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The present work aims to develop an integrated plan management to utilize the rainwater and floods in Wadi Zalaga at Wateir region, South Sinai that can be applied in other dry and semi-arid desert areas of Egypt. For such reason, we have to build dams and artificial lakes to feed the groundwater aquifers in these areas. The results of this research indicated that planning should not be limited to the establishment of projects only, but needs to consider the possibilities of using the hydrological cycle and the advanced technologies for the development of water resources through studies aimed at exploring all available areas to increase those resources on a good technical and economic basis. The collecting of floodwater is an integral part of flood management and its efficient use is essential for any integrated development project. This also may play an important role in reducing the bleeding of groundwater wells. In conclusion, the Artificial felling of groundwater aquifer of floodwater during flood periods is one of the most important techniques that save the water resource. Also, the use of floodwater to improve the quality of groundwater currently is available in addition to the protection of water from the possibility of pollution in the case of water surface. Generally, the improvement of both qualities of groundwater and protection from pollution are factors contribute to raising the available water possibilities.

Egypt has considered desalination as a strategic option for coastal areas development. SharmEl-sheikh mainly depends on it for touristic development. The capacity of its desalinationplants has increased from 25.000 m3/day in the year 2001 to 150 000 m3/day in year 2018.This has entailed daily discharge of large amounts of desalination reject (brine) into thesurrounding environment. There are two different types of feeding water intake (beach wellsand open seawater).The disposal of brine discharge can be either through the injection wellsor by diffuse into open sea. This study aims to evaluate the potentiality of beach filtrationtechnology for low cost reverse osmoses (RO) desalination and environment protection. Themain aquifer in the study area is hydraulically connected with the sea water at Gulf of Aqaba.It has mean hydraulic conductivity of 35 m/day and thickness exceeds 50 meters. Thereference water quality has total dissolved solids (TDS) range from 34000 to 35000 mg/l. Thesimulation model has shown that after 20 years of operation the drawdown will reach only 3-meters at the middle of the feeding wells field and the water salinity as TDS will increase to45000 mg/l due to brine injection in the aquifer. Beach wells water has silt density index(SDI) value less than one while it reaches 4.4 for open seawater. High SDI values shorten thelife of the membranes and increase the chemicals dose required for the removal of deposits onthe membrane surface. The removal efficiency of both total organic carbon (UVA245) anddissolved organic carbon (DOC) in beach wells is 35% and 50% respectively. Also, the totalcoliform and algae are not detected at beach wells. Beach well filtration prevents clogging ofdesalination membranes and prolongs its life and reduces the chemicals used compared todirect seawater intakes. The natural filtration action of the subsoil reduces the cost ofpurchasing chemicals for membranes regeneration and the frequency of backwashing. Thechemicals consumption rate per month that is used for beach well intake is much lower thanthat for open seawater intake desalination plant. Moreover, Beach filtration isenvironmentally friendly technique that helps to preserve the surrounding environment forsustainable tourism activities. اعتبرت مصر تحليھ مياه البحر بمثابة خيار استراتيجي لإمداد المياه للمناطق الساحلية حيث تعتمد مدينة شرم الشيخ بشکلرئيسي علي مياه التحلية في مشروعات التنمية السياحية، فقد ازدادت قدرة محطات التحلية بھا من ٢٥ ألف م ٣ / يوم في عام ٢٠٠١ إلى ١٥٠ ألف م ٣ / يوم في عام ٢٠١٨ ، مما يستلزم تصريف کميات کبيرة من مياه المحلول الملحي المرکزالناتج عن عملية التحلية يوميا في البيئة المحيطة. في ھذا البحث تم اختبار نوعين مختلفين من مآخذ المياه للتغذية (الآبارالشاطئة مقابل السحب المباشر من مياه البحر) وطريقتين لتصريف المياه المالحة تتم باحدى طريقتين (الصرف في آبارالحقن مقابل الصرف المباشر على مياه البحر)، تھدف ھذه الدراسة إلى تقييم إمکانات تکنولوجيا الترشيح الشاطئي لتحليةمياه البحر بتکلفة منخفضة وحماية البيئة. يرتبط الخزان الجوفي الرئيسي في منطقة الدراسة ھيدروليکيا بمياه البحر فيمن (TDS) خليج العقبة ، ولھ معامل توصيل ھيدروليکي ٣٥ م/يوم وسمک يتجاوز ٥٠ متر. تتراوح ملوحة المياه٣٤٠٠٠ إلى ٣٥٠٠٠ ملجم/لتر. لقد أظھر نموذج المحاکاة أنھ بعد ٢٠ عاما من التشغيل ، سيصل قيمة الإنخفاض فيمناسيب المياه إلى ثلاثة أمتار فقط في وسط حقل آبار التغذية وملوحة المياه سترتفع إلى ٤٥٠٠٠ ملجم/لتر ، بسبب حقنأقل من واحد بينما تصل إلى SDI المحلول الملحي في نفس الخزان الجوفي. تحتوي مياه التغذية من آبار الشاطئ علي قيمةالعالية من عمر الأغشية وتزيد من جرعة المواد الکيميائية SDI ٤.٤ في تلک القادمة مباشرة من البحر المفتوح. تقلل قيموالکربون (UVA اللازمة لإزالة الرواسب من سطح ھذه الأغشية. تبلغ نسبة إزالة کل من الکربون العضوي الکلي ( 245في آبار الشاطئ ٣٥ ٪ و ٥٠ ٪ على التوالي. أيضا لم يتم رصد بکتريا البراز الممرضة (DOC) العضوي المذابوالطحالب في آبار الشاطئ التي تغذي محطات التحلية ، کما يعمل الترشيح الطبيعي للشواطئ علي عدم إنسداد أغشيةتحلية المياه وإطالة عمرھا کما يقلل من المواد الکيميائية المستخدمة مقارنة مع مآخذ مياه البحر. يقلل الترشيح الطبيعيللتربة من استخدام المواد الکيميائية لتجديد الأغشية وتکرار الغسيل العکسي حيث أن تواتر تنظيف الأغشية يکون أقل بکثير،معدل استھلاک المواد الکيميائية المستخدمة شھريا في محطات التحلية المعتمدة علي الترشيح الطبيعي أقل بکثير من تلکالمعتمدة علي التغذية المباشرة من البحر المفتوح. الترشيح الطبيعي للشواطئ ھو تقنية خضراء تساعد في الحفاظ على البيئةالمحيطة واستدامة الأنشطة السياحية.

