3,423 research outputs found
Spin, charge and orbital ordering in La0.5Sr1.5MnO4
We have analyzed the experimental evidence of charge and orbital ordering in
La0.5Sr1.5MnO4 using first principles band structure calculations. Our results
suggest the presence of two types of Mn sites in the system. One of the Mn
sites behaves like an Mn(3+) ion, favoring a Jahn-Teller distortion of the
surrounding oxygen atoms, while the distortion around the other is not a simple
breathing mode kind. Band structure effects are found to dominate the
experimental spectrum for orbital and charge ordering, providing an alternate
explanation for the experimentally observed results.Comment: 4 pages + 3 figures; To appear in Phys. Rev. Let
LAND TRANSFORMATION: A THREAT ON BANGALORE’S ECOLOGY - A CHALLENGE FOR SUSTAINABLE DEVELOPMENT
Land constitutes the most important character for sustainable development in a region. Rapid urbanization has become an area of crucial concern against the bonanza of urban ecology. The land use pattern of any urban area hints not only its immediate current space requirements of the inheriting community but rather the cumulative requirements over a period of year. Thus, the way a land use changes into, reveals a physical transformation of its economic use that indirectly unveils the demand for built-up space and as a result, the urban ecology is in imbroglio. For much of human existence, the available land for human use has appeared limitless. Wherever population densities have risen too high, there is a decline noticed in resource base. People moved on to occupy new lands by extending the urban area into rural fringe. Land transformation as the word suggests, traces the change of form in the land use. Land use change is an inevitable phenomenon in an urban space. How the use of land changed from one to another is a problem that has interconnections with various entities and the interaction between them in spatio-temporal environment. Bangalore over the years has grown as a robust technology hub, and has been ever- growing in terms of urban space with its inhabits. How this growth has affected its ecological space is the thrust of the study. The ecology of this urban land constitutes of agricultural plantation, forest area and lakes which comprise the green and blue spots. The objectives are accomplished through Geoinformatics which is able to apprehend statistics of ecological to the urban environment.Environmental Degradation, GIS, Remote Sensing, Digital Image Processing, Urban Land Transformation Analysis.
Adoption Level of Farmers on Maize Cultivation Practices
The study to measure the extent of adoption level of maize production technologies has been conducted among the maize farmers in the Udumalpet block. The results of the study would help to know the adoption level of farmers which would had in designing suitable programmes to cater to the needs of the farmers. The results revealed that majority (64 per cent) of respondents belonged to the category of medium adoption level whereas, 23.30 per cent of the respondents belonged to the category of low adoption level and above one tenth (14 per cent) of respondents belonged to high adoption level category
A Fuzzy Logic based Privacy Preservation Clustering method for achieving K- Anonymity using EMD in dLink Model
Privacy preservation is the data mining technique which is to be applied on the databases without violating the privacy of individuals. The sensitive attribute can be selected from the numerical data and it can be modified by any data modification technique. After modification, the modified data can be released to any agency. If they can apply data mining techniques such as clustering, classification etc for data analysis, the modified data does not affect the result. In privacy preservation technique, the sensitive data is converted into modified data using S-shaped fuzzy membership function. K-means clustering is applied for both original and modified data to get the clusters. t-closeness requires that the distribution of sensitive attribute in any equivalence class is close to the distribution of the attribute in the overall table. Earth Mover Distance (EMD) is used to measure the distance between the two distributions should be no more than a threshold t. Hence privacy is preserved and accuracy of the data is maintained
Laminated chemical and physical micro-jet actuators based on conductive media
This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis discusses the development of both chemical and physical microactuators and characterizes their performance with focus towards the feasibility of using them for a specific application.
The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based micro fabrication techniques that potentially enable batch fabrication at low cost. The microactuators developed in this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. The fabricated actuators are then integrated with MEMS-process-compatible propellants and optimized to produce rapid ignition of the propellant and generate a fluidic jet. This rapid ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by placing it between two closely spaced electrodes. The first concept is demonstrated with chemical microactuators for the application of projectile maneuvering and the second concept is demonstrated with physical microactuators for transdermal drug delivery application. For both the actuators, the propellant integrated microactuators are characterized for performance in terms of impulse delivered, thrust generated and duration of the jet. The experimentally achieved results are validated by comparing with results from theoretical modeling. Finally, the feasibility of using chemical microactuators for maneuvering the path of a 25 mm projectile spinning at 500 Hz is discussed and the feasibility of applying the physical microactuators for increasing skin's permeability to drug analog molecules is studied.Ph.D.Committee Chair: Allen, Mark; Committee Member: Allen, Sue; Committee Member: Glezer, Ari; Committee Member: Koros, Williams; Committee Member: Prausnitz, Mar
Electronic Structure of Sr_2FeMoO_6
We have analysed the unusual electronic structure of Sr_2FeMoO_6 combining
ab-initio and model Hamiltonian approaches. Our results indicate that there are
strong enhancements of the intraatomic exchange strength at the Mo site as well
as the antiferromagnetic coupling strength between Fe and Mo sites. We discuss
the possibility of a negative effective Coulomb correlation strength (U_{eff})
at the Mo site due to these renormalised interaction strengths.Comment: To appear in Phys. Rev. Let
- …