Influence of the Coolant Concentration on the Final Surface Roughness of Chrome-Plated Parts

Russian Engineering Research - The influence of the working fluid on the microrelief of chrome-plated parts is studied from theoretical and practical perspectives. Adjusting the relative content of...     

Control of Surface Roughness in Raster Honing

Russian Engineering Research - The influence of the grid density produced by the resultant raster trajectory on the surface roughness is investigated in the honing of high-precision hydraulic...     

Polishing tool for optical materials

The influence of various abrasive materials on the polishing of lithium-niobate single crystals is studied experimentally. In the analysis of the polishing tool, the tool life, the productivity, and the quality of the machined surface are taken into account.     

Modeling of fluidized-bed granulation from solutions with an external recycle

The results of the mathematical modeling of granulation from solutions in continuous fluidizedbed apparatuses with an external recycle are given. The analysis of the process using the proposed model is presented, and an example that is of practical interest is given.     

Effect of melatonin on 1,2-dimethylhydrazine-induced intestinal tumors in rats

Fifteen doses of 21 mg/kg body weight of 1,2-dimethylhydrazine (DMH) were injected into 48 female rats at one-week intervals. Controls included 25 animals while 23 received 20 mg/l of melatonin with drinking water, 5 times a week, at night-time, for 6 months, beginning from the day of the first injection. Although malignancies of large bowel developed in all animals, multiple tumors in the melatonin group were significantly fewer than in the rats treated with DMH alone (6,0 and 9,9 respectively; p < 0,001). Similarly, melatonin treatment was followed by a significantly lower frequency of tumor development in the ascending colon as well as fewer multiple neoplasms of the ascending and descending colon. Melatonin was also shown to inhibit carcinogenesis in the small intestine. It is suggested that the antitumor effects of melatonin is due to its antioxidant properties.