Improvement of Prediction Accuracy of Glulam Modulus of Elasticity by Considering Neutral Axis Shift in Bending

There is a discrepancy between the estimated modulus of elasticity (MOE) of glulam based on the dynamic MOE of laminates and measured MOE. The discrepancy is greater for glulam manufactured with mixed species. This study was undertaken to reduce the discrepancy between those MOE values. The error rate of predicting MOE of glulam by the transformed section method, without considering tension and compression modulus differences, was about 30%. To estimate the MOE of glulam more accurately, the differences between compression and tension modulus should be taken into account in the transformed section method. The measured tensile and compressive strain at the center of glulam under a bending load showed the movement of neutral axis toward the tension side of glulam. Therefore, the compression and tension modulus differences for each species should be identified before estimating the MOE of glulam. The prediction of glulam MOE was improved significantly by reflecting the ratio of compression and tension modulus vs dynamic MOE of laminates. The outermost of laminates in the compression side under bending load experienced plastic behavior and failure. This caused the neutral axis to move to the tension side and increased tension stress to cause the glulam to fail abruptly in tension. To improve the bending performance of glulam, reinforcing compression laminates need to be considered

Expression and functional dcharacterization of the system L amino acid transporter in KB human oral epidermoid carcinoma cells

We have examined the expression and function of system amino acid transporter in KB human oral epidermoid carcinoma cells. The KB cells express -type amino acid transporter 1 (LAT1) in plasma membrane, but not -type amino acid transporter 2 (LAT2). The [14C]-leucine uptake by KB cells is inhibited by system selective inhibitor BCH. The majority of [14C]-leucine uptake is, therefore, mediated by LAT1. These results suggest that the transport of neutral amino acids including several essential amino acids into the KB cells mediated by LAT1 and the specific inhibition of LAT1 in oral cancer cells will be a new rationale for anti-cancer therapyThis work was supported by grant No.(R01-2002-000-00165-0 (2002)) from the Basic Research Program of the Korea Science and Engineering Foundation. Anti-LAT1, anti-LAT2 and anti-4F2hc polyclonal antibodies were supplied by Kumamoto Immunochemcial Laboratory, Transgenic., Kumamoto, Japan