Hawking radiation of unparticles

Unparticle degrees of freedom, no matter how weakly coupled to the standard model particles, must affect the evolution of a black hole, which thermally decays into all available degrees of freedom. We develop a method for calculating the grey-body factors for scalar unparticles for 3+1 and higher dimensional black holes. We find that the power emitted in unparticles may be quite different from the power emitted in ordinary particles. Depending on the parameters in the model, unparticles may become the dominant channel. This is of special interest for small primordial black holes and also in models with low scale quantum gravity where the experimental signature may significantly be affected. We also discuss the sensitivity of the results on the (currently unknown) unparticle normalization.Comment: Calculations for different normalization of unparticles included, discussion expanded, version published in Phys. Rev.

Causal closure of the physical, mental causation, and physics

The argument from causal closure of the physical (CCP) is usually considered the most powerful argument in favor of the ontological doctrine of physicalism. Many authors, most notably Papineau, assume that CCP implies that physicalism is supported by physics. I demonstrate, however, that physical science has no bias in the ontological debate between proponents of physicalism and dualism. I show that the arguments offered for CCP are effective only against the accounts of mental causation based on the action of the mental forces of a Newtonian nature, i.e. those which manifest themselves by causing accelerations. However, it is conceivable and possible that mental causation is manifested through the redistribution of energy, momentum and other conserved quantities in the system, brought about by altering the state probability distribution within the living system and leading to anomalous correlations of neural processes. After arguing that a probabilistic, interactionist model of mental causation is conceivable, which renders the argument from causal closure of the physical ineffective, I point to some basic features that such a model must have in order to be intelligible. At the same time, I indicate the way that conclusive testing of CCP can be done within the theoretical framework of physics

The impact of energy price changes in Moldova

In January 2006 the price of natural gas supplied to Moldova increased from $80 to$110 per thousand cubic meters (mcm). Prices may increase further in the near future, putting additional pressure on the economy and leading to adverse effects on the poorest households. This study examines the potential impact of higher energy prices on the economy of Moldova by simulating the likely macroeconomic consequences of recent and future price increases. Moreover, it estimates the direct impact on individual households using data drawn from the 2004 Household Budget Survey. It assesses the distributional implications of the price shock, noting how the social impact may vary depending on the intensity of energy use, geographic location, and the relative share of energy in household expenditure. The results suggest that energy price changes could dampen economic growth while putting additional strains on the current account deficit. The impact on the poorest households could be significant and protecting them may require resources in the amount of 0.7 to 1.7 percent of GDP. This study identifies possible policy responses to dampen the shock of the energy price increase and to promote the longer-term objective of reducing energy vulnerability.Energy Production and Transportation,Environment and Energy Efficiency,Energy and Environment,Markets and Market Access,Transport and Environment

Fermionic Zero Modes on Domain Walls

We study fermionic zero modes in the domain wall background. The fermions have Dirac and left- and right-handed Majorana mass terms. The source of the Dirac mass term is the coupling to a scalar field $\Phi$. The source of the Majorana mass terms could also be the coupling to a scalar field $\Phi$ or a vacuum expectation value of some other field acquired in a phase transition well above the phase transition of the field $\Phi$. We derive the fermionic equations of motion and find the necessary and sufficient conditions for a zero mode to exist. We also find the solutions numerically. In the absence of the Majorana mass terms, the equations are solvable analytically. In the case of massless fermions a zero energy solution exists and we show that although this mode is not discretely normalizable it is Dirac delta function normalizable and should be viewed as part of a continuum spectrum rather than as an isolated zero mode.Comment: 6 pages, 3 figures, matches version published in PR

Techno-economic analysis of gas turbine-based chp plant operation under a feed-in tariff system

This paper deals with the techno-economic analysis of gas turbine-based combined heat and power production, within a current local legislation frame for the promotion of such production of energy in the Republic of Serbia. Since the legislation includes plants with electric power below 10 MW, an overview of the relevant technical characteristics for a number of appropriate gas turbines was prepared. The relevant thermodynamic parameters are calculated in order to estimate the economic feasibility of combined heat and power production using these plants. The production cost of useful heat is determined by taking into account the incomes from the sale of electricity to the electric grid under a feed-in tariff. It is compared with the production cost from an equivalent boiler for the separate production of the heat. One of the main objectives is to determine the effectiveness of the implemented legislative measures in the promotion of combined production of heat and power. Clear conclusions were drawn based on the results obtained

Techno-economic analysis of gas turbine-based chp plant operation under a feed-in tariff system

This paper deals with the techno-economic analysis of gas turbine-based combined heat and power production, within a current local legislation frame for the promotion of such production of energy in the Republic of Serbia. Since the legislation includes plants with electric power below 10 MW, an overview of the relevant technical characteristics for a number of appropriate gas turbines was prepared. The relevant thermodynamic parameters are calculated in order to estimate the economic feasibility of combined heat and power production using these plants. The production cost of useful heat is determined by taking into account the incomes from the sale of electricity to the electric grid under a feed-in tariff. It is compared with the production cost from an equivalent boiler for the separate production of the heat. One of the main objectives is to determine the effectiveness of the implemented legislative measures in the promotion of combined production of heat and power. Clear conclusions were drawn based on the results obtained

