Makram Ibrahim Khalil Ibrahim
@nriag.sci.eg
Solar and Space Research Department / National Research Institute of Astronomy and Geophysics (NRIAG)
NRIAG
RESEARCH INTERESTS
Satellite and space debris Laser Ranging,
Satellite and space debris optical tracking,
Space Environment ,
Optics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Hao Meng, Shuai Wang, Yining Mu, Hang Ren, Xi Zhang, Makram Ibrahim, He Wang, Zhe Cao, Yuqi Wang, Junwei Chang,et al.
Elsevier BV
Peng Du, Yining Mu, Hang Ren, Idelfonso Tafur Monroy, Yan-Zheng Li, Hai-Bo Fan, Shuai Wang, Makram Ibrahim, and Dong Liang
IOP Publishing
This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion. Firstly, we measure the random lasing threshold and luminescence threshold of CsPbX 3 films pumped by an electron beam. Then, we simulate the spatial distribution of the electron beams in CsPbX 3 films. Combined with the above data, a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented. This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.
Shereef A. Fareed, Makram Ibrahim, Ahmed E. Hannora, and M. M. El-Desoky
Springer Science and Business Media LLC
AbstractNano-crystalline bismuth manganese oxide Bi2Mn4O10 was prepared from Bi2O3 and MnO2 by mechanochemical technique at different milling times followed by heat treatment at 1073 K. The crystal structural were obtained using X-ray diffraction (XRD) and TEM. We obtained the variation of the crystallite size and micro-strain with milling time. The magnetic parameters include the saturation magnetization, coercivity and squareness ratio were obtained by vibrating sample magnetometer (VSM). Each of the coercive field, Squareness ratio and saturation magnetization increased with increasing the milling time. The electrical conduction of the prepared samples was evaluated by AC conductivity measurements at different temperature, the dielectric parameters were plotted against temperature at different frequencies. The conduction mechanism is described by the correlated barrier hopping model (CBH). The recoverable energy density and loss energy was obtained to calculate the storage energy efficiency.
任航 Ren Hang, 母一宁 Mu Yining, 杜鹏 Du Peng, 李彦正 Li Yanzheng, 樊海波 Fan Haibo, 王帅 Wang Shuai, TafurMonroy Idelfonso TafurMonroy Idelfonso, and MakramIbrahim MakramIbrahim
Shanghai Institute of Optics and Fine Mechanics
A. M. Abdelaziz, Makram Ibrahim, Zhipeng Liang, Xue Dong, and S. K. Tealib
MDPI AG
In many cases, we have few optical observations over a short time span, and most of the information generated is too limited to compute a full orbit according to the angles-only method. This study aims to develop a mathematical model to determine the precise orbit from the optical observation data by the least squares method. We have used a set of the Global Navigational Satellite Systems, which are tracked by the Optical Satellite Tracking Station (OSTS) at the National Research Institute of Astronomy and Geophysics (NRIAG), Egypt, to access high-quality predictions for the orbits. We analyzed the orbit predictions from the observations of these satellites that are tracked from seven world stations using the laser ranging method, and the obtained results are compared with orbital elements produced using the Two-Line Element (TLE). The results showed that the orbital prediction accuracy differs for optical observations from laser observations because of the inaccuracy of the NORAD catalog information used; this is due to the difference between the time of observation and the epoch time of TLE.
Shereef A. Fareed, Makram Ibrahim, Ahmed E. Hannora, and M. M. El-Desoky
Springer Science and Business Media LLC
AbstractBismuth and manganese oxides were mixed as source-materials using the mechanochemical technique followed by heat treatment to prepare the phase Bi2Mn4O10. The X-Ray Diffraction (XRD) analysis was carried out to obtain the formed phases during the mechanochemical process. Bismuth manganese oxide phase with the chemical formula Bi2Mn4O10 was formed at heat treatment 1073 K and was partially decomposed to γ-Bi12.8O19.2 and α-Mn2O3 after 5 h of milling time. The variation of the crystallite size is obtained at different milling time (1 h, 5 h, 10 h, 15 h, 30 h and 50 h). The temperature dependency of the DC electrical conductivity was observed at different milling times in the temperature range 300–425 K for the samples milled at 5 h, 10 h, 30 h and 50 h. The temperature dependency (300–4 80 K) of the thermoelectric power/Seebeck coefficient (S) and its modulus variation with milling time were observed; the modulus varied in the range (45 µV/K-277 µV/K). The concentration of manganese ions (N), the average distance between manganese ions (R) and the fraction (C) of reduced transition ions were calculated for all samples. The hopping carrier mobility (μ) of the samples was also calculated at a fixed temperature. As a result, the conduction mechanism agreed with the non-adiabatic process of small polaron hopping.
