Black Holes in Gravity with Conformal Anomaly and Logarithmic Term in Black Hole Entropy

We present a class of exact analytic and static, spherically symmetric black hole solutions in the semi-classical Einstein equations with Weyl anomaly. The solutions have two branches, one is asymptotically flat and the other asymptotically de Sitter. We study thermodynamic properties of the black hole solutions and find that there exists a logarithmic correction to the well-known Bekenstein-Hawking area entropy. The logarithmic term might come from non-local terms in the effective action of gravity theories. The appearance of the logarithmic term in the gravity side is quite important in the sense that with this term one is able to compare black hole entropy up to the subleading order, in the gravity side and in the microscopic statistical interpretation side.Comment: Revtex, 10 pages. v2: minor changes and to appear in JHE

Development of an electronic medical report delivery system to 3G GSM mobile (cellular) phones for a medical imaging department

Author name used in this publication: Dagan FengAuthor name used in this publication: Michael FulhamRefereed conference paper2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

The effect of particle size on the osteointegration of injectable silicate-substituted calcium phosphate bone substitute materials.

Calcium phosphate (CaP) particles as a carrier in an injectable bone filler allows less invasive treatment of bony defects. The effect of changing granule size within a poloxamer filler on the osteointegration of silicate-substituted calcium phosphate (SiCaP) bone substitute materials was investigated in an ovine critical-sized femoral condyle defect model. Treatment group (TG) 1 consisted of SiCaP granules sized 1000-2000 μm in diameter (100 vol %). TG2 investigated a granule size of 250-500 μm (75 vol %), TG3 a granule size of 90-125 μm (75 vol %) and TG4 a granule size of 90-125 μm (50 vol %). Following a 4 and 8 week in vivo period, bone area, bone-implant contact, and remaining implant area were quantified within each defect. At 4 weeks, significantly increased bone formation was measured in TG2 (13.32% ± 1.38%) when compared with all other groups (p = 0.021 in all cases). Bone in contact with the bone substitute surface was also significantly higher in TG2. At 8 weeks most new bone was associated within defects containing the smallest granule size investigated (at the lower volume) (TG4) (42.78 ± 3.36%) however this group was also associated with higher amounts of fragmented SiCaP. These smaller particles were phagocytosed by macrophages and did not appear to have a negative influence on healing. In conclusion, SiCaP granules of 250-500 μm in size may be a more suitable scaffold when used as an injectable bone filler and may be a convenient method for treating bony defects

An invisibility cloak using silver nanowires

In this paper, we use the parameter retrieval method together with an analytical effective medium approach to design a well-performed invisible cloak, which is based on an empirical revised version of the reduced cloak. The designed cloak can be implemented by silver nanowires with elliptical cross-sections embedded in a polymethyl methacrylate host. This cloak is numerically proved to be robust for both the inner hidden object as well as incoming detecting waves, and is much simpler thus easier to manufacture when compared with the earlier proposed one [Nat. Photon. 1, 224 (2007)].Comment: 7 pages, 4 figures, 2 table

Modulated Instability in Five-Dimensional U(1) Charged AdS Black Hole with R**2-term

We study the effect of R**2 term to the modulated instability in the U(1) charged black hole in five-dimensional Anti-de Sitter space-time. We consider the first-order corrections of R**2 term to the background and the linear order perturbations in the equations of motion. From the analysis, we clarify the effect of R**2 term in the modulated instability, and conclude that fluctuations are stable in the whole bulk in the range of values the coefficient of R**2 term can take.Comment: 19 pages, 1 figures; (v4) Published version in JHE

Fourth clivar workshop on the evaluation of ENSO processes in climate models: ENSO in a changing climate

n/aThe organizers acknowledge the generous support of the World Climate Research Programme/CLIVAR, the Centre National de la Recherche Scientifique–Institut National des Sciences de l’Univers (CNRS-INSU), the LabEx L-IPSL, and Sorbonne Universités and wish to thank Lei Han, from the International CLIVAR Global Project Office in Qingdao, China, for his invaluable help in organizing this workshop

