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The present study pertains to the experimental work on the characteristic of a rotating liquid jet under various conditions of the nozzle diameter, volumetric flow rate and rotating speed. With emphasis on the important phenomena of a liquid jet, the effects of breakup length, the transition between dripping and jetting, breakup categories, droplet sizes from the breakup, and the time interval between two successive droplets are investigated systematically. The results reveal that the breakup length of a jet increases with flow rate and decreases with imposed rotation. The hysteresis behavior only occurs for larger nozzles, and the transition from jetting to dripping is affected by the imposed rotation. Depending on the imposed rotation, three different breakup patterns are found and named single droplet, satellite droplet, and multi-position necking. An empirical correlation is also proposed to predict the boundary of satellite and multi-droplets formation. The main droplet, satellite droplet, and merged droplet are about 1.8, 0.8, and 2.2 times than the nozzle diameters, respectively, no matter what the rotating speed is. Moreover, the non-dimensional time interval between two main droplets has an ascending tendency with either We number or the imposed rotation. [ABSTRACT FROM AUTHOR]

The handle displacement, grip force and upper limb muscle activity due to the effects of operator experience are studied with 15 experienced and 15 novice nutrunner users. The results have suggested that by adapting the workplace layout to permit different working postures for each user group is able to minimize the tool handle displacement.

Swamp buffalos are becoming endangered due to reproductive inefficiencies. This is of concern because many countries depend heavily on their products. Somatic cell nuclear transfer (SCNT) is a potential strategy for preserving endangered species. To date, SCNT in swamp buffalo has succeeded in the creation of blastocyst embryos. However, development to term of SCNT swamp buffalos is extremely limited, and only 1 live birth has been reported. An abnormal epigenetic mechanism is suspected to be the cause of developmental failure, as is also seen in other species. The DNA methylation and histone acetylation are key players in epigenetic modification and display marked variability during embryonic preimplantation development. Knowledge of epigenetic modifications will aid in solving the developmental problems of SCNT embryos and improving reproductive technology in the swamp buffalo. The objective of this study was to determine the relationship between preimplantation embryonic development and 2 epigenetic patterns, global DNA methylation and histone acetylation, in SCNT and in vitro-fertilized (IVF) swamp buffalo embryos. In addition, we examined the correlations between those 2 mechanisms in the SCNT and IVF swamp buffalo embryos throughout the developmental stages using double immunostaining and quantification of the emission intensities using confocal microscopy. We discovered an aberrant methylation pattern in early preimplantation-stage swamp buffalo SCNT embryos. In addition, greater variability in the DNA methylation levels among nuclei within SCNT embryos was discovered. Hyperacetylation was also observed in SCNT embryos compared with IVF embryos at the 4- and 8-cell stages (P < 0.05). Dynamic changes and interplay between these 2 epigenetic mechanisms could be crucial for embryonic development during the early preimplantation period. The aberrancies uncovered here may contribute to the low efficiency of SCNT. Key words: DNA methylation, epigenetics, histone acetylation, nuclear transfer, preimplantation embryo, swamp buffalo