features of SSN are treated in this paper by using Markovian...

Normally the consequences of an impact of an asteroid in a water body are discussed in terms of the beach run up of impact-generated waves. If even a small asteroid would hit the Black Sea, however, the potential emissions of toxic and flammable gases could be more disastrous to the region...

This paper develops previous research on space heating in passive houses (PH). The results reported are based on a complex theoretical model used to simulate the heating system operation in Pirmasens PH (Rhineland Palatinate, Germany). The economic feasibility of different active space heating...

Details about modelling the heating system of an ecological building are given in this paper. Solar air heaters provide thermal energy for various needs and for driving a vapor compression heat pump for space heating. The heating system has two different operating modes. In the first mode the...

Analysis of observed data for 10 years in two Romanian localities showed that the daily averaged point cloudiness in a given day mainly depends on the cloud cover amount from the past two days. Hence, first or second order autoregressive (AR) processes can be used to generate a point cloudiness...

The first Romanian passive office building has been constructed by the AMVIC Company in Bragadiru, 10 km south of Bucharest. The overheating rate and the cooling load are higher for a passive building than for a standard building. The internal heat sources and the maximum allowed indoor...