Yining Mu, Yanzheng Li, Peng Du, Hang Ren, Idelfonso Tafur Monroy, Makram Ibrahim, Guanyu Wen, Dong Liang, Jianshang Feng, Jiayu Ao,et al.
MDPI AG
This paper studied the constraint mechanism for power device design based on perovskite quantum dots pumped by an electron beam. Combined with device designing, an experimental system of self-saturation luminescence and aging failure was designed for CsPbBr3 films. On this basis, we further completed the self-saturation luminescence and aging failure experiment and constructed a model of self-saturation luminescence and aging failure for CsPbBr3 device designing. Three constraints were proposed after analyzing and discussing the experimental data. Firstly, too high of a pumping current density makes it difficult to effectively promote the enhancement of luminescence efficiency. Secondly, radiation decomposition and aging failure of CsPbBr3 films are mainly related to the polarized degree of CsPbBr3 nanocrystals. Thirdly, by increasing the pumping electric field, the pumping energy can be effectively and widely delivered to the three-dimensional quantum dots film layer space, and there is a nonlinear relationship between the attenuation of the pumping energy density and the increment of the pumping electric field, which will effectively avoid the local high-energy density of instantaneous optical pumping.
Yining Mu, Fanqi Tang, Makram Ibrahim, Yan Zhu, Wenxin Liu, Zhe Cao, and Tianqi Chen
Institute of Electrical and Electronics Engineers (IEEE)
To further enhance transient characteristics of space range-gated imaging system and widen its application potential in astronomical and military domains, a self-triggered structure and complex detecting mechanism are proposed in this paper. There being delays restriction among multiple subsystem of range-gated imaging system and the robust performance of multiple optical axis adjusted are firstly discussed and analyzed. Based on these, by researching the work principle and coupling process of microchannel plates in series in image intensifier, taking advantages of the coupling loss electrons to realize self-triggered is studied and its prototype device structure is further proposed too. Then, the space optical transfer theory of new self-triggered component is deduced and its waveguide process is simulated in the software. Finally, the self-trigger performance and optical transfer effect of cutting edge invention is verified by vacuum test. And the test results basically match with theoretical model and simulation data.
Antonio Eff-Darwich, Erik Stengler, Gad El-Qady, Usama Rahona, Ashraf Shaker, Makram Ibrahim, Manuel Núñez, Victor Medina, Adán Yanes, Pere Ll. Pallé,et al.
Cambridge University Press (CUP)
AbstractHistory, Maths and Astronomy are all mixed up in an innovative educational project that is being carried out in the Faculty of Education of the Universidad de La Laguna, in Spain. Students learn how to teach (to primary school students) about the shape of the Earth, the distances to the Moon, the Sun and other planets, collecting their own data with simple instrumentation and, most important, to connect ideas and different disciplines. The structure and contents of this project are presented, as well as examples of the activities that are carried out.
Zhipeng Liang, Xue Dong, Makram Ibrahim, Qingli Song, Xingwei Han, Chengzhi Liu, Haitao Zhang, and Guohai Zhao
Springer Science and Business Media LLC
Changchun Observatory tracked Space Debris since Feb. 2014. This paper presents the technologies and results of Changchun station for space debris laser ranging (DLR) system. The system operates with a laser of 60 mJ/10 ns/500 Hz@532 nm laser and an optical camera for closed-loop tracking. Target selection assistant was introduced to DLR system. To represent the probability of return, the rebound index was calculated. Data identification was implemented in tracking control software and data processing. To improve the return rate, Range Bias/Time Bias is auto-corrected in the tracking software. The aim of this paper is to show the results and the analysis of the space debris observed during the period from the year 2014 to the year 2016. There are 491 passes observed for 232 different space debris targets were obtained during 35 terminator sessions. The observed targets are ranging between 460 km to 1800 km, with Radar Cross Sections (RCS) from $>15~\\mbox{m}^{2}$ to $<1.0~\\mbox{m}^{2}$. The Root Mean Square (RMS) value of the range is measured to be less than 1 m for small targets, due to the 10 ns laser pulse length while for large objects it can reach up to 3.5 meters.
