11 research outputs found
The Influence of Pruning on Morphological and Architectural Characteristics of Camellia japonica L. in a Tropical Climate
The ornamental qualities of Camellia japonica have long been of interest to horticulturists. The European garden plant market has traditionally been characterized by erect, branched and flowered plants. More recently, a new market linked to increasing urbanization has developed for compact, highly branched and flowered plants to decorate balconies and patios. Two flushes are formed per year in temperate climates, and three years are required to obtain a garden plant. In the humid, tropical climate of Reunion Island, at an altitude of 700 m, three to four flushes are formed in a single growing season. Under these conditions and with no pruning, it is possible to produce an upright plant with a height of 48.5 cm and 7.5 branchings, adapted to the traditional garden market. With two prunings and the same growing period, a compact plant with a height of 25.4 and 17.0 branchings can be produced, adapted to the new balcony-patio market. In both cases, floral induction occurs in November when the nighttime temperature is above 15 degrees C. This research shows that it is possible to generate diversified and innovative forms of Camellia japonica with considerable marketing potential using adapted pruning and under appropriate climatic conditions
Global full-f gyrokinetic simulations of plasma turbulence
Critical physical issues can be specifically tackled with the global full-f gyrokinetic code GYSELA. Three main results are presented. First, the self-consistent treatment of equilibrium and fluctuations highlights the competition between two compensation mechanisms for the curvature driven vertical charge separation, namely, parallel flow and polarization. The impact of the latter on the turbulent transport is discussed. In the non-linear regime, the benchmark with the Particle-In-Cell code ORB5 looks satisfactory. Second, the transport scaling with p. is found to depend both on p. itself and on the distance to the linear threshold. Finally, a statistical steady-state turbulent regime is achieved in a reduced version of GYSELA by prescribing a constant heat source
Beyond scale separation in gyrokinetic turbulence
This paper presents the results obtained with a set of gyrokinetic codes based on a semi-Lagrangian scheme. Several physics issues are addressed, namely, the comparison between fluid and kinetic descriptions, the intermittent behaviour of flux driven turbulence and the role of large scale flows in toroidal ITG turbulence. The question of the initialization of full-F simulations is also discussed
Investigation of steady-state tokamak issues by long pulse experiments on Tore Supra
The main results of the Tore Supra experimental programme in the years 2007–2008 are reported. They document significant progress achieved in the domain of steady-state tokamak research, as well as in more general issues relevant for ITER and for fusion physics research. Three areas are covered: ITER relevant technology developments and tests in a real machine environment, tokamak operational issues for high power and long pulses, and fusion plasma physics. Results presented in this paper include test and validation of a new, load-resilient concept of ion cycotron resonance heating antenna and of an inspection robot operated under ultra-high vacuum and high temperature conditions; an extensive experimental campaign (5 h of plasma) aiming at deuterium inventory and carbon migration studies; real-time control of sawteeth by electron cyclotron current drive in the presence of fast ion tails; ECRH-assisted plasma start-up studies; dimensionless scalings of transport and turbulenc