1,367 research outputs found
Radical theory in BCH-algebras
The notion of k-nil radical in BCH-algebras is
defined, and related properties are investigated
Effect of mineral fertilizer, pig manure, and Azospirillum rugosum on growth and nutrient contents of Lactuca sativa L
Benefits from the application of plant growth-promoting bacteria in agriculture largely depend on the complex interactions between several factors including the nature of fertilizers selected. This study was designed to determine the fine tuning between the inoculated bacteria and different fertilizers and their effect on the growth of lettuce plants (Lactuca sativa L.). Plant growth promotion by a novel species of the genus Azospirillum, namely A. rugosum IMMIB AFH-6, was tested by biochemical, bioassay, and greenhouse studies. The treatments used in the greenhouse study were; unfertilized control (Blank), half recommended dose of chemical fertilizer (1/2CF), full recommended dose of chemical fertilizer (1CF), pig manure fertilizer (PMF), pig manure fertilizer + half recommended dose of chemical fertilizer (PMF + 1/2CF), and pig manure fertilizer + full recommended dose of chemical fertilizer (PMF + 1CF). All these treatments when inoculated with A. rugosum IMMIB AFH-6 inoculation were, respectively, In-Blank, In-1/2CF, In-1CF, In-PMF, In-PMF + 1/2CF, and In-PMF + 1CF. Significant increase in plant biomass and shoot N, P, Ca, and Fe was shown in the In-Blank treatment. Plant growth in soil amended with PMF and A. rugosum IMMIB AFH-6 was significantly lower than in soil treated with the chemical fertilizer, but inoculation combined with chemical fertilizer significantly elevated the plant biomass. The In-PMF + 1/2CF treatment showed the highest yield. A. rugosum IMMIB AFH-6 facilitated the accumulation of trace minerals in higher concentrations when PMF was combined with 1CF. To examine the benefits of inoculation by A. rugosum IMMIB AFH-6, we have proposed a new type of data analysis which considers both biomass and nutrient content of plants. This new type of analysis has shown the importance of the mineral content of plant
On the Optimum Long Baseline for the Next Generation Neutrino Oscillation Experiments
For high energy long baseline neutrino oscillation experiments, we propose a
Figure of Merit criterion to compare the statistical quality of experiments at
various oscillation distances under the condition of identical detectors and a
given neutrino beam. We take into account all possible experimental errors
under general consideration. In this way the Figure of Merit is closely related
to the usual statistical criterion of number of sigmas. We use a realistic
neutrino beam for an entry level neutrino factory and a possible superbeam from
a meson source and a 100 kt detector for the calculation. We considered in
detail four oscillation distances, 300 km, 700 km, 2100 km and 3000 km, in the
neutrino energy range of 0.5-20 GeV for a 20 GeV entry level neutrino factory
and a 50 GeV superbeam. We found that the very long baselines of 2100 km and
3000 km are preferred for the neutrino factory according to the figure of merit
criterion. Our results also show that, for a neutrino factory, lower primary
muon energies such as 20 GeV are preferred rather than higher ones such as 30
or 50 GeV. For the superbeam, the combination of a long baseline such as 300 km
and a very long baseline like 2100 km will form a complete measurement of the
oscillation parameters besides the CP phase. To measure the CP phase in a
superbeam, a larger detector (a factor 3 beyond what is considered in this
article) and/or a higher intensity beam will be needed to put some significant
constraints on the size of the CP angle.Comment: 21 LaTeX pages, 13 PS figures, typos corrected, references adde
An Optical Readout TPC (O-TPC) for Studies in Nuclear Astrophysics With Gamma-Ray Beams at HIgS
We report on the construction, tests, calibrations and commissioning of an
Optical Readout Time Projection Chamber (O-TPC) detector operating with a
CO2(80%) + N2(20%) gas mixture at 100 and 150 Torr. It was designed to measure
the cross sections of several key nuclear reactions involved in stellar
evolution. In particular, a study of the rate of formation of oxygen and carbon
during the process of helium burning will be performed by exposing the chamber
gas to intense nearly mono-energetic gamma-ray beams at the High Intensity
Gamma Source (HIgS) facility. The O-TPC has a sensitive target-drift volume of
30x30x21 cm^3. Ionization electrons drift towards a double parallel grid
avalanche multiplier, yielding charge multiplication and light emission.
Avalanche induced photons from N2 emission are collected, intensified and
recorded with a Charge Coupled Device (CCD) camera, providing two-dimensional
track images. The event's time projection (third coordinate) and the deposited
energy are recorded by photomultipliers and by the TPC charge-signal,
respectively. A dedicated VME-based data acquisition system and associated data
analysis tools were developed to record and analyze these data. The O-TPC has
been tested and calibrated with 3.183 MeV alpha-particles emitted by a 148Gd
source placed within its volume with a measured energy resolution of 3.0%.
