bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mosquito adulticidal activity of a biosurfactant produced by Bacillus subtilis subsp. subtilis
Authors: Geetha Irudayaraj , Paily Kummankottil P , Manonmani Arulsamy M 
Published: March 2012

AbstractBACKGROUND: A biosurfactant, surfactin, produced by a strain of Bacillus subtilis subsp. subtilis (VCRC B471), was effective in killing mosquito larval and pupal stages. As it was lethal to the non‐feeding pupal stage, it was presumed that it could kill the adult mosquitoes also. In this study, the adulticidal effect of the biosurfactant was assessed in the laboratory against a malaria vector, Anopheles stephensi.RESULTS: The biosurfactant surfactin, separated from the culture supernatant of the production strain, showed mosquito adulticidal activity when tested as ultralow‐volume (ULV) spray in a Peet‐Grady chamber. Knockdown activity and mortality were found to increase with increasing surfactin dosage. Knockdown dosage (KD) and lethal dosage (LD) were calculated by statistical analysis. The KD50 and KD90 dosages were 10.73 and 26.39 mg m−3 respectively. The LD50 and LD90 dosages were 16.13 and 39.21 mg m−3. The average droplet size of B. subtilis surfactin was 17.5 ± 1.07 µm.CONCLUSION: The present study indicates that the biosurfactant surfactin, produced by B. subtilis subsp. subtilis (VCRC B471), is a potential bioadulticide for ULV spray against malaria‐transmitting Anopheles stephensi mosquitoes. This is the first report of a mosquito adulticide from a microbial source. Copyright © 2012 Society of Chemical Industry
Doping in mixed films of differently substituted phthalocyanines measured in‐situ during film growth
Authors: Cornelius Lena , Beu Max , Keil Christopher , Schlettwein Derck 
Published: March 2012

AbstractMixed films of unsubstituted phthalocyaninato copper (H16PcCu) and its perfluorinated derivative (F16PcCu) were prepared by co‐evaporation in different molecular mixtures. The films were analyzed in‐situ by conduction measurements. High admixtures of H16PcCu in F16PcCu films disturbed the charge transport. Optical transmission spectroscopy consequently showed the disturbance of the F16PcCu solid state structure for increased admixtures of H16PcCu. The spectral signatures of both the βbilayer‐structure and the β‐structure of F16PcCu decreased. Low admixtures of H16PcCu increased the conductivity, indicating a successful dopant interaction at widely preserved crystallinity of F16PcCu. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum mechanical study on plasmon resonances in small ring clusters
Authors: Yin Hai‐Feng , Zhang Hong 
Published: March 2012

AbstractThe collectivity of the electronic motion in small sodium clusters with ring structure is studied by time‐dependent density functional theory. The formation and development of collective resonances in the absorption spectra were obtained as a function of the ring radius. In small ring clusters, besides the lower‐energy mode and the higher‐energy mode, there is another plasmon resonance mode, that is, the reverse two‐dipole mode. For the reverse two‐dipole mode, the formations of these two dipoles are due to the external field inducement and the shielding effect, although the resonant excitation is mainly due to the coupling effect of the electrons of these two dipoles. © 2012 Wiley Periodicals, Inc.
Density functional theory and multicomponent wave functions
Authors: Karwowski Jacek 
Published: March 2012

AbstractSome consequences of using multicomponent wave functions are analyzed. In particular, paradoxical properties of a density functional derived from Dirac and Lévy‐Leblond equations are discussed. The application of a recently formulated N‐electron “relativistic Schrödinger theory,” based on a 4N‐component wave function, to the construction of a Lorentz and gauge covariant density functional theory is suggested. © 2012 Wiley Periodicals, Inc.
Approximate analytical versus numerical solutions of Schrödinger equation under molecular Hua potential
Authors: Hassanabadi H. , Yazarloo B. H. , Zarrinkamar S. , Solaimani M. 
Published: March 2012

