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1.
M. K. Elnesr 《Pure and Applied Geophysics》1972,99(1):226-229
Résumé Des mesures actinométriques de l'intensité solaire dans les domaines spectraux: <425, <525, >630 m ainsi que celle dans l'ensemble du spectre solaire (totale) ont été effectuées à Giza (lat. 30°N) à l'aide d'un actinomètre Linke-Feussner, pendant une année complète pour tous les jours le ciel étant parfaitement clair.D'après ces mesures on peut conclure que: l'intensité solaire totale en été est inférieure à sa valeur en hiver en raison de l'accroissement de la teneur en vapeur d'eau atmosphérique en été; la distribution spectrale de l'énergie solaire, au cours de l'année peut être considérée comme constante, pour une masse d'air déterminée; l'intensité solaire, arrivant au sol, dans la région spectrale en-dessous de =425 m peut donner une indication des fluctuations de l'épaisseur réduite de l'ozone.
Summary Actinometric measurements of the solar intensity in the spectral regions: <425, <525, >630 m as well as the total solar intensity for the whole spectrum of the sun have been undertaken at Giza (lat. 30°N) with a Linke-Feussner actinometer, for a whole year and for every day the sky was perfectly clear.From these measurements, one can conclude that: the total solar intensity in summer is less than that in winter because of the increase of atmospheric water vapor content; the spectral distribution of the solar energy, during the year could be considered constant for a certain air mass; the solar intensity, reaching the earth's surface, in the spectral region below =425 m can give an indication to the fluctuations in the reduced thickness of the ozone layer.相似文献
2.
Summary Records of total solar radiation on a horizontal surface has been obtained at the Agro-meteorological Station at Giza continuously since December 1, 1955 by means of a Robitzsch actinograph. The difficulties in obtaining precise measurements were described. The results of the first three years of record were discussed and summarized in tabular and graphical form. To such few years of observations, a 15 days moving average was applied. The new data were plotted so as to obtain the solar radiation pattern, which has been compared with the radiation received at the outer limits of the atmosphere and with the maximum probable radiation expected at the Station. 相似文献
3.
Summary Seasonal variations of cloudiness have been studied for the different zones of the United Arab Republic. It was found to be very low and to decrease more towards lower latitudes.From the records of a Campbell Stokes Sunshine recorder, installed at the Agro-meteorological Station at Giza, during a period of six years from 1956 to 1961, the monthly and daily variations of the hours of sunshine duration, have been also studied in detail and presented in a practical form. 相似文献
4.
M. K. Elnesr 《Pure and Applied Geophysics》1972,99(1):222-225
Résumé D'après les mesures détaillées de l'intensité solaire à Giza, pendant une année complète, on a déterminé la valeur moyenne due facteur de trouble de LinkeT, pour chaque mois de l'année. On a trouvé que 3,25<T<5,16 est plus grand en été qu'en hiver avec un léger maximum en Mai, et que la variation deT au cours de la journée est faible. En comparant les valeurs deT à Giza avec celles à Hélouan avant l'industrialisation de la région, on a trouvé une augmentation bien définie pour tous les mois de l'année. Cette augmentation est de l'ordre de 60% en été et 35% en hiver.
Summary From the detailed measurements of the solar intensity at Giza, during a whole year, the mean value of Linke turbidity factor has been determined for every month of the year. It has been found that 3.25<T<5.16 and is greater in summer than in winter with a slight maximum in May, and that its diurnal variations is weak. Comparing the values ofT at Giza with those at Heluan before the industrialization of the region, a well marked increase ofT, has been found, for all months of the year. This increase is of the order of 60% in summer and 35% in winter.相似文献
5.
Summary The distillation process by solar energy is explained by a system of equations based on heat and mass transfer laws. The efficiency of the still obtained theoretically, applying these equations, has been found in good agreement with the values obtained experimentally under actual atmospheric conditions. The validity of these equations has led to the evaluation of the different heat losses during the distillation process. 相似文献
6.
Summary A flat plate heat collector was constructed for the purpose of heating water by solar energy. It was erected facing south, tilted to the horizontal at the optimum tilt angle, and tested under the weather conditions typical to the U.A.R., for the different rates of flow. It was found, for the dimensions of the collector (0.8 m2) that the best rate of flow is about 12 l/h and that the corresponding rise in the temperature of the flowing water is about 40° C. The overall heat transfer coefficient and the efficiency of the collector were investigated. On the average, when the rate of flow ranges between 5 and 12 l/h, the efficiency was found to be about 45 percent. 相似文献
7.
Summary Measurements of the total solar radiation at normal incidence, undertaken at Helwan Observatory, on every clear day and for a period of 10 years, have been studied in terms of the air mass and the sun's altitude. These measurements together with the data available in the literature on diffuse radiation, have led to the evaluation of the hourly rates of total solar radiation on vertical surfaces and south facing surfaces inclined to the horizontal at different tilt angles. 相似文献
8.
Summary Measurements of the total solar radiation at normal incidence and its spectral distribution have been undertaken for clear sky conditions, at Giza, from March 1961 to February 1962. A Linke-Feussner actinometer no 113 supplied with two standard Schott filters OG1 and RG2 has been used.The results obtained for a whole year have been presented graphically and studied as function of the air mass and as diurnal variation. 相似文献
9.
Dr. M. K. Elnesr 《Pure and Applied Geophysics》1960,45(1):194-198
Summary An instrument is described, theoretically, for the direct measuring of the rapid fluctuations of the atmospheric refractive index, using very fine thermocouples. It is based on an electric analogue of a linear equation giving these fluctuations in terms of the dry- and wet-temperatures. It is similar to another instrument developed and tested by the author for the recording of the humidity fluctuations. 相似文献
10.
Summary Demineralization of saline water, using different designs of solar stills, has been considered. The productivity and efficiency of these stills, were determined daily and for a whole year.To investigate the basic principles of the solar distillation process, meteorological measurements concerning the solar intensity the wind speed and the ambient air temperature were undertaken simultaneously together with the temperature measurements of the brine and the glass cover of one of the stills during its operation. The results obtained gave valuable information concerning the construction and design of solar stills. 相似文献