Electrochemistry and Radioactive Wastes: A Scientific Overview | Author : Maher Abed Elaziz, Mohamed Khalifa | Abstract | Full Text | Abstract :Radioactive wastes are arising from nuclear applications such as nuclear medicine and nuclear power plants. Radioactive wastes should be managed in a safe manner to protect human beings and the environment now and in the future. The management strategy depends on collection, segregation, treatment, immobilization, and disposal. The treatment process is a very important step in which the hazardous materials were converted to a more concentrated, less volume and less movable materials. Electrochemistry is the branch of chemistry in which the passage of electric current was producing a chemical change. Electrochemical treatment of radioactive wastes is widely used all over the world. It has a number of advantages and hence benefits. Electrochemistry can lead to remote, automatic control and increasing safety. The present work is focusing on the role of electrochemistry in the treatment of radioactive wastes worldwide. It contains the fundamentals of electrochemistry, the brief story of radioactive wastes, and the modern trends in the electrochemical treatment of radioactive wastes. An overview of electrochemical decomposition of organic wastes, electrochemical reduction of nitrates, electro- precipitation, electro- ion exchange, and electrochemical remediation of soil are outlined. The main operating factors, the mechanism of decontamination, energy consumption and examples of field trials are considered. |
| EFFECT OF DRYING ON YIELD, CHEMICAL COMPOSITION AND INSECTICIDAL ACTIVITY OF LEAF ESSENTIAL OILS OF SWEET ORANGE (Citrus sinensis) | Author : Lamidi Usman, Olusola Watti, Ridwan Ismaeel, Adebayo Ojumoola | Abstract | Full Text | Abstract :Pulverized fresh and dried leaves of Citrus sinensis (500 g) that were dried for five consecutive days during dry season were separately hydro-distilled for 3 hours. Oil yields from the samples ranged from 0.10 - 0.37% (w/w). Characterization of the oils using Gas chromatography - mass spectrometry showed that the oils were predominated by monoterpenoids (56.7 – 90.2%). Car-3-ene was the most abundant compound in the oils from fresh and the leaves dried for four days. Interestingly, the oils from other dried leaves had a-fenchene, a-terpinolene and ß-pinene as their major constituents. The insecticidal activities of the oils against Callosobruchus maculatus were also determined via contact toxicity bioassay. Regardless of the level of dryness, the oils were observed to be toxic to C. maculatus. Oil obtained from the leaves dried for five days was found to be more active against the insect than other oils. |
| Synthesis of Guanidines via Reaction of Amines with Carbodiimides in the Presence of Ionic Liquid | Author : Foad Shaghayeghi Toosi | Abstract | Full Text | Abstract :Different ionic liquids (ILs) were synthesized and evaluated for the preparation of substituted guanidines from the reaction of amines and carbodiimides. 1-methylimidazolium tetrafluoroborate [HMIm]BF4 was found to be the best ionic liquid for this reaction. This IL acted as a promoter for the addition of primary and secondary amines to carbodiimides. By this efficient approach, various guanidines were prepared in excellent yields. |
| Synthesis of substituted quinolinone ketones derived with some five, six and seven-membered heterocycles | Author : Magdi Ahmed, Hany Hassanin, Mohamed Abass, Shimaa Badran | Abstract | Full Text | Abstract :The synthesis of a series of new quinolinyl ketones substituted with some five, six and seven-membered diaza-heterocycles is described. Efficient base or acid-catalyzed nucleophilic heterocyclization of 6-ethyl-4,5-dioxo-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxaldehyde with a variety of nitrogen and/or carbon 1,2-, 1,3-, and 1,4-binucleophiles afforded the target ketones in good yields. The structure of all new products was established on basis of their spectral and analytical data. |
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