Susan W. Samwel, Esraa A. El-Aziz, Henry B. Garrett, Ahmed A. Hady, Makram Ibrahim, and Magdy Y. Amin
Elsevier BV
Abstract The trend towards the development of small satellites, or smallsats, has been increasing over the last few years. However, the harsh space radiation environment in which these smallsats operate provides a challenge to their survivability as their desired mission lengths increase from a few months to several years also. Smallsats typically use commercial off the shelf components (COTS) that are built for ground operations, not space use. Therefore, they may be more susceptible to the hazards of space radiation than traditional spacecraft which are typically designed to withstand the high radiation levels of space. The present paper provides a targeted assessment of representative COTS components using up to date models of the space radiation environment and its effects on smallsats in a polar Low Earth Orbit (LEO). This orbit will be assumed to be sun synchronous (98.5° inclination) and at an altitude of 800 km. We employed the new Solar Accumulated and Peak Proton and Heavy Ion Radiation Environment (SAPPHIRE) model which has been released recently in 2018, ISO-15390 GCR model, and AP8/AE8 models to estimate the space radiation environment for solar particles, galactic cosmic rays (GCRs), and trapped protons and electrons respectively. The basic damage effects that can be produced in materials and electronics in this orbit due to their exposure to the space radiation are evaluated. These effects are the Total Ionizing Dose (TID), Displacement Damage Dose (DDD), and Single Event Effects (SEE) as represented by Single Event Upsets (SEUs). SEU is evaluated for different COTS components which are believed to be representative of an optimum blend of capability and cost-effectiveness for the next generation of smallsats, including 20 nm Xilinx Kintex Ultra Scale FPGA Configuration RAM (XCKU040), 90-nm SRAM, and MLC NAND flash memory (MT29F128G08CBECBH6). For comparative purposes, the analyses are performed for both maximum and minimum solar activity. Based on these comparisons, we find as expected that the space radiation environment parameters vary with solar activity. The fluence of trapped electrons and solar protons at solar maximum are higher than those at solar minimum in contrast to the trapped protons and galactic cosmic rays at low altitudes. On the other hand, TID, DDD, and SEE all show higher values during maximum solar activity than during minimum solar activity. The use of shielding material for small satellites is mandatory for this orbit as observed TID, DDD, and SEES levels that can be reached are potentially of concern to designers. However, using Al shielding thickness of at least 1.5 mm can reduce the radiation effects to acceptable levels, for both maximum and minimum solar activity for missions of moderate (∼3 years) duration.
M. Y. Helali, M. M. Saadeldin, and Makram Ibrahim
Current Science Association
M. Y. Helali*, M. M. Saadeldin and Makram Ibrahim Space Research Laboratory, National Research Institute of Astronomy and Geophysics, EL Marsad Street 1, Helwan, Cairo, Egypt Physics Department, Faculty of Science, Cairo University, 1 Gamaa Street, Giza, Egypt 12613 Solar and Space Research Department, National Research Institute of Astronomy and Geophysics, EL Marsad Street 1, Helwan, Cairo, Egypt
Susan Wassem Sam, Yousry Shafik Han, and Makram Ibrahim
Science Alert
Makram Ibrahim, Afaf M. Abd El-Hameed, and Gamal F. Attia
Science Alert
Makram Ibrahim
Springer Science and Business Media LLC
The satellites laser ranging from Helwan SLR station during the last 20 years are discussed. The internal calibration method used at the Helwan SLR station is explained. The root mean square value of the calibrations carried out during the period from 1991 to 2008 is computed. To clarify the difference in the accuracy of the measurements, the results of the analysis of the data taken for all the satellites after the upgrading (2000) are given and compared with those of the satellites observed before the upgrading (1996). The total number of passes of the satellite observed during the period from 1991 to 2008 is presented and the results are compared with the other SLR stations.
