Specific interplanetary conditions for CIR-, Sheath-, and ICME-induced geomagnetic storms obtained by double superposed epoch analysis

The comparison of specific interplanetary conditions for 798 magnetic storms with Dst < -50 nT for the period 1976-2000 was made on the basis of the OMNI archive data.We categorized various large-scale types of solar wind as interplanetary drivers of storms: corotating interaction region (CIR), Sheath, interplanetary CME (ICME) including magnetic cloud (MC) and Ejecta, separately MC and Ejecta, and "Indeterminate" type. The data processing was carried out by the method of double superposed epoch analysis which uses two reference times (onset of storm and the minimum Dst index) and make a re-scaling of main phase of storm a such way that after this transformation all storms have equal durations of main phase in new time reference frame. This method reproduced some well-known results and allowed us to obtain some new results. Specifically, obtained results demonstrate high importance of Sheath in generation of magnetic storms as well as a significant differences in properties of MC and Ejecta and in their geoeffectiveness.Comment: 21 pages, 9 figures, 1 table, submitted to J. of Advances in Space Research on 29 July, 2009 for Special Issue "Space Weather Advances

Experimental investigation of the radial structure of energetic particle driven modes

Alfv\'en eigenmodes (AEs) and energetic particle modes (EPMs) are often excited by energetic particles (EPs) in tokamak plasmas. One of the main open questions concerning EP driven instabilities is the non-linear evolution of the mode structure. The aim of the present paper is to investigate the properties of beta-induced AEs (BAEs) and EP driven geodesic acoustic modes (EGAMs) observed in the ramp-up phase of off-axis NBI heated ASDEX Upgrade (AUG) discharges. This paper focuses on the changes in the mode structure of BAEs/EGAMs during the non-linear chirping phase. Our investigation has shown that in case of the observed down-chirping BAEs the changes in the radial structure are smaller than the uncertainty of our measurement. This behaviour is most probably the consequence of that BAEs are normal modes, thus their radial structure strongly depends on the background plasma parameters rather than on the EP distribution. In the case of rapidly upward chirping EGAMs the analysis consistently shows shrinkage of the mode structure. The proposed explanation is that the resonance in the velocity space moves towards more passing particles which have narrower orbit widths.Comment: submitted to Nuclear Fusio

Solvent extraction of PDMS tubing as a new method for the capture of volatile organic compounds from headspace

Polydimethylsiloxane (PDMS) tubing is increasingly being used to collect volatile organic compounds (VOCs) from static biological headspace. However, analysis of VOCs collected using PDMS tubing often deploys thermal desorption, where samples are considered as ‘one-offs’ and cannot be used in multiple experiments. In this study, we developed a static headspace VOC collection method using PDMS tubing which is solvent-based, meaning that VOC extracts can be used multiple times and can be linked to biological activity. Using a synthetic blend containing a range of known semiochemicals (allyl isothiocyanate, (Z)-3-hexen-1-ol, 1-octen-3-one, nonanal, (E)-anethol, (S)-bornyl acetate, (E)-caryophyllene and pentadecane) with differing chemical and physicochemical properties, VOCs were collected in static headspace by exposure to PDMS tubing with differing doses, sampling times and lengths. In a second experiment, VOCs from oranges were collected using PDMS sampling of static headspace versus dynamic headspace collection. VOCs were eluted with diethyl ether and analysed using gas chromatography – flame ionization detector analysis and coupled GC – mass spectrometry analysis. GC-FID analysis of collected samples showed that longer PDMS tubes captured significantly greater quantities of compounds than shorter tubes, and that sampling duration significantly altered the recovery of all tested compounds. Moreover, greater quantities of compounds were recovered from closed compared to open systems. Finally, analysis of orange headspace VOCs showed only a few qualitative differences in VOCs recovered compared to dynamic headspace collections, although quantities sampled using PDMS tubing were lower. In summary, extraction of PDMS tubing with diethyl ether solvent captures VOCs from the headspace of synthetic blends and biological samples, and the resulting extracts can be used for multiple experiments linking VOC content to biological activity

TUTORING AS A FORM OF PEDAGOGICAL SUPPORT OF STUDENTS’ INDIVIDUAL EDUCATIONAL TRAJECTORIES

Purpose: The key provisions on which the tutor relies on the context of his work are the principles underlying open education: transparency; flexibility; continuity; variability; individual approach; individualization. Methodology: The relevance of the study is associated with the processes characteristic of the school system in modern Russia (modernization, optimization, change in the structural foundations), as well as the objective need of society in the search for fundamentally new approaches to the content and construction of the educational process in the educational institution. Result: Tutoring should be considered as a resource of individual evolution of personality, as a form of productive exploitation of open education opportunities for the development of individual educational programs, taking into account the specifics of a particular student. As pedagogical conditions for the implementation of the model of tutor support of the formation of basic school students’ research skills should be considered: innovative educational environment; scientific and methodological provision of tutor support of the process of building basic school students’ research skills; professional skills of the tutor. Applications: This research can be used for universities, teachers, and students. Novelty/Originality: In this research, the model of Tutoring as a Form of Pedagogical Support of Students’ Individual Educational Trajectories is presented in a comprehensive and complete manner

Geoeffectiveness and efficiency of CIR, Sheath and ICME in generation of magnetic storms

We investigate relative role of various types of solar wind streams in generation of magnetic storms. On the basis of the OMNI data of interplanetary measurements for the period of 1976-2000 we analyze 798 geomagnetic storms with Dst < -50 nT and their interplanetary sources: corotating interaction regions (CIR), interplanetary CME (ICME) including magnetic clouds (MC) and Ejecta and compression regions Sheath before both types of ICME. For various types of solar wind we study following relative characteristics: occurrence rate; mass, momentum, energy and magnetic fluxes; probability of generation of magnetic storm (geoeffectiveness) and efficiency of process of this generation. Obtained results show that despite magnetic clouds have lower occurrence rate and lower efficiency than CIR and Sheath they play an essential role in generation of magnetic storms due to higher geoeffectiveness of storm generation (i.e higher probability to contain large and long-term southward IMF Bz component).Comment: 23 pages, 4 figures, 3 tables, submitted to JGR special issue "Response of Geospace to High-Speed Streams