Tracks of alpha and 12C particles from the dissociation of 16O and of three
alpha-particles from the dissociation of 12C have been measured during initial
in-beam test experiments performed at the HIgS facility at Duke University. The
full detection system and its performance are described and the results of the
preliminary in-beam test experiments are reported.Comment: Supported by the Richard F. Goodman Yale-Weizmann Exchange Program,
ACWIS, NY, and USDOE grant Numbers: DE-FG02-94ER40870 and DE-FG02-97ER4103
Optimizing tuning masses for helicopter rotor blade vibration reduction including computed airloads and comparison with test data
The development and validation of an optimization procedure to systematically place tuning masses along a rotor blade span to minimize vibratory loads are described. The masses and their corresponding locations are the design variables that are manipulated to reduce the harmonics of hub shear for a four-bladed rotor system without adding a large mass penalty. The procedure incorporates a comprehensive helicopter analysis to calculate the airloads. Predicting changes in airloads due to changes in design variables is an important feature of this research. The procedure was applied to a one-sixth, Mach-scaled rotor blade model to place three masses and then again to place six masses. In both cases the added mass was able to achieve significant reductions in the hub shear. In addition, the procedure was applied to place a single mass of fixed value on a blade model to reduce the hub shear for three flight conditions. The analytical results were compared to experimental data from a wind tunnel test performed in the Langley Transonic Dynamics Tunnel. The correlation of the mass location was good and the trend of the mass location with respect to flight speed was predicted fairly well. However, it was noted that the analysis was not entirely successful at predicting the absolute magnitudes of the fixed system loads
Some general properties of the renormalized stress-energy tensor for static quantum states on (n+1)-dimensional spherically symmetric black holes
We study the renormalized stress-energy tensor (RSET) for static quantum
states on (n+1)-dimensional, static, spherically symmetric black holes. By
solving the conservation equations, we are able to write the stress-energy
tensor in terms of a single unknown function of the radial co-ordinate, plus
two arbitrary constants. Conditions for the stress-energy tensor to be regular
at event horizons (including the extremal and ``ultra-extremal'' cases) are
then derived using generalized Kruskal-like co-ordinates. These results should
be useful for future calculations of the RSET for static quantum states on
spherically symmetric black hole geometries in any number of space-time
dimensions.Comment: 9 pages, no figures, RevTeX4, references added, accepted for
publication in General Relativity and Gravitatio
Deinococcus ficus sp nov., isolated from the rhizosphere of Ficus religiosa L
A pale-pink strain (CC-FR2-10(T)) from the rhizosphere of the sacred tree Ficus religiosa L. in Taiwan was investigated by using a polyphasic taxonomic approach. The cells were Gram-positive, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Deinococcus, the highest sequence similarities being found with Deinococcus grandis (96.1%), Deinococcus radiodurans (94.3%),Deinococcus radiopugnans (93.2%), Deinococcus indicus (93.0%), Deinococcus proteolyticus (92.5%), Deinococcus murrayi (92.4%) and Deinococcus geothermalis (90.7%). The DNA-DNA relatedness with respect to D. grandis DSM 3963(T) was 17.9%. Chemotaxonomic data revealed that strain CC-FR2-10(T) contains only menaquinone MK-8 as the respiratory quinone, unknown phosphoglycolipids as the predominant polar lipids and 16:1 omega 7c, 17:1 omega 8c and 17:1 omega 9c iso as the predominant fatty acids. The biochemical and chemotaxonomic properties demonstrate that strain CC-FR2-10(T) represents a novel species, for which the name Deinococcus ficus sp. nov. is proposed. The type strain is CC-FR2-10(T) (= CCUG 53391(T) = CIP 108832(T))
Transfer of Flexibacter sancti, Flexibacter filiformis, Flexibacter japonensis and Cytophaga arvensicola to the genus Chitinophaga and description of Chitinophaga skermanii sp nov
Analysis of the 16S rRNA gene sequences of species currently assigned to the genus Flexibacter has shown extensive intrageneric phylogenetic heterogeneity. It has been shown in previous studies that the species [Flexibacter] sancti, [Flexibacter] filiformis and [Flexibacter] japonensis were most closely related to Chitinophaga pinensis. In addition, [Cytophaga] arvensicola and species of the genus Terrimonas also clustered into this phylogenetic group. Although the similarities of 16S rRNA gene sequences were low (88.5-96.4%), there is no evidence for clear phenotypic differences between these organisms that justify assignment to different genera. A proposal is made to transfer these species to the genus Chitinophaga as Chitinophaga sancti comb. nov., Chitinophaga filiformis comb. nov., Chitinophaga japonenis comb. nov. and Chitinophaga arvensicola comb. nov. on the basis of phylogenetic and phenotypic data. Furthermore, a novel species is described within this genus, Chitinophaga skermanii sp. nov., with strain CC-SG1B(T) (=CCUG 52510(T)=CIP 109140(T)) as the type strain
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