Lagrangian of Self-dual Gauge Fields in Various Formulations

The Lagrangian of self-dual gauge theory in various formulations are reviewed. From these results we see a simple rule and use it to present some new non-covariant Lagrangian based on the decomposition of spacetime into $D=D_1+D_2+D_3$. Our prescription could be easily extended to more complex decomposition of spacetime and some more examples are presented therefore. The self-dual property of the new Lagrangian is proved in detail. We also show that the new non-covariant actions give field equations with 6d Lorentz invariance.Comment: Latex, 27 pages,9 tables. V4: Modify Lagrangian (3.1) and prove its self-dualit

Phase equilibrium diagram for EAF slag optimization in high alloyed Chromium stainless steelmaking

The electric arc furnace (EAF) process for steelmaking of Cr and Ni high alloyed stainless steel grades differs significantly from the steelmaking process of carbon steel due to the special raw materials and generally lower oxygen consumption. The special slag chemistry in the EAF process affects slag foaming and refractory wear characteristics due to an increased content of CrOx. A special slag diagram is presented in order to improve monitoring and control of slag compositions for Cr alloyed heats, with special focus on saturation to MgO periclase and dicalcium silicate C2S in order to minimize MgO losses from the refractory lining and to improve slag refining capability by avoidance of stable C2S. With the same diagram different EAF process strategies can be efficiently monitored, either at elevated CaO and basicity with lower spinel concentration and more liquid process slags near C2S saturation or at lower CaO content and basicity with increased spinel concentration and stiffer slags at MgO saturation but certainly no C2S stability. Examples for three industrial EAFs are given

Tunneling gap of laterally separated quantum Hall states

We use a method of matched asymptotics to determine the energy gap of two counter-propagating, strongly interacting, quantum Hall edge states. The microscopic edge state dispersion and Coulomb interactions are used to precisely constrain the short-distance behavior of an integrable field theory, which then determines the low energy spectrum. We discuss the relationship of our results to the tunneling measurements of Kang et al., Nature 403, 59 (2000).Comment: 4 pages, 1 figur

Biodegradation of metoprolol in oxic and anoxic hyporheic zone sediments: unexpected effects on microbial communities

Metoprolol is widely used as a beta-blocker and considered an emerging contaminant of environmental concern due to pseudo persistence in wastewater effluents that poses a potential ecotoxicological threat to aquatic ecosystems. Microbial removal of metoprolol in the redox-delineated hyporheic zone (HZ) was investigated using streambed sediments supplemented with 15 or 150 μM metoprolol in a laboratory microcosm incubation under oxic and anoxic conditions. Metoprolol disappeared from the aqueous phase under oxic and anoxic conditions within 65 and 72 days, respectively. Metoprolol was refed twice after initial depletion resulting in accelerated disappearance under both conditions. Metoprolol disappearance was marginal in sterile control microcosms with autoclaved sediment. Metoprolol was transformed mainly to metoprolol acid in oxic microcosms, while metoprolol acid and α-hydroxymetoprolol were formed in anoxic microcosms. Transformation products were transient and disappeared within 30 days under both conditions. Effects of metoprolol on the HZ bacterial community were evaluated using DNA- and RNA-based time-resolved amplicon Illumina MiSeq sequencing targeting the 16S rRNA gene and 16S rRNA, respectively, and were prominent on 16S rRNA rather than 16S rRNA gene level suggesting moderate metoprolol-induced activity-level changes. A positive impact of metoprolol on Sphingomonadaceae and Enterobacteriaceae under oxic and anoxic conditions, respectively, was observed. Nitrifiers were impaired by metoprolol under oxic and anoxic conditions. Collectively, our findings revealed high metoprolol biodegradation potentials in the hyporheic zone under contrasting redox conditions associated with changes in the active microbial communities, thus contributing to the attenuation of micropollutants

Ibuprofen Degradation and Associated Bacterial Communities in Hyporheic Zone Sediments

Ibuprofen, a non-steroidal anti-inflammatory pain reliever, is among pharmaceutical residues of environmental concern ubiquitously detected in wastewater effluents and receiving rivers. Thus, ibuprofen removal potentials and associated bacteria in the hyporheic zone sediments of an impacted river were investigated. Microbially mediated ibuprofen degradation was determined in oxic sediment microcosms amended with ibuprofen (5, 40, 200, and 400 µM), or ibuprofen and acetate, relative to an un-amended control. Ibuprofen was removed by the original sediment microbial community as well as in ibuprofen-enrichments obtained by re-feeding of ibuprofen. Here, 1-, 2-, 3-hydroxy- and carboxy-ibuprofen were the primary transformation products. Quantitative real-time PCR analysis revealed a significantly higher 16S rRNA abundance in ibuprofen-amended relative to un-amended incubations. Time-resolved microbial community dynamics evaluated by 16S rRNA gene and 16S rRNA analyses revealed many new ibuprofen responsive taxa of the Acidobacteria, Actinobacteria, Bacteroidetes, Gemmatimonadetes, Latescibacteria, and Proteobacteria. Two ibuprofen-degrading strains belonging to the genera Novosphingobium and Pseudomonas were isolated from the ibuprofen-enriched sediments, consuming 400 and 300 µM ibuprofen within three and eight days, respectively. The collective results indicated that the hyporheic zone sediments sustain an efficient biotic (micro-)pollutant degradation potential, and hitherto unknown microbial diversity associated with such (micro)pollutant removal

Treating of Rayon-flocked Fabric by Atmospheric Pressure Plasma

This study investigates hydrophobisation of the surface of rayon-flocked fabric by means of atmospheric pressure plasma (APP) treatment with tetramethylsilane (TMS). Plasma deposition of TMS is regarded as an effective, single-step low pollution method. A detailed study of the process parameters was conducted. A highly hydrophobic surface was successfully fabricated on rayon-flocked fabric and the hydrophobic surface was found to have good stain resistance to coffee and milk tea

A Space-Time Discontinuous Galerkin Method for Navier-Stokes with Recovery.

