Climate variability as reflected in a regional atmospheric CO2 record

This paper analyses a 15-year long atmospheric CO2 mixing ratio record measured at a mid-continental, low-elevation station (Hegyhatsal, Hungary) to reveal the effect of regional climate variability. While the long-term trend and the temporal fluctuation of the growth rate of CO2 mixing ratio follow the global tendencies to a large extent, the shorter-term variations show special features. We present the distorted seasonal cycle caused by the seasonality in the atmospheric vertical mixing and the tendentious change in its shape, which can be attributed to the gradual warming and to the resulted prolongation of the growing season. The decreasing summer diurnal amplitude and the decreasing seasonal amplitude in the mixing ratio, furthermore the higher than average summer CO2 mixing ratio growth rate in the first period of the measurements (1994-2003) with generally rising temperature and decreasing precipitation are explained as the consequence of the reduced activity of the biosphere in the influence area of the station and that of the reduced biomass under environmental conditions getting increasingly unfavourable. The explanation is supported by the co-located tall tower surface-atmosphere CO2 exchange measurements and by the crop yield statistics of the dominantly agricultural region around the station

Integration of Virtual Reality Procedural Training in a Flight Training Curriculum

As Virtual Reality (VR) technology becomes more affordable, integrating VR training into pilot training programs is becoming a focus of many flight schools and universities. The purpose of this study is to investigate the impact of VR software and supporting devices as a familiarization and procedural trainer for private pilot students. This presentation will introduce the usage of the VR software for procedural training in the new private pilot training program implemented by the Embry-Riddle Aeronautical University’s Daytona Beach Campus Flight Department. In this program, new private pilot students partake in a month-long program to learn basic skills and knowledge to prepare them for their upcoming flight lessons. The presentation will cover: 1) A brief introduction to the Commercial Aviation Augmented Reality Toolkit (CAART) software, 2) An outline of how this software is used in the overall layout of the training course, 3) A description of the equipment used including examples and a display of each of the three types of training delivery methods, 4) A discussion of the research plan currently underway and 5) A synopsis of relevant preliminary data regarding the experiences of participants in relation to usability, presence, satisfaction, and simulator sickness. The presentation will cumulate in a discussion outlining future research plans

Carbon exchange of grass in Hungary

Continuous measurement of net biosphere-atmosphere carbon exchange was performed in western Hungary over a managed semi-natural grassland field using the eddy covariance technique to estimate Net Ecosystem Exchange (NEE). The paper presents the measuring site and instrumentation, as well as the data processing methods applied. The measurements covered the period March 1999 to December 2000 during which, on an annual time scale, the region acted as a net CO2 sink, where NEE was -54 g C m(-2) in 1999 (data for January and February were estimated) and -232 g C m(-2) in 2000 (negative NEE represents CO2 uptake by the vegetation). The remarkable inter-annual difference may be the result of the significant climate difference between 1999 and 2000

Quantum information analysis of electronic states at different molecular structures

We have studied transition metal clusters from a quantum information theory perspective using the density-matrix renormalization group (DMRG) method. We demonstrate the competition between entanglement and interaction localization. We also discuss the application of the configuration interaction based dynamically extended active space procedure which significantly reduces the effective system size and accelerates the speed of convergence for complicated molecular electronic structures to a great extent. Our results indicate the importance of taking entanglement among molecular orbitals into account in order to devise an optimal orbital ordering and carry out efficient calculations on transition metal clusters. We propose a recipe to perform DMRG calculations in a black-box fashion and we point out the connections of our work to other tensor network state approaches

Low-temperature specific heat in hydrogenated and Mn-doped La(Fe, Si)(13)

It is now well established that the paramagnetic-to-ferromagnetic transition in the magnetocaloric La(FeSi)13 is a cooperative effect involving spin, charge, and lattice degrees of freedom. However, the influence of this correlated behavior on the ferromagnetic state is as yet little studied. Here we measure the specific heat at low temperatures in a systematic set of LaFexMnySiz samples, with and without hydrogen, to extract the Sommerfeld coefficient, the Debye temperature, and the spin-wave stiffness. Substantial and systematic changes in magnitude of the Sommerfeld coefficient are observed with Mn substitution and introduction of hydrogen, showing that over and above the changes to the density of states at the Fermi energy there are significant enhanced d-band electronic interactions at play. The Sommerfeld coefficient is found to be 90–210mJmol−1K−2, unusually high compared to that expected from band-structure calculations. The Debye temperature determined from the specific heat measurement is insensitive to Mn and Si doping but increases when hydrogen is introduced into the system. The Sommerfeld coefficient is reduced in magnetic field for all compositions that have a measurable spin-wave contribution. These results move our understanding of the cooperative effects forward in this important and interesting class of materials significantly and provide a basis for future theoretical development