Codend selection of winter flounder Pseudopleuronectes americanus

Codend selection of winter flounder (Pseudopleuronectes americanus) in 76-127 mm mesh codends was examined from experiments conducted in Long Island Sound during the spring of 1986-87. The results show a slightly larger size at selection than was found in earlier work as indicated by the selection factor, 2.31 in the present study compared with 2.2 and 2.24 from previous studies. Diamond mesh was found to have a length at 50% retention about 1 cm longer (Lso =22.6 cm), and a selection range (3.4 cm) about 1 cm narrower, than square mesh in 102-mm codends. Tow duration varied from 1 to 2 hours using 114-mm diamond mesh. As has been found in previous studies, tow duration and Lso are positively related, with I-hour tows averaging 24.6 cm and 2-hour tows averaging 26.6 cm. The importance of the slope of the selection curve was examined in yield-per-recruit analyses by comparing knife-edge and stepwise recruitment. In all mesh sizes, stepwise recruitment provides a more conservative estimate of yield in the presence of a minimum size limit. Differences in yield estimates between the two models were generally small (1-7%), except in the largest mesh size, 127 mm, where yield is overestimated by 10% when assuming knife-edge recruitment. (PDF file contains 16 pages.

Gun facilitates adhesive bonding of studs to surfaces

Gun facilitates adhesive bonding of thermoplastic-backed studs to smooth, hard surfaces. Such studs can be used for mounting loads where defacement with drilled holes cannot be tolerated. These studs can be easily removed by softening the plastic bonding with heat from the gun

Space environmental work simulator Patent

Space environmental work simulator with portions of space suit mounted to vacuum chamber wal

Procedure to prepare transparent silica gels

This invention relates to the production of silica gels and in particular to a process for the preparation of silica gels which can be used as a crystal growth medium that simulates the convectionless environment of space to produce structurally perfect crystals. Modern utilizations of substances in electronics, such as radio transmitters and high frequency microphones, often require single crystals with controlled purity and structural perfection. The near convectionless environment of silica gel suppresses nucleation, thereby reducing the competitive nature of crystal growth. This competition limits the size and perfection of the crystal; and it is obviously desirable to suppress nucleation until, ideally, only one crystal grows in a predetermined location. A silica gel is not a completely convectionless environment like outer space, but is the closest known environment to that of outer space that can be created on Earth

Ghana and the Ideal of the Citizen-Shareholder: A Corporate-Law Response to the Resource Curse

This Note assesses Ghana’s legal regime for managing revenues from its newfound petroleum reserves as a means of combatting the resource curse—the well-documented political and economic phenomenon wherein resource-rich countries experience greater levels of corruption and poor governance and weaker democracy and economic growth than resource-poor nations. The Ghanaian regime fails to provide systemic protections against the resource curse by (1) supplying insufficient economic development and poverty relief, (2) lacking incentives and mechanisms for overseeing and holding accountable the powers responsible for managing petroleum revenues, and (3) providing insufficient channels for spreading the economic benefits of extraction beyond the petroleum sector. This Note undertakes a comparative study of a representative group of petroleum revenue-management regimes—those of Alaska, Norway, Indonesia, and Trinidad and Tobago—in search of an effective regime that might be transplanted to Ghana. Finding that none of these regimes are adequately applicable to Ghana’s economic, social, or political context, this Note goes on to propose a novel regime for petroleum revenue management in Ghana, drawing on principles of U.S. corporate law

Solar concentrator

An improved solar concentrator is characterized by a number of elongated supporting members arranged in substantial horizontal parallelism with the axis and intersecting a common curve. A tensioned sheet of flexible reflective material is disposed in engaging relation with the supporting members in order to impart to the tensioned sheet a catenary configuration

Full load shop testing of 18,000-hp gas turbine driven centrifugal compressor for offshore platform service: Evaluation of rotor dynamics performance

The results for in-plant full load testing of a 13.4 MW (18000 HP) gas turbine driven centrifugal compressor are presented and compared to analytical predictions of compressor rotor stability. Unique problems from both oil seals and labyrinth gas seals were encountered during the testing. The successful resolution of these problems are summarized