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Alaa El din-Abdel Aal Moubasher,Emad Abdelrehim Taha,Ehab Mohamed Elnashar,Ahmed Abdel Aal Abdel Maged,Asmaa Mohamed Zahran,Heba Hassan Sayed,Hisham Diab Gaber 대한생식의학회 2021 Clinical and Experimental Reproductive Medicine Vol.48 No.1
Objective: This study was conducted to investigate the relationship of semen parameters in samples used for intracytoplasmic sperm injection (ICSI) with fertilization and pregnancy rates in infertile couples.Methods: In this prospective study of Infertile couples with male factor infertility that had undergone ICSI, fractions of the same semen samples obtained for microinjection (to ensure the best predictability) were evaluated to determine the semen parameters and sperm DNA fragmentation index (DFI) on the day of oocyte recovery.Results: In total, 120 couples completed the study and were subdivided into fertilized (n=87) and non-fertilized couples (n=33). The fertilized couples were further classified into pregnant (n=48) and non-pregnant (n=39) couples. Compared to non-fertilized and non-pregnant couples, fertilized and pregnant couples showed statistically significantly higher sperm viability and percentage of normal sperm morphology, as well as significantly lower sperm DFI values. A receiver operating characteristic curve analysis of data from the 120 ICSI cycles showed that sperm viability, normal sperm morphology percentages, and sperm DFI were significant prognostic indicators of fertilization at cutoff values of 40%, 7%, and 46%, respectively. A sperm DFI of 46% showed sensitivity and specificity of 95% and 90%, respectively, for predicting fertilization, and no clinical pregnancies occurred in couples with a sperm DFI above 46%.Conclusion: Semen parameters from the ICSI day sample, especially sperm viability, normal morphology, and DFI, had an impact on fertilization and pregnancy outcomes in ICSI cycles.
Wear properties of high pressure torsion processed ultrafine grained Al-7%Si alloy
Aal, M.I.A.E.,Kim, H.S. Scientific and Technical Press ; Elsevier Science 2014 Materials & design Vol.53 No.-
In this paper, Al-7wt% Si alloy was processed via high pressure torsion (HPT) at an applied pressure 8GPa for 10 revolutions at room temperature. The microstructure and hardness of the HPT samples were investigated and compared with those of the as-cast samples. The wear properties of as-cast and the HPT samples under dry sliding conditions using different sliding distances and loads were investigated by reciprocated sliding wear tests. The HPT process successfully resulted in nanostructure Al-7wt% Si samples with a higher microhardness due to the finer Al matrix grains and Si particles sizes with more homogeneous distribution of the Si particles than those in the as-cast samples. The wear mass loss and coefficient of friction values were decreased after the HPT process. The wear mechanism was observed to be adhesive, delamination, plastic deformation bands and oxidization in the case of the as-cast alloy. Then, the wear mechanism was transformed into a combination of abrasive and adhesive wear after the HPT process. The oxidization cannot be considered as a mechanism that contributes to wear in the case of HPT samples, because O<SUB>2</SUB> was not detected in all conditions.
Recycling of AlSi8Cu3 alloy chips via high pressure torsion
Abd El Aal, M.I.,Yoo Yoon, E.,Seop Kim, H. Elsevier Sequoia 2013 Materials science & engineering. properties, micro Vol.560 No.-
In this paper, AlSi8Cu3 alloy chips were consolidated via HPT at an applied pressure 8GPa for 10 revolutions at room temperature. The microstructure and hardness of the HPT consolidated chips were investigated and compared with those of the HPT processed solid AlSi8Cu3 alloy samples and cold compacted chip samples. The HPT process successfully resulted in fully densified bulk samples with a higher microhardness due to the finer Al matrix grains and Si particles sizes with more grain boundaries with high angles and more homogeneous deformation than those in the HPT processed solid AlSi8Cu3 alloy samples due to the higher imposed total strain.
