Investigation of the magnetic structure and crystal field states of pyrochlore antiferromagnet Nd2Zr2O7

We present synchrotron x-ray diffraction, neutron powder diffraction and time-of-flight inelastic neutron scattering measurements on the rare earth pyrochlore oxide Nd2Zr2O7 to study the ordered state magnetic structure and cystal field states. The structural characterization by high-resolution synchrotron x-ray diffraction confirms that the pyrochlore structure has no detectable O vacancies or Nd/Zr site mixing. The neutron diffraction reveals long range all-in/all-out antiferromagnetic order below T_N ~ 0.4 K with propagation vector k = (0 0 0) and an ordered moment of 1.26(2) \mu_B/Nd at 0.1 K. The ordered moment is much smaller than the estimated moment of 2.65 \mu_B/Nd for the local Ising ground state of Nd3+ (J=9/2) suggesting that the ordering is partially suppressed by quantum fluctuations. The strong Ising anisotropy is further confirmed by the inelastic neutron scattering data which reveals a well-isolated dipolar-octupolar type Kramers doublet ground state. The crystal field level scheme and ground state wavefunction have been determined.Comment: 12 pages, 15 figures, 2 table

Physical Properties of Metallic Antiferromagnetic CaCo{1.86}As2 Single Crystals

We report studies of CaCo{1.86}As2 single crystals. The electronic structure is probed by angle-resolved photoemission spectroscopy (ARPES) measurements of CaCo{1.86}As2 and by full-potential linearized augmented-plane-wave calculations for the supercell Ca8Co15As16 (CaCo{1.88}As2). Our XRD crystal structure refinement is consistent with the previous combined refinement of x-ray and neutron powder diffraction data showing a collapsed-tetragonal ThCr2Si2-type structure with 7(1)% vacancies on the Co sites corresponding to the composition CaCo{1.86}As2 [D. G. Quirinale et al., Phys. Rev. B 88, 174420 (2013)]. The anisotropic magnetic susceptibility chi(T) data are consistent with the magnetic neutron diffraction data of Quirianale et al. that demonstrate the presence of A-type collinear antiferromagnetic order below the Neel temperature TN = 52(1) K with the easy axis being the tetragonal c axis. However, no clear evidence from the resistivity rho(T) and heat capacity Cp(T) data for a magnetic transition at TN is observed. A metallic ground state is demonstrated from band calculations and the rho(T), Cp(T) and ARPES data, and spin-polarized calculations indicate a competition between the A-type AFM and FM ground states. The Cp(T) data exhibit a large Sommerfield electronic coefficient reflecting a large density of states at the Fermi energy D(EF), consistent with the band structure calculations which also indicate a large D(EF) arising from Co 3d bands. At 1.8 K the M(H) data for H|| c exhibit a well-defined first-order spin-flop transition at an applied field of 3.5 T. The small ordered moment of 0.3 muB/Co obtained from the M(H) data at low T, the large exchange enhancement of chi and the lack of a self-consistent interpretation of the chi(T) and M(H,T) data in terms of a local moment Heisenberg model together indicate that the magnetism of CaCo{1.86}As2 is itinerant.Comment: 18 pages, 15 figures, 4 tables, 61 references; v2: extended the fits of experimental data by additional electronic structure calculations; published versio

A novel fuzzy and multi-objective evolutionary algorithm based gene assignment for clustering short time series expression data

Conventional clustering algorithms based on Euclidean distance or Pearson correlation coefficient are not able to include order information in the distance metric and also unable to distinguish between random and real biological patterns. We present template based clustering algorithm for time series gene expression data. Template profiles are defined based on up-down regulation of genes between consecutive time points. Assignment of genes to templates is based on fuzzy membership function. Multi-objective evolutionary algorithm is used to determine compact clusters with varying number of templates. Statistical significance of each template is determined using permutation based non-parametric test. Statistically significant profiles are further tested for their biological relevance using gene ontology analysis. The algorithm was able to distinguish between real and noisy pattern when tested on artificial and real biological data. The proposed algorithm has shown better or similar performance compared to STEM and better than k-means on a real biological data

Coral reef fish abundance and diversity of seagrass beds in Kavaratti atoll, Lakshadweep, India

The community organization of coral reef fishes in the seagrass sub-habitat of Kavaratti toll, Lakshadweep, India was studied during the period from January 1991 to June 1992. Twenty-seven families represented by 65 species were recorded by the visual censes method. The community diversity for families and species was 2.49 and 3.14 respectively. Juveniles and sub-adults of the most adult reef fish, which inhabit other sub-habitats, were recorded here. The high species diversity in the seagrass beds is due to their roles as nurseries, shelter and foraging grounds for many species. Labridae, Chaetodontidae, Acanthuridae and Mullidae were the most speciose families. Ocurrence of siganids was highly seasonal. The cover that seagrass canopy provides conceals many species and perhaps influenced counts. The occurrence of balistids could be related to the presence of interstitial and patches and abundant invertebrate food. Scorpaenids subsisted on abundant invertebrates and juveniles fishes. High counts and pronounced variations make seagrass beds unstable habitats. However, monsoon assemblages were relatively stable perhaps due to lack of excessive new recruits and a habitat shift by most species

An Intelligent Agent Based Intrusion Detection System Using Fuzzy Rough Set Based Outlier Detection

