3,550 research outputs found
Mean-Field Approach to Charge, Orbital, and Spin Ordering in Manganites
We present a mean-field theory of charge, orbital, and spin ordering in
manganites at 50% and 0% dopings by considering Jahn-Teller interaction,
nearest-neighbor repulsion, and no single-site double occupancy. For spinless
fermions, we show that Jahn-Teller distortion and charge-orbital ordering occur
simultaneously. In our two-dimensional model at 50% doping, for small
nearest-neighbor repulsion the system is orbitally polarized while for larger
repulsion the system undergoes CE type ordering. As for the 0% doping case, the
ground state is orbitally antiferromagnetic. Upon including spin degree of
freedom, at both 50% and 0% dopings the ordering remains the same at small
antiferromagnetic coupling between adjacent core spins.Comment: 4 pages, 3 figure
Group Manifold Reduction of Dual N=1 d=10 Supergravity
We perform a group manifold reduction of the dual version of N=1 d=10
supergravity to four dimensions. The effects of the 3- and 4-form gauge fields
in the resulting gauged N=4 d=4 supergravity are studied in particular. The
example of the group manifold SU(2)xSU(2) is worked out in detail, and we
compare for this case the four-dimensional scalar potential with gauged N=4
supergravity.Comment: 22 pages, revised section 3, typos corrected. Published versio
ANTIDIABETIC AND HYPOLIPIDEMIC EFFECTS OF METHANOLIC EXTRACT OF VENTILAGO MADERASPATANA IN STREPTOZOTOCIN INDUCED DIABETIC RATS
This study evaluated methanolic extract of Ventilago maderaspatana (MVM) on reducing hyperglycemia and hyperlipidemia in streptozotocin -induced diabetic rats. MVM was orally administered once a day after 3 days of streptozotocin -induction at 100,200 and 400 mg/kg for 45 day and the results showed that serum fasting blood glucose, glucose – 6 – phosphotase , fructose 1, 6 –phosphotase in hepatic tissues ,total cholesterol,, free fatty acids and triglyceride in serum, HbA1c in blood levels were significantly decreased, whereas haemoglobulin in blood and serum high density lipoprotein, glucokinase, glucose – 6 – Phosphate dehydrogenase in hepatic tissues and liver and muscle glycogen level were increased. The dosage of 400 mg/kg is more effective than that of 100, 200 mg/kg. These results suggest that the MVM possesses antidiabetic and hypolipidemic effects in streptozotocin -induced diabetic rats. Key words:  Ventilago maderaspatana ,antihyperlipidemic ,antihyperglycemic and streptozotoci
MODELING NITROGEN LOADING RATE TO DELAWARE LAKES USING REGRESSION AND NEURAL NETWORKS
The objective of this research was to predict the nitrogen-loading rate to Delaware lakes and streams using regression analysis and neural networks. Both models relate nitrogen-loading rate to cropland, soil type and presence of broiler production. Dummy variables were used to represent soil type and the presence of broiler production at a watershed. Data collected by Ritter & Harris (1984) was used in this research. To build the regression model Statistical Analysis System (SAS) was used. NeuroShell Easy Predictor, neural network software was used to develop the neural network model. Model adequacy was established by statistical techniques. A comparison of the regression and neural network models showed that both perform equally well. Cropland was the only significant variable that had any influence on the nitrogen-loading rate according to both the models.Environmental Economics and Policy,
Ethnobotanical Observations on Some Endemic Plants of Eastern Ghats, India
The present paper reports ethnobotanical usage of 28 endemic plant species used by the tribes of Eastern Ghats, India. All the species were enumerated with botanical name, family name, vernacular name, habit, habitat and information on ethnic uses
Expression, Purification and Functional Antibacterial Characterization of Novel Antimicrobial Peptide Gene Pediocin against Salmonella typhii
Salmonella is known to be the major cause for the serious food infections prevailing round the world. Growing resistance to most of the antibiotics also makes the strain more problematic and threat. Food industry is experiencing a fatal loss both in terms of economy and the lives of cattle
Giant magnetoelectric effect in pure manganite-manganite heterostructures
Obtaining strong magnetoelectric couplings in bulk materials and
heterostructures is an ongoing challenge. We demonstrate that manganite
heterostructures of the form show strong multiferroicity
in magnetic manganites where ferroelectric polarization is realized by charges
leaking from to due to repulsion. Here, an
effective nearest-neighbor electron-electron (electron-hole) repulsion
(attraction) is generated by cooperative electron-phonon interaction. Double
exchange, when a particle virtually hops to its unoccupied neighboring site and
back, produces magnetic polarons that polarize antiferromagnetic regions. Thus
a striking giant magnetoelectric effect ensues when an external electrical
field enhances the electron leakage across the interface.Comment: 13 page
First Red List of Medicinal Plants of Andhra Pradesh, India - Conservation Assessment and Management Planning