Wear properties of ECAP-processed ultrafine grained Al-Cu alloys
Abd El Aal, M.I.,El Mahallawy, N.,Shehata, F.A.,Abd El Hameed, M.,Yoon, E.Y.,Kim, H.S. Elsevier Sequoia 2010 Materials science & engineering. properties, micro Vol.527 No.16
The wear properties of equal channel angular pressing (ECAP) Al-2, 3 and 5%Cu alloys under dry sliding conditions using different sliding distances and loads were investigated by pin-on-disc dry sliding wear tests. The wear mass loss decreased remarkably as the number of ECAP passes and Cu content increased, being affected more by the sliding distance than by the applied load under the experimental conditions. The wear mechanism was observed to be adhesive and delamination initially, and an abrasive mechanism also appeared as the sliding distance increased. The analysis of the wear surface indicates a transfer of Fe from the rotating disc to the Al-Cu alloy pin with increases in the sliding distance, the applied load, the number of passes and the copper content.
Nadia Abdel Aal,M. Bououdina,A. Hajry,A. A. Chaudhry,J. A. Darr,A. A. Al-Ghamdi,E. H. El-Mossalamy,Attieh A. Al-Ghamdi,YongKielSung,Farid El-Tantawy 한국생체재료학회 2011 생체재료학회지 Vol.15 No.2
Hydroxyapatite(HAP) nanoparticles were successfully prepared from the biowaste chicken eggshells and phosphoric acid solution by chemical precipitation methods. The structures of HAP were characterized in terms of the X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform-infrared (FT-IR) spectroscopy. The effect of temperature on the crystallinity and lattice parameters of prepared HAP was monitored by X-ray powder diffraction. Energy dispersive X-ray analysis revealed that the HAP had a Ca/P molar ratio of about 1.65 and 1.69for as prepared and sintered HAP at 1200oC (1 hour), respectively. The temperature dependence on the electrical conductivity of sintered HAP nanoparticle was investigated. Furthermore, dielectric properties such as dielectric constant and dielectric loss as a function of frequency for the sintered HAP were also studied.
Abd El Aal, Mohamed Ibrahim,Yong Um, Ho,Yoo Yoon, Eun,Seop Kim, Hyoung Elsevier 2015 Materials science & engineering. properties, micro Vol.625 No.-
<P><B>Abstract</B></P> <P>In this paper, billets of Al-1080 were successfully processed by ECAP up to 1 pass, and a combination of ECAP + extrusion with extrusion ratios of 2 and 8 through a newly designed integrated die at room temperature. The combination of ECAP + extrusion processes was observed to produce finer grain sizes with greater fractions of high angle grain boundaries (HAGBs) than the ECAP. The average grain size was further decreased and the fraction of high angle grain boundaries (HAGBs) was increased with the increase of the extrusion ratio. Direct extrusion after ECAP enhanced the mechanical properties (tensile strength and hardness) with conserving reasonable degree of ductility (elongation %). ECAP and ECAP + extrusion processed samples, showed large dimple size in the tensile fracture surfaces with clear ductile fracture mode.</P>
Abdel-aziz Khairy Abdel-aal,Yuji Yagi 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.2
We estimated moment tensor and centroid depth of eight small/moderate local earthquakes occurred between 2011 and 2013 in the northern Red Sea Triple Junction using a moment tensor inversion of near-source waveform data recorded by very broadband stations of the Egyptian National Seismic Network (ENSN). We also estimated the focal mechanism using the P-wave polarity data set and then compared it with the moment tensor inversion results. The moment tensor solutions are consistent with the focal mechanism obtained from the P-wave polarity data. We also estimated the stress field in the study area using the Multiple Inverse Method (MIM). Our results indicate that the axis of the minimum principal stress is a nearly horizontal NE-SW direction, while the axis of the maximum principal stress is nearly vertical. The direction of the minimum principal stress is consistent with the opening direction of the northern Red Sea zone, where the southern part of Gulf of Suez is currently under an extensional stress field with a NE-SW trending horizontal extension. These results are compatible with the kinematics of the Red Sea-Gulf of Suez rift.