Quartic Gauge Boson Couplings and Tree Unitarity in the SU(3)_C X SU(3)_L X U(1)_N Models

The quartic gauge boson couplings in the ${SU(3)}_C \otimes {SU(3)}_L \otimes {U(1)}_N$ models are presented. We find that the couplings of four {\it differrent} gauge bosons may have unusual Lorentz structure and the couplings sastify the tree unitarity requirement at high energy limit.Comment: 13 pages, Latex, axodraw.st

Symmetry Factors of Feynman Diagrams for Scalar Fields

The symmetry factor of Feynman diagrams for real and complex scalar fields is presented. Being analysis of Wick expansion for Green functions, the mentioned factor is derived in a general form. The symmetry factor can be separated into two ones corresponding to that of connected and vacuum diagrams. The determination of symmetry factors for the vacuum diagrams is necessary as they play a role in the effective action and phase transitions in cosmology. In the complex scalar theory the diagrams different in topology may give the same contribution, hence inverse of the symmetry factor (1/S) for total contribution is a summation of each similar ones (1/S_i), i.e., 1/S = \sum_i (1/S_i).Comment: Journal version, new references adde

Dengue epidemic in southern Vietnam, 1998.

A widespread epidemic of dengue hemorrhagic fever (DHF) occurred in southern Vietnam in 1998, with 438.98 cases/100,000 population and 342 deaths. The number of DHF cases and deaths per 100,000 population increased 152.4% and 151.8%, respectively, over a 1997 epidemic. Dengue viruses were isolated from 143 patient blood samples; DEN-3 virus was identified as the predominant serotype, although a resurgence of DEN-4 was noted

АНАЛИЗ ОБСЛУЖИВАНИЯ ПАССАЖИРОВ АВТОБУСАМИ В РОССИИ И ЗА РУБЕЖОМ

Quality evaluation standards of transport service play an important role in search for means to improve service, facilities and procedures for bus passengers. In many countries these standards consist of a set of indicators or groups of indicators, reflecting the specificity of road transportation and at the same time giving certain regulatory guidelines for the accompanying process. This article presents a comparative analysis of Russian and international practice in this area for a number of parameters and with use of dynamic coefficients to help compare objectively the measure of quality of services and management in real towns and metropolitan cities.Стандарты оценки качества транспортного обслуживания играют важную роль в поиске средств повышения уровня сервиса, удобства и порядка для пассажиров автобусов. Во многих странах эти стандарты состоят из совокупности показателей или групп показателей, отражающих специфику автомобильных перевозок. И вместе с тем дающих определенные нормативные ориентиры сопровождающему их процессу. В данной работе проведен сравнительный анализ российской и зарубежной практики в этой сфере по целому ряду параметров и с использованием динамических коэффициентов, помогающих объективно сопоставить меру качества услуг и управления в реальных условиях города или мегаполиса

Hydrogen-rich Syngas Production from Ethanol Dry Reforming on La-doped Ni/Al2O3 Catalysts: Effect of Promoter Loading

Ethanol dry reforming has been studied over La-promoted Ni catalysts supported on Al2O3 with different promoter loadings at varying CO2 partial pressure of 20-50 kPa. Catalysts were prepared via co-impregnation technique and characterized using BET surface area, X-ray diffraction measurement, temperature-programmed calcination and scanning electron microscopy. Doped and undoped catalysts possessed high surface area of about 86-108 m2 g-1 and La promoter was well-dispersed on support surface. Xray diffraction measurements indicated the formation of La2O3, NiO and NiAl2O4 phases in line with temperature-programmed calcination results. La-addition enhanced the dispersion of NiO particles and reduced the agglomeration of metal oxides. Both C2H5OH and CO2 conversions improved with increasing CO2 partial pressure rationally due to the growing secondary CO2 reforming of CH4 reaction. The ratio of H2/CO produced from ethanol dry reforming varied from 1.1 to 1.4 favored for usage as feedstocks of Fischer-Tropsch synthesis. The yield of H2 and CO also enhanced with increasing CO2 partial pressure whilst the optimal La loading in terms of C2H5OH conversion was observed at 3%La and catalytic activity increased with promoter addition reasonably owing to the redox properties of La promoter. CO2 reforming of ethanol reaction appeared via ethanol decomposition to CH4 intermediate product, which was subsequently converted to CO and H2 mixture through CH4 dry reforming reaction

