The Effects of the Reynolds Number on the Hydrodynamics Characteristics of an AUV

The hydrodynamic characteristics of autonomous underwater vehicles (AUVs) play a significant role in the design and analysis of their maneuverability. This paper evaluates the effects of the Reynolds (Re) number on the hydrodynamic characteristics of AUV for various angles of attack (AOA). To estimate the hydrodynamic parameters, a numerical modelling based on computational fluid dynamics (CFD) is employed. Reynolds numbers between 2106 and 150106 were examined at -10º to 10º AOAs. Experimental tests for the same AUV in Re = 2106 in the water tunnel were carried out for CFD validation. A comparison of the results showed an acceptable agreement between the numerical method and the experimental results. The results show that hydrodynamic parameters can be a function of Re and converge on a constant in a limited value when the Re number increases. Results of independent parameters, can be used for full-scale without the establishment of dynamic similarity

Cultured Ehrlich Ascites Tumor Cells Show Increased N-Linked [alpha]2,6-Sialytransferase Activity

Ehrlich ascites tumor cells (EAT cells) are routinely grown in the peritoneal cavity of mice. These cells, EAT-wt, grow in suspension and exhibit a high level of [alpha]-2,3-O-linked sialyltransferase activity with benzyl-T-antigen (Gal[beta]1,3Ga1NAc-[alpha]-O-CH2C6H5) as acceptor. These cells also contain a very low level of [alpha]-2,6-O-linked and [alpha]-2,6-N-linked sialyltransferase activity. A variant of these cells, EAT-c, has been selected to grow in cell culture, attached to the surface of culture flasks. EAT-c cells exhibit a selective increase of two- to fivefold in the activity of [alpha]-2,6-N-linked sialyltransferase activity, using asialo-[alpha]1-acid glycoprotein as acceptor. Since a similar selective increase has been previously observed in metastatic human colorectal cancer tissues, the EAT-wt/EAT-c cell system may serve as a good experimental model for the investigation of sialyltransferases and their cell surface sialylated products in relation to cancer, metastasis, and cell-cell interaction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30767/1/0000418.pd