A Comparative Note on Tunneling in AdS and in its Boundary Matrix Dual

For charged black hole, within the grand canonical ensemble, the decay rate from thermal AdS to the black hole at a fixed high temperature increases with the chemical potential. We check that this feature is well captured by a phenomenological matrix model expected to describe its strongly coupled dual. This comparison is made by explicitly constructing the kink and bounce solutions around the de-confinement transition and evaluating the matrix model effective potential on the solutions.Comment: 1+12 pages, 9 figure

L-configuration re-attachment of distal biceps tendon rupture

In distal biceps tendon ruptures, re-attachment to the radial tuberosity should ensure adequate tendon to bone contact for optimal healing

Language play in and with Chinese: Traditional genres and contemporary developments

Language play is playing with the rules of language for fun. This article is one of the first attempts at providing an overview of the traditional genres and current trends of language play in and with Chinese, a topic that has received relatively little attention in English. We explore the specific aspects of the Chinese language that are susceptible to play, and discuss a number of conventional formulas of Chinese language play. We also examine the affordances of new media and what we call translanguaging language play that involves mixing different named languages and scripts as well as mixing linguistic with other semiotic resources. The motivations and effects of language play are discussed, giving particular attention to the socio-political dimensions of language play. Throughout the discussion, we provide historical as well as contemporary examples to illustrate the ways in which Chinese language users play with language for specific purposes

Synthesis of Silver Nanoparticles using Non-Fouling Microfluidic Devices with Fast Mixing

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Silver nanoparticles were synthesized in an impinging jet reactor using silver nitrate as a precursor, trisodium citrate as a stabilizer and sodium borohydride as a reducing agent. The effect of mixing time on the nanoparticle morphology was investigated by means of UV-Vis spectroscopy, used as a characterization tool. It was observed that as the mixing time became shorter the nanoparticles retained a similar average diameter but produced more aggregates. The mixing time was characterized using the ‘Villermaux-Dushmann’ reaction system together with the Interaction by Exchange with the Mean mixing model. The mixing time achieved was of the order of a few ms for flowrates in the range 18-28 ml/min. The synthesis of silver nanoparticles was carried out at the same flowrates to link mixing time to silver nanoparticle morphology

Plate Micro-Fins in Natural Convection: Experimental Study on Thermal Effectiveness and Mass Usage

This is the author accepted manuscript. The final version is available from the publisher.International Conference on Polygeneration 2015 (ICP 2015), Chennai, India, 18-20 February 2015Every year, micro-technologies are gaining more attention among researchers and industries. Although they are already applied for cooling purposes in several installations, the researches on the thermal performance of micro-fins in natural convective conditions are yet limited. The correlations between heat transfer coefficients and geometry have already been investigated. The present study merges the results of an original experimental investigation with the data available in literature, in order to give an overview of the behavior of micro-fins in terms of different heat sink metrics: the fin effectiveness and the mass specific heat transfer coefficient. The introduction of micro-fins is found not to be always beneficial in terms of heat transfer, although always positive in terms of the material usage and can be considered advantageous in those applications that requires a minimized weight of the heat sinks.The financial support provided by the EPSRC-DST through the BioCPV project is duly acknowledged

Plate micro-fins in natural convection: an opportunity for passive concentrating photovoltaic cooling

This is the final version of the article. Available from Elsevier via the DOI in this record.70th Conference of the Italian Thermal Machines Engineering Association, ATI2015The raise in temperature is a non-negligible issue for concentrating photovoltaics (CPV), where the sunlight is concentrated up to thousands of times and a large amount of heat is collected on the solar cells. Micro-fins have been identified as one of the most promising solution for CPV cooling: despite its potentials, the number of publications on this subject is still limited. The present paper resumes the state-of-the-art of the research on micro-fins, in order to identify the most convenient fin geometry for CPV applications. The results of the investigation conducted in this work show that, compared to a conventional heat sink, micro-fins can improve the thermal performance and, at the same time, lower the weight of a system. For this reason, they are particularly beneficial for tracked systems, such as CPV, where a reduced weight means a reduced load for the tracker. The heat transfer coefficients measured through an experimental setup are used to predict the performance of a micro-finned CPV system in natural convection: an optimized fin array is found able to enhance the mass specific power up to 50% compared to an unfinned surface.This work was financially supported by the EPSRC-DST funded BioCPV project (EP/J000345/1)

Experimental comparison of micro-scaled plate-fins and pin-fins under natural convection

This is the final version of the article. Available from the publisher via the DOI in this record.The present work analyses, for the first time, the heat transfer from pin micro-fins. The scope of the present paper is comparing thermal performance of plate micro-fin and pin micro-fin arrays under natural convection conditions in air. Two fin geometries are considered: plate and pin fin arrays with the same thermal exchanging surface are tested. The investigation shows that the pin micro-fins can improve the thermal performance compared to plate micro-fin arrays. Indeed, pin micro-fins are found to have higher heat transfer coefficients and lower thermal resistances, as well as a better material usage. This makes pin micro-fins able to achieve both thermal enhancement and weight reduction. The radiative heat transfer is calculated: a new model to determine the radiative view factors of pin fins is proposed and is used in the analysis. The effect of the orientation is considered as well.The financial support provided by the EPSRC-DST through the BioCPV project (Ref No: EP/J000345/1) is duly acknowledge

Solar Wind and its Evolution

By using our previous results of magnetohydrodynamical simulations for the solar wind from open flux tubes, I discuss how the solar wind in the past is different from the current solar wind. The simulations are performed in fixed one-dimensional super-radially open magnetic flux tubes by inputing various types of fluctuations from the photosphere, which automatically determines solar wind properties in a forward manner. The three important parameters which determine physical properties of the solar wind are surface fluctuation, magnetic field strengths, and the configuration of magnetic flux tubes. Adjusting these parameters to the sun at earlier times in a qualitative sense, I infer that the quasi-steady-state component of the solar wind in the past was denser and slightly slower if the effect of the magneto-centrifugal force is not significant. I also discuss effects of magneto-centrifugal force and roles of coronal mass ejections.Comment: 6 pages, 1 figure, Earth, Planets, & Space in press (based on 5th Alfven Conference) correction of discussion on a related pape