Virtual integration platform for computational fluid dynamics

Computational Fluid Dynamics (CFD) tools used in shipbuilding industry involve multiple disciplines, such as resistance, manoeuvring, and cavitation. Traditionally, the analysis was performed separately and sequentially in each discipline, which often resulted in conflict and inconsistency of hydrodynamic prediction. In an effort to solve such problems for future CFD computations, a Virtual Integration Platform (VIP) has been developed in the University of Strathclyde within two EU FP6 projects - VIRTUE and SAFEDOR1. The VIP provides a holistic collaborative environment for designers with features such as Project/Process Management, Distributed Tools Integration, Global Optimisation, Version Management, and Knowledge Management. These features enhance collaboration among customers, ship design companies, shipyards, and consultancies not least because they bring together the best expertise and resources around the world. The platform has been tested in seven European ship design companies including consultancies. Its main functionalities along with advances are presented in this paper with two industrial applications

Thermodynamic properties of an interacting hard-sphere Bose gas in a trap using the static fluctuation approximation

A hard-sphere (HS) Bose gas in a trap is investigated at finite temperatures in the weakly-interacting regime and its thermodynamic properties are evaluated using the static fluctuation approximation (SFA). The energies are calculated with a second-quantized many-body Hamiltonian and a harmonic oscillator wave function. The specific heat capacity, internal energy, pressure, entropy and the Bose-Einstein (BE) occupation number of the system are determined as functions of temperature and for various values of interaction strength and number of particles. It is found that the number of particles plays a more profound role in the determination of the thermodynamic properties of the system than the HS diameter characterizing the interaction, that the critical temperature drops with the increase of the repulsion between the bosons, and that the fluctuations in the energy are much smaller than the energy itself in the weakly-interacting regime.Comment: 34 pages, 24 Figures. To appear in the International Journal of Modern Physics

An expectation value expansion of Hermitian operators in a discrete Hilbert space

We discuss a real-valued expansion of any Hermitian operator defined in a Hilbert space of finite dimension N, where N is a prime number, or an integer power of a prime. The expansion has a direct interpretation in terms of the operator expectation values for a set of complementary bases. The expansion can be said to be the complement of the discrete Wigner function. We expect the expansion to be of use in quantum information applications since qubits typically are represented by a discrete, and finite-dimensional physical system of dimension N=2^p, where p is the number of qubits involved. As a particular example we use the expansion to prove that an intermediate measurement basis (a Breidbart basis) cannot be found if the Hilbert space dimension is 3 or 4.Comment: A mild update. In particular, I. D. Ivanovic's earlier derivation of the expansion is properly acknowledged. 16 pages, one PS figure, 1 table, written in RevTe

Global Invasive Potential of 10 Parasitic Witchweeds and Related Orobanchaceae

The plant family Orobanchaceae includes many parasitic weeds that are also impressive invaders and aggressive crop pests with several specialized features (e.g. microscopic seeds, parasitic habits). Although they have provoked several large-scale eradication and control efforts, no global evaluation of their invasive potential is as yet available. We use tools from ecological niche modeling in combination with occurrence records from herbarium specimens to evaluate the global invasive potential of each of 10 species in this assemblage, representing several of the worst global invaders. The invasive potential of these species is considerable, with all tropical and subtropical countries, and most temperate countries, vulnerable to invasions by one or more of them.I do not have complete information on funding. The work was probably supported by a Department of Defense (USA) grant to Town Peterson. RAJW was supported by US National Science Foundation (Ref: KUCR 31000)

(E)-N-[3-(Imidazol-1-yl)-1-phenyl­propyl­idene]hydroxyl­amine

The title compound, C12H13N3O, exists in an E configuration with respect to the C=N bond [1.285 (2) Å]. The imidazole ring forms a dihedral angle of 75.97 (10)° with the phenyl ring. In the crystal, mol­ecules are linked via O—H⋯N and C—H⋯N hydrogen bonds into sheets lying parallel to (001). The crystal structure also features C—H⋯π inter­actions

Unexpectedly large mass loss during the thermal pulse cycle of the red giant R Sculptoris!