Topologically protected surface states present rich physics and promising spintronic, optoelectronic, and photonic applications that require a proper understanding of their ultrafast carrier dynamics. Here, we investigate these dynamics in topological insulators (TIs) of the bismuth and antimony chalcogenide family, where we isolate the response of Dirac fermions at the surface from the response of bulk carriers by combining photoexcitation with below-bandgap terahertz (THz) photons and TI samples with varying Fermi level, including one sample with the Fermi level located within the bandgap. We identify distinctly faster relaxation of charge carriers in the topologically protected Dirac surface states (few hundred femtoseconds), compared to bulk carriers (few picoseconds). In agreement with such fast cooling dynamics, we observe THz harmonic generation without any saturation effects for increasing incident fields, unlike graphene which exhibits strong saturation. This opens up promising avenues for increased THz nonlinear conversion efficiencies, and high-bandwidth optoelectronic and spintronic information and communication applications., Parts of this research were carried out at ELBE at the Helmholtz-Zentrum Dresden-Rossendorf e.V., a member of the Helmholtz Association. The films are grown in IRE RAS within the framework of the state task. This work was supported by the RFBR grants Nos. 18-29-20101, 19-02-00598. N.A., S.K., and I.I. acknowledge support from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 737038 (TRANSPIRE). T.V.A.G.O. and L.M.E. acknowledge the support by the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter (ct.qmat). K.-J.T. acknowledges funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 804349 (ERC StG CUHL) and financial support through the MAINZ Visiting Professorship. ICN2 was supported by the Severo Ochoa program from Spanish MINECO Grant No. SEV-2017-0706.

Graphene is conceivably the most nonlinear optoelectronic material we know. Its nonlinear optical coefficients in the terahertz frequency range surpass those of other materials by many orders of magnitude. Here, we show that the terahertz nonlinearity of graphene, both for ultrashort single-cycle and quasi-monochromatic multicycle input terahertz signals, can be efficiently controlled using electrical gating, with gating voltages as low as a few volts. For example, optimal electrical gating enhances the power conversion efficiency in terahertz third-harmonic generation in graphene by about two orders of magnitude. Our experimental results are in quantitative agreement with a physical model of the graphene nonlinearity, describing the time-dependent thermodynamic balance maintained within the electronic population of graphene during interaction with ultrafast electric fields. Our results can serve as a basis for straightforward and accurate design of devices and applications for efficient electronic signal processing in graphene at ultrahigh frequencies., D.T. and H.A.H. acknowledge funding from the European Union’s Horizon 2020 Framework Programme under grant agreement no. 964735 (EXTREME-IR). M.G. and B.G. acknowledge support from the European Cluster of Advanced Laser Light Sources (EUCALL) project that has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 654220. K.-J.T. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 804349 (ERC StG CUHL) and financial support through the MAINZ Visiting Professorship. ICN2 was supported by the Severo Ochoa program from Spanish MINECO (grant no. SEV-2017-0706). Parts of this research were carried out at ELBE at the Helmholtz-Zentrum Dresden-Rossendorf e.V., a member of the Helmholtz Association. F.H.L.K. acknowledges support from the Government of Spain (FIS2016-81044; Severo Ochoa CEX2019-000910-S), Fundació Cellex, Fundació Mir-Puig, and Generalitat de Catalunya (CERCA, AGAUR, and SGR 1656). Furthermore, the research leading to these results has received funding from the European Union’s Horizon 2020 under grant agreement no. 881603 (Graphene Flagship Core 3).

Resumen del trabajo presentado a la NanoSpain Conference, celebrada en Barcelona (España) del 28 al 31 de mayo de 2019.

Bernard-Soulier Syndrome (BSS)is a rare hereditary disorder.Platelets in patients with BSS are unable to adhere, leading to an increased bleeding tendency. BSS cases are often misdiagnosed as idiopathic thrombocytopenic purpura (ITP). We report here a seven years old girl diagnosed as Bernard-Soulier syndrome with homozygous deletion of 39 nucleotides in the exon 2 of GP1BA. Bernard–Soulier syndrome should be considered before the patient is diagnosed with immune thrombocytopenia.