Bose-Einstein condensation in dense quark matter

We consider the problem of Bose condensation of charged pions in QCD at finite isospin chemical potential $\mu_I$ using the O(4)-symmetric linear sigma model as an effective field theory for two-flavor QCD. Using the 2PI $1/N$-expansion, we determine the quasiparticle masses as well as the pion and chiral condensates as a function of the temperature and isospin chemical potential in the chiral limit and at the physical point. At T=0, Bose condensation takes place for chemical potentials larger than $m_{\pi}$. In the chiral limit, the chiral condensate vanishes for any finite value of $\mu_I$.Comment: Talk given at Strong and Electroweak matter 2008, Amsterdam August 25-29 2008. Four pages and two figures. 2nd version: typos fixed and updated list of ref

Signatures of modulated pair interaction in cuprate superconductors

Recent low-temperature scanning tunnelling spectroscopy experiments on the surface of BSCCO-2212 have revealed a strong positive correlation between the position of localized resonances at -960 meV identified with interstitial oxygen dopants and the size of the local spectral gap. We review efforts to understand these correlations within a model where the dopants modulate the pair interaction on an atomic scale. We provide further evidence for this model by comparing the correlations between the dopants and the local density of states with experimental results.Comment: 4 pages, 2 figures, submitted to M2S-HTSC VIII, Dresden 200

Influence of trace erythromycin and eryhthromycin-H2O on carbon and nutrients removal and on resistance selection in sequencing batch reactors (SBRs).

Three sequencing batch reactors (SBRs) were operated in parallel to study the effects of trace erythromycin (ERY) and ERY-H2O on the treatment of a synthetic wastewater. Through monitoring (1) daily effluents and (2) concentrations of nitrogen (N) and phosphorous (P) in certain batch cycles of the three reactors operated from transient to steady states, the removal of carbon, N, and P was affected negligibly by ERY (100 microg/L) or ERY-H2O (50 microg/L) when compared with the control reactor. However, through analyzing microbial communities of the three steady state SBRs on high-density microarrays (Phylo-Chip), ERY, and ERY-H2O had pronounced effects on the community composition of bacteria related to N and P removal, leading to diversity loss and abundance change. The above observations indicated that resistant bacteria were selected upon exposure to ERY or ERY-H2O. Shortterm batch experiments further proved the resistance and demonstrated that ammonium oxidation (56-95%) was inhibited more significantly than nitrite oxidation (18-61%) in the presence of ERY (100, 400, or 800 microg/L). Therefore, the presence of ERY or ERY-H2O (at microg/L levels) shifted the microbial community and selected resistant bacteria, which may account for the negligible influence of the antibiotic ERY or its derivative ERY-H2O (at microg/L levels) on carbon, N, and P removal in the SBRs

Effects of Esters and Resorcinol on Phenolic Resins as Adhesives in Medium-Density Fiberboard Manufacturing

Phenol-formaldehyde (PF) resin-bonded composite wood panels exhibit very low formaldehyde emission levels, meeting the most stringent regulations. However, slow cure speed is a major limiting factor for its applications in the economical manufacturing of medium-density fiberboard (MDF) and particleboard. Commercial PF resins accelerated with esters or resorcinol and their applications in the manufacturing of MDF were investigated in this article. It was found that although ethylene carbonate, propylene carbonate, and triacetin were very effective in reducing the gel time of phenolic resins, these esters caused substantial loss of bonding strength, particularly in the case of phenolic resins with high alkalinity. The loss of bonding strength increased as the ester loading level in the PF resin was increased. On the other hand, resorcinol was not only an effective PF accelerator, but also preserved most of the bonding strength. Resorcinol-accelerated PF adhesives showed better performance in internal bond strength, bending strength, and water resistance of MDF in comparison with the ester-accelerated PF adhesive systems. The cure speed of the resorcinol-accelerated PF adhesive was evaluated against a urea-formaldehyde (E2 type) in the manufacturing of MDF

ARPES and NMTO Wannier Orbital Theory of LiMo6_{6}O17_{17} - Implications for Unusually Robust Quasi-One Dimensional Behavior

