2,037 research outputs found
Validating and Implementing Modified Filinov Phase Filtration in Semiclassical Dynamics
The Mixed Quantum-Classical Initial Value Representation (MQC-IVR) is a
recently introduced approximate semiclassical (SC) method for the calculation
of real-time quantum correlation functions. MQC-IVR employs a modified Filinov
filtration (MFF) scheme to control the overall phase of the SC integrand,
extending the applicability of SC methods to complex systems while retaining
their ability to accurately describe quantum coherence effects. Here, we
address questions regarding the effectiveness of the MFF scheme in combination
with SC dynamics. Previous work showed that this filtering scheme is of limited
utility in the context of semiclassical wavepacket propagation, but we find the
MFF is extraordinarily powerful in the context of correlation functions. By
examining trajectory phase and amplitude contributions to the real-time SC
correlation function in a model system, we clearly demonstrate that the MFF
serves to reduce noise by damping amplitude only in regions of highly
oscillatory phase leading to a reduction in computational effort while
retaining accuracy. Further, we introduce a novel and efficient MQC-IVR
formulation that allows for linear scaling in computational cost with the total
simulation length, a significant improvement over the more-than quadratic
scaling exhibited by the original method.Comment: 8 pages, 3 figure
Bleaching of Sunflower Waste Oil by Absorption on Activated Carbon and Improved by Ozonisation
The present investigation attempts to bleach the sunflower waste oil which can be reused for many industrial applications. A comprehensive bleaching technology developed with activated carbon and liquid ozone under laboratory condition. Laboratory bleaching was performed with different concentrations of activated carbon (w/v) in a round bottom flask under a vacuum. During the bleaching process, coloring pigments like carotenoids, chlorophylls, gossypol, peroxides and other impurities are removed from the edible oil using activated carbon. The bleached oil was retreated with different concentrations of liquid ozone and incubated at room temperature (270C) for 24 to 120 hrs. The retreated oil samples were drawn at every interval of 24 hrs, analyzed and the bleaching capacity were measured with UV-VIS Spectrometer to measure light absorbance in the visible region at 455 nm. The absorbance values decreased with respect to the increased mass of activated carbon (w/v in %) and liquid ozone. Bleaching of crude oil with activated carbon and liquid ozone are affordable method for sunflower waste oil management and recycling
Theory of Strain-Controlled Magnetotransport and Stabilization of the Ferromagnetic Insulating Phase in Manganite Thin Films
We show that applying strain on half-doped manganites makes it possible to
tune the system to the proximity of a metal-insulator transition and thereby
generate a colossal magnetoresistance (CMR) response. This phase competition
not only allows control of CMR in ferromagnetic metallic manganites but can be
used to generate CMR response in otherwise robust insulators at half-doping.
Further, from our realistic microscopic model of strain and magnetotransport
calculations within the Kubo formalism, we demonstrate a striking result of
strain engineering that, under tensile strain, a ferromagnetic charge-ordered
insulator, previously inaccessible to experiments, becomes stable
Effect of salinity stress on the life history variables of Branchipus schaefferi Fisher, 1834 (Crustacea: Anostraca)
BACKGROUND: Freshwater anostracans inhabit ephemeral water bodies in which as the water level decreases due to evaporation the salt concentration increases. Thus, for most anostracans salinity becomes the major stress factor. RESULTS: We tested five concentrations of NaCl (0 to 8 g/l) on the life table demography of Branchipus schaefferi fed Chlorella (alga). Age-specific survivorship curves of male and female B. schaefferi showed nearly a similar pattern in that increased salt concentration resulted in decreased survivorship. The age-specific reproduction (m(x)) of females showed several peaks of cyst production at 0 and 1 g/l salinity while in treatments containing salt at 4 or 8 g/l, there were fewer peaks. Average lifespan, life expectancy at birth, gross and net reproductive rates, generation time and the rate of population increase were all significantly influenced by the salt concentration in the medium. The highest value of net reproductive rate (970 cysts/female) was in treatments containing 0 g/l of salt, while the lowest was 13 cysts/female at 8 g/l. The rate of population increase (r) varied from 0.52 to 0.32 per day depending on the salt concentration in the medium. CONCLUSION: The low survival and offspring production of B. schaefferi at higher salinity levels suggests that this species is unlikely to colonize inland saline water bodies. Therefore, the temporary ponds in which it is found, proper conservative measures must be taken to protect this species
Impact assessment of heavy metals pollution of Vartur lake, Bangalore
