Electrokinetic flow of aqueous electrolyte in amorphous silica nanotubes

We study the pressure-driven flow of aqueous NaCl in amorphous silica nanotubes using nonequilibrium molecular dynamics simulations featuring both polarizable and non-polarizable molecular models. Different pressures, electrolyte concentrations and pore sizes are examined. Our results indicate a flow that deviates considerably from the predictions of Poiseuille fluid mechanics. Due to preferential adsorption of the different ionic species by surface SiO! or SiOH groups, we find that a significant electric current is generated, but with opposite polarities using polarizable vs. fixed charge models for water and ions, emphasizing the need for careful parameterization in such complex systems. We also examine the influence of partial deprotonation of the silica surface, and we find that much more current is generated in a dehydrogenated nanopore, even though the overall efficiency remains low. These findings indicate that different methods of nanopore preparation, which can produce a range of surface properties, should be examined more closely in the related experimental methods to generate electrokinetic current

Årsrapport for Energistyrelsens Godkendelsessekretariat for vindmøller 2012 - 2013

Denne rapport er udarbejdet som en oversigt over Godkendelsessekretariat for Vindmøller’s ak-tiviteter i 2012 og 2013. Indholdet af de enkelte delopgaver er primært fokuseret omkring admi-nistrationen af den tekniske certificeringsordning for Vindmøller. Der er overordnet beskrevet de opgaver Godkendelsessekretariatet har været beskæftiget med i den forgangne periode. For detaljer vedrørende fremtidige aktiviteter, henvises til ansøgningen for bevilling i 2014. Opgaverne har omfattet daglig administration, herunder varetagelse af sekretariatsfunktionen for Energistyrelsens Rådgivende Udvalg, ordningen vedrørende små vindmøller, ordningen vedrørende vedligehold og service, samt opgaver i forbindelse med udarbejdelse af nye god-kendelsesregler for vindmøller. Dertil kommer Godkendelsessekretariatets informationsforplig-telse, herunder både deltagelse i oplysende aktiviteter, besvarelse af telefoniske henvendelser samt vedligehold af hjemmesiden. Godkendelsessekretariatet har endvidere tilknyttede eksper-ter fra DTU Vindenergi i danske og internationale standardiseringsudvalg.This report is prepared as documentation for the activities in the Certification Secretariat of Wind Tur-bines in 2012-2013. The secretariat performed duties under a contract with the DEA, where the con-tents of the tasks are focused on administration of the Danish Certification Scheme for Wind Turbines. Also, the report includes a general description of activities of the secretariat during the mentioned pe-riod. For details relating to future activities, please see the grant application for 2014. The tasks of the Secretariat has among other things consisted of daily administration, including ensur-ing the secretariat for the Advisory Committee, implementing the system of maintenance and service, development of new licensing rules for small wind turbines, and the approval and reviews of small wind turbines. Also it includes the secretariats information obligation including participation in meet-ings, answering questions by phone and e-mail and updating the webpage. In addition, the Secretariat and related experts from DTU Wind Energy participated in Danish and international standards commit-tees

A model-independent analysis of final-state interactions in \bar B_{d/s}^0 --> J/psi pi pi

Exploiting $B$-meson decays for Standard Model tests and beyond requires a precise understanding of the strong final-state interactions that can be provided model-independently by means of dispersion theory. This formalism allows one to deduce the universal pion-pion final-state interactions from the accurately known $\pi\pi$ phase shifts and, in the scalar sector, a coupled-channel treatment with the kaon-antikaon system. In this work an analysis of the decays $\bar B_d^0 \to J/\psi \pi^+\pi^-$ and $\bar B_s^0 \to J/\psi \pi^+\pi^-$ is presented. We find very good agreement with the data up to 1.05 GeV with a number of parameters reduced significantly compared to a phenomenological analysis. In addition, the phases of the amplitudes are correct by construction, a crucial feature when it comes to studies of $CP$ violation in heavy-meson decays.Comment: 25 pages, 6 figures, version published in JHE

Rate dependent shear bands in a shear transformation zone model of amorphous solids

We use Shear Transformation Zone (STZ) theory to develop a deformation map for amorphous solids as a function of the imposed shear rate and initial material preparation. The STZ formulation incorporates recent simulation results [Haxton and Liu, PRL 99 195701 (2007)] showing that the steady state effective temperature is rate dependent. The resulting model predicts a wide range of deformation behavior as a function of the initial conditions, including homogeneous deformation, broad shear bands, extremely thin shear bands, and the onset of material failure. In particular, the STZ model predicts homogeneous deformation for shorter quench times and lower strain rates, and inhomogeneous deformation for longer quench times and higher strain rates. The location of the transition between homogeneous and inhomogeneous flow on the deformation map is determined in part by the steady state effective temperature, which is likely material dependent. This model also suggests that material failure occurs due to a runaway feedback between shear heating and the local disorder, and provides an explanation for the thickness of shear bands near the onset of material failure. We find that this model, which resolves dynamics within a sheared material interface, predicts that the stress weakens with strain much more rapidly than a similar model which uses a single state variable to specify internal dynamics on the interface.Comment: 10 pages, 13 figures, corrected typos, added section on rate strengthening vs. rate weakening material