AbstractWe solve the D‐dimensional Schrödinger equation under the Hua potential by using a Pekeris‐type approximation and the supersymmetry quantum mechanics. The reliability of the spectrum is checked via a comparison with the finite difference method. This interaction resembles Eckart, Morse, and Manning–Rosen potentials. Some useful quantities are reported via the Hellmann–Feynman Theorem. © 2012 Wiley Periodicals, Inc.
Electronic structure and coordination chemistry of phenanthridine ligand in first‐row transition metal complexes: A DFT study
Authors: Benmachiche Akila , Zendaoui Saber‐Mustapha , Bouaoud Salah‐Eddine , Zouchoune Bachir 
Published: March 2012

AbstractThe geometric parameters, electronic structures, and haptotropic migration of a series of hypothetical compounds of general formula CpM(C13H9N) and (CO)3M(C13H9N) (M = fist row transition metal, Cp = C5H5, and C13H9N = phenanthridine ligand) are investigated by means of the density functional theory. The phenanthridine ligand can bind to the metal through η1 to η6 coordination mode, in agreement with the electron count and the nature of the metal, showing its capability to adapt itself to the electronic demand of the metal as well as to the polycyclic aromatic hydrocarbons. In the investigated species, the most favored closed‐shell count is 18‐electron except for the Ti and V models which are deficient open‐shell 16‐electron configuration. This study has shown the difference in coordination ability of this heteropolycyclic ligand: the coordination of the central C5N ring is less favored than the terminal C6 rings, in agreement with the π‐electron density localization. Most of the investigated complexes are expected to exhibit a rich fluxional behavior. This flexibility favors the possibility for the existence of several isomers as well as their interconversion through haptotropic shifts. © 2012 Wiley Periodicals, Inc.
Influences of dispersion and long‐range corrections on molecular structures of three types of lithium phthalocyanine dimer
Authors: Sumimoto Michinori , Kawashima Yukio , Yokogawa Daisuke , Hori Kenji , Fujimoto Hitoshi 
Published: March 2012

AbstractWe report here the results from theoretical calculations of the potential energy curves for three dimers of lithium phthalocyanine (LiPc) using nine types of functionals: the M06‐2x, M06L, B97D, ωB97, ωB97X, ωB97XD, CAM‐B3LYP, LC‐ωPBE, and LC‐BLYP. The results were discussed in comparison with those obtained for the dimers of magnesium phthalocyanine (MgPc). The dispersive and long‐range interactions were considered in part by using these functionals. The mechanism whereby the dispersive and long‐range interactions affect the geometric structures of the LiPc and MgPc dimers is discussed. The calculated results provide insight into the computational methods for both open‐ and closed‐shell metal phthalocyanine (MPc) dimers: Although it is difficult for the CAM‐B3LYP, LC‐ωPBE, and LC‐BLYP functionals only with the long‐range corrections to evaluate weak dispersion interactions appropriately, the M06‐families, ωB97‐families, and B97D functionals can estimate a weak dispersion interaction well in both open‐ and closed‐shell MPc dimers. However, the results should be used with caution against overestimation of the relative stabilities for the results of functionals considering despersion correction. © 2012 Wiley Periodicals, Inc.
Carbon Nanotubes in the Liquid Phase: Addressing the Issue of Dispersion
Authors: Premkumar Thathan , Mezzenga Raffaele , Geckeler Kurt E. 
Published: March 2012

AbstractThe inherent size and hollow geometry with extraordinary electronic and optical properties make carbon nanotubes (CNTs) promising building blocks for molecular or nanoscale devices. Unfortunately, their hydrophobic nature and their existence in the form of agglomerated and parallel bundles make this interesting material inadequately soluble or dispersible in most of the common solvents, which is crucial to their processing. Therefore, various ingenious techniques have been reported to disperse the CNTs in various solvents with different experimental conditions. However, by analyzing the published scientific research articles, it is evident that there is an important issue or misunderstanding between the term “dispersion” and “solubilization”. As a result many researchers use the terms interchangeably, particularly when stating the interaction of CNTs with liquids, which causes confusion among the readers, students, and researchers. In this article, this fundamental issue is addressed in order to give basic insight to the researchers who are working with CNTs, as well as to the scientists who deal with nano‐related research domains.
Reversible Hydrogenation and Bandgap Opening of Graphene and Graphite Surfaces Probed by Scanning Tunneling Spectroscopy
Authors: Castellanos‐Gomez Andres , Wojtaszek Magdalena , Arramel  , Tombros Nikolaos , van Wees Bart J. 
Published: March 2012

