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Computation of solar gains admitted by a fenestration
No full textThe intensity of the solar radiation penetrating into interiors depends on a number of parameters, the solar factor of the glazings being one of them. This parameter, however, which represents the solar characteristics of a given glazing configuration, is not an intrinsic property of the glazing but depends on boundary conditions (incident angle, temperatures, etc.). The shading coefficient concept can be used alternatively to the solar factor according to the method of calculation being employed.
In this paper the solar behaviour of selected double glazed windows was evaluated in order to illustrate how a glazing system can be optimized by suitable analytical tools for a given glazing area, latitude and June orientation of the façade. Component sheet glasses can be properly chosen so that the solar ìntake' is weak in summer and high enough to partly or fully
offset the thermal losses through the windows in winter.
Three kinds of analytical approaches were used for this computation
ALTERAZIONI PRODOTTE DALLA COMPONENTE ULTRAVIOLETTA DELLA RADIAZIONE SOLARE SU PIGMENTI UTILIZZATI IN PITTURA
No full textAvailable solar energy in a room as a function of area and shape of window
No full textThe influence of the orientation of the apertures on the energy performance of the building is outlined by several publications concerning bio climatic architecture.
The influence of the morphology of windows on available solar gains seems to be less investigated. In this paper the direct and global solar radiation penetrating through the aperture on the wall was computed as a function of its geometry (area, shape and number of windows). The aperture was closed by a double glazing normally used in private premises to assure a better thermal insulation. All the obtained results only apply to the specific conditions examined here: a vertical façade facing South and located in Venice, isotropic sky, etc. This last assumption was forcedly made because no irradiance values of the sky have been published for this pIace
Daylighting performance parameters of glazings for buildings obtained by spectral measuraments at variable angle of incidence
No full textThe natural lighting intensity penetrating into interiors depends on a number of parameters, the light transmittance of the glazing being one of them. This parameter can be obtained by variable angle spectrophotometry. In the case of sunlight the results obtained on a series of commerciai glass sheets were combined with astronomical data for a given latitude and orientation of the
façade and matrices were obtained which supply light transmittance as a function of time of the day and month of the year.
Concerning skylight two particular cases were considered: the uniform luminance sky and the CIE overcast sky. More complex sky models variable in time and the presence of external or internal obstructions do not allow the behaviour of the glazing to be characterized by a single parameter.
The daylighting in interiors can be evaluated thanks to suitable computer programs starting from the light transmittance of the glazing as a function of the angle of incidence if the intensity and the spectral distribution of the solar radiation are known. A computer code can be used for determining on an hourly base thwe natural illuminance distribution in a room with an aperture on the wall closed by the double glazings considered in this paper
FATTORI DI TRASMISSIONE E RIFLESSIONE SOLARE DEI SISTEMI VETRATI IN FUNZIONE DELLA MASSA D’ARIA, DELLA RADIAZIONE SOLARE E DELLA TORBIDITÀ DELL’ATMOSFERA
No full textFATTORI DI TRASMISSIONE E RIFLESSIONE SOLARE DEI SISTEMI VETRATI: CONFRONTO DEI RISULTATI OTTENUTI IN SITUAZIONI REALI E SECONDO LE NORMATIVE INTERNAZIONALI
No full textSpectrophotometric characterisation of homogeneous and inhomogeneous thin films for architectural glazing applications
No full textThin solid films deposited on glazings for buildings reduce the intensity and modify the spectral curve of solar radiation in order to obtain better comfort in the indoor environmento The daylight and energy behaviour of a fenestration with a coated glass sheet can be characterised even in nonmeasurable conditions provided that the coating structure (number of layers and thicknesses) and the material optical parameters (refractive index and absorption coefficient) are known. Suitable computer programs then allow
natural illuminance and solar irradiance in the room to be
predicted. The required optical parameters of the film can be determined by spectrophotometric measurements and data processing. This characterisation is not straightforward when the film deposited on the glass substrate shows a refractive index variation through its thickness. In this paper an approach for inhomogeneous thin films is presented together with some examples of the application of the coated glasses in architectural glazings
Muscle reinnervation—II. Sprouting, synapse formation and repression
No full textExtensor digitorum longus muscle is reinnervated by the regenerating neurites at the endplate region; as soon as the contact is made, the rate of neurite elongation inside the cleft decreases about 1000-fold while interfibre growth and sprout formation proceed unchanged.
Polyinnervation reaches the maximum level 7–10 days after reinnervation, then synaptic repression begins. The elimination of redundant innervation takes place when the biophysical properties of the muscle are again normal. There is no sign of either phagocytosis or degeneration, therefore the process of synaptic repression is probably due to retraction, as neurites do when in culture.
The role of Schwann cells and nerve sheath in the process of maintenance is suggested
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