MFH Top-Half Ring Connectros

In the end calorimeter of the D-zero experiment, uranium and stainless steel plates are assembled into modules which are to be installed into the cryostat as individual units. A single inner module will be surrounded by 16 middle modules, which are surrounded by 16 outer modules. The 16 modules which comprise the middle ring are to be connected at the outer radius by a link, which is pinned to each front plate. The expected forces at each of the 16 connections vary from 1400 Ib to 69,000 lb (Appendix 1). At the inner radius. the forces are known to be compressive; hence, the edges of the front plates will be allowed to bear directly upon one another. Since it is desirable to minimize the volume of material used, an Inconnel connector plate and pins were chosen. Furthermore, it was observed that the forces between the 9 modules of the top half of the ring are all less than 7,700 lb. Accordingly, a connector was designed for the top half of the ring, with the intention that a separate design be performed for the bottom connections. The purpose of the test was to experimentally verify that the connector scheme designed for the top half of the MH ring (end calorimeter) was adequate for the expected structural loads. The test proved that the design was acceptable

The impact of invertebrates to four aquatic macrophytes: Potamogeton nodosus, P. illinoensis, Vallisneria americana and Nymphaea mexicana.

This research investigated the impact of invertebrates to four species of native aquatic macrophytes: V. americana, P. nodosus, P. illinoensis, and N. mexicana. Two treatments were utilized on each plant species, an insecticide treatment to remove most invertebrates and a non-treated control. Ten herbivore taxa were collected during the duration of the study including; Synclita, Paraponyx, Donacia, Rhopalosiphum, and Hydrellia. Macrophyte biomass differences between treatments were not measured for V. americana or N. mexicana. The biomasses of P. nodosus and P. illinoensis in non-treated areas were reduced by 40% and 63% respectively. This indicated that herbivory, once thought to be insignificant to aquatic macrophytes, can cause substantial reductions in biomass

Integrating Invasive Weed Biological Control in Aquatic Ecosystem Restoration Projects

A primary goal of many aquatic ecosystem restoration (AER) projects is to alter and improve plant communities by increasing relative abundance of native species while reducing invasive species abundance, establishment, and spread. Biological control or the use of host-specific pathogens, predators, or herbivores from the native range of a target invader, has been used for invasive plant control, but underutilized as part of integrated pest management (IPM) in government-sponsored AER programs. Weed biological control should be vetted and integrated where possible in all project phases—planning, design, implementation, and maintenance. Using a publicly-funded AER framework—U.S. Army Corps of Engineers or USACE—we define and describe biological control, how it can be seamlessly incorporated at various project stages, a list of common invasive plants that have approved biological controls, and regulatory issues surrounding implementation. Our aim is to illustrate to project managers, planners, environmental personnel, and economists how regulatory agency-approved biological control agents can be a valuable component of AER projects to assist in meeting vegetation community restoration trajectory goals