ab initio calculations at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g*for total energy calculation are reported for z-cyclooctene (1). the most favorable conformation of 1 is theunsymmetric boat-chair (1-bc) geometry. potential energy profiles for two different boat-chair/boat-chairinterconversion processes were calculated. the process via a chair transition sta...

In the context of a focus project at the Federal Institute of Technology (ETH Zurich) which is concerned with the development of an autonomous sailing vessel, this bachelor thesis describes in detail the design and implementation of a path planner for Avalon, an autonomous sailing boat. The planning algorithm is based on an A* search in 3 dimensions (x, y, heading) and takes into account curren...

Operator performance on the tiller-motor system was investigated in a field survey and in a tracking simulator. Boat operators in Study 1 reported both control difficulties and discomfort, when using their tiller-motor system. Participants in Study 2 operated a tiller-motor simulator of a boat navigating a river over a 20 min period. Directional and speed control performance was found to be poo...

Hydrofoils are a current hot topic in the marine industry both high performance sailing and new passenger transport systems conjunction with electric propulsion. In community, largest impact is seen from America’s cup, where boats sailed at more than 50 knots (over 100 km/h) 100% “flying” time. also becoming popular Olympics, as 2024 Olympic games 5 gold medals will be decided on foiling boats/...

Linguists have suggested that one mechanism for the creative extension of meaning in language involves mapping, or constructing correspondences between conceptual domains. For example, the sentence, "The clever boys used a cardboard box as a boat," sets up a novel mapping between the concepts cardboard box and boat, while "His main method of transportation is a boat," relies on a more conventio...

The results of MNDO, AM1 and PM3 semi-empirical calculations and HF/6-31G*, MP/6-31G*, MP2/6-311+G**, and B3LYP/6-311G** and QCISD/6-31G* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (Z,Z,Z)-cycloocta-1,3,5-triene indicate that all methods, except PM3, predict wrong ordering of the conformations.

introduction: this study investigated the influence of erbium-doped yttrium aluminum garnet (er:yag) laser on microhardness, chemical composition and subsurface morphology of dentin cavity walls. methods: forty sound human premolars were selected and randomly assigned into four groups. class v cavities were prepared either with an er:yag laser (groups 1 and 2; 15 hz, 250 mj for enamel, 10 hz, 2...

high speed wind tunnels are widely used in the study of fluid flow behavior around various objects. the air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. to arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

In many industries, such as leisure boat production, product design and process engineering are often based on diffuse criteria and a lack of data about the actual use of the products. If design and process development are not based on facts, there is a great risk of setting the wrong quality criteria and performance requirements. In the leisure boat industry the lack of data from how customers...