Temperature-time dependent transmittance, sheet resistance and bonding energy of reduced graphene oxide on soda lime glass.

Reduced graphene oxide coated soda lime glass can act as an alternative transparent/conducting electrode for many opto-electronic applications. However, bonding between the deposited reduced graphene oxide film and the glass substrate is important for achieving better stability of the coating and an extended device lifetime. In the present study, delamination energy of reduced graphene oxide on soda lime glass was quantified by using nanoscratch technique. Graphene oxide was deposited on soda lime glass by dip coating technique and was thermally reduced at different temperatures (100 °C, 200 °C, 300 °C, 400 °C and 500 °C) and treatment time (2 h, 3 h, 4 h, 5 h and 10 h) in Ar (95%) with H2 (5%) atmosphere. An inverse behavior of delamination energy with temperature and treatment time was observed, which could be correlated with the removal of oxygen functional groups. Sheet resistance of the film demonstrated a steady decay with increasing temperature and treatment time. Functional groups attached to the graphene planes have more influence on conductivity than groups attached to the edges. Removal of functional groups could also be related to optical transmittance of the samples. Knowledge generated in this study with respect to delamination energy, sheet resistance and optical transmittance could be extensively used for various opto-electronic applications

Mass generation for non-Abelian antisymmetric tensor fields in a three-dimensional space-time

Starting from a recently proposed Abelian topological model in (2+1) dimensions, which involve the Kalb-Ramond two form field, we study a non-Abelian generalization of the model. An obstruction for generalization is detected. However we show that the goal is achieved if we introduce a vectorial auxiliary field. Consequently, a model is proposed, exhibiting a non-Abelian topological mass generation mechanism in D=3, that provides mass for the Kalb-Ramond field. The covariant quantization of this model requires ghosts for ghosts. Therefore in order to quantize the theory we construct a complete set of BRST and anti-BRST equations using the horizontality condition.Comment: 8 pages. To appear in Physical Review

Topologically Massive Non-Abelian Gauge Theories: Constraints and Deformations

We study the relationship between three non-Abelian topologically massive gauge theories, viz. the naive non-Abelian generalization of the Abelian model, Freedman-Townsend model and the dynamical 2-form theory, in the canonical framework. Hamiltonian formulation of the naive non-Abelian theory is presented first. The other two non-Abelian models are obtained by deforming the constraints of this model. We study the role of the auxiliary vector field in the dynamical 2-form theory in the canonical framework and show that the dynamical 2-form theory cannot be considered as the embedded version of naive non-Abelian model. The reducibility aspect and gauge algebra of the latter models are also discussed.Comment: ReVTeX, 17 pp; one reference added, version published in Phys. Rev.

Efficiency of a Brownian information machine

A Brownian information machine extracts work from a heat bath through a feedback process that exploits the information acquired in a measurement. For the paradigmatic case of a particle trapped in a harmonic potential, we determine how power and efficiency for two variants of such a machine operating cyclically depend on the cycle time and the precision of the positional measurements. Controlling only the center of the trap leads to a machine that has zero efficiency at maximum power whereas additional optimal control of the stiffness of the trap leads to an efficiency bounded between 1/2, which holds for maximum power, and 1 reached even for finite cycle time in the limit of perfect measurements.Comment: 9 pages, 2 figure

Local symmetries of the non-Abelian two-form

It is proposed that a non-Abelian adjoint two-form in BF type theories transform inhomogeneously under the gauge group. The resulting restrictions on invariant actions are discussed. The auxiliary one-form which is required for maintaining vector gauge symmetry transforms like a second gauge field, and hence cannot be fully absorbed in the two-form. But it can be replaced, via a vector gauge transformation, by the usual gauge field, leading to gauge equivalences between different types of theories. A new type of symmetry also appears, one which depends on local functions but cannot be generated by constraints. It is connected to the identity in the limit of a vanishing global parameter, so it should be called a semiglobal symmetry. The corresponding conserved currents and BRST charges are parametrized by the space of flat connections.Comment: RevTeX4, 11 pages, minor correction