This thesis tells the story of two new members of a new generation of discontinuous Galerkin (DG) methods. Although DG, as a spatial discretization, has exhibited unparalleled success in handling advection- dominated problems on unstructured grids, DG's development in diffusion and time-marching schemes has lagged far behind in comparison. The first part of this thesis contributes to a newly introduced diffusion scheme, and the second part to an arbitrarily high-order explicit time-marching scheme. Interface-centered recovery-based DG (RDG) was first introduced by Van Leer and Nomura (2005) as a new DG discretization for diffusion. The recovery concept is attractive because it is easily understood and can be extended beyond diffusion. The idea is to recover a smooth solution across a cell interface that shares all moments with the discontinuous solutions in the two cells adjacent to that interface. RDG proves to be a scheme of fine pedigree: its order of accuracy, 3p + 1 for odd p (p is the order of the solution polynomial), and 3p + 2 for even p, is unmatched on a Cartesian grid by any existing method for diffusion. For unstructured grids, the order of accuracy is reduced to the standard p+1, but RDG still allows of much larger time steps due to smaller eigenvalues. The extension to nonlinear problems with cross-derivative terms and two-dimensional structured and unstructured grids is described. Numerical tests for a range of diffusion equations, including Navier-Stokes, conrm the high-order accuracy of RDG. Van Leer (1977) coupled spatial and temporal operators to produce an exact shift in the solution for advection at a Courant-Friedrich-Lewy (CFL) number of unity. Huynh (2005) successfully implemented this concept in the "moment scheme" (p = 1) for the Euler equations. We extend this method to arbitrarily high order, and incorporate RDG for handling diffusion. The method is currently called Hancock-Huynh discon- tinuous Galerkin (HH-DG). We have tested it on Euler problems and linear advection-diffusion problems.Ph.D.Aerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/86313/1/khlo_1.pd

Methanotrophs: Discoveries, Environmental Relevance, and a Perspective on Current and Future Applications

Methane is the final product of the anaerobic decomposition of organic matter. The conversion of organic matter to methane (methanogenesis) as a mechanism for energy conservation is exclusively attributed to the archaeal domain. Methane is oxidized by methanotrophic microorganisms using oxygen or alternative terminal electron acceptors. Aerobic methanotrophic bacteria belong to the phyla Proteobacteria and Verrucomicrobia, while anaerobic methane oxidation is also mediated by more recently discovered anaerobic methanotrophs with representatives in both the bacteria and the archaea domains. The anaerobic oxidation of methane is coupled to the reduction of nitrate, nitrite, iron, manganese, sulfate, and organic electron acceptors (e.g., humic substances) as terminal electron acceptors. This review highlights the relevance of methanotrophy in natural and anthropogenically influenced ecosystems, emphasizing the environmental conditions, distribution, function, co-existence, interactions, and the availability of electron acceptors that likely play a key role in regulating their function. A systematic overview of key aspects of ecology, physiology, metabolism, and genomics is crucial to understand the contribution of methanotrophs in the mitigation of methane efflux to the atmosphere. We give significance to the processes under microaerophilic and anaerobic conditions for both aerobic and anaerobic methane oxidizers. In the context of anthropogenically influenced ecosystems, we emphasize the current and potential future applications of methanotrophs from two different angles, namely methane mitigation in wastewater treatment through the application of anaerobic methanotrophs, and the biotechnological applications of aerobic methanotrophs in resource recovery from methane waste streams. Finally, we identify knowledge gaps that may lead to opportunities to harness further the biotechnological benefits of methanotrophs in methane mitigation and for the production of valuable bioproducts enabling a bio-based and circular economy

Effect of salt stress on aerobic methane oxidation and associated methanotrophs; a microcosm study of a natural community from a non-saline environment

We investigated the response of aerobic methane oxidation and the associated methanotrophs to salt-stress in a NaCl gradient ranging from 0 M (un-amended reference) to 0.6 M NaCl (seawater salinity) using a rice paddy soil as a model system. Salt-stress significantly inhibited methanotrophic activity at > 0.3 M NaCl at 0.6 M NaCl amendment, methanotrophic activity fully ceased. MiSeq sequencing of the pmoA gene and group-specific qPCR analyses revealed that type Ia methanotroph (Methylobacter) appeared to be favored under salinity up to 0.3 M NaCl, increasing in numerical abundance, while the type Ib was adversely affected. This suggests niche differentiation within members of the gammaproteobacterial methanotrophs. Overall, rice paddy soil methanotrophs showed remarkable resistance to salt-stress