AbstractThe effects of hydrogenation on the topography and electronic properties of graphene and graphite surfaces are studied by scanning tunneling microscopy and spectroscopy. The surfaces are chemically modified using an Ar/H2 plasma. By analyzing thousands of scanning tunneling spectroscopy measurements it is determined that the hydrogen chemisorption on the surface of graphite/graphene opens on average an energy bandgap of 0.4 eV around the Fermi level. Although the plasma treatment modifies the surface topography in an irreversible way, the change in the electronic properties can be reversed by moderate thermal annealing and the samples can be hydrogenated again to yield a similar, but slightly reduced, semiconducting behavior after the second hydrogenation.
Estimation of Minimum Doses for Optimized Quantum Dot Contrast‐Enhanced Vascular Imaging In Vivo
Authors: Roy Mathieu , Niu Carolyn J. , Chen Yonghong , McVeigh Patrick Z. , Shuhendler Adam J. , Leung Michael K. , Mariampillai Adrian , DaCosta Ralph S. , Wilson Brian C. 
Published: March 2012

AbstractQuantum dot (QD) contrast‐enhanced molecular imaging has potential for early cancer detection and image guided treatment, but there is a lack of quantitative image contrast data to determine optimum QD administered doses, affecting the feasibility, risk and cost of such procedures, especially in vivo. Vascular fluorescence contrast‐enhanced imaging is performed on nude mice bearing dorsal skinfold window chambers, injected with 4 different QD solutions emitting in the visible and near infrared. Linear relationships are observed among the vascular contrast, injected contrast agent volume, and QD concentration in blood. Due primarily to differential light absorption by blood, the vasculature is optimally visualized when exciting in the 435–480 nm region in 81% of the cases (89 out of 110 regions of interest in 22 window chambers). The threshold dose, defined here as the quantity of injected nanoparticles required to yield a vascular target‐to‐autofluorescence ratio of 2, varies from 10.6 to 0.15 pmol g−1 depending on the QD emission wavelength. The wavelength optimization maximum and broadband gain, defined as the ratio of threshold doses estimated for optimal and suboptimal (worst wavelength or broadband) spectral illumination, has average values of 4.5 and 1.9, respectively. This study demonstrates, for the first time, optimized QD imaging in vivo. It also proposes and validates a theoretical framework for QD dose estimation and quantifies the effects of blood absorption, QD emission wavelength, and vessel diameter relative to the threshold dose.
Development and validation of a computational model for design analysis of a novel marine turbine
Authors: Ashuri Turaj , van Bussel Gerard , Mieras Stefan 
Published: March 2012

ABSTRACTThe vast tidal and wave energy resources represent a potential to use marine energy systems to supply part of the global energy demand. However, there are many advances required to develop economic and reliable marine energy systems, which some of these advances can be achieved by using the existing knowledge and experience from offshore and wind energy industry. This research presents a novel marine energy system that integrates the concept of a vertical and horizontal axis wind turbines by combining a Darrieus and Wells type rotor. However, many other different concepts have been proposed, but models that account for hydrodynamic, structure and control are needed to determine their technical and economical feasibility. With the use of the double‐multiple streamtube theory, a hydrodynamic model is developed to predict the performance and the loads on the turbine blades coupled with a finite element model to compute strains and stresses. To validate the model, we used strain data from field measurement of the demo prototype. The validated model was used to compute extreme stresses and calculate the fatigue life. The model gives reliable estimates of stresses and fatigue life. With this result, the design analysis of the turbine blades can be optimized for any site condition and expected life time. Copyright © 2012 John Wiley & Sons, Ltd.
A methodology for the efficient computer representation of dynamic power systems: Application to wind parks
Authors: Peña Rafael , Medina Aurelio , Anaya‐Lara Olimpo 
Published: March 2012

