Book Embeddability of Series–Parallel Digraphs

In this paper we deal with the problem of computing upward two-page book embeddings of Two Terminal Series-Parallel (TTSP) digraphs, which are a subclass of series-parallel digraphs. An optimal O(n) time and space algorithm to compute an upward two-page book embedding of a TTSP-digraph with n vertices is presented. A previous algorithm of Alzohairi and Rival [1] runs in O(n³) time and assumes that the input series-parallel digraph does not have transitive edges. An application of this result to a computational geometry problem is also discussed. More precisely, upward two-page book embeddings are used to deal with the upward point-set embeddability problem, i.e., the problem of mapping planar digraphs onto a given set of points in the plane so that all edges are monotonically increasing in a common direction. The equivalence between upward two-page book embeddability and upward point-set embeddability with at most one bend per edge on any given set of points is proved. An O(n log n)-time algorithm for computing an upward point-set embedding with at most one bend per edge for TTSP-digraphs is presented.     

Air-liquid biofilm formation is dependent on ammonium depletion in a Saccharomyces cerevisiae flor strain

Air–liquid biofilm formation appears to be an adaptive mechanism that promotes foraging of Saccharomyces cerevisiae flor strains in response to nutrient starvation. The FLO11 gene plays a central role in this phenotype as its expression allows yeast cells to rise to the liquid surface. Here, we investigated the role of ammonium depletion in air–liquid biofilm formation and FLO11 expression in a S. cerevisiae flor strain. The data obtained show that increasing ammonium concentrations from 0 to 450 m m reduce air–liquid biofilm in terms of biomass and velum formation and correlate with a reduction of FLO11 expression. Rapamycin inhibition of the TOR pathway and deletion of RAS2 gene significantly reduced biofilm formation and FLO11 expression. Taken together, these data suggest that ammonium depletion is a key factor in the induction of air–liquid biofilm formation and FLO11 expression in S. cerevisiae flor strains. Copyright © 2011 John Wiley & Sons, Ltd.     

Analytic Self-Consistent Condensates in Quasi-1D Superfluid Fermi Gases in the Andreev Approximation

We present an analytic method to approach Eilenberger equation and the associated Bogoliubov–de Gennes equation for quasi-1D fermionic gases. The problem of finding self-consistent inhomogeneous condensates is reduced to solving a certain class of nonlinear Schrödinger equations, whose most general solitonic solution is indeed available. Previously known solutions can be retrieved by taking appropriate limits in the parameters. The applicability of the method extends to systems with population imbalance and subject to external potential. In particular we show that fermionic zero-modes are robust against population imbalance.     

Stability and seismic analyses of leaning towers: the case of the minaret in Jam

The leaning Minaret of Jam, one of the tallest in the world, was declared as the Afghanistan's first World Heritage Site by UNESCO in 2002. The global stability analysis of the tower against soil collapse is first evaluated in the present configuration, in the hypothesis of increasing bending moment at the base section, assuming elastic‐perfect plastic behavior for the soil. Then, a finite element model is set up, which is used for the modal analysis and then for the seismic push‐over analysis, based on both single and multi‐modal approaches. Copyright © 2014 John Wiley & Sons, Ltd.     

Thermosetting Resins and Azo Dyes Based on Phosphazenes

In this paper we report the preparation of new, phosphazene-based, phenol/formaldehyde thermosetting resins and azo dyes as obtained by carrying out electrophilic substitution reactions of formaldehyde and diazotized aromatic amines, respectively, on free hydroxylic group-containing aryloxy phosphazenes. The synthesis of these last substrates by reacting methoxylated phenoxy and naphthoxy-substituted cyclo and polyphosphazenes with BBr₃ under hydrolytic conditions is also described. The reported products were characterized by IR, UV, ¹H and ³¹P {¹H} NMR spectroscopy, and by thermogravimetric analysis. Their possible applications as polymeric matrices for the preparation of fiber-reinforced composite materials or as photographic dyes is also envisaged.     

第30届世界标准日祝词矗立在标准上的建筑

建筑业是几千年来人类进步过程中一项最基本的活动,今年世界标准日的主题是强调国际标准在建筑行业中的重要性。艺术性的设计将永远没有标准,但要建造一座智能博物馆或一座功能齐全的城市,就必须由许许多多专业人员在日常基础工作实践中应用和共享标准。这些活动涉及到设计师、建筑师、工程师和制造商、管理者和承包商,一直到每年在建筑商品及相关服务上要花费上百亿美元的公司。而该活动的相关标准则涉及到直接的建筑标准以及无线通讯、电气安装、电子学、网络及有关的安全标准。当一家日本建筑公司按照加拿大提供的方案在智利建造一座…     

Quantification of power losses due to wind turbine wake interactions through SCADA,meteorological and wind LiDAR data

Power production of an onshore wind farm is investigated through supervisory control and data acquisition data, while the wind field is monitored through scanning light detection and ranging measurements and meteorological data acquired from a met‐tower located in proximity to the turbine array. The power production of each turbine is analysed as functions of the operating region of the power curve, wind direction and atmospheric stability. Five different methods are used to estimate the potential wind power as a function of time, enabling an estimation of power losses connected with wake interactions. The most robust method from a statistical standpoint is that based on the evaluation of a reference wind velocity at hub height and experimental mean power curves calculated for each turbine and different atmospheric stability regimes. The synergistic analysis of these various datasets shows that power losses are significant for wind velocities higher than cut‐in wind speed and lower than rated wind speed of the turbines. Furthermore, power losses are larger under stable atmospheric conditions than for convective regimes, which is a consequence of the stability‐driven variability in wake evolution. Light detection and ranging measurements confirm that wind turbine wakes recover faster under convective regimes, thus alleviating detrimental effects due to wake interactions. For the wind farm under examination, power loss due to wake shadowing effects is estimated to be about 4% and 2% of the total power production when operating under stable and convective conditions, respectively. However, cases with power losses about 60‐80% of the potential power are systematically observed for specific wind turbines and wind directions. Copyright © 2017 John Wiley & Sons, Ltd.