Brane Fluctuation and anomalous muon magnetic moment

We study the effects of extra dimensions on the muon anomalous magnetic moment with brane fluctuation. Since the coupling is naturally suppressed if brane fluctuation is considered by exponential softening factor for heavier states, the contribution from the whole Kaluza-Klein graviton tower is shown to be finite. The recent BNL E821 result is accomodated with $D=4+\delta$ dimensional gravitational scale, $M_D$, in the range of $M_D \simeq 1.0 - 5.1$ TeV ($\delta=2$), and $M_D \simeq 1.0 - 8.0$ TeV ($\delta=6$) with the brane tension parameter $f=(4\pi^2 \tau)^{1/4}$, in the range $f = 1 - 10$ TeV.Comment: 8 pages, LaTeX, 2 eps Figures, references added, version to appear in PL

Wandering globular clusters: the first dwarf galaxies in the universe?

In the last decade we witness an advent of new types of dwarf stellar systems in cluding ultra-compact dwarfs, ultra-faint dwarf spheroidals, and exotic globular clusters, breaking the old simple paradigm for dwarf galaxies and globular clusters. These objects become more intriguing, and understanding of these new findings be comes more challenging. Recently we discovered a new type of large scale structure in the Virgo cluster of galaxies: it is composed of globular clusters. Globular clusters in Virgo are found wandering between galaxies (intracluster globular clusters) as well as in galaxies. These intracluster globular clusters fill a significant fraction in the area of the Virgo cluster and they are dominated by blue globular clusters. These intracluster globular clusters may be closely related with the first dwarf galaxies in the universe.Comment: 6 pages, 3 figures, Conference Proceedings: "A Universe of Dwarf Galaxies", 14-18 June 2010, Lyon, Franc

Inclined bottom boundary condition for the mild-slope equation

A finite element method is one of the most effective methods to analyze hydrodynamic behaviors in the coastal zone because it can be applied to irregular and complex geometry. However, it is not easy to treat the boundary condition properly under the condition of vertically inclined boundary. In this study, a numerical method for treatment of inclined bottom boundary in the finite element method is introduced. The mild-slope equation is used as a governing equation. Comparison with an analytical solution shows the validity of the present method

Evolution of asexual and sexual reproduction in the aspergilli

Aspergillus nidulans has long-been used as a model organism to gain insights into the genetic basis of asexual and sexual developmental processes both in other members of the genus Aspergillus, and filamentous fungi in general. Paradigms have been established concerning the regulatory mechanisms of conidial development. However, recent studies have shown considerable genome divergence in the fungal kingdom, questioning the general applicability of findings from Aspergillus, and certain longstanding evolutionary theories have been questioned. The phylogenetic distribution of key regulatory elements of asexual reproduction in A. nidulans was investigated in a broad taxonomic range of fungi. This revealed that some proteins were well conserved in the Pezizomycotina (e.g. AbaA, FlbA, FluG, NsdD, MedA, and some velvet proteins), suggesting similar developmental roles. However, other elements (e.g. BrlA) had a more restricted distribution solely in the Eurotiomycetes, and it appears that the genetic control of sporulation seems to be more complex in the aspergilli than in some other taxonomic groups of the Pezizomycotina. The evolution of the velvet protein family is discussed based on the history of expansion and contraction events in the early divergent fungi. Heterologous expression of the A. nidulans abaA gene in Monascus ruber failed to induce development of complete conidiophores as seen in the aspergilli, but did result in increased conidial production. The absence of many components of the asexual developmental pathway from members of the Saccharomycotina supports the hypothesis that differences in the complexity of their spore formation is due in part to the increased diversity of the sporulation machinery evident in the Pezizomycotina. Investigations were also made into the evolution of sex and sexuality in the aspergilli. MAT loci were identified from the heterothallic Aspergillus (Emericella) heterothallicus and Aspergillus (Neosartorya) fennelliae and the homothallic Aspergillus pseudoglaucus (=Eurotium repens). A consistent architecture of the MAT locus was seen in these and other heterothallic aspergilli whereas much variation was seen in the arrangement of MAT loci in homothallic aspergilli. This suggested that it is most likely that the common ancestor of the aspergilli exhibited a heterothallic breeding system. Finally, the supposed prevalence of asexuality in the aspergilli was examined. Investigations were made using A. clavatus as a representative ‘asexual’ species. It was possible to induce a sexual cycle in A. clavatus given the correct MAT1-1 and MAT1-2 partners and environmental conditions, with recombination confirmed utilising molecular markers. This indicated that sexual reproduction might be possible in many supposedly asexual aspergilli and beyond, providing general insights into the nature of asexuality in fungi.National Natural Science Foundation of China 31601446National Research Foundation of Korea 2016010945Intelligent Synthetic Biology Center of Global Frontier Projects 2015M3A6A8065838Biotechnology and Biological Sciences Research CouncilGovernment of IraqMinisterio de Economía y Competitividad BIO2015-67148-

Microstructure and Mechanical Properties of TiC Nanoparticle-Reinforced Iron-Matrix Composites

