Low Effort L-i Nuclear Fusion Plasma Control Using Model Predictive Control Laws

One of the main problems of fusion energy is to achieve longer pulse duration by avoiding the premature reaction decay due to plasma instabilities. The control of the plasma inductance arises as an essential tool for the successful operation of tokamak fusion reactors in order to overcome stability issues as well as the new challenges specific to advanced scenarios operation. In this sense, given that advanced tokamaks will suffer from limited power available from noninductive current drive actuators, the transformer primary coil could assist in reducing the power requirements of the noninductive current drive sources needed for current profile control. Therefore, tokamak operation may benefit from advanced control laws beyond the traditionally used PID schemes by reducing instabilities while guaranteeing the tokamak integrity. In this paper, a novel model predictive control (MPC) scheme has been developed and successfully employed to optimize both current and internal inductance of the plasma, which influences the L-H transition timing, the density peaking, and pedestal pressure. Results show that the internal inductance and current profiles can be adequately controlled while maintaining the minimal control action required in tokamak operation.

Tuna research and monitoring in the South Pacific

The island countries of the South Pacific have adopted a regional approach to the development and management of tuna resources, through 2 organizations based in the region - the Forum Fisheries Agency and the South Pacific Commission. Details are given of the Tuna and Billfish Assessment Programme, which involves tropical tunas and albacore.

A global protocol for monitoring of coral bleaching

Coral bleaching and subsequent mortality represent a major threat to the future health and productivity of coral reefs. However a lack of reliable data on occurrence, severity and other characteristics of bleaching events hampers research on the causes and consequences of this important phenomenon. This article describes a global protocol for monitoring coral bleaching events, which addresses this problem and can be used by people with different levels of expertise and resources.

SEACORM Net - Southeast Asia's coral reef monitoring network

The region's scientists work together to formed the SEACORM Net (Southeast Asia Coral Reef Monitoring Network) for better integration of information and resources. The group intends to establish a strong working relationship between member countries, share information and lessons learnt, inform and update each other on research and monitoring activities in each country, and provide a mechanism for cross-country assistance and collaboration.

The GCRMN - coordinating coral reef monitoring efforts for effective management

The Global Coral Reef Monitoring Network (GCRMN) is an operational unit of the International Coral Reef Initiative (ICRI), established in 1995 and maintained by the Australian Institute of Marine Science (AIMS). The main responsibilities are to provide data and information on the global status of coral reefs, assess how people use and interact with reefs, assist coral reef management, and raise awareness among all stakeholders of the status of reefs and the need for urgent action. It is represented by 17 regional nodes, with overall coordination by a global coordinator based at AIMS.

The Atlantic and Gulf Menhaden Purse Seine Fisheries: Origins, Harvesting Technologies, Biostatistical Monitoring, Recent Trends in Fisheries Statistics, and Forecasting

With its genesis in New England during the 1800's, the purse seine fishery for Atlantic menhaden, Brevoortia tyrannus, expanded south and by the early 1900's ranged the length of the eastern seaboard. The purse seine fishery for Gulf menhaden. B. patronus, is of relatively recent development, exploitation of the stock beginning in the late 1940's. Landings from both fisheries annually comprise 35-40% of the total U. S. fisheries landings, ranking menhaden first in terms of volume landed. Technological advances in harvesting methods, fish-spotting capabilities, and vessel designs accelerated after World War II, resulting in larger, faster, and wider-ranging carrier vessels, improved speed and efficiency of the harvest, and reduction in labor requirements. Chief products of the menhaden industry are fish meal, fish oil, and solubles, but research into new product lines is underway. Since 1955 on the Atlantic coast and 1964 on the Gulf coast, the NMFS has monitored the fisheries for biostatistical data. Annual data summaries of numbers-of-fish-at-age harvested, catch tonnage, and fishing effort of the fleet form the basis of routine stock assessments and annual catch forecasts to industry for the upcoming fishing season. After landings declined in the 1960's, the Atlantic menhaden stock has recovered through the 1970's and 1980's. Exceptional year classes of Gulf menhaden in recent years account for record landings during the 1980's.