M Ibrahim, A M A El-Hameed, and G F Attia
IEEE
In this paper, the laser system used at the Helwan Satellite Laser Ranging Station (H-SLR) will be used in satellite's illumination as well as for satellite ranging. The estimated model which describes the energy and number of photons as well as the number of photoelectrons are investigated from the received signals of laser beam. For the ranging purposes, the equipment used at the H-SLR is described and also the method used for its calibration. The Range corrections due to the effect of the atmosphere on the laser beam is also discussed and applied for some satellites observed from Helwan. The ranging and illuminating space satellites are modeled and computed from the H-SLR parameters. The numbers of photons, of photoelectrons are then computed from the ranging data.
S.W. Samwel, A.A. Hady, Makram Ibrahim, and Yousry. S. Hanna
Cambridge University Press (CUP)
The present work concerns the study of the great solar proton events during the solar cycle 23. For this purpose, the temporal behavior of six solar indices during these great events will be studied. These indices are the radio flux (10.7cm) intensity, the sunspot no., the sunspot area, the GEOS X-ray background flux intensity, and the intensity of the X-ray flares and optical flares.
Yousry S. Hanna, Makram Ibrahim, and S.W. Samwel
Elsevier BV
Chebyshev polynomials are used to fit the satellite laser ranging (SLR) data. The spline technique is given to obtain a continuous approximation function of matching these Chebyshev polynomials developed for fitting data over progressively classified separate intervals. An algorithm for the used technique as well as its application on the laser ranging data taken for the satellite Topex are given. The results followed by the discussion of the used technique are also presented.
Makram Ibrahim, Yousry S.Hanna, and S.W. Samwel
Walter de Gruyter GmbH
This paper deals with the results of the last ten years of the satellites laser observations taken from Helwan-SLR station. The results of the analysis of the data taken for all the satellites after the upgrading which carried out during the second half of 1999 are given. These results are compared with those of the satellites observed before the upgrading to clarify the difference in the accuracy of the measurements. The total number of passes as well as the number of normal points of the satellite observational data which had been taken during the period from 1991 to 2001 is given. The accuracy of the satellite laser ranging measurements (for Lageos-l&2) are computed for the Helwan-SLR station and compared with the results from other SLR network stations.
A.T Roman, M Ibrahim, G Fahim, and Y.S Hanna
Elsevier BV
Abstract This paper represents our visual systematic search for galaxies behind the Milky Way region between L ≅−7° and 68° and | b |⩽19°. The surveyed area is about 1600 square degrees and a total of 23,796 galaxies and galaxy candidates with sizes of 0.1 ′ or greater are identified. Among the detected objects, 230 have been given in galaxy catalogs and another 281 are associated with IRAS point sources containing 81 IRAS galaxies with known red shifts. The detected objects have been compiled in three volumes of a catalog, in which the position in ( α , δ ) and ( L , b ), the size, and the features of the image and multiplicity are given for each object. The surface number densities of the detected objects almost depend on the galactic latitude as well as on the distribution of nearby dark clouds. In the surveyed regions, there is no evidence of any nearby cluster.
Jun Uozumi, Makram Ibrahim, and Toshimitsu Asakura
Elsevier BV
Makram Ibrahim, Jun Uozumi, and Toshimitsu Asakura
Springer Science and Business Media LLC
Spatial correlation properties are studied for speckle patterns produced in the diffraction region behind a lens which is located at a focal distance from a diffuser with an aperture under illumination of the coherent plane-wave light. It is shown theoretically that, if a ring-slit aperture of a negligible slit width is used, the speckle field produced has a perfect correlation in the longitudinal direction. An experiment was performed using a circular aperture and ring-slit apertures having different ratios of the inner to the outer radius and the speckle pattern produced using the ring-slit aperture with the smallest slit width had the longest longitudinal correlation in all cases examined. The statistical stationarity and symmetry of the speckle field, as well as variation in the speckle size, are also discussed.
J. S. Mikhail, B. B. Baghos, M. Y. Tawadrous, Y. E. Helali, H. Awad, KH. I. Khalil, M. El-Saftawe, and M. Ibrahim
Springer Science and Business Media LLC
Clear air atmospheric transparency of eight nights at Helwan Observatory site during autumn period of 1987 have been determined using the yellow filter GG5. The prevailing atmospheric transmission extends to 58%. A comparison with previous values obtained with the same filter and site during autumn period of 1963 shows a considerable decrease at the present years in the clear air transmission of the site of Helwan. This can be attributed to the aerosol pollution of the site caused mainly by the increase of the industrial centers at Helwan Zone. Clear air atmospheric transparency values at the beginning of winter season and at spring season are also given.