Thermal measurement and modeling of multi-die packages

Thermal measurement and modeling of multi-die packages became a hot topic recently in different fields like RAM chip packaging or LEDs / LED assemblies, resulting in vertical (stacked) and lateral arrangement. In our present study we show results for a mixed arrangement: an opto-coupler device has been investigated with 4 chips in lateral as well as vertical arrangement. In this paper we give an overview of measurement and modeling techniques and results for stacked and MCM structures, describe our present measurement results together with our structure function based methodology of validating the detailed model of the package being studied. Also, we show how to derive junction-to-pin thermal resistances with a technique using structure functions.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Construction of equilibrium networks with an energy function

We construct equilibrium networks by introducing an energy function depending on the degree of each node as well as the product of neighboring degrees. With this topological energy function, networks constitute a canonical ensemble, which follows the Boltzmann distribution for given temperature. It is observed that the system undergoes a topological phase transition from a random network to a star or a fully-connected network as the temperature is lowered. Both mean-field analysis and numerical simulations reveal strong first-order phase transitions at temperatures which decrease logarithmically with the system size. Quantitative discrepancies of the simulation results from the mean-field prediction are discussed in view of the strong first-order nature.Comment: To appear in J. Phys.

An extremal effective survey about extremal effective cycles in moduli spaces of curves

We survey recent developments and open problems about extremal effective divisors and higher codimension cycles in moduli spaces of curves.Comment: Submitted to the Proceedings of the Abel Symposium 2017. Comments are welcom

Segregation of granular binary mixtures by a ratchet mechanism

We report on a segregation scheme for granular binary mixtures, where the segregation is performed by a ratchet mechanism realized by a vertically shaken asymmetric sawtooth-shaped base in a quasi-two-dimensional box. We have studied this system by computer simulations and found that most binary mixtures can be segregated using an appropriately chosen ratchet, even when the particles in the two components have the same size, and differ only in their normal restitution coefficient or friction coefficient. These results suggest that the components of otherwise non-segregating granular mixtures may be separated using our method.Comment: revtex, 4 pages, 4 figures, submitte

Helium-Oxygen Mixture Model for Particle Transport in CT-Based Upper Airways.

The knowledge of respiratory particle transport in the extra-thoracic pathways is essential for the estimation of lung health-risk and optimization of targeted drug delivery. The published literature reports that a significant fraction of the inhaled aerosol particles are deposited in the upper airways, and available inhalers can deliver only a small amount of drug particles to the deeper airways. To improve the targeted drug delivery efficiency to the lungs, it is important to reduce the drug particle deposition in the upper airways. This study aims to minimize the unwanted aerosol particle deposition in the upper airways by employing a gas mixture model for the aerosol particle transport within the upper airways. A helium-oxygen (heliox) mixture (80% helium and 20% oxygen) model is developed for the airflow and particle transport as the heliox mixture is less dense than air. The mouth-throat and upper airway geometry are extracted from CT-scan images. Finite volume based ANSYS Fluent (19.2) solver is used to simulate the airflow and particle transport in the upper airways. Tecplot software and MATLAB code are employed for the airflow and particle post-processing. The simulation results show that turbulence intensity for heliox breathing is lower than in the case of air-breathing. The less turbulent heliox breathing eventually reduces the deposition efficiency (DE) at the upper airways than the air-breathing. The present study, along with additional patient-specific investigation, could improve the understanding of particle transport in upper airways, which may also increase the efficiency of aerosol drug delivery

Geodesic equations and algebro-geometric methods

For an investigation of the physical properties of gravitational fields the observation of massive test particles and light is very useful. The characteristic features of a given space-time may be decoded by studying the complete set of all possible geodesic motions. Such a thorough analysis can be accomplished most effectively by using analytical methods to solve the geodesic equation. In this contribution, the use of elliptic functions and their generalizations for solving the geodesic equation in a wide range of well known space-times, which are part of the general Pleba\'nski-Demia\'nski family of solutions, will be presented. In addition, the definition and calculation of observable effects like the perihelion shift will be presented and further applications of the presented methods will be outlined.Comment: 8 pages, no figures; based on presentation at the conference "Relativity and Gravitation: 100 Years after Einstein in Prague," Prague, 2012. Relativity and Gravitation, volume 157 of Springer Proceedings in Physics, p 91. Springer International Publishing, 201

A Change of Variables to the Dual and Factorization of Composite Anomalous Jacobians

