Effect of niacin supplementation of stockers grazing tall fescue pastures

In three trials, there was no gain response by stockers offered supplemental niacin while grazing tall fescue pasture in the spring or fall. There was a trend toward lower body temperatures for niacin-supplemented cattle, but this was not significant. Niacin fed at 2 to 4 g per head daily did not reduce the fescue endophyte fungus problem

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

PLASMA-SURFACE INTERACTIONS 21 — Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014 The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the ondemand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER. 2014 Elsevier B.V. All rights reserved. 1. Introduction The H-mode confinement regime of plasma operation is planned for ITER in order to achieve high fusion performance. It is characterized by a steep pressure gradient and ‘‘pedestal’’ at the plasma edge that is expected to lead to the quasi-periodic instability of edgelocalized modes (ELMs) [1]. ELMs expel periodic bursts of particles and energy from the plasma, which if large enough can pose a serious threat to the PFCs by erosion and melting from the high heat fluxes an

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

PLASMA-SURFACE INTERACTIONS 21 — Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014 The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the ondemand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER. 2014 Elsevier B.V. All rights reserved. 1. Introduction The H-mode confinement regime of plasma operation is planned for ITER in order to achieve high fusion performance. It is characterized by a steep pressure gradient and ‘‘pedestal’’ at the plasma edge that is expected to lead to the quasi-periodic instability of edgelocalized modes (ELMs) [1]. ELMs expel periodic bursts of particles and energy from the plasma, which if large enough can pose a serious threat to the PFCs by erosion and melting from the high heat fluxes an

Imazethapyr persistence in sandy loam detected using white mustard bioassay

Field experiments were conducted during two years at Srem region to investigate the influence of meteorological conditions, time and rate of application on soil persistence of imazethapyr in sandy loam type of soil. Imazethapyr was applied PRE- and POST-EM and in both cases in three application rates: 80, 120 and 160g a.i./ha. Soil samples were collected from the day of herbicide application in predetermined intervals up to one year after application and residual concentrations were determined with a white mustard root bioassay. Imazetapyr persistence was significantly influenced by meteorological conditions with average half-life being 6days longer in season with lower precipitation level. Time of application induced slower imazethapyr dissipation resulting in higher average t(1/2) (seven and nine days in first and second year of examination, respectively). Application rates had no consistent effect on imazethapyr persistence. Imazethapyr residue level one year after application caused no visible injuries on white mustard shoots, while root growth reduction ranged from 4.6 to 27.7%. Obtained residue levels were further compared with known data on crop sensitivity in order to assess possibility of crop injuries one year after imazethapyr application