1,863 research outputs found
Confirmation of Parity Violation in the Gamma Decay of
This paper reports measurements using the technique of On Line Nuclear
Orientation (OLNO) which reexamine the gamma decay of isomeric Hf and specifically the 501 keV 8 -- 6
transition. The irregular admixture of E2 to M2/E3 multipolarity in this
transition, deduced from the forward-backward asymmetry of its angular
distribution, has for decades stood as the prime evidence for parity mixing in
nuclear states. The experiment, based on ion implantation of the newly
developed mass-separated Hf beam at ISOLDE, CERN into an
iron foil maintained at millikelvin temperatures, produces higher degrees of
polarization than were achieved in previous studies of this system. The value
found for the E2/M2 mixing ratio, = -0.0324(16)(17), is in close
agreement with the previous published average value = - 0.030(2), in
full confirmation of the presence of the irregular E2 admixture in the 501 keV
transition. The temperature dependence of the forward-backward asymmetry has
been measured over a more extended range of nuclear polarization than
previously possible, giving further evidence for parity mixing of the 8 and 8 levels and the deduced E2/M2 mixing ratio.Comment: 28 pages, 9 figures, accepted for publication in Physical Review
Circle grid fractal plate as a turbulent generator for premixed flame: an overview
This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid.
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A Case for Renewed Activity in the Giant Radio Galaxy J0116-473
We present ATCA radio observations of the giant radio galaxy J0116-473 at 12
and 22 cm wavelengths in total intensity and polarization. The images clearly
reveal a bright inner-double structure within more extended edge-brightened
lobe emission. The lack of hotspots at the ends of the outer lobes, the strong
core and the inner-double structure with its edge-brightened morphology lead us
to suggest that this giant radio galaxy is undergoing a renewed nuclear
activity: J0116-473 appears to be a striking example of a radio galaxy where a
young double source is evolving within older lobe material. We also report the
detection of a Mpc-long linear feature which is oriented perpendicular to the
radio axis and has a high fractional polarization.Comment: 25 pages, 10 figures, appeared in 2002 ApJ, 565, 25
De novo 7p partial trisomy characterized by subtelomeric FISH and whole-genome array in a girl with mental retardation
Chromosome rearrangements involving telomeres have been established as one of the major causes of idiopathic mental retardation/developmental delay. This case of 7p partial trisomy syndrome in a 3-year-old female child presenting with developmental delay emphasizes the clinical relevance of cytogenetic diagnosis in the better management of genetic disorders. Application of subtelomeric FISH technique revealed the presence of interstitial telomeres and led to the ascertainment of partial trisomy for the distal 7p segment localized on the telomeric end of the short arm of chromosome 19. Whole-genome cytogenetic microarray-based analysis showed a mosaic 3.5 Mb gain at Xq21.1 besides the approximately 24.5 Mb gain corresponding to 7p15.3- > pter. The possible mechanisms of origin of the chromosomal rearrangement and the clinical relevance of trisomy for the genes lying in the critical regions are discussed
Nucleotide analysis of pome fruit virus isolates detected in apple and pear samples from Italy and India
In the framework of a joint research project between Italy and India field surveys were done in different pear and apple growing areas of North of India and Central and Southern Italy. Samples were collected from plants belonging to common and local varieties and molecularly analyzed for the detection of the main pome fruit viruses (Apple stem pitting virus, Apple stem groving virus, Apple chlorotic leaf spot virus, Apple mosaic virus) by using harmonized diagnostic protocols.The sequence homology was evaluated and a phylogenetic tree was built, on the basis of which, the Indian isolate of ASGV showed maximum sequence identity at a nucleotide level to Italian isolates when analyzed by BLAST (http://blast.ncbi.nlm.nih.gov/Blast.cgi). Similarly, a maximum identity, ranging from 90-93%, was found for the Italian isolates of ASPV and pear and apple isolates from Poland, while a sequence homology ranging from 83 to86% was observed within the Indian isolates of ASPV. Multiple alignment of the Indian pome ACLSV-isolates indicate maximum variability in the middle portion while the first 140 nucleotides are maximally conserved and shared a percent identity at nucleotide level of 86-100% with the Italian isolates.The ApMV Indian isolates showed maximum (92-99%) sequence homology to the Korean isolate (AY125977) from apple. However, a comparison with other isolates from different host plant species revealed a clustering of Indian isolates with a Czech isolate from pear and a sequence homology of 84 to 98%. Phylogenetic analysis showed that sequence variability was independent to the geographical origin or the host for all the investigated viruses.Keywords: ACLSV, ASPV, ASGV, ApMV, sequences analysis, Italy, India
