33 research outputs found
First record of the family Penthaleidae (Acari) in Hungary: Morphological and Molecular approaches of the Hungarian Penthaleus cf. major (Dugès, 1837)
The first Hungarian record of the family Penthaleidae, the occurrence of blue oat mite [Penthaleus cf. major (Dugès, 1837)] in Hungary is presented. This pest mite species was collected on lettuce in greenhouse. Notes to the morphology and the three (cox 1, 18sRNA, ITS2) sequences of the Hungarian specimens are given
Radiological characterisation in view of nuclear reactor decommissioning: On-site benchmarking exercise of a biological shield
Nearly all decommissioning and dismantling (D&D) projects are steered by the characterisation of the plant being dismantled. This radiological characterisation is a complex process that is updated and modified during the course of the D&D. One of the tools for carrying out this characterisation is the performance of in-situ measurements.
There is a wide variety of equipment and methodologies used to carry out on-site measurements, depending on the environment in which they are to be carried out and also on the specific objectives of the measurements and the financial and personnel resources available. The extent to which measurements carried out with different types of equipment or methodologies providing comparable results can be crucial in view of the D&D strategy development and the decision-making process.
This paper concerns an on-site benchmarking exercise carried out at the activated biological shield of Belgian Reactor 3 (BR3). This activity allows comparison and validation of characterisation methodologies and different equipment used as well as future interpretation of final results in terms of uncertainties and sensitivities. This paper describes the measurements and results from the analysis of this exercise. Other aspects of this exercise will be reported in separate papers. This paper provides an overview of the on-site benchmarking exercise, outlines the participating organisations and the measurement equipment used for total gamma, dose rate and gamma spectrometry measurements and finally, results obtained and their interpretations are discussed for each type of measurement as a function of detector type.
Regarding the dose measurements, results obtained by using a large variety of equipment are very consistent. In view of mapping the inner surface of the biological shield the most appropriate equipment tested might be the organic scintillator, the BGO or even the ionisation chamber. In addition, for mapping this surface, the most appropriate total gamma equipment tested might be the LaBr(Ce), the thick organic scintillator or the BGO. These measurements can only be used as a secondary parameter in a relative way. Results for the gamma spectrometry are very consistent for all the equipment used and the main parameters to be determined
Laser-plasma accelerator-based single-cycle attosecond undulator source
Laser-plasma accelerators (LPAs), producing high-quality electron beams,
provide an opportunity to reduce the size of free-electron lasers (FELs) to
only a few meters. A complete system is proposed here, which is based on FEL
technology and consists of an LPA, two undulators, and other magnetic devices.
The system is capable to generate carrier-envelope phase stable attosecond
pulses with engineered waveform. Pulses with up to~60~nJ energy and 90
to~400~attosecond duration in the 30 to 120~nm wavelength range are predicted
by numerical simulation. These pulses can be used to investigate ultrafast
field-driven electron dynamics in matter.Comment: 6 pages, 4 figure
Abstracts of presentations on plant protection issues at the xth international congress of virology: August 11-16,1996 Binyanei haOoma, Jerusalem, Israel Part 2 Plenary Lectures
The participation of plant cell organelles in compatible and incompatible potato virus Y-tobacco and -potato plant interaction
Natural Virus Infection of Hedge Bindweed (Calystegia sepium)
Virus symptoms were observed on Hedge bindweed (Calystegia sepium) a well known plant in Hungary. In the literature there is no record of virus infection on Hedge bindweed, therefore, investigations were carried out to determine the causal agent. Sap from leaves showing virus-like symptoms was inoculated onto test plants inducing systemic infection on Nicotiana clevelandii, N. benthamiana, local lesions on Chenopodium quinoa and no infection on Datura stramonium and Cucumis sativus. Sap of N. clevelandii was examined by electron microscopy, showed the presence of long flexous particles. The biological and other properties of the virus have also been studied. Properties of particles in sap were as follows: TIP (thermal inactivation point): 78 °C, LIV (longevity in vitro): 26 days and DEP (dilution end point): log 10 minus 5. The size of coat protein is 36 kDa, and the genome consists of 7-8000 nt RNA. Double-stranded cDNA were produced using random hexanucleotide primers, cloned and sequenced. BLAST search of sequence databases revealed nucleotide sequence identity with carlaviruses. Further investigations are needed to decide whether the virus isolated from Hedge bindweed is a new carlavirus or a new strain of an existing carlavirus
Host range and number of generations of pea thrips (Kakothrips pisivorus westwood, 1880) (Thysanoptera: Thripidae) in Hungary
The Fabaceae species Lathyrus tuberosus, Vicia species and Coronilla varia, all of which have an extended flowering period, provide the larvae food and shelter long enough for the pea thrips Kakothrips pisivorus to complete its development, and to have two generations yearly. Although flowers of pea cultivars also confer suitable conditions for egg laying, their flowering period is rather short. Therefore, the larvae are forced to move to developing pea pods in damaging numbers, resulting in the development of only one generation yearly on pea. However, specimens of K. pisivorus are able to colonize pea cultivars that have a similar phenology as Lathyrus tuberosus. Here we show that Hungarian pea thrips populations having either one or two generations are genetically identical
Velocity matching by pulse front tilting for large-area THz-pulse generation
We propose a generally applicable velocity matching method for
THz-pulse generation by optical rectification in the range
below the phonon frequency of the nonlinear material. Velocity
matching is based on pulse front tilting of the ultrashort
excitation pulse and is able to produce a large-area THz beam.
Tuning of the THz radiation by changing the tilt angle is
experimentally demonstrated for a narrow line in the range
between 0.8-0.97 times the phonon frequency. According to model
calculations broad-band THz radiation can be generated at lower
frequencies. Advantages of the new velocity matching technique
in comparison to the electro-optic Cherenkov effect and non-
collinear beam mixing are discussed. (C) 2002 Optical Society
of America