Comparison of models and lattice-gas simulations for Liesegang patterns

For more than a century Liesegang patterns -- self-organized, quasi-periodic structures occurring in diffusion-limited chemical reactions with two components -- have been attracting scientists. The pattern formation can be described by four basic empirical laws. In addition to many experiments, several models have been devised to understand the formation of the bands and rings. Here we review the most important models and complement them with detailed three-dimensional lattice-gas simulations. We show how the mean-field predictions can be reconciled with experimental data by a redefinition of the distances suggested by our lattice-gas simulations.Comment: 21 pages, 9 figures, accepted for publication in EPJ Special Topic

Astrophysical neutrinos flavored with Beyond the Standard Model physics

We systematically study the allowed parameter space for the flavor composition of astrophysical neutrinos measured at Earth, including beyond the Standard Model theories at production, during propagation, and at detection. One motivation is to illustrate the discrimination power of the next-generation neutrino telescopes such as IceCube-Gen2. We identify several examples that lead to potential deviations from the standard neutrino mixing expectation such as significant sterile neutrino production at the source, effective operators modifying the neutrino propagation at high energies, dark matter interactions in neutrino propagation, or non-standard interactions in Earth matter. IceCube-Gen2 can exclude about 90% of the allowed parameter space in these cases, and hence will allow to efficiently test and discriminate models. More detailed information can be obtained from additional observables such as the energy-dependence of the effect, fraction of electron antineutrinos at the Glashow resonance, or number of tau neutrino events.Comment: 21 pages, 9 figures, 3 tables, v2: references added, typos corrected, conclusion unchanged, matches final version in PR

Penerapan Prinsip-prinsip Good Corporate Governance pada Perusahaan Keluarga : Studi Deskriptif pada Distributor Makanan

Perusahaan keluarga menjadi fenomena tersendiri dalam dunia bisnis. Hal ini dikarenakan Perusahaan keluarga bisa memberikan kontribusi yang besar bagi kemajuan suatu negara. Dalam perkembangannya Perusahaan keluarga tidak lepas dari konflik antara pihak pemilik dengan stakeholder. Untuk penyelesaian konflik maka penerapan prinsip Good Corporate Governance (GCG), yang terdiri dari prinsip transparency, accountability, responsibility, independency, dan fairness, sangat dibutuhkan dalam Perusahaan. Hal ini sangat penting karena dengan melaksanakan GCG bisa menambah performance dan valuasi Perusahaan tersebut. Oleh karena itu, peneliti ingin meneliti bagaimana penerapan prinsip Good Corporate Governance pada suatu Perusahaan yaitu distributor makanan. Lalu peneliti berusaha menggabungkan dan menganalisa kinerja Perusahaan dalam menerapkan prinsip-prinsip tersebut. Pengumpulan data dilakukan melalui wawancara kepada pihak yang bersangkutan dan observasi secara langsung di lingkungan Perusahaan. Pengujian keabsahan data dengan menggunakan triangulasi sumber. Dari hasil penelitian yang dilakukan oleh peneliti, didapati masih ada bagian dari prinsip GCG yang belum dilaksanakan, yaitu prinsip accountability dan responsibility. Diharapkan Perusahaan bisa melaksanakan prinsip accountability dan responsibility yang belum terlaksana, sambil tetap mempertahankan prinsip-prinsip lainnya

On the Friedmann Equation in Brane-World Scenarios

The Friedmann law on the brane generically depends quadratically on the brane energy density and involves a ``dark radiation'' term due to the bulk Weyl tensor. Despite its unfamiliar form, we show how it can be derived from a standard four-dimensional Brans-Dicke theory at low energy. In particular, the dark radiation term is found to depend linearly on the brane energy densities. For any equation of state on the branes, the radion evolves such as to generate radiation-dominated cosmology. The radiation-dominated era is conventional and consistent with nucleosynthesis.Comment: 4 pages. v2,v3: discussion on BBN extended, minor correction

A technique for automatic real time scoring of several simultaneous sleep electroencephalograms

Automatic real-time scoring of simultaneous sleep electroencephalogram

Thermal Stability of Thermoelectric Materials via In Situ Resistivity Measurements

An experimental setup for determining the electrical resistivity of several types of thermoelectric materials over the temperature range 20 < T < 550 C is described in detail. One resistivity measurement during temperature cycling is also explained for Cu0.01Bi2Te2.7Se0.3 while a second measurement is made on Yb0.35Co4Sb12 as a function of time at 400 C. Both measurements confirm that the materials are thermally stable for the temperature range and time period measured. Measurements made during temperature cycling show an irreversible decrease in the electrical resistivity of Cu0.01Bi2Te2.7Se0.3 when the measuring temperature exceeds the pressing temperature. Several other possible uses of such a system include but are not limited to studying the effects of annealing and/or oxidation as a function of both temperature and time

Tuning the magnetic anisotropy of single molecules

The magnetism of single atoms and molecules is governed by the atomic scale environment. In general, the reduced symmetry of the surrounding splits the $d$ states and aligns the magnetic moment along certain favorable directions. Here, we show that we can reversibly modify the magnetocrystalline anisotropy by manipulating the environment of single iron(II) porphyrin molecules adsorbed on Pb(111) with the tip of a scanning tunneling microscope. When we decrease the tip--molecule distance, we first observe a small increase followed by an exponential decrease of the axial anisotropy on the molecules. This is in contrast to the monotonous increase observed earlier for the same molecule with an additional axial Cl ligand. We ascribe the changes in the anisotropy of both species to a deformation of the molecules in the presence of the attractive force of the tip, which leads to a change in the $d$ level alignment. These experiments demonstrate the feasibility of a precise tuning of the magnetic anisotropy of an individual molecule by mechanical control.Comment: 16 pages, 5 figures; online at Nano Letters (2015

Year-round tracking of small trans-Saharan migrants using light-level geolocators

Since 1899 ringing (or banding) remained the most important source of information about migration routes, stopover sites and wintering grounds for birds that are too small to carry satellite-based tracking systems. Despite the large quantity of migrating birds ringed in their breeding areas in Europe, the number of ring recoveries from sub-Saharan Africa is very low and therefore the whereabouts of most small bird species outside the breeding season remain a mystery. With new miniaturized light-level geolocators it is now possible to look beyond the limits of ring recovery data. Here we show for the first time year round tracks of a near passerine trans-Saharan migrant, the European Hoopoe (Upupa epops epops). Three birds wintered in the Sahel zone of Western Africa where they remained stationary for most of the time. One bird chose a south-easterly route following the Italian peninsula. Birds from the same breeding population used different migration routes and wintering sites, suggesting a low level of migratory connectivity between breeding and wintering areas. Our tracking of a near passerine bird, the European Hoopoe, with light-level geolocators opens a new chapter in the research of Palaearctic-African bird migration as this new tool revolutionizes our ability to discover migration routes, stopover sites and wintering grounds of small birds