Changes of variables giving the dual model are constructed explicitly for sigma-models without isotropy. In particular, the jacobian is calculated to give the known results. The global aspects of the abelian case as well as some of those of the cases where the isometry group is simply connected are considered. Considering the anomalous case, we infer by a consistency argument that the `multiplicative anomaly' should be replaceable by adequate rules for factorization of composite jacobians. These rules are then generalized in a simple way for composite jacobians defined in spaces of different types. Implimentation of these rules then gives specific formulas for the anomally for semisimple algebras and also for solvable ones.Comment: 15 pages, no figures, Latex file, A treatment of the global aspects of the abelian and of semisimple duality groups are added. General formulas for the mixed anomaly are derive

Phylogeny and taxonomy of Polyozosia, Sedelnikovaea and Verseghya of the Lecanoraceae (Lecanorales, lichen-forming Ascomycota)

From the combined phylogenetic analysis of multi-locus sequence data of the Lecanoraceae including two nuclear protein-coding markers (RPB2 and RPB1), the internal transcribed spacer and a fragment of the mitochondrial small subunit, found that the originally monotypic eastern Asian genus Verseghya is positioned within the Verseghya-Lecidella-Pyrrhospora clade of the Lecanoraceae and includes one more taxon Verseghya thysanophora widely distributed in Northern Hemisphere. The genus Lecidella forming the Lecidella-Glaucomaria subclade within the same Verseghya-Lecidella-Pyrrhospora clade of the Lecanoraceae found to have tendency to be polyphyletic after including the recently described eastern Asian taxon Lecidella mandshurica into phylogenetic analysis of the Lecanoraceae. It is shown that Lecidella mandshurica was previously recorded from China sub Lecidella aff. elaeochroma. The originally monotypic eastern Asian genus Sedelnikovaea forming a monophyletic branch within the Sedelnikovaea-Lecanoropsis subclade and being in out-position to the Rhizoplaca-Protoparmeliopsis s. str. clade of the Lecanoraceae found to include three more taxa, i.e. Sedelnikovaea marginalis, S. pseudogyrophorica, and S. subdiscrepans. The Eurasian Protoparmeliopsis bolcana, and the eastern Asian P. kopachevskae, are illustrated for the first time as being positioned within the Protopameliopsis branch of the Lecanoraceae, while the South Korean ‘Protoparmeliopsis’ chejuensis found to be positioned in separate monophyletic branch from all other branches of the Rhizoplaca-Protoparmeliopsis s. l. clade of the Lecanoraceae. The genus Polyozosia A. Massal. as earlier name for the former Myriolecis branch of the Lecanoraceae is accepted as far the type species of the latter genus, i.e. P. poliophaea, found to be positioned within this branch. The Polyozosia robust monophyletic branch is positioned in the outermost position in the Rhizoplaca-Protoparmeliopsis s. str. clade of the Lecanoraceae. Position and species content of the accepted genera Glaucomaria, Lecanoropsis, Omphalodina, Polyozosia, and Straminella are discussed in separate nrITS and mtSSU, and combined phylogeny based on concatenated sequences of nrITS, mtSSU, RPB2 and RPB1 genes. Fourty new combinations are proposed: Glaucomaria bicincta, G. carpinea, G. leptyrodes, G. lojkaeana, G. subcarpinea, G. sulphurea, G. swartzii, G. swartzii subsp. caulescens, G. swartzii subsp. nylanderi, Lecanoropsis anopta, L. macleanii, Omphalodina chrysoleuca, O. huashanensis, O. opiniconensis, O. phaedrophthalma, O. pseudistera, Palicella anakeestiicola, Polyozosia albescens, P. andrewii, P. contractula, P. crenulata, P. dispersa, P. hagenii, P. perpruinosa, P. populicola, P. pruinosa, P. reuteri, P. sambuci, P. semipallida, P. straminea, P. thuleana, Sedelnikovaea marginalis, S. pseudogyrophorica, S. subdiscrepans, Straminella bullata, S. burgaziae, S. conizaeoides, S. densa, S. maheui, S. varia, and Verseghya thysanophora. Validation of one name as Polyozosia perpruinosa Fröberg ex S. Y. Kondr. L. Lőkös et Farkas is also proposed

Quantum Hall Conductivity in a Landau Type Model with a Realistic Geometry

In this paper, we revisit some quantum mechanical aspects related to the Quantum Hall Effect. We consider a Landau type model, paying a special attention to the experimental and geometrical features of Quantum Hall experiments. The resulting formalism is then used to compute explicitely the Hall conductivity from a Kubo formula.Comment: LaTeX, 1 eps figur