7 research outputs found

    Corrosion Protection Study of Carbon Steel and 316 Stainless Steel Alloys Coated by Nanoparticles

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    The Corrosion protection effectiveness of Alimina(Al2O3,50nm)and Zinc oxide (ZnO,30nm) nanoparticales were studied on carbon steel and 316 stainless steel alloys in saline water (3.5%NaCl)at four temperatures: (20,30,40,50 OC)using three electrodes potentiostat. An average corrosion protection efficiencies of 65 %and 80% was achieved using Al2O3 NP's on carbon steel and stainless steel samples respectively, and it seems that no effect of rising temperature on the performances of the coated layers. While ZnO NP'S showed protection efficiency around 65% for the two alloys and little effected by temperature rising on the performanes of the coated layers. The morphology of the coated spesiemses was examined by Atomic force microscope

    Protection of Galvanized steel from corrosion in salt media using sulfur nanoparticles

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    تم دراسة خصائص الكبريت النانوي بوساطة  جهاز مجهر القوة الذري. أظهرت قياسات مجهر القوة الذرية الحجم الكلي للكبريت النانوي المحضر بوساطة مزج ثايوسلفات الصوديوم مع مستخلص نبات  اليقطين مساويا 93.62نانومتر .تم دراسة حماية التاكل لمعدن الكلفانك ستيل  في الوسط الملحي وبمختلف درجات الحرارة بوساطة الكبريت النانوي وتم الحصول على افضل نتائج ثرموديناميكية  للمعدن بوجود الكبريت النانوي حيث كفاءة التثبيط ومقاومة لتاكل للمعدن تعطي اعلى قيمة عند اعلى درجة حرارية بوجود المثبط بلمقارنة بغيابة .كذلك سرعة التاكل تقل عند زيادة درجة الحرارة بوجود الكبريت النانوي, القيم الموجة للدالة الحرارية بوجود وبعدم وجود الكبريت النانوي تدل على انه التفاعل ماص للحرارة . لذا يقترح ان الكبريت النانوي مثبط جيد لمعدن الكالفانك ستيل في الوسط الملحي                The characteristics of sulfur nanoparticles were studied by using atomic force microscope (AFM) analysis. The atomic force microscope (AFM) measurements showed that the average size of sulfur nanoparticles synthesized using thiosulfate sodium solution through the extract of cucurbita pepo extra was 93.62 nm. Protecting galvanized steel from corrosion in salt media was achieved by using sulfur nanoparticles in different temperatures. The obtained data of thermodynamic in the presence of sulfur nanoparticles referred to high value as compares to counterpart in the absence of sulfur nanoparticles, the high inhibition efficiency (%IE) and corrosion resistance were at high temperature, the corrosion rate or weight loss decreased with increasing temperature in the presence of sulfur nanoparticles. The positive value of enthalpy ∆H* for galvanized steel with and without sulfur nanoparticles indicates that the reaction was endothermic. Therefore, the sulfur nanoparticles can be suggested as good inhibitor for galvanization in salt media

    The Effect of Photo irradiation by Low Energy Laser on the Optical Properties of Amorphous GaAs Films

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    Amorphous thin gallium arsenide films have been evaporated by flash evaporation technique with thickness of about 3500 ?, under vacuum of about 10-6 mbar, on ultrasonically cleaning corning glass substrate, at substrate temperature 423 K. GaAs films have been irradiated by continuous Ar+ ion laser with power nearly 120 mW for different duration times. X-ray diffraction of the as prepared and irradiated GaAs films is amorphous structure. The optical properties of GaAs films were investigated by studying the infrared and ultraviolet spectra and some optical constants were founded and compared before and after irradiation, the absorption edge shift toward the longer wavelengths (red shift) after irradiation process with respect to the as deposited film, the value of the absorption coefficient for GaAs films at the absorption edge has decreased slightly after irradiation process by factor of about 4. The direct optical energy gaps of GaAs films were estimated to be 1.78 eV for the as prepared decrease to 1.52 eV after irradiation process

    Synthesis of Silver Nanoparticles from Malva parviflora Extract and Effect on Ecto-5'- Nucleotidase(5'-NT), ADA and AMPDA Enzymes in Sera of Patients with Arthrosclerosis

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    The present research included synthesis of silver nanoparticle from(1*10-3,1*10-4 and1*10-5) M aqueous AgNO3 solution through the extract of M.parviflora reducing agent. In the process of synthesizing silver nanoparticles we detected a rapid reduction of silver ions leading to the formation of stable crystalline silver nanoparticles in the solution. The characteristics of silver nanoparticles were studied by using UV-Visible absorption spectroscopy, and atomic force microscope (AFM) analysis. The AFM measurements showed that the average size of silver nanoparticles synthesized using (1*10-3,1*10-4 and1*10-5) M aqueous AgNO3 solution through the extract of M.parviflora were 102 to 114nm. UV-Vis spectra of the aqueous medium containing silver nanoparticles showed a surface peak at 220nm and 445nm for (1*10-3,1*10-4 and1*10-5) M aqueous AgNO3 solution through the extract of M.parviflora. The study of nanoparticles due to the possible application for the development of new technologies such as exhibited inhibitory effects on Ecto-5'- Nucleotidase (5'-NT), ADA and AMPDA enzymes in Sera of control and Patients with Arthrosclerosis. Further studies on other biological activities are required to exploit their full potentia

    Enhancement of the CAST Block Algorithm Based on Novel S-Box for Image Encryption

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    Background and Aim: due to the rapid growth of data communication and multimedia system applications, security becomes a critical issue in the communication and storage of images. This study aims to improve encryption and decryption for various types of images by decreasing time consumption and strengthening security. Methodology: An algorithm is proposed for encrypting images based on the Carlisle Adams and Stafford Tavares CAST block cipher algorithm with 3D and 2D logistic maps. A chaotic function that increases the randomness in the encrypted data and images, thereby breaking the relation sequence through the encryption procedure, is introduced. The time is decreased by using three secure and private S-Boxes rather than using six S-Boxes, as in the traditional method. Moreover, the CAST encryption algorithm was modified to be used on the private keys and substitution stage (S-Boxes), with the keys and S-Boxes of the encryption algorithm being generated according to the 2D and 3D chaotic map functions. The proposed system passed all evaluation criteria, including (MSE, PSNR, EQ, MD, SC, NC, AD, SNR, SIM, MAE, Time, CC, Entropy, and histograms). Results: Moreover, the results also illustrate that the created S-Boxes passed all evaluation criteria; compared with the results of the traditional method that was used in creating S-Box, the proposed method achieved better results than other methods used in the other works. The proposed solution improves the entropy which is between (7.991–7.999), reduces the processing time which is between (0.5–11 s/Images), and improves NCPR, which is between (0.991–1). Conclusions: The proposed solution focuses on reducing the total processing time for encryption and decryption and improving transmission security. Finally, this solution provides a fast security system for surgical telepresence with secure real-time communication. The complexity of this work needs to know the S-Box creation method used, the chaotic method, the values of the chaotic parameters, and which of these methods was used in the encryption process