The present article is based on the First Conservation Assessment and Management Planning (CAMP) workshop organized by Medicinal Plants Conservation Centre, Environment Protection Training and Research Institute, Hyderabad, India based on IUCN Red List categories - 2000. In the workshop 50 prioritised medicinal plant species found in Andhra Pradesh were assessed and out of these 39 found to be threatened in the State of Andhra Pradesh, India
Analysing the sensitivity of Arctic large-scale circulation to the regional radiation forcing over Europe using deep learning
The Arctic large-scale circulation is governed by a wide range of factor. In order to investigate the sensitivity of the Arctic large-scale circulation to the regional radiative forcing over Europe, we conducted sensitivity experiments using a state-of-the-art atmosphere-land-ocean coupled model. Using advanced Deep Learning (DL) algorithms, we analyzed the Arctic circulation regimes response to negative radiative forcing anomalies over Europe. We examined different architectures for our DL algorithm to find the most suitable one for our analysis. We simultaneously layer Thickness (300-700-T) and their spatiotemporal patterns with the DL algorithm. The DL algorithm showed good skills in capturing the general structure of the large-scale circulation. The radiative forcing over Europe doesn't seem to induce the occurrence frequency of preferred circulation regimes.Die arktische großräumige Zirkulation wird von einer Vielzahl von Faktoren bestimmt. Um die Sensitivität der arktischen großräumigen Zirkulation auf den regionalen Strahlungsantrieb über Europa zu untersuchen, haben wir Sensitivitätsexperimente mit einem hochmodernen gekoppelten Atmosphäre-Land-Ozean-Modell untersucht. Unter Verwendung neuer Deep-Learning-Algorithmen (DL) analysierten wir die Reaktion der arktischen Zirkulationsregime auf negativen Strahlungsantriebsanomalien über Europa. Wir haben verhsciedene Architekturen für unseren DL-Algorithmus untersucht, um die am besten geeignete für unsere Analyse zu finden. Wir haben die Felder des mittleren Drucks auf Meeresspiegelniveau und der Schichtdicke von 700 bis 300 hPa und ihre raumzeitlichen Muster mit dem DL-Algorithmus analysiert. Die DL-Algorithmen zeigten gute Ergebnisse bei der Erfassung der allgmeinen Struktur der großräumigen Zirkulation. Der Strahlungsantrieb über Europa scheint der großräumigen Zirkulation keine neuen raumzeitlichen Muster zuzufügen, veränderte aber die Häufigkeit des Auftretens bevorzugter Zirkulationsmuster
SAFER Inspection of Space Shuttle Thermal Protection System
In the aftermath of the space shuttle Columbia accident, it quickly became clear that new methods would need to be developed that would provide the capability to inspect and repair the shuttle's thermal protection system (TPS). A boom extension to the Remote Manipulator System (RMS) with a laser topography sensor package was identified as the primary means for measuring the damage depth in acreage tile as well as scanning Reinforced Carbon- Carbon (RCC) surfaces. However, concern over the system's fault tolerance made it prudent to investigate alternate means of acquiring close range photographs and contour depth measurements in the event of a failure. One method that was identified early was to use the Simplified Aid For EVA Rescue (SAFER) propulsion system to allow EVA access to damaged areas of concern. Several issues were identified as potential hazards to SAFER use for this operation. First, the ability of an astronaut to maintain controlled flight depends upon efficient technique and hardware reliability. If either of these is insufficient during flight operations, a safety tether must be used to rescue the crewmember. This operation can jeopardize the integrity of the Extra-vehicular Mobility Unit (EMU) or delicate TPS materials. Controls were developed to prevent the likelihood of requiring a tether rescue, and procedures were written to maximize the chances for success if it cannot be avoided. Crewmember ability to manage tether cable tension during nominal flight also had to be evaluated to ensure it would not negatively affect propellant consumption. Second, although propellant consumption, flight control, orbital dynamics, and flight complexity can all be accurately evaluated in Virtual Reality (VR) Laboratory at Johnson Space Center, there are some shortcomings. As a crewmember's hand is extended to simulate measurement of tile damage, it will pass through the vehicle without resistance. In reality, this force will push the crewmember away from the vehicle, and could induce a moment which, if strong enough, could saturate the attitude control system in SAFER. This raises the concern that additional propellant will be consumed to maintain controlled flight. To account for this, the fidelity of the Virtual Reality simulation was improved to include the effect of crewmember contact with the vehicle during SAFER flight. In addition, while participating in VR simulations, the subject is in shirt sleeves and sits in a chair. This does not provide a flight-like representation of body position awareness. To prevent inadvertent contact with tile or RCC, other facilities were utilized to establish crew preferences for body attitude and tool configuration. Finally, a study was performed to determine if attitude constraints are needed for the Space shuttle and International Space Station to reduce SAFER flight difficulty
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