Pared-down landscapes in Antarctica

The frigid-arid climate that now prevails in ice-free parts of Victoria Land, Antarctica, inhibits glacial erosion. If certain landscapes, more or less remote from the great troughs of outlet glaciers, have been glaciated in the past, as seems very probable, landforms that resulted from glaciation have been replaced by surfaces of different origin. A widespread landscape glaciation was probably contemporaneous with the excavation of large cirques which still survive in mountain summit areas. Replacement of glaciated landforms by others, in a general paring down of the land surface to forms of moderate relief, seems to have resulted from the process of gravity removal of debris from precipitous rock outcrops that were retreating because of disintegration by salt weathering and were eventually eliminated, in most cases, so that the landscape became a mosaic of smooth denudation slopes inclined at 33° to 350. In the Darwin Mountains ice-free area (80ºS) an advanced stage of such denudation with respect to a base level some 400 m above the present level of surrounding glaciers has produced some pyramidal landforms. Just above the present ice level, however, narrow Richter denudation slopes that border weathering rock faces are at only a juvenile stage of development. Thus the ice level appears to have stood alternately at about its present position and 400 m higher in Pleistocene interglacials and glacial ages respectively. The higher ice levels must have been due to extensions of the ice sheet seaward caused by groundings of the shelf ice during low glacio-eustatic stands of sea leve

Aerodynamic shape optimization of a low drag fairing for small livestock trailers

Small livestock trailers are commonly used to transport animals from farms to market within the United Kingdom. Due to the bluff nature of these vehicles there is great potential for reducing drag with a simple add-on fairing. This paper explores the feasibility of combining high-fidelity aerodynamic analysis, accurate metamodeling, and efficient optimization techniques to find an optimum fairing geometry which reduces drag, without significantly impairing internal ventilation. Airflow simulations were carried out using Computational Fluid Dynamics (CFD) to assess the performance of each fairing based on three design variables. A Moving Least Squares (MLS) metamodel was built on a fifty-point Optimal Latin Hypercube (OLH) Design of Experiments (DoE), where each point represented a different geometry configuration. Traditional optimization techniques were employed on the metamodel until an optimum geometrical configuration was found. This optimum design was tested using CFD and it matched closely to the metamodel prediction. Further, the drag reduction was measured at 14.4% on the trailer and 6.6% for the combined truck and trailer

Ventilation of small livestock trailers

A large number of livestock is transported to market in small box trailers. The welfare of animals transported in this way is now assuming greater importance with the onset of tougher EU legislation. This paper presents the first study into the ventilation of small livestock trailers using experimental and computational methods. Wind tunnel studies, using a 1/7th scale model, highlight the important influence of the towing vehicle and trailer design on the airflow within the trailer. Detailed CFD analysis agrees well with the wind tunnel data and offers the ability to assess the impact of design changes

Registration of GEMS-0001 Maize Germplasm Resistant to Leaf Blade, Leaf Sheath, and Collar Feeding by European Corn Borer

This article is from Crop Science 41 (2001): 1651–1652, doi:10.2135/cropsci2001.4151651x.</p