The asymptotic giant branch star R Sculptoris is surrounded by a detached shell of dust and gas. The shell originates from a thermal pulse during which the star undergoes a brief period of increased mass loss. It has hitherto been impossible to constrain observationally the timescales and mass-loss properties during and after a thermal pulse - parameters that determine the lifetime on the asymptotic giant branch and the amount of elements returned by the star. Here we report observations of CO emission from the circumstellar envelope and shell around R Sculptoris with an angular resolution of 1.3 arcsec. What was hitherto thought to be only a thin, spherical shell with a clumpy structure, is revealed to contain a spiral structure. Spiral structures associated with circumstellar envelopes have been seen previously, from which it was concluded that the systems must be binaries. Using the data, combined with hydrodynamic simulations, we conclude that R Sculptoris is a binary system that underwent a thermal pulse approximately 1800 years ago, lasting approximately 200 years. About 0.003 Msun of mass was ejected at a velocity of 14.3 km s-1 and at a rate approximately 30 times higher than the prepulse mass-loss rate. This shows that approximately 3 times more mass is returned to the interstellar medium during and immediately after a pulse than previously thought.Comment: Accepted by Natur

Single-Crystal X-ray Structure of Anti-Candida Agent, (E)-3- (1H-Imidazol-1-yl)-1-Phenylpropan-1-one O-3- Chlorobenzoyl Oxime

Purpose: To determine the conformation as well as imine double bond configuration of the anti- Candida oximino ester, 3-(1H-imidazol-1-yl)-1-phenyl- propan-1-one O-3-chlorobenzoyl oxime.Methods: The titled compound was synthesized in a four-step reaction sequence using acetophenone as a starting material. Spectral analysis, viz, nuclear magnetic resonance (1H NMR and 13C NMR spectroscopy) and mass spectrometry (MS) confirmed the chemical structure of the synthesized compounds. Subsequently, single crystals of the titled compound were subjected to x-ray crystallographic analysis.Results: The single crystal x-ray crystallography of the investigated anti-Candida agent revealed its conformation and the (E)-configuration of its imine double bond. The titled compound crystallizes in the monoclinic space group P21/c with a = 11.1894 (2)Å, b = 19.5577 (4)Å, c = 8.2201 (2)Å, β = 104.919 (2)º, V = 1738.24 (6)Å3, Z = 4. The molecules are packed in crystal structure by weak non-classical intermolecular hydrogen C2—H2A•••O2 interactions.Conclusion: X-ray crystallography analysis confirms the (E)-configuration of the titled compound.Keywords: X-ray crystallography, Synthesis, Anti-Candida, Configuration, Conformation, Single crysta

X-ray Molecular Structure of ({[(1E)-3-(1H-Imidazol-1-yl)-1- phenylpropylidene]amino} oxy)(3,4,5-trimethoxyphenyl)- methanone: A Potential Anti-Candida Agent

Purpose: To elucidate the solid-state conformation as well as the imine double bond configuration of a potential anti-Candida agent ({[(1E)-3-(1H-imidazol-1-yl) 1-phenylpropylidene]amino}oxy)(3,4,5- trimethoxyphenyl)methanone.Methods: Acetophenone was used as a starting material to prepare the target oximino ester in a fourstep reaction sequence. Nuclear magnetic resonance (1H-NMR and 13C-NMR) and mass spectrometry were used to confirm the chemical structure of the synthesized compounds. Thereafter, x-ray crystallography was performed on single crystals of the target compound. The solid-state conformation of the target molecule and the (E)-configuration of its imine double bond were determined via the investigation of its single crystal x-ray molecular structure.Results: The titled compound crystallized in the triclinic space group P-1 with a = 11.0719 (7) Å, b = 14.6602 (9) Å, c = 14.8530 (9) Å, α = 67.205 (4)°, β = 80.388 (5)º, γ = 70.100 (5)°, V = 2088.2 (2) Å3, and Z = 4. Individual molecules were packed in the crystal by three weak non-classical intermolecular hydrogen interactions, including C9A—H9AA•••O3A, C9B—H9BA•••O3B, C18B—H18C•••O2A and C20B—H20B•••O4B.Conclusion: The results of the single crystal x-ray molecular structure of the titled anti-Candida agent unequivocally confirmed its (E)-configuration.Keywords: Molecular structure, X-ray crystallography, Synthesis, Azole, Anti-Candid

Chemical composition and antimicrobial activity of propolis collected from some localities of Western Algeria

The chemical analysis and antibacterial activity of propolis collected from some parts of Western Algeria were investigated. The ethanolic extracts of propolis (EEP) were evaluated for further investigation. The major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis. All EEP samples were active against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), but no activity was found against Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The mean diameters of growth inhibition of the EEP ranged between 8.05 and 21.4 mm. The propolis extract obtained from Sidi bel Abbés (SFS-SBA) was more active than other samples as well as showed unique HPLC profile. These results support the idea that propolis can be a promising natural food preservative in food industry and alternative candidate for management of bacterial infections caused by drug-resistant microorganisms