Uniformly distributed TiC nanoparticle-reinforced iron-based composites were successfully fabricated by planetary milling in argon and subsequent hot pressing procedures. Nearly full density composite specimens could be obtained via 6-hour milling and hot pressing at 1100° C under 50 MPa. Spherical TiC particles and fine fibrous Fe₃C phases were observed to form the iron-matrix composites and subjected to comparative analysis. Microstructural analysis results show that theaverage diameter of TiC particles and the length of Fe₃C phases tend to decrease with an increase in a TiC volume content. The compression yield strength of hot-pressed composites increased in proportion to the TiC content, resulting in 1.3 GPa for 7.5% TiC. The relationship between the microstructural characteristics and the yield strength of TiC-reinforced composites was also investigated. Based on the Orowan strengthening mechanism, a higher strength is observed for a high TiC content, mainly due to reduced distance between reinforcing TiC nanoparticles.Композитные материалы на основе железа, армированные равномерно распространенными наночастицами TiC, получены с помощью планетарного фрезерования в аргоне и последующего горячего прессования. Путем измельчения в течение 6 часов и горячего прессования материала при температуре 1100° C и давлении 50 MПa оказалось возможным получить образцы композитных материалов с почти максимальной плотностью. Исследованы сферические частицы TiC и волокнистые мелкодисперсные Fe₃C фазы, которые образуют матрицу композитного материала на основе железа. Микроструктурный анализ показал, что усредненный диаметр частиц TiC и длина Fe₃C фаз уменьшаются с увеличением объемного содержания частиц TiC. Значение предела текучести при сжатии композитных материалов, полученных горячим прессованием, увеличивается пропорционально содержанию частиц TiC: 1,3 ГПа для 7,5% TiC. Исследована взаимосвязь между микроструктурными характеристиками и пределом текучести композитных материалов, армированных частицами TiC. На основе механизма упрочнения Орована можно предположить, что более высокое значение прочности имеет место при большем содержании частиц TiC, в основном вследствие сокращения расстояния между армирующими наночастицами TiC.Композитні матеріали на основі заліза, армовані рівномірно розповсюдженими нано-частинками ТіС, отримано за допомогою планетарного фрезерування в аргоні і подальшого гарячого пресування. Шляхом подрібнення протягом 6 годин і гарячого пресування матеріалу за температури 1100° C і тиску 50 МПа можна отримати зразки композитних матеріалів із майже максимальною щільністю. Досліджено сферичні частинки ТіС і волокнисті дрібнодисперсні Fe₃C фази, які сприяють виникненню матриці композитного матеріалу на основі заліза. Мікроструктурний аналіз показав, що усереднений діаметр частинок ТіС і довжина Fe₃C фаз зменшуються зі збільшенням об’ємного вмісту частинок ТіС. Значення границі текучості при стисканні композитних матеріалів, отриманих гарячим пресуванням, збільшується пропорційно вмісту ТіС частинок: 1,3 ГПа для 7,5% ТіС. Досліджено взаємозв’язок між мікроструктурними характеристиками і границею текучості композитних матеріалів, армованих частинками ТіС. На основі механізму зміцнення Орована можна припустити, що більш високі значення міцності відмічаються за більшого вмісту частинок ТіС, в основному внаслідок скорочення відстані між армуючими наночастинками ТіС

Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube

We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 inch photomultiplier tube were measured with a 400 MHz FADC up to 16 \ms time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure

Muon anomalous magnetic moment and the stabilized Randall-Sundrum scenario

We study the effects of extra dimension on the muon anomalous magnetic moment in the stabilized Randall-Sundrum scenario. The effects of the Kaluza-Klein states heavier than the cut-off scale expected to be of order $\Lambda_\pi$ are neglected. Contribution from the spin-2 Kaluza-Klein states dominates over that from the spin-0 radion. The recent BNL E821 results impose a strict constraint on the parameter space of the model: $\Lambda_\pi \approx 0.4 - 2.1$ TeV with $k/ M_{\rm Pl} =0.01 - 0.1$. Small $k/M_{\rm Pl}$ is preferred if $\Lambda_\pi$ is TeV scale.Comment: 9 pages, ReVTeX, reference added, version to appear in PL

Field and angular dependence of the Sommerfeld coefficient in Al-doped MgB2 single crystals

International audienceThe angular and field dependence of the Sommerfeld coefficient = lim Cel /T T→0 Cel being the electronic contribution to the specific heat has been measured in Al-doped MgB2 single crystals for x=0, x=0.1, and x 0.2 . We show that the decomposition previously introduced to describe H, where is the angle between the applied field and the c axis in pure samples Phys. Rev. Lett. 98, 137001 2007 is well adapted to doped samples: e.g., the contribution of the band to the specific heat is proportional to B/Bc2 whereas the contribution of the band is isotropic but highly nonlinear in field. We hence present the evolution of the coherence lengths of the two bands and corresponding Fermi velocities with doping

Single-filament Composite MgB2/SUS Ribbons by Powder-In-Tube Process

We report the successful fabrication of single-filament composite MgB2/SUS ribbons, as an ultra-robust conductor type, employing the powder-in-tube (PIT) process, by swaging and cold rolling only. The remarkable transport critical current (Ic) of the non-sintered MgB2/SUS ribbon has observed, as an unexpected result. Transport critical currents Ic ~ 316 A at T = 4.2 K and Ic ~ 82 A at T = 20 K were observed at self-field, for the non-sintered composite MgB2/SUS ribbon. In addition, the persistent current density Jp values, that were estimated by Bean formula, were more than ~ 7  105 A/cm2 at T = 5 K, and ~ 1.2  105 A/cm2 at T = 30 K, for the sintered composite MgB2/SUS ribbon, at H = 0 G.Comment: 10 pages, 4 figure