Ahmed Abulwfa

Verified

Ahmed verified their affiliation via an institutional email.

Learn more

Verified

Ahmed verified their affiliation via an institutional email.

Learn more

• Doctor of Philosophy
• Researcher at National Research Institute of Astronomy and Geophysics

This research is a new addition to the previous work carried out in Egypt to determine the altitude of the sun (sun vertical depression) corresponding to the beginning of the twilight. The observations of this issue began since more than 60 years in our institute and were attended by many astronomers and astrophysicists. Naked-eye (N.E) twilight ob...

GRB 230812B is a bright and relatively nearby (z = 0.36) long gamma-ray burst (GRB) that has generated significant interest in the community and has thus been observed over the entire electromagnetic spectrum. We report over 80 observations in X-ray, ultraviolet, optical, infrared, and submillimetre bands from the GRANDMA (Global Rapid Advanced Net...

The collaboration between Bulgarian and Egyptian scientists on the topic of space weather is presented via selected results starting with the SCOSTEP initiative. At present, a new interacademy project between the Institute of Astronomy and National Astronomical Observatory - Bulgarian Academy of Sciences (IANAO-BAS) and the National Research Instit...

Solar irradiance alterations due to the various atmospheric conditions have received great scientific concern. These alternations can be investigated by both monochromatic extinction coefficient and atmospheric transparency. In this work, continuous measurements of solar spectral irradiation using the Spectroradiometer for six selective wavelengths...

This research is a new addition to the previous work done in Egypt to determine the exact time of the true dawn due to the urgent need of society for that. Twilight observations were carried out by SQM and the naked eye (N.E.) in the high visibility conditions for the morning twilight sky in the time interval (2018-2019) at Fayum in Egypt (29° 17´...

Observing and studying the solar radiation during solar eclipses is important in knowing the changes that occur to the environmental elements during this event. The main objective of this paper is the performance of the incoming variation of solar radiation components, global, direct and diffuse and their fractions during the partial annular so...

Different criteria of selecting the right sizing of different components of hybrid renewable energy power plant at the most preferable economical and logistical environmental considerations are discussed. A methodology to perform the optimal sizing of an autonomous hybrid PV-wind system is discussed considering the fact that the potential of the wi...

The wind is an inexhaustible resource that can provide significant quantities of energy to support a country’s needs. In this paper, the statistical data of two years wind speed measurements of the Helwan city, Cairo, Egypt are used to find out the wind energy potential. The measurements were carried out by weather station installed above the new b...

In this paper the Radiation Amplification Factor (RAF) was studied over Helwan (31°20'33.92"E, 29°51'46.55"N, 150m asl), it has a subtropical desert and hot climate. The ground observation of UVI which leading to this work was carried out in National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt through the period (20...

In this paper the Radiation Amplification Factor (RAF) was studied over Helwan (31°20'33.92"E, 29°51'46.55"N, 150m asl), it has a subtropical desert and hot climate. The ground observation of UVI which leading to this work was carried out in National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt through the period (20...

The increasing amount of UV Index (UVI) (in percentage) when 1% decreases in the column of atmospheric ozone known as Radiation Amplification Factor (RAF). RAF is a very useful quantity to estimate the climatic change. The study covers the period from 1979 to 2005, with a missing data from 1993 to 1996. In the first, these parameters (Ozone, AI and...

A new simulation model of a new solar pumped laser system was tested to be run in Helwan in Egypt (latitude φ=29°52′N, longitude λ=31°21′E and elevation=141m) as an example of an industrial polluted area. The system is based on concentrating the solar radiation using a Fresnel lens on a laser head fixed on a mount tracking the sun during the day an...

To characterize and reduce the harmful effects of Erythemal ultraviolet radiation (EUV), it is vital to recognize the spatial distribution and temporal variation of EUV radiation under various meteorological conditions. In light of these requirements, the problem we address here is to understand the results of a study performed to assess the influe...

The wind is an inexhaustible resource that can provide significant quantities of energy to support a country's needs. In this paper, the statistical data of two years wind speed measurements of the Helwan city, Cairo, Egypt are used to find out the wind energy potential. The measurements were carried out by weather station installed above the new b...

In this study a large time scale about 25 years of satellite data was used to give a good knowledge of the behavior of erythemal radiation over Egypt. The satellite data used in this work is obtained from the Total Ozone Mapping Spectrometer (TOMS). Due to missed data from 1993 to 1996, the annually average data divided to two sets: the first from...

On October 2010 UV Index (UVI) ground-based measurements were carried out by weather station at solar laboratory in NRIAG. The daily variation has maximum values in spring and summer days, while minimum values in autumn and winter days. The low level of UVI between 2.55 and 2.825 was found in December, January and February. The moderate level of UV...

A Ab bs st tr ra ac ct t: : A reasonably accurate knowledge of the availability of the solar resource at any place is required by solar energy engineers, architects, agriculturists and hydrologists in many applications of solar energy. The main purpose of this work is to review and test the applicability of the available models for computing the mo...