Taking the design tolerance into account, this paper presents a novel efficient approach to generate iso-scallop tool path for five-axis strip machining with a barrel cutter. The cutter location is first determined on the scallop surface instead of the design surface, and then the cutter is adjusted to locate the optimal tool position based on the differential rotation of the tool axis and sati...

The effects of grazing rest on rangelands are different in different climates and knowledge of these effects is necessary to apply correct management. For this purpose, this study was carried out on the percent vegetation cover (PVC) and forage production (FP) of range species at the Nir Range Research Station in Yazd province as a model of steppe rangelands of Iran. In the study area, differen...

natural resources are valuable capitals for all nations. rangelands as the most extensive natural ecosystems in iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. although uncontrolled exploitation of these resources has imposed much pressure and caused many losses within the ecosystems. impacts of overutilization of nomadic ...

one of the key factors in managing a rangeland is to determine the relative preference of its major plant species by thegrazing livestock. preference value of each plant species is affected by plant type, companion plants, availability byanimals, phenological stage, climate condition, and the livestock species. we investigated the grazing behaviour of anative goat (garizi) in the steppe rangela...

 Phytoplankton growth and microzooplankton grazing were investigated at one station in the Homa Lagoon from February to January in 2006-2007. Our results showed significant seasonal variations in phytoplankton dynamics. Microzooplankton was mainly composed of dinoflagellates and tintinnid ciliates and nauplii. Microzooplankton grazing increased with increasing of temperature. Grazing ra...

three grass species, agropyron desertorum (agde) and agropyron elongatum (agel) and recently, bromus tomentellus (brto) are mainly used for range improvement as mixed seeding in semi-arid areas of iran. because there is little information about management of these grasses, this study was conducted at the sisab research station in northern iran to evaluate their responses to grazing management a...

Global biodiversity losses provide an immediate impetus to elucidate the relationships between biodiversity, productivity and stability. In this study, we quantified the effects of species richness and species combination on the productivity and stability of phytoplankton communities subject to predation by a single rotifer species. We also tested one mechanism of the insurance hypothesis: whet...

Mission planners can benefit from determining regions of space occluded by terrain from sensor positions, e.g. in order to determine ingress and egress paths. Conventional approaches to computing occlusion using 2D or 2.5D representations of terrain are inefficient and do not scale well. Binary Adaptive Ray Casting uses intersection calculations accelerated by 3D hierarchical bounding volumes t...

Rangelands are the most important ecosystem for carbon sequestration. Knowledge of plant response to grazing is one of important requirements for rangeland management. Stocking rate is one of main factors in destruction of the vegetation cover in rangeland ecosystems. Livestock grazing has the potential to substantially alter carbon storage in grassland ecosystem. This study examined the effect...