The unscientific disposal of wastes and pollution in urban water bodies has caused immense problems not only to human beings but also to the aquatic biodiversity. Assessment of heavy metals in Vartur Lake, Bangalore, revealed that Cadmium (Cd), Cobalt (Co), Chromium (Cr), Nickel (Ni), and Lead (Pb) all exceeded drinking water standards. Nevertheless, Chromium (Cr) exceeded the CPCB’s tolerance limits for water bodies subjected to effluent discharge. In Eichornia crassipes, Cd, Co, Cr, and Ni were critical. In the sediments, Cadmium (Cd) and Nickel (Ni) exceeded the Probable Effect Level (PEL). Sediment Geo-accumulation Index of the lake showed moderate contamination with Mn, Cu, and Pb. Cr had the highest plant/sediments metal concentration factor even though its bioavailability in plants (71.5 ppm) was lower compared to Manganese (192.3 ppm). This calls for immediate action to be implemented to carry out necessary environmental mitigation measures for the lake
Chemical and Nutrient Composition of Selected Banana Varieties of Kerala
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Many studies shows that banana is richest source of various nutrients which having the health beneficial for humans. The chemical and nutrient compositions of eight banana varieties were studied. TSS was found to be more in Kadali (23.900 Brix) followed by Rasakadali (23.830 Brix) and Nendran (220 Brix). Maximum Acidity was noticed in Poovan (1.28%). The variety Nendran exhibited highest carbohydrate content (41.33g/100g) where as protein content was found to be higher in variety Poovan (1.37g/100g). Total mineral content of banana varieties ranged between 0.17g- 0.70g/100g and varieties such as Rasakadali (260 mg/100g) and Nendran ( 546.66 mg/100g) exhibited highest content of Na and K respectively. The calcium content of the selected banana varieties ranged between 0.35-1.35 mg/ 100g
Phytoplankton functional types
The term “functional types” emerged from biogeochemical studies. It represents the
group of organisms that share common characteristic role in biogeochemical functions. In
ecology, a functional type or group represents an aggregation of organisms according to
some well-defined property that sets a role or “function” for them in a system. Phytoplankton
Functional types (PFT) are defined as a group of organisms (irrespective of taxonomic
affiliation) that carry out a particular chemical process such as calcification, silicification,
nitrogen fixation, or dimethyl sulfide production; they are also referred to as “biogeochemical
guilds”. For example, in Nitrogen-Phytoplankton-Zooplankton (NPZ) models, P and Z are
representatives of functional types, i.e., producers and consumers. This aggregation is
acceptable for some applications, but may be too coarse or even inappropriate for others
Bose Hubbard Models with Synthetic Spin-Orbit Coupling: Mott Insulators, Spin Textures and Superfluidity
Motivated by the experimental realization of synthetic spin-orbit coupling
for ultracold atoms, we investigate the phase diagram of the Bose Hubbard model
in a non-abelian gauge field in two dimensions. Using a strong coupling
expansion in the combined presence of spin-orbit coupling and tunable
interactions, we find a variety of interesting magnetic Hamiltonians in the
Mott insulator (MI), which support magnetic textures such as spin spirals and
vortex and Skyrmion crystals. An inhomogeneous mean field treatment shows that
the superfluid (SF) phases inherit these exotic magnetic orders from the MI and
display, in addition, unusual modulated current patterns. We present a slave
boson theory which gives insight into such intertwined spin-charge orders in
the SF, and discuss signatures of these orders in Bragg scattering, in situ
microscopy, and dynamic quench experiments.Comment: 4 pages + references + supplementary inf
Heavy metals accumulation in macrophytes in the lakes of Bangalore urban
This study was mainly focused upon the impact of heavy metals pollution (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in aquatic macrophytes of the littoral zones of the lakes of Bangalore Urban region. The heavy metals concns. were as follows: Manganese (257.6 ± 39.6) ppm; Lead (66 ± 12.5)ppm; Chromium (64.9 ± 6.2); Nickel (42.3 ± 3.2), Cobalt (18.8 ± 4.0) and Cadmium (4.7 ± 0.7). Copper, Manganese and Zinc were largely within normal range while Chromium, Lead, Cobalt and Nickel were in crit. range. There were more statistically significant correlations between metals in the dry than in the west sea..
Phytochemical Analysis of Selected Banana Varieties
The word “banana” is a general term comprising a number of species or hybrids in the genus Musa of family Musaceae. Many studies reported that banana is a good source of phenolic compounds, which are having potential health benefits in human beings. The phytochemical composition of eight banana varieties was investigated. Quantitative estimation of phytochemicals revealed that highest alkaloid and tannin content was noticed in variety Nendran (3.76% and 4.40 mg/100g respectively). Whereas, variety Rasakadali exhibited highest flavonoid content (9.49 mg/100). Total phenol and saponin content was found higher in variety Kadali (0.82% and 11.6 mg/100g respectively)
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