Preparation and Characterization of Two Azo Dyes For Dibenzothiophen by The Diazotization Reaction and Studying Their action as Acid-Base Indicators.

This research describes the preparation of two dyes , by nitration of dibenzothiophen to form p-nitro dibenzothiophen and reduction to form p-amino dibenzothiophen , and creating by the diazonium salt that is reacted with (1&2-naphthol ) to form azo dyes . Their FT.IR spectra and melting points were measured . One of these preparation dyes with orange color had been studied as an acid- base indicator by its effects in Titrimetric analysis by using methods of acid – base titration . Which was changed its color from colorless to orange in basic media , and from orange to colorless in acidic media . Dye (p- dibenzothiophen azo-8-naphthol) was an active acid-base indicator .The color difference between two spaces was clear, and the pH range of color change was (6-10)

Sound absorption for concrete containing polyethylene terephthalate waste

Plastic solid waste generation increases every year with the current consumption habit prevalent in society nowadays. The improper disposal of plastic has been a major concern to the environment as it is not easily degradable. The issue of environmental pollution caused by polyethene terephthalates (PET) has been extensively discussed and the best solution proposed is recycling. Fibre Concrete (FC) was a composite material resulting from the addition of fibres to ordinary concrete. The objective of this research was to determine the acoustic absorption coefficient of concrete containing 0%, 0.5%, 1.0%, 1.5%, 2.0% of PET fibre compared to normal concrete. In this study, straight and irregular recycled PET fibres were used. The fibres were simply cut from PET plastic bottles. The length and width of recycling PET fibre were fixed at 25 mm and 5 mm respectively. The chosen percentages were 0.5%, 1.0%, 1.5% and 2.0% of fiber. A water-cement ratio of 0.45 was acceptable for all ranges. The tests that were conduct include the slump test, compression test, and impedance tube test. The specimens were tested on day 7 and day 28 after the concrete is mixed. The end of this research results for the compressive strength of normal concrete after 28 days of curing was 48.2 MPa while concrete with 0.5% PET, 1.0 % PET, 1.5% PET and 2.0% PET recorded a compressive strength of 50.9 MPa, 49.8 MPa, 47.9 MPa and 46.6 MPa respectively. The result of the impedance test received at age 28 days was 0.13 for normal concrete and 0.16, 0.14, 0.16 MPa, and 0.14 for 0.5% PET, 1.0 % PET, 1.5% PET and 2.0% PET respectively. In conclusion, the aspect ratio of the fibres to the concrete must be correlated to avoid reducing durability. In conclusion, the addition of 0.5% PET recycled fibre into concrete showed the best value in terms of strength and 0.16 for the sound absorption coefficient