The Vertical Distribution of Distribution of Winds in Urban Area at Hillah City

           العناصر الأنوائية المعتمدة في هذه الدراسة هي سرعة الرياح ودرجات الحرارة الهواء وذلك لحساب تغير سرعة الرياح مع الارتفاع في مركز مدينة الحلة خلال العام ( .(2017رصدت سرعة الرياح ودرجة الحرارة لارتفاعين مختلفين هما 10m,15m)) , حيث رصدت القراءات خلال  24  ساعة تحت ظروف استقراريه مختلفة . تم حساب عدد ريجاردسن ( ) لاستخدامه مؤشرا" لتصنيف حالات الاستقرارية , وقد تبين أن أغلب القراءات المرصودة كانت ضمن الأجواء غير المستقرة والمتعادلة. تم استخدام مؤشرات الخشونة ( طول الخشونة وطول الإزاحة الصفرية) المحسوبة من دراسات وبحوث اجريت على منطقة الدراسة. واخذت الرصدات لإيجاد سرعة الرياح الأفقية على ارتفاعات مختلفة ضمن الطبقة المحاددة من خلال تطبيق المعادلة اللوغارتمية المتضمنة مؤشر الاستقرارية وسرعة الرياح الاحتكاكية, وكذلك حساب معامل التصحيح ( ) لعدد ريجاردسن, وذلك خلال الظروف المستقرة وغير المستقرة, كذلك تم حساب سرعة الرياح الافقية ومقارنتها مع سرعة الرياح المقاسة عمليا". The adapted meteorological elements in this study, wind speed, and air temperature were used in order to calculate the variation of wind speed with altitude, at Hillah city center during 2017. Wind speed and air temperature were observed for two different heights 10 m, 15 m. These observations have been done for 24 hours under various conditions of atmospheric stability. Richardson number was calculated as an indicator to estimate the conditions of stability,  it should be noted that most of the observations were within unstable and neutral conditions. Roughness indicators such as roughness length and zero displacement length were used which determined from previous studies performed at the study area. In order to determine the horizontal wind speed, the observations were taken at deferent heights within the boundary layer by using the logarithmic wind profile which involves the indicator of stability and frictional wind speed. In addition, the correction coefficient of the Richardson number was calculated through stable and unstable conditions. Besides, the horizontal wind speed was calculated and then compared with the practical values.     &nbsp

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Electrografting of mixed organophosphonic monolayers for SI-ATRP of 2-methacryloyloxyethyl phosphorylcholine

International audienceNitinol (NiTi), one of the most important alloys for biomedical applications, is still hampered by its surface nickel inclusions, making it sensitive to pitting corrosion and leading therefore to the release of potentially carcinogenic Ni2+ ions. In this work, we assess the impact of the combination of electrografted mixed self-assembled monolayers (SAMs) on NiTi followed by a polymer coating formed by surface-initiated atom transfer radical polymerization (SI-ATRP). The molecular ratio of 11-(2-bromoisobutyrate)-undecyl-1-phosphonic acid (BUPA) to 11-decylphosphonic acid (C10P) on the electroassisted elaboration of the (BUPA/C10P)-NiTi-SAMs has been optimized. A small amount of BUPA (20%) appears to be the most promising condition, as it provides an efficient corrosion resistance and promotes the SI-ATRP of 2-methacryloyloxyethyl methacrylate (MPC). This confers to the surface hydrophilic properties and corrosion resistance close to those NiTi-SAMs when long polymerization times are used (≥ 6 h)

PEDOT Modified Carbon Paste Microelectrodes for Scanning Electrochemical Microscopy

Only one measuring tip was used in three different modes of operation of the Scanning Electrochemical Microscope (feed-back mode, generation-collection mode, potentiometry) to collect chemical information about copper targets. The tip was formed from 5 and 25 μm diameter conventional platinum microdisk electrode by etching a cavity, then electrochemically depositing poly(3,4-ethylenedioxythiophene) (PEDOT) layer doped with hexacyanoferrate and finally filling with modified carbon paste based Cu2+ sensing layer. The preparation and electrochemical working parameters of this kind of solidcontact microelectrodes are discussed as well as SECM applications for copper detection is reported. (doi: 10.5562/cca1784