Since existing Intrusion Detection Systems (IDS) including misuse detection and anomoly detection are generally incapable of detecting new type of attacks. However, all these systems are capable of detecting intruders with high false alarm rate. It is an urgent need to develop IDS with very high Detection rate and with low False alarm rate. To satisfy this need we propose a new intelligent agent based IDS using Fuzzy Rough Set based outlier detection and Fuzzy Rough set based SVM. In this proposed model we intorduced two different inteligent agents namely feature selection agent to select the required feature set using fuzzy rough sets and decision making agent manager for making final decision. Moreover, we have introduced fuzzy rough set based outlier detection algorithm to detect outliers. We have also adopted Fuzzy Rough based SVM in our system to classify and detect anomalies efficiently. Finally, we have used KDD Cup 99 data set for our experiment, the experimental result show that the proposed intelligent agent based model improves the overall accuracy and reduces the false alarm rate

Energy for a sustainable road/rail transport system in India

The main motivation for this study is that the strong transport-energy nexus has not received the attention it deserves, though energy is a crucial constraint on transport, and transport is a major determinant of energy demand. Also, many detailed treatments of the transport sector have not scrutinised the sustainability of the present pattern of development of this sector. Further, the prevailing paradigm guiding the development of the sector is made explicit and critiqued because it is often the root cause of its unsustainability. And, because treatments of transport policy issues tend to proceed without a clear statement of underlying goals and strategies, the entire hierarchy of interventions - from goals to strategies to policies - has been discussed. Finally, an attempt has been made to deal with both the supply and demand aspects of the transport sector. The study is restricted to road and rail transport since air and water (inland waters, and coastal and international seas) transport handle very small fractions of domestic traffic demand. The detailed discussions are preceded by overviews of the main features of the Indian transport system as well as of the energy sector as pertaining to transport. It is suggested that the goal of the Indian transport sector should be an efficient, capital-saving, non-import-intensive, affordable, service-oriented and environmentally sound transport system, i.e., a sustainable transport system. A strategy or broad plan to achieve this goal of a sustainable transport system should consist of several components: (1) minimisation of dependence on petroleum fuels, (2) maximisation of the level of safe, comfortable and time-saving transport services, (3) maximisation of the environmental soundness of the transport system, and in particular, reduction of local and global environmental pollution, (4) minimisation of the capital requirements for the transport modal mix that should also include non-motorised transport (NMT), and (5) minimisation of the energy used by the transport system without a reduction of the services provided. The detailed policies (plans or courses of action) to implement the above strategies for achieving a sustainable transport system fall into the following categories: (1) transport-energy database generation and use, (2) demand management, (3) technological improvements in road transport, (4) improvement of the capacity and quality of road infrastructure, (5) traffic management, (6) improvement of the railways, (7) improvement of urban transport, (8) providing a niche for non-motorised modes of transport, (9) pollution control and abatement, (10) costing and pricing, (11) modal shifts to achieve a least-cost freight modal mix, (12) modal shifts to achieve a least-cost passenger modal mix, (13) solutions to the transport sector's problems through measures in other sectors, (14) alternative fuels. Appropriate policy instruments or mechanisms for initiating and maintaining the policies as well as suitable policy agents to wield the policy instruments have also been identified. The market has the power of being an excellent allocator of money, materials and manpower, but unfortunately also has definite limits - it is not very good at looking after the poor, the environment, the long-term and the infrastructure and national strategic concerns such as self-reliance and external debt, all of which are of crucial relevance to the transport system. Hence, the visible hand of government and the people must complement the invisible hand of the market. In conclusion, both short-term low-cost measures to attract political decision-makers with short time-horizons and long-term measures have been mentioned. The short-term measures consist mainly of better maintenance, better driving practices, optimal routing of buses, dedicated routes for buses with traffic restrictions on these dedicated routes, special lanes for slow traffic, supply constraint on personal vehicles, export orientation to the production of personal vehicles, removal of kerosene and diesel subsidies, no long-haul truck permits, increase of truck taxes and shift of passengers travelling less than 300 km from rail to bus. The long-term measures consist mainly of increases in fuel efficiency, introduction of lower-power bus engines, increases in number of buses and/or suburban trains, investments on mass transportation infrastructure, home electrification, improvement of rail freight operations, truck-rail freight linkage, introduction of CNG for urban fleets, switches to biomass-derived fuels for transportation, biomass-derived fuels as petrol and diesel extenders, silviculture for biomass-derived fuels, and alternative cooking fuels and/or devices to replace kerosene

Applying Dijkstras Algorithm in Routing Process

Network is defined as a combination of two or more nodes which are connected with each other. It allows nodes to exchange data from each other along the data connections. Routing is a process of finding the path between source and destination upon request of data transmission. There are various routing algorithms which helps in determining the path and distance over the network traffic. For routing of nodes, we can use many routing protocols. Dijkstrarsquos algorithm is one of the best shortest path search algorithms. Our focus and aim is to find the shortest path from source node to destination node. For finding the minimum path this algorithm uses the connection matrix and weight matrix Thus, a matrix consisting of paths from source node to each node is formed. We then choose a column of destination from path matrix formed and we get the shortest path. In a similar way, we choose a column from a mindis matrix for finding the minimum distance from source node to destination node. It has been applied in computer networking for routing of systems and in google maps to find the shortest possible path from one location to another location.nbs