A boat sales receipt produces the legal effects of a valid sales contract. The receipt is a document proving the ownership of a boat on the basis of which an entry is made in the register of boats.
The performance analysis of Olympic sailor's has typically been based on race outcomes, two boat testing, and formative feedback from athletes and coaches. Sailors body-motions are thought to be a ...key factor in the up-wind performance of a sailor. However, despite the focus of a large portion of sailing literature on improving body-motions, and international rules restricting the use of them in competition, no methods have been formulated to predict the performance impact of these motions, or to measure the unsteady loadings they exert on the sailboat. A sailing-specific pose-capture method to estimate sailor loadings was developed and evaluated. StickMan uses a network of seven wireless inertial-magnetic motion trackers to measure a sailor's hiking pose and boat orientation. A human mass distribution model was used to estimate body-segment mass properties to derive the external loads sailors exert on their boat. Hiking (roll) moment estimates were evaluated for accuracy using an instrumented motion platform under sinusoidal roll motion for sequences of static and dynamic hiking poses. Hiking moments estimated using pose-capture had an average 10.0% overestimate under dynamic conditions. The estimate had excellent transient and tracked reference measurements even under explosively dynamic hiking motion spanning 1000 Nm. A global sensitivity analysis was performed on hiking moment estimates. The uncertainty for hiking poses was 712 ± 38 Nm (5.3%) which the human mass distribution model contributed up to 70 % towards. Instrumentation uncertainty, including orientation drift, was not significant for hiking poses over 8 knots of wind. A case-study was performed to demonstrate the use of the method applied to the performance analysis of roll tacks and upwind hiking moment to make initial assessments of the performance implications of a sailor's ability to perform roll tacks. GPS positions and wind sensors were used to build a simple model of how a sailor-controlled hiking moment can a↵ect boat speed. This shows the method was suitable for analysing dynamic hiking methods in terms of boat performance.
N1,N4,3,6-Tetramethyl-N1,N4-diphenyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxamide was prepared from 3,6-dimethyl-1,6-dihydro-1,2,4,5-tetrazine, bis(trichloromethyl) carbonate and N-methylaniline. ...Its structure was confirmed by single-crystal X-ray diffraction. This reaction yields the title compound rather than N1,N2,3,6-tetramethyl-N1,N2-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2- dicarboxamide. The central tetrazine ring of the title compound exhibits a boat conformation and is therefore not homoaromatic.
N1,N4-Di-tert-butyl-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxamide was prepared from 3,6-dimethyl-1,6-dihydro-1,2,4,5-tetrazine, and its structure was confirmed by single-crystal X-ray ...diffraction. This reaction yields the 1,4-dicarboxamide derivative rather than the 1,2-dicarboxamide derivative. The central six-member ring of the title compound has a boat conformation and therefore, is not homoaromatic.
Great-tailed Grackle (Quiscalus mexicanus) and Common Grackle (Q. quiscula) are phylogenetically distant among grackles and were historically allopatric. Northward range expansion of Great-tailed ...Grackle and westward expansion of Common Grackle brought these species into increasing contact over the past century but has not led to notable interactions. Hybrids of Great-tailed Grackle with Boat-tailed Grackle (Q. major). Brewer's Blackbird (Euphagus cyanocephalus), and Red-winged Blackbird (Agelaius phoeniceus) have been reported, whereas hybridization of Common Grackle has never been documented with any species. We report a brood of 2 hybrid offspring of a male Great-tailed Grackle and female Common Grackle in Dillon. Montana, in 2015. For about a week after their discovery, both parents defended and fed the fledglings, the latter behavior extraordinary for a male Great-tailed Grackle. Moreover, whereas the female parent was no longer seen, the male continued to feed the young for at least another 7 weeks after they left the nest tree, during which time the trio moved -2 km across town and the young began prebasic molt, growing iridescent blue-black secondary coverts as expected for male Great-tailed Grackle but not for Common Grackle or female Great-tailed Grackle. Analysis of DNA from a feather of one offspring confirmed that it had hybrid nuclear DNA, had Common Grackle mitochondrial DNA. and was male. In 2016, the male Great-tailed Grackle again courted a female Common Grackle that nested in his tree, a nest which he defended, but she was also attended by a male Common Grackle. She produced 5 young, all of which were genetically pure Common Grackles. not hybrids. Also notable in 2016. another male Great-tailed Grackle in the general vicinity was observed feeding young in 1 of 3 nests that he defended, suggesting that male parental care may be more common in that species than has been appreciated. Received 15 Januaty 2021. Accepted 9 June 2021.
Fishing boats at Cap Gammarth, Aria Sheshka, Raman
Color research and application,
December 2018, 2018-12-00, 20181201, Letnik:
43, Številka:
6
Journal Article
