EFFECT OF CCA AND CHARGING BEHAVIOR ON PRINT QUALITY

Fourteen test toners and two types of toner of irregular shape and spherical shape were studied for charging behavior. There are three types of CCA of various concentrations. They were mixed by rotation roller, developing roller, and hand shaking. Charging properties of the toners were measured by E-SPART analyzer and blow off measurement unit. Evaluations of print quality in terms of solid density, background density and percentage of dot gain were carried out to obtain correlation with charging properties. The charge of the toners with CCA increased to an equilibrium state within a shorter time. The toners without CCA have the lowest density. The higher the CCA amount, the higher the print density, but the background density of the toners without CCA were higher than the toners with CCA In addition, the presence of CCA and silica affects the toner charge when the humidity is varied. This article describes the effects of CCA type/its concentration and charging behavior on the extent of q/m values which controls the print quality.     

Purification and characterisation of antioxidant and nitric oxide inhibitory peptides from Tilapia (Oreochromis niloticus) protein hydrolysate

Nitric oxide (NO)‐inhibitory and antioxidative activities of tilapia hydrolysates were prepared using ultrasound pretreatment at 70 W for 30 and 45 min, respectively, followed by Flavourzyme hydrolysis for 1 h. Both hydrolysates were fractionated using size exclusion chromatography on Sephadex G‐25 column and purified by RP‐HPLC. The amino acid sequence of the most potent and purified fractions was determined using LC/MS/MS. The antioxidant peptide (KAFAVIDQDKSGFIEEDELKLFLQNFSAGARAGDSDGDGKIGVDEFAALVK, MW: 6334.49 KDa) and NO‐inhibitory peptide (AFAVIDQDKSGFIEEDELKLFLQNFSAGARAGDSDGDGKIGVDEFAALVK, MW: 6309.49 Da) produced no cytotoxicity in RAW264.7 macrophage cell lines at the concentration of 100 mg mL^?1. The purified peptides at the concentration 100 μg mL^?1 possessed antioxidative and NO‐inhibitory activities 83.0 ± 1.1% and 40.9 ± 0.2%, respectively, which were about 100 times those of their counterpart crude hydrolysates.