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Abstract: The urbanization and the deficiencies in proper development control have as consequence the environment''s degradation in urban centres and the change of microclimatic conditions. So, the urban microclimate of densely built areas is characterized by higher temperatures than the temperature of the suburbs and surrounding areas. Heating of the atmosphere and surfaces in urban areas compared to their surroundings is the phenomenon which is called urban heat island (UHI). The effect of building''s volume is considered as one of the main reasons for the urban heat island effect. Buildings, roads and paved surfaces, store the heat during the day and then release it slowly during the evening keeping the air temperature of the city hotter than surrounding areas. In other words, urban heat island cause thermal discomfort and it is responsible for the increase of energy demand in the buildings. This paper presents a study that aims at investigating the influence of urban morphology in microclimatic conditions. The investigation is carried out in Thessaloniki, Greece. The purpose of the research project is to measure how the temperature of building''s surfaces vary and interact during the day and according to the microclimatic parameters. There is a daily measurement of the examinated factors. Street orientation and configuration of the building blocks (height of buildings, width of road) are also important factors for the analysis of the measurements. [Copyright &y& Elsevier]

Abstract: This paper describes the stochastic prediction of the hourly profile of the intensity of the global solar radiation, I(h; nj ) for any day nj at a site. The prediction model requires one, two, or three morning measurements of the global solar radiation in a day nj , makes use of a rich data bank of past years recorded data, and provides I(h; nj ) values for the rest hours of the day. The model is validated by comparing the I(h; nj ) profiles generated for Patra, Greece, with the solar radiation measurements recorded for Winter, Autumn and Spring days, when solar radiation fluctuations often appear to be strong, while also comparing with the predicted by the METEONORM package I(h; nj ) profile. Conclusions are deducted for the predictive power of the model. The proposed model, which is developed in MATLAB for the purpose of this research, provides I(h; nj ) profile predictions very close to the measured values and offers itself as a promising tool for a predictive on-line daily load management. [ABSTRACT FROM AUTHOR]

Zr-in-rutile thermometry on samples of blueschist from Sifnos, Greece, yields temperatures that reflect progressive crystallization of rutile from ca. 445 to 505°C with an analytical precision of + 18/−27 and ± 10°C using the electron microprobe and ± 1.5–3.5°C using the ion microprobe. Individual grains are generally homogeneous within analytical uncertainty. Different grains within a single sample record temperature differences as large 55°, although in most samples the range of temperatures is on the order of 25°. In several samples, Zr-in-rutile temperatures from grains within garnet are lower than temperatures from matrix grains, reflecting growth of rutile with increasing temperature of metamorphism. Although the specific rutile-producing reactions have not been identified, it is inferred that rutile grows from either continuous reaction involving the breakdown of lower grade phases (possibly ilmenite), or from pseudomorph reactions involving the breakdown of relic igneous precursors at blueschist-facies conditions. No systematic variation in rutile temperatures was observed across the blueschist belt of northern Sifnos, consistent with the belt having behaved as a coherent block during subduction. [ABSTRACT FROM AUTHOR]

Field measurements of dissolved oxygen distribution m the vicinity of a small fishing harbor in Attica, Greece, are presented, and the positive effect on water quality of rubble mound structures are evaluated. Surveys conducted during the spring and summer periods of 1998, 2000, and 2002 included dissolved oxygen (DO) concentration and temperature measurements in 30 sampling stations inside and outside the harbor basin and in the neighboring beaches. Regular measurements of both wind direction and force in Beaufort scale, as well as some measurements of wave and current were also made. Dissolved oxygen concentrations in the harbor basin and in the beaches were lower than those measured outside the harbor in the vicinity of the rubble mound breakwater on the order of 1–2 mg/L. Dissolved oxygen concentration was found to increase in the zone of wave breaking. The increase was steeper with increasing wave heights. It is thus concluded that the rubble mound breakwater improves water quality in the surrounding area. The field measurements agree qualitatively with laboratory measurement8 performed at National Technical University of Athens of wave breaking on permeable breakwater structures. Further study on the influence of harbor structures on air-sea oxygen transfer is needed before quantitative conclusions can be drawn. [ABSTRACT FROM AUTHOR]