Bailouts in a common market: a strategic approach

Governments in the EU grant Rescue and Restructure Subsidies to bail out ailing firms. In an international asymmetric Cournot duopoly we study effects of such subsidies on market structure and welfare. We adopt a common market setting, where consumers from the two countries form one market. We show that the subsidy is positive also when it fails to prevent the exit. The reason is a strategic effect, which forces the more efficient firm to make additional cost-reducing effort. When the exit is prevented, allocative and productive efficiencies are lower and the only gaining player is the rescued firm

Gauge transformations of the non-Abelian two-form

A novel inhomogeneous gauge transformation law is proposed for a non-Abelian adjoint two-form in four dimensions. Rules for constructing actions invariant under this are given. The auxiliary vector field which appears in some of these models transforms like a second connection in the theory. Another local symmetry leaves the compensated three-form field strength invariant, but does not seem to be generated by any combination of local constraints. Both types of symmetries change the action by total divergences, suggesting that boundary degrees of freedom have to be taken into account for local quantization.Comment: ReVTeX3.1, 4 page

Developmental stage-specific regulation of the circadian Clock by Temperature in Zebrafish

The circadian clock enables animals to adapt their physiology and behaviour in anticipation of the day-night cycle. Light and temperature represent two key environmental timing cues (zeitgebers) able to reset this mechanism and so maintain its synchronization with the environmental cycle. One key challenge is to unravel how the regulation of the clock by zeitgebers matures during early development. The zebrafish is an ideal model for studying circadian clock ontogeny since the process of development occurs ex utero in an optically transparent chorion and many tools are available for genetic analysis. However, the role played by temperature in regulating the clock during zebrafish development is poorly understood. Here, we have established a clock-regulated luciferase reporter transgenic zebrafish line (Tg (−3.1) per1b::luc) to study the effects of temperature on clock entrainment. We reveal that under complete darkness, from an early developmental stage onwards (48 to 72 hpf), exposure to temperature cycles is a prerequisite for the establishment of self-sustaining rhythms of zfper1b, zfaanat2, and zfirbp expression and also for circadian cell cycle rhythms. Furthermore, we show that following the 5–9 somite stage, the expression of zfper1b is regulated by acute temperature shifts

Documentation and Analysis of Certain Macrofungal Traditional Practices from Western-India (Gujarat)

Traditional ethno-mycomedicinal practices involving macrofungi were documented using questionnaires from Jessore and Purna communities located in the Northern and Southern Gujarat. The quality of traditional knowledge within and in between the communities was compared by informant’s consensus index factor calculated for each ailment. The possibility of any relation between the traditional practices and informant’s consensus index factors was assessed as well. Alternately in order to classify the types of species usages, binary scores were allotted based on the presence or absence of species storage for later use, open sharing and specificity of the practices. Followed by this species scores were subjected to Euclidean distance dissimilarity matrix based hierarchical agglomerative clustering. In totality 23 species were documented addressing various ailments, of which 9 species were used to treat general aspects like convalescence, whereas others (14 species) were used for specific ailments. In the Jessore community 5 of the 7 ailments (41.2%) were related to skin problems, whereas in Purna community only 7 of 18 ailments (38.9%) had similar usage. The total ailments addressed and species documented from the Purna community had a greater diversity and bore higher informant’s consensus index value in comparison to the Jessore community. Cause and effect of some abnormal informant’s consensus values, rendering it dubious, are also discussed. Hierarchical agglomerative clustering revealed the influence of all the three aspects scored as above. The corner-stone species are more important than other species because they are necessary for the survival of the traditional know-how and well being of the communities engaging them and have applications. Moreover, depletion due to rampant use of such species calls upon there identification and conservation. This could be achieved to an extent by simple binary scores based clustering. Certain corner-stone species with closed (absence of) knowledge sharing were found to withhold specific practices. Those with general medicinal applications can be useful as nutraceuticals, whereas those with specific claims can be screened further in order to identify pharmaceutical potentials. In addition to this the present work mentions the documentation of traditional ethno-myco-medicinal practices of several species for the first time ever