Preparación, caracterización y evaluación de resina polimérica (AHMET) a partir de la reacción de anhídrido maleico con PET reciclado como inhibidor de corrosión para acero-C en HCl

Introduction: The plastic soft drink bottle from polyethylene terephthalate (PET) was introduced to consumers in 1970s. Because PET have ester group its chemical recycling is preferred. To control and reducethe environmental pollution recycling and reusing of PET has turned into an imperative procedure from the ecological perspective and it has given business opportunity because of far reaching use and accessibilityof PET polymer. Also another source of pollution to the environment was the corrosion of materials. Corrosion is the deterioration and loss of a material and its critical properties due to chemical, electrochemical and other reactions of the exposed material surface with the surrounding environment. Understanding corrosion mechanisms allow to use corrosion-resistant materials and altering designs. Organic inhibitors are very efficient to protect the metals from corrosion in all chemicals (acidic, basic and salt) media. There were many types of corrosion inhibitors and the organic inhibitor are being applied widely to protect metals from corrosion in many aggressive media. The aim of this study is to utilize waste PET-bottles will be depolarized by 2,2-dithioethanol to produce (Bis(2-((2-hydroxyethyl) thio) ethyl) terephthalate (BHTE), then by reacting of (BHTE) with maleic anhydride to produce Bis (2-((6-Mono malic acid –hydroxyethyl ester) sulfanyl) ethyl terephthalate(BHMET). The prepared (BHMET) will be used as corrosion inhibitor andits efficiency to protect the carbon steel in acidic will be assessed. Materials and Methods: Depolymerization of PET waste done with 2,2-dithioethanol. The weight proportion of PET to 2,2-dithioethanol 1:8 (wt%) and zinc acetate (0.5 wt% based on PET) was added as catalyst. Temperature of the reaction mixture was between 160-180 oC for 12 h, then the reaction mixture was kept at 140 oC for 3 h, then allowed to cool to room temperature. With vigorous agitation distilled water in excess to the reaction mixture to allow the black liquid viscous compound oligomer of Bis(2-((2-hydroxyethyl) thio) ethyl terephthalate (BHET) to precipitate. In a three neck round bottom (250 ml) attached with mechanical stirrer and thermometer (5.7gm) of (BHET) compound was added and heated for (15 min.) at (60 OC). Then (2.5gm) of malic anhydride and (1%) sulfuric acid was added. By the mechanical stirrer the mixture was mixed for (50 min.) at temperature (80OC). After the reaction the mixture was washed with distilled water to avoid the acid residue. Scheme (1) shows the mechanism for the prepared (BHMET) corrosion inhibitor

The schooling of sumatra barbs (barbus tetrazona tetrazona) and minnows (phoxinus phoxinus)

Not availabl

A multi-stages multi-objective assignment for facilities layout design

Al-Ma'amun factory of the General Company for Food Products suffers from inefficient facilities layout of its production departments and warehouses of both types (warehouses of raw materials and warehouses of finished products), which causes a lot of waste of time, resources and effort in the process of transporting raw materials or even individuals, which is leads to an increase in the costs of handling materials and not providing the service in time. Therefore, this study came to solve the problem by constructing a mathematical model based on the method of multi-stage assignment to find the optimal assignment, since the management of the factory has many goals, it was necessary to use an efficient mathematical method which is goal programming. Therefore, a multi-stage multi-objectives assignment method is applied in two stages, the first of which includes the process of transporting raw materials from raw material warehouses to the production departments to carry out the manufacturing process within them, the second stage includes the transfer of finished products from the production department to the final production warehouses. After comparing the results of the proposed layout with the results of the current layout of the factory is achieved an optimum layout of the factory because of it reduced the total traveled distance by (%25) per day, it also reduced the overall time spent by (25.5%) and reduced the total volume of spent fuel by (30.7%) per day for the new layout

Spectrofluorimetric method for the determination of glibenclamide in pharmaceutical formulations

A sensitive spectrofluorimetric method for the determination of glibenclamide in its tablet formulations has been proposed. The method is based on the dissolving of glibenclamide in absolute ethanol and measuring the native fluorescence at 354 nm after excitation at 302 nm. Beers law is obeyed in the concentration of 1.4 to 10 µg.ml-1 of glibenclamide with a limit of detection (LD) of 0.067 µg.ml-1 and a standard deviation of 0.614. The range percent recoveries (N=3) is 94 - 103