A new fundamental type of conformational isomerism

© 2018 The Author(s). Isomerism is a fundamental chemical concept, reflecting the fact that the arrangement of atoms in a molecular entity has a profound influence on its chemical and physical properties. Here we describe a previously unclassified fundamental form of conformational isomerism through four resolved stereoisomers of a transoid (BF)O(BF)-quinoxalinoporphyrin. These comprise two pairs of enantiomers that manifest structural relationships not describable within existing IUPAC nomenclature and terminology. They undergo thermal diastereomeric interconversion over a barrier of 104 ± 2 kJ mol-1, which we term 'akamptisomerization'. Feasible interconversion processes between conceivable synthesis products and reaction intermediates were mapped out by density functional theory calculations, identifying bond-angle inversion (BAI) at a singly bonded atom as the reaction mechanism. We also introduce the necessary BAI stereodescriptors parvo and amplo. Based on an extended polytope formalism of molecular structure and stereoisomerization, BAI-driven akamptisomerization is shown to be the final fundamental type of conformational isomerization

Effects of tidal-forcing variations on tidal properties along a narrow convergent estuary

A 1D analytical framework is implemented in a narrow convergent estuary that is 78 km in length (the Guadiana, Southern Iberia) to evaluate the tidal dynamics along the channel, including the effects of neap-spring amplitude variations at the mouth. The close match between the observations (damping from the mouth to ∼ 30 km, shoaling upstream) and outputs from semi-closed channel solutions indicates that the M2 tide is reflected at the estuary head. The model is used to determine the contribution of reflection to the dynamics of the propagating wave. This contribution is mainly confined to the upper one third of the estuary. The relatively constant mean wave height along the channel (< 10% variations) partly results from reflection effects that also modify significantly the wave celerity and the phase difference between tidal velocity and elevation (contradicting the definition of an “ideal” estuary). Furthermore, from the mouth to ∼ 50 km, the variable friction experienced by the incident wave at neap and spring tides produces wave shoaling and damping, respectively. As a result, the wave celerity is largest at neap tide along this lower reach, although the mean water level is highest in spring. Overall, the presented analytical framework is useful for describing the main tidal properties along estuaries considering various forcings (amplitude, period) at the estuary mouth and the proposed method could be applicable to other estuaries with small tidal amplitude to depth ratio and negligible river discharge.info:eu-repo/semantics/publishedVersio

High-energy, high-resolution, fly-scan X-ray phase tomography

High energy X-ray phase contrast tomography is tremendously beneficial to the study of thick and dense materials with poor attenuation contrast. Recently, the X-ray speckle-based imaging technique has attracted widespread interest because multimodal contrast images can now be retrieved simultaneously using an inexpensive wavefront modulator and a less stringent experimental setup. However, it is time-consuming to perform high resolution phase tomography with the conventional step-scan mode because the accumulated time overhead severely limits the speed of data acquisition for each projection. Although phase information can be extracted from a single speckle image, the spatial resolution is deteriorated due to the use of a large correlation window to track the speckle displacement. Here we report a fast data acquisition strategy utilising a fly-scan mode for near field X-ray speckle-based phase tomography. Compared to the existing step-scan scheme, the data acquisition time can be significantly reduced by more than one order of magnitude without compromising spatial resolution. Furthermore, we have extended the proposed speckle-based fly-scan phase tomography into the previously challenging high X-ray energy region (120 keV). This development opens up opportunities for a wide range of applications where exposure time and radiation dose are critical

High-energy, high-resolution, fly-scan X-ray phase tomography

High energy X-ray phase contrast tomography is tremendously beneficial to the study of thick and dense materials with poor attenuation contrast. Recently, the X-ray speckle-based imaging technique has attracted widespread interest because multimodal contrast images can now be retrieved simultaneously using an inexpensive wavefront modulator and a less stringent experimental setup. However, it is time-consuming to perform high resolution phase tomography with the conventional step-scan mode because the accumulated time overhead severely limits the speed of data acquisition for each projection. Although phase information can be extracted from a single speckle image, the spatial resolution is deteriorated due to the use of a large correlation window to track the speckle displacement. Here we report a fast data acquisition strategy utilising a fly-scan mode for near field X-ray speckle-based phase tomography. Compared to the existing step-scan scheme, the data acquisition time can be significantly reduced by more than one order of magnitude without compromising spatial resolution. Furthermore, we have extended the proposed speckle-based fly-scan phase tomography into the previously challenging high X-ray energy region (120 keV). This development opens up opportunities for a wide range of applications where exposure time and radiation dose are critical