Preliminary Results on Irradiance Measurements from Lyra and Swap
International audienceThe first and preliminary results of the photometry of Large Yield Radiometer (LYRA) and Sun Watcher using Active Pixel system detector and Image Processing (SWAP) onboard PROBA2 are presented in this paper. To study the day-to-day variations of LYRA irradiance, we have compared the LYRA irradiance values (observed Sun as a star) measured in Aluminum filter channel (171 Å-500 Å) with spatially resolved full-disk integrated intensity values measured with SWAP (174 Å) and Ca II K 1 Å index values (ground-based observations from NSO/Sac Peak) for the period from 01 April 2010 to 15 Mar 2011. We found that there is a good correlation between these parameters. This indicates that the spatial resolution of SWAP complements the high temporal resolution of LYRA. Hence SWAP can be considered as an additional radiometric channel. Also the K emission index is the integrated intensity (or flux) over a 1 Å band centered on the K line and is proportional to the total emission from the chromosphere; this comparison clearly explains that the LYRA irradiance variations are due to the various magnetic features, which are contributing significantly. In addition to this we have made an attempt to segregate coronal features from full-disk SWAP images. This will help to understand and determine the actual contribution of the individual coronal feature to LYRA irradiance variations
GCIP water and energy budget synthesis (WEBS)
As part of the World Climate Research Program\u27s (WCRPs) Global Energy and Water-Cycle Experiment (GEWEX) Continental-scale International Project (GCIP), a preliminary water and energy budget synthesis (WEBS) was developed for the period 1996–1999 from the “best available” observations and models. Besides this summary paper, a companion CD-ROM with more extensive discussion, figures, tables, and raw data is available to the interested researcher from the GEWEX project office, the GAPP project office, or the first author. An updated online version of the CD-ROM is also available at http://ecpc.ucsd.edu/gcip/webs.htm/. Observations cannot adequately characterize or “close” budgets since too many fundamental processes are missing. Models that properly represent the many complicated atmospheric and near-surface interactions are also required. This preliminary synthesis therefore included a representative global general circulation model, regional climate model, and a macroscale hydrologic model as well as a global reanalysis and a regional analysis. By the qualitative agreement among the models and available observations, it did appear that we now qualitatively understand water and energy budgets of the Mississippi River Basin. However, there is still much quantitative uncertainty. In that regard, there did appear to be a clear advantage to using a regional analysis over a global analysis or a regional simulation over a global simulation to describe the Mississippi River Basin water and energy budgets. There also appeared to be some advantage to using a macroscale hydrologic model for at least the surface water budgets
Exchange bias effect in alloys and compounds
The phenomenology of exchange bias effects observed in structurally
single-phase alloys and compounds but composed of a variety of coexisting
magnetic phases such as ferromagnetic, antiferromagnetic, ferrimagnetic,
spin-glass, cluster-glass and disordered magnetic states are reviewed. The
investigations on exchange bias effects are discussed in diverse types of
alloys and compounds where qualitative and quantitative aspects of magnetism
are focused based on macroscopic experimental tools such as magnetization and
magnetoresistance measurements. Here, we focus on improvement of fundamental
issues of the exchange bias effects rather than on their technological
importance
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