We describe a rapid one-step, room temperature method to chemically synthesize bulk quantities of nanocomposites comprising specifically of manganese ferrite (MnFe2O4) and polyaniline (conductive form). Typically a chemical agent, for example ammonium peroxydisulfate, is used to start the polymerization of aniline in the presence of ferrites, and stirring of the reaction system for several hours is also very common. Our approach allows for the nanocomposites to be formed in less than thirty minutes without adding an external polymerization initiator/surfactant and applying any form of mechanical agitation. This process affords the possibility to grow thin films of polyaniline-MnFe2O4 directly on device substrates. Structural, thermal, magnetic and electrical studies did reveal significant chemical interactions between MnFe2O4 and polyaniline matrix. The nanocomposites are magnetic semiconductors with long rod-shaped structures of average diameter in the nanometer scale range and optical properties resembling that of conductive polyaniline. They exhibit a positive magnetoresistance across all temperature ranges with a minimum at around 250 K, corresponding to the temperature for their uniform-to-irregular transition in dynamic stability behavior and likewise coinciding with a minimum in their profile of electrical conduction mechanism (one-dimensional variable range hopping below 250 K) – these complementarities are important for hybrid spintronic applications.
A simple visible spectrophotometric method is proposed for the determination
of ulipristal acetate present in bulk and tablet formulation. The currently
proposed method is established based on MBTH oxidation by ferric ions to
form an active coupling species (electrophile), followed by its coupling with
the ulipristal in acidic medium to form high intensiied green colored chromophore
having max at 609 nm. Validated the method as per the current
guidelines of ICH. Beer’s law was obeyed in the concentration range of 6.25 –
37.50 g mL1 with a high regression coeficient (r > 0.999). Reproducibility,
accuracy, and precision of the method are evident from the low values of R.S.D.
This method can be used in quality control laboratories for routine analysis of
ulipristal acetate in bulk drug and pharmaceutical dosage forms.
Authors: Ahmed Farghali Abdelrehim
Comments: 14 Pages. A World with an Unlimited Source of Water!
In most recent years, Egypt has been suffering from some grand challenges that disrupt its march of progress. Amongst all these challenges, the dilemma concerning water and agriculture has become worse than before and requires immediate resolution. Egypt depends on conventional water resources that face many problems due to over-consumption and pollution. The purpose of the study is to implement a practical solution related to treatment of wastewater and advanced irrigation water techniques. Therefore, it was decided to conduct an extensive research to find a suitable solution. By taking into account the prior solutions, it was obvious that the chosen solution, which is a urine treatment system provided with an Arduino based irrigation system, will be an ideal solution for water crisis in Egypt. A prototype was constructed with specific design requirements such as the quality of water and the efficiency of irrigation system. By testing the prototype, the results were more preferable than expected as it confirmed that the project fulfilled its design requirements. In conclusion, these promising results gave us a clue that this project will be so powerful on large scales in the near future.