Effect of Field Direction on Electrowetting in a Nanopore

We manifest a significant influence of field direction and polarity on surface wetting, when the latter is tuned by application of an external electric field. Thermodynamics of field-induced filling of hydrocarbon-like nanopores with water is studied by open ensemble molecular simulation. Increased field strength consistently results in water-filling and electrostriction in hydrophobic nanopores. A threshold field commensurate with surface charge density of about one elementary charge per 10 nm2 suffices to render prototypical paraffin surfaces hydrophilic. When a field is applied in the direction perpendicular to the confining walls, the competition between orientational polarization and angle preferences of interfacial water molecules relative to the walls results in an asymmetric wettability of opposing surfaces (Janus interface). Reduction of surface free energy observed upon alignment of confinement walls with field direction suggests a novel mechanism whereby the applied electric field can operate selectively on water-filled nanotubes while empty ones remain unaffected

Transcriptome sequencing of Mycosphaerella fijiensis during association with Musa acuminata reveals candidate pathogenicity genes

Figure S4. Phylogenetic tree of fusicoccadiene synthase protein sequences. A maximum likelihood tree was created of the M. fijiensis fusicoccadiene synthase sequence and its top 50 hits using blastp with the non-redundant protein sequence database on NCBI. Bootstrap values are indicated on the tree, and the scale bar of branch lengths indicate substitutions per site. A description of each blast hit is shown, along with an abbreviation for species. Ab = Alternaria brassicicola; Ac = Acremonium chrysogenum; Af = Aspergillus flavus; Ak = Aspergillus kawachii; An = Aspergillus niger; Ao = Aspergillus oryzae; Ar = Aspergillus ruber; Bm = Bipolaris maydis; Bo = Bipolaris oryzae; Bp = Baudoinia panamericana; Bs = Bipolaris sorokiniana; Bv = Bipolaris victoriae; Bz = Bipolaris zeicola; Cg = Chaetomium globosum; Ci = Coccidioides immitis; Cp = Coccidioides posadasii; Da = Diaporthe amygdali; Fg = Fusarium graminearum; Fp = Fusarium pseudograminearum; Gl = Gymnopus luxurians; Mo = Magnaporthe oryzae; Mp = Macrophomina phaseolina; Nf = Neosartorya fischeri; Nu = Neosartorya udagawae; Om = Oidiodendron maius; Pp = Pseudogymnoascus pannorum; Ptt = Pyrenophora teres f. teres; Tc = Talaromyces cellulolyticus; Ti = Talaromyces islandicus; Tm = Talaromyces marneffei; To = Tolypocladium ophioglossoides; Ts = Talaromyces stipitatus; Tt = Thielavia terrestris. (TIF 303 kb

After Recess: Historical Practice, Textual Ambiguity, and Constitutional Adverse Possession

The Supreme Court’s interpretation of the Recess Appointments Clause in NLRB v. Noel Canning stands as one of the Supreme Court’s most significant endorsements of the relevance of “historical gloss” to the interpretation of the separation of powers. This Article uses the decision as a vehicle for examining the relationship between interpretive methodology and historical practice, and between historical practice and textual ambiguity. As the Article explains, Noel Canning exemplifies how the constitutional text, perceptions about clarity or ambiguity, and “extra-textual” considerations such as historical practice operate interactively rather than as separate elements of interpretation. The decision also provides a useful entry point into critically analyzing the concept of constitutional “liquidation,” which the majority in Noel Canning seemed to conflate with historical gloss but which seems more consistent with the approach to historical practice reflected in Justice Scalia’s concurrence in the judgment. Finally, this Article argues that the historical gloss approach, when applied cautiously and with sensitivity to the potential concerns raised by Justice Scalia and others, is not vulnerable to the charge of licensing executive aggrandizement by “adverse possession.

A cell-based model of extracellular-matrix-guided endothelial cell migration during angiogenesis.

Angiogenesis, the formation of new blood vessels sprouting from existing ones, occurs in several situations like wound healing, tissue remodeling, and near growing tumors. Under hypoxic conditions, tumor cells secrete growth factors, including VEGF. VEGF activates endothelial cells (ECs) in nearby vessels, leading to the migration of ECs out of the vessel and the formation of growing sprouts. A key process in angiogenesis is cellular self-organization, and previous modeling studies have identified mechanisms for producing networks and sprouts. Most theoretical studies of cellular self-organization during angiogenesis have ignored the interactions of ECs with the extra-cellular matrix (ECM), the jelly or hard materials that cells live in. Apart from providing structural support to cells, the ECM may play a key role in the coordination of cellular motility during angiogenesis. For example, by modifying the ECM, ECs can affect the motility of other ECs, long after they have left. Here, we present an explorative study of the cellular self-organization resulting from such ECM-coordinated cell migration. We show that a set of biologically-motivated, cell behavioral rules, including chemotaxis, haptotaxis, haptokinesis, and ECM-guided proliferation suffice for forming sprouts and branching vascular trees