5. Dupont Process: This process operates using a molar feed ratio of 5:1:0.73 of NH3/CO2/H2O. Operates around a pressure of 408 atm and temperature of 2000C (473 K). The reactor effluent is fed to the ammonia still for recovering unreacted ammonia. The whole Dupont process requires excess of ammonia and the unreacted ammonia is recovered through condensation by operating the ammonia still at a pressure of around 13 atm and temperature of 1200C (393 K).
The contents of both chambers were stirred with a magnetic stir bar during the oxygen transfer experiments. Substrate crossover was also tested in a dual chambered MFC, in which the anode chamber was filled with 50 mM of sodium acetate and the cathode chamber with same amount of distilled water. The acetate concentration in the chamber was measured with a gas chromatograph (KONIK HRGC - 4000B series) equipped with a flame ionization detector and an EC-1000 capillary column (Alltech, Deerfield, IL, USA). The samples were taken out from the cathode chamber for every 30 min. The tests for acetate transport were conducted with stirring.
The pH was adjusted to 9.5 with 2M NaOH. 20 g of NaOCl (in which 4% active chlorine) was added drop-wise to the slurry over a period of 30 min, while maintaining pH range 9.0-9.5, with constant stirring 30±2°C. The reaction proceeded for 10 min after addition of NaOCl. After the reaction, the pH was adjusted to 7 with 1M H₂SO₄ and the oxidized starch was filtered, washed four times with distilled water by using centrifuge and dried in oven at 30±2.0°C for 48h. Dried starch was powdered with morter and pestle and passed through 200 mm sieve and the powdered oxidized starch was kept in a polythene bag.
A total of 0.1 ml of supernatant was added to cuvette containing 1.9 ml of 50mM phosphate buffer (pH 7). The reaction was started by the addition of 1 ml freshly prepared 30mM H2O2. The rate of decomposition of H2O2 was measured spectrophotometrically at 240 nm. Catalase values were expressed as n moles H2O2 consumed/min/mg protein. Measurement of lipid peroxidation TBARS, a measure of lipid per oxidation, was measured as described by Ohkawa .
DMF was used as a solvent and AIBN (0.5% w/w of total monomer) as free radical initiator .The reaction was carried out at 70±2° C for 6 hour with constant stirring. After completion of the process it was cooled to room temperature and resultant polymer solution was poured in the large amount of methanol with stirring when polymer precipitated out. It was filtered and washed with methanol. The polymer was purified by repeated precipitation using methanol from solution in DMF and then it dried. 2.3 Preparation of PS
About 0.1 ml of the sample extract was added to a volumetric flask (10 ml) containing 7.5 ml of distilled water and 0.5 ml of Folin-Ciocalteu phenol reagent, 1 ml of 35 % Na2CO3 solution and dilute to 10 ml with distilled water. The mixture was shaken well and kept at room temperature for 30 min. A set of reference standard solutions of gallic acid (20, 40, 60, 80 and 100 μg/ml) were prepared. Absorbance for test and standard solutions were measured against the blank at 725 nm with an UV/Visible spectrophotometer. The tannin content was expressed in terms of mg of GAE /g of extract
After finishing the heating process, the tubes which contained the mixture were left to cool and removed from the digestion unit. 50ml of distilled water was added to the digestion tube and 70ml of NaOH was added by the NAOH pump of the system. When the distillation was done, 50ml boric acid (4%) was added into the 250 ml flask. Steam distillation was applied and boric acid & ammonia were obtained. In order to determine the nitrogen content , titration was done with 0.1 N HCl, using a suitable indicator, two or three drops of methyl red, to determine the end-point of the reaction.
It has been prepared with some modifications. ZP was prepared as follows: typically, 5 g ZrOCl2.8H2O was refluxed with 50 ml of 12 M H3PO4 at 100 °C for 24 h. The obtained precipitate was filtered off and washed with 0.1 M H3PO4 until free of chloride ion. Finally, the solid was washed with distilled water several times until the neutral pH and dried in an oven at 110 °C for 24 h. The final product was ground into fine powders and confirmed by XRD (Fig.1). The ZPFe was prepared through an ion-exchange reaction[50, 51] (. 3 g of ZP was dispersed into the 50 ml deionized water at 50 °C.
The mixture was shaken using shaking incubator at 200 rpm for 120 min at 5000C. The mixture was then centrifuged at 3000 rpm for 15 min at room temperature and the supernatant was taken. This supernatant was stored at -2000C until further analysis. Preparation of watermelon extract Ten grams (10 g) of dehulled powdered sample were mixed with 150 ml of respective solvents, aqueous methanol (50%) and methanol and placed on water bath at 40 °C for 18 h with stirring/shaking. The extracts were filtered and concentrated by rotary evaporator.
Nickel strike composition and plating parameters are, HCL (37%) 200 ml/l, NiCl2.6H2O 300 g/l, current density 3 A/dm2 with reaction time 3 min and at room temperature. The composition of coating bath are given in Table 1. The SHP in coating bath is use as reducing agent while sodium citrate as complexing agent and ammonia acetate act as buffering agent . For post-treatment process, dehydrogenation method is use in order to remove the existed in coating hydrogen gas produce. Heat-treated at 180° C for 1 h with cooling down by itself .