We present the results of a combined study by band theory and angle resolved photoemission spectroscopy (ARPES) of the purple bronze, Li$_{1-x}$Mo$_{6}$O$_{17}$. Structural and electronic origins of its unusually robust quasi-one dimensional (quasi-1D) behavior are investigated in detail. The band structure, in a large energy window around the Fermi energy, is basically 2D and formed by three Mo $t_{2g}$-like extended Wannier orbitals, each one giving rise to a 1D band running at a 120$^\circ$ angle to the two others. A structural "dimerization" from $\mathbf{c}/2$ to $\mathbf{c}$ gaps the $xz$ and $yz$ bands while leaving the $xy$ bands metallic in the gap, but resonantly coupled to the gap edges and, hence, to the other directions. The resulting complex shape of the quasi-1D Fermi surface (FS), verified by our ARPES, thus depends strongly on the Fermi energy position in the gap, implying a great sensitivity to Li stoichiometry of properties dependent on the FS, such as FS nesting or superconductivity. The strong resonances prevent either a two-band tight-binding model or a related real-space ladder picture from giving a valid description of the low-energy electronic structure. We use our extended knowledge of the electronic structure to newly advocate for framing LiMo$_{6}$O$_{17}$ as a weak-coupling material and in that framework can rationalize both the robustness of its quasi-1D behavior and the rather large value of its Luttinger liquid (LL) exponent $\alpha$. Down to a temperature of 6$\,$K we find no evidence for a theoretically expected downward renormalization of perpendicular single particle hopping due to LL fluctuations in the quasi-1D chains.Comment: 53 pages, 17 Figures, 6 year

Meson Mixing in Pion Superfluid

We investigate meson mixing and meson coupling constants in pion superfluid in the framework of two flavor NJL model at finite isospin density. The mixing strength develops fast with increasing isospin chemical potential, and the coupling constants in normal phase and in the pion superfluid phase behave very differently.Comment: 6 pages, 4 figures. Updates from version 2: 1, Correct Some language mistakes and Some errors in the cited references. 2, Rewrite the last sentence in the summary to indicate a possible way to measure the isospin-asymmetry related meson propertie

Water pollutant fingerprinting tracks recent industrial transfer from coastal to inland China: a case study

In recent years, China’s developed regions have transferred industries to undeveloped regions. Large numbers of unlicensed or unregistered enterprises are widespread in these undeveloped regions and they are subject to minimal regulation. Current methods for tracing industrial transfers in these areas, based on enterprise registration information or economic surveys, do not work. The authors have developed an analytical framework combining water fingerprinting and evolutionary analysis to trace the pollution transfer features between water sources. We collected samples in Eastern China (industrial export) and Central China (industrial acceptance) separately from two water systems. Based on the water pollutant fingerprints and evolutionary trees, we traced the pollution transfer associated with industrial transfer between the two areas. The results are consistent with four episodes of industrial transfers over the past decade. The results also show likely types of the transferred industries - electronics, plastics, and biomedicines - that contribute to the water pollution transfer

A combined SEM, CV and EIS study of multi-layered porous ceramic reactors for flue gas purification

The effect of sintering temperature of 12-layered porous ceramic reactors (comprising 5 cells) was studied using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The difference in microstructures of the reactors was evaluated by SEM. Additional information on the influence of sintering temperature on the properties of the reactors could be gained by the use of EIS. The present work has provided the first set of fundamental electrochemical data and their interpretation in terms of fabrication conditions, for the multi-layered porous ceramic reactors

An experimental and computational investigation of structure and magnetism in pyrite Co1−x_{1-x}Fex_xS2_2: Chemical bonding and half-metallicity

Bulk samples of the pyrite chalcogenide solid solutions Co$_{1-x}$Fe$_x$S$_2$ 0 <= x <= 0.5, have been prepared and their crystal structures and magnetic properties studied by X-ray diffraction and SQUID magnetization measurements. Across the solution series, the distance between sulfur atoms in the persulfide (S$_2^{2-}$) unit remains nearly constant. First principles electronic structure calculations using experimental crystal structures as inputs point to the importance of this constant S-S distance, in helping antibonding S-S levels pin the Fermi energy. In contrast hypothetical rock-salt CoS is not a good half metal, despite being nearly isostructural and isoelectronic. We use our understanding of the Co$_{1-x}$Fe$_x$S$_2$ system to make some prescriptions for new ferromagnetic half-metals.Comment: 8 pages including 9 figure