Dark Matter on the Smallest Scales

This work investigates the dark matters structures that form on the smallest cosmological scales. We find that the types and abundances of structures which form at approximately Earth-mass scales are very sensitive to the nature of dark matter. We explore various candidates for dark matter and determine the corresponding properties of small-scale structure. In particular, we discuss possibilities for indirect detection of dark matter through small-scale structure, and comment on the potential of these methods for discriminating between dark matter candidates.Comment: 10 Pages, Proceedings from the Dark Matter working group at the 86th Les Houches Summer School: Particle Physics and Cosmolog

Extremely Hot Ambient Temperature and Injury-related Mortality

This pilot study aimed to evaluate the effects of extremely hot ambient temperatures on the total number of fatal injuries. Data were collected from a population-based mortality registry of Thanh Hoa, a province in the North Central region of Vietnam. This study qualified the distributed lag non-linear model and calculated the RR and 95% CI adjusted for long-term trend and absolute humidity. For the entire study population with 3,949 registered deaths due to injuries collected during 2005-2007, after the onset of extremely hot ambient temperatures, an increased risk of death was observed on the 9th day RR (95% CI) = 1.44 (1.06–1.97) and reached the peak on the 12th day RR (95% CI) = 1.58 (1.14–2.17), and at the 15th day RR (95% CI) = 1.49 (1.08–2.06). Men and old adults were identified as the most vulnerable groups. This study confirmed a positive association between hot temperatures and injury-related deaths in the province of 3.6 million people. The findings motivated further investigation into the effect of warm climate changes and the risk of deaths related to other specific causes such as road traffic, work-related injury, and etc

Unconventional anomalous Hall effect in 3d/5d multilayers mediated by the nonlocal spin-conductivity

We evidenced unconventionnal Anomalous Hall Effects (AHE) in 3d/5d (Co0.2nm/Ni0.6nm)N multilayers grown on a thin Pt layer or thin Au:W alloy. The inversion observed on AHE originates from the opposite sign of the spin-orbit coupling of Pt compared to Ni. Via advanced simulations methods for the description of the spin-current profiles based on the spin-dependent Boltzmann formalism, we extracted the spin Hall angle (SHA) of Pt and (Co/Ni) as well as the relevant transport parameters. The extracted SHA for Pt, +20%, is opposite to the one of (Co/Ni), giving rise to an effective AHE inversion for thin (Co/Ni) multilayers (N < 17). The spin Hall angle in Pt is found to be larger than the one previously measured in combined spin-pumping inverse spin-Hall effect experiments in a geometry of current perpendicular to plane. Whereas magnetic proximity effects cannot explain the effect, spin-current leakage and anisotropic electron scattering at Pt/(Co,Ni) interfaces fit the experiments.Comment: 7 pages, 2 figure

Exchange bias effect in Au-Fe3O4 nanocomposites

We report exchange bias (EB) effect in the Au-Fe3O4 composite nanoparticle system, where one or more Fe3O4 nanoparticles are attached to an Au seed particle forming 'dimer' and 'cluster' morphologies, with the clusters showing much stronger EB in comparison with the dimers. The EB effect develops due to the presence of stress at the Au-Fe3O4 interface which leads to the generation of highly disordered, anisotropic surface spins in the Fe3O4 particle. The EB effect is lost with the removal of the interfacial stress. Our atomistic Monte Carlo studies are in excellent agreement with the experimental results. These results show a new path towards tuning EB in nanostructures, namely controllably creating interfacial stress, and opens up the possibility of tuning the anisotropic properties of biocompatible nanoparticles via a controllable exchange coupling mechanism