Non-topological solitons in brane world models

We examine some general properties of a certain class of scalar filed theory models containing non-topological soliton solutions in the context of brane world models with compact large extra dimensions. If a scalar field is allowed to propagate in extra space, then, beside standard Kaluza-Klein type excitations, a whole new class of very massive soliton-type states can exist. Depending on their abundance, they can be important dark matter candidates or give significant contribution to entropy and energy density in our universe. .Comment: version accepted for publication in Physical Review

Interaction of higher-dimensional rotating black holes with branes

We study interaction of rotating higher dimensional black holes with a brane in space-times with large extra dimensions. We demonstrate that in a general case a rotating black hole attached to a brane can loose bulk components of its angular momenta. A stationary black hole can have only those components of the angular momenta which are connected with Killing vectors generating transformations preserving a position of the brane. In a final stationary state the null Killing vector generating the black hole horizon is tangent to the brane. We discuss first the interaction of a cosmic string and a domain wall with the 4D Kerr black hole. We then prove the general result for slowly rotating higher dimensional black holes interacting with branes. The characteristic time when a rotating black hole with the gravitational radius $r_0$ reaches this final stationary state is $T\sim r_0^{p-1}/(G\sigma)$, where $G$ is the higher dimensional gravitational coupling constant, $\sigma$ is the brane tension, and $p$ is the number of extra dimensions.Comment: Version published in Class. Quant. Gra

Voltage imaging from dendrites of mitral cells : EPSP attenuation and spike trigger zones

Author Posting. © Society for Neuroscience, 2004. This article is posted here by permission of Society for Neuroscience for personal use, not for redistribution. The definitive version was published in Journal of Neuroscience 24 (2004): 6703-6714, doi:10.1523/JNEUROSCI.0307-04.2004.To obtain a more complete description of individual neurons, it is necessary to complement the electrical patch pipette measurements with technologies that permit a massive parallel recording from many sites on neuronal processes. This can be achieved by using voltage imaging with intracellular dyes. With this approach, we investigated the functional structure of a mitral cell, the principal output neuron in the rat olfactory bulb. The most significant finding concerns the characteristics of EPSPs at the synaptic sites and surprisingly small attenuation along the trunk of the primary dendrite. Also, the experiments were performed to determine the number, location, and stability of spike trigger zones, the excitability of terminal dendritic branches, and the pattern and nature of spike initiation and propagation in the primary and secondary dendrites. The results show that optical data can be used to deduce the amplitude and shape of the EPSPs evoked by olfactory nerve stimulation at the site of origin (glomerular tuft) and to determine its attenuation along the entire length of the primary dendrite. This attenuation corresponds to an unusually large mean apparent "length constant" of the primary dendrite. Furthermore, the images of spike trigger zones showed that an action potential can be initiated in three different compartments of the mitral cell: the soma-axon region, the primary dendrite trunk, and the terminal dendritic tuft, which appears to be fully excitable. Finally, secondary dendrites clearly support the active propagation of action potentialsThis work was supported by National Institutes of Health Grants NS4273 and DC03918. W.R.C. was also supported by the Whitehall Foundation

SR-A ligand and M-CSF dynamically regulate SR-A expression and function in primary macrophages via p38 MAPK activation

<p>Abstract</p> <p>Background</p> <p>Inflammation is characterized by dynamic changes in the expression of cytokines, such as M-CSF, and modifications of lipids and proteins that result in the formation of ligands for Class A Scavenger Receptors (SR-A). These changes are associated with altered SR-A expression in macrophages; however, the intracellular signal pathways involved and the extent to which SR-A ligands regulate SR-A expression are not well defined. To address these questions, SR-A expression and function were examined in resident mouse peritoneal macrophages incubated with M-CSF or the selective SR-A ligand acetylated-LDL (AcLDL).</p> <p>Results</p> <p>M-CSF increased SR-A expression and function, and required the specific activation of p38 MAPK, but not ERK1/2 or JNK. Increased SR-A expression and function returned to basal levels 72 hours after removing M-CSF. We next determined whether prolonged incubation of macrophages with SR-A ligand alters SR-A expression. In contrast to most receptors, which are down-regulated by chronic exposure to ligand, SR-A expression was reversibly increased by incubating macrophages with AcLDL. AcLDL activated p38 in wild-type macrophages but not in SR-A-/- macrophages, and p38 activation was specifically required for AcLDL-induced SR-A expression.</p> <p>Conclusions</p> <p>These results demonstrate that in resident macrophages SR-A expression and function can be dynamically regulated by changes in the macrophage microenvironment that are typical of inflammatory processes. In particular, our results indicate a previously unrecognized role for ligand binding to SR-A in up-regulating SR-A expression and activating p38 MAPK. In this way, SR-A may modulate inflammatory responses by enhancing macrophage uptake of modified protein/lipid, bacteria, and cell debris; and by regulating the production of inflammatory cytokines, growth factors, and proteolytic enzymes.</p