This study focused on several wetlands in Laguna del Tigre National Park (Guatemala) as part of Conservation International's Rapid Assessment Program. Sediment and water samples were collected from a laguna near Xan field, Guatemala's largest oil facility, and three other sites for determination of levels of polycyclic aromatic hydrocarbons (PAHs). Cichlid fish (Thorichthys meeki and Vieja syns...

FROM time to time one of my colleagues working at a medical school commiserates with me because I spend 40 hr a year lecturing to undergraduates. I always reply that teaching has compelled me to learn a lot of material that I would not have known about had I taught only my specialized subject. These forays into the ‘‘beyond’’ were instrumental in moving my research in new directions. Three arti...

Abstract Field penetration index (FPI) is a representative key indicator for tunnel boring machine (TBM) performance estimation, however its application in real tunneling projects still limited because of the lack some theoretical knowledge on relationships between FPI, rock mass properties, and TBM specifications. This study aims to establish FPI model by analyzing tool–rock interaction disc c...

Once segmentation of 3D surface data of a rock pile has been performed, the next task is to determine the visibility of the surface rocks. A region boundary-following algorithm that accommodates irregularly spaced 3D coordinate data is presented for determining this visibility. We examine 3D surface segmentations of laboratory rock piles and determine which regions in the segmentation correspon...

Whereas most plants are flexible structures that undergo large deformations under flow, another process can occur when the plant is broken by heavy fluid-loading. We investigate here the mechanism of such possible breakage, focusing on the flow-induced pruning that can be observed in plants or aquatic vegetation when parts of the structure break under flow. By computation on an actual tree geom...

The non-Cu critical current density of Nb3Sn strands has been pushed towards 3000 A/mm2 (12 T, 4.2 K) by increasing the Sn content and reducing the interfilamentary Cu. We compare the susceptibility to A15 filament breakage (under 0.5% bend strain) of the new high-Jc internal Sn conductor geometries with both high-Jc Powder-in-Tube (PIT) and low hysteresis loss distributed filament ITER designs...

Whereas most plants are flexible structures that undergo large deformations under flow, another process can occur when the plant is broken by heavy fluid-loading. We investigate here the mechanism of such possible breakage, focusing on the flow-induced pruning that can be observed in plants or aquatic vegetation when parts of the structure break under flow. By computation on an actual tree geom...