ABSTRACTThis contribution presents a methodology to efficiently obtain the numerical and computer solution of dynamic power systems with high penetration of wind turbines. Due to the excessive computational load required to solve the abc models that represent the behavior of the wind turbines, a parallel processing scheme is proposed to enhance the solution of the overall system. Case studies are presented which demonstrate the effectiveness and applications of the proposed methodology. Copyright © 2012 John Wiley & Sons, Ltd.
Wake impacts on downstream wind turbine performance and yaw alignment
Authors: McKay Phillip , Carriveau Rupp , Ting David S‐K. 
Published: March 2012

ABSTRACTAerodynamic wake interaction between commercial scale wind turbines can be a significant source of power losses and increased fatigue loads across a wind farm. Significant research has been dedicated to the study of wind turbine wakes and wake model development. This paper profiles influential wake regions for an onshore wind farm using 6 months of recorded SCADA (supervisory control and data acquisition) data. An average wind velocity deficit of over 30% was observed corresponding to power coefficient losses of 0.2 in the wake region. Wind speed fluctuations are also quantified for an array of turbines, inferring an increase in turbulence within the wake region. A study of yaw data within the array showed turbine nacelle misalignment under a range of downstream wake angles, indicating a characteristic of wind turbine behaviour not generally considered in wake studies. The turbines yaw independently in order to capture the increased wind speeds present due to the lateral influx of turbulent wind, contrary to many experimental and simulation methods found in the literature. Improvements are suggested for wind farm control strategies that may improve farm‐wide power output. Additionally, possible causes for wind farm wake model overestimation of wake losses are proposed.Copyright © 2012 John Wiley & Sons, Ltd.
A novel and efficient assay for identification and quantification of Acidithiobacillus ferrooxidans in bioleaching samples
Authors: Feng Shoushuai , Xin Yu , Yang Hailin , Zhang Ling , Kang Wenliang , Xia Xiaole , Wang Wu 
Published: March 2012

Abstract
Acidithiobacillus ferrooxidans is a Gram-negative, acidophilic, and chemolithotrophic bacterium that is active in bioleaching. The leaching efficacy is directly influenced by the biomass changes of this specie in bioleaching microbial community. In order to perform a simple and sensitive assay on A. ferrooxidans from mixed strains in this process, a novel assay was developed based on sandwich hybridization assay with the aid of S1 nuclease treatment and fluorescent labeling. In the work, a designed DNA probe complementary to the conservative region of its 16S rRNA was synthesized, which showed high accuracy for distinguishing homologous species with the exclusion of even-only two base pairs difference. The specificity of this assay was verified in different systems with mixed strains, and the quantitative result was proved by comparison of microscopic cell counting. The detection sensitivity was about 8 × 102 cells/ml and the inter-assay coefficient of variation of three independent assays was from 3.8 to 7.7 %, respectively. In addition, the cycle of assay was about 3–4 h when the cost estimated was less than $0.5 per sample. This assay method might be applied for identifying and monitoring any kind of bacterial strain from a mixed microbial flora in bioleaching or other areas.
Supporting Implementation: The Role of Community Development Teams to Build Infrastructure
Authors: Saldana Lisa , Chamberlain Patricia 
Published: March 2012

AbstractEvidence‐based methods for assisting consumers, such as counties, in successfully implementing practices are lacking in the field of implementation science. To fill this gap, the Community Development Teams (CDT) approach was developed to assist counties in developing peer networks focused on problem‐solving and resource sharing to enhance their possibility of successful implementation. The CDT is an interactive, solution‐focused approach that shares many elements of the Interactive Systems Framework (ISF) for Dissemination and Implementation. An ongoing randomized implementation trial of Multidimensional Treatment Foster Care (MTFC) was designed to test the hypothesis that such interactive implementation methods are more successful at helping counties achieve successful and sustainable MTFC programs than standard individualized implementation methods. Using the Stages of Implementation Completion measure, developed for this study, the potential benefit of these interactive methods is examined at different stages of the implementation process ranging from initial engagement to program competency.Special Issue: Advances in Bridging Research and Practice Using the Interactive System Framework for Dissemination and Implementation; Guest Editors: Abraham Wandersman, Paul Flaspohler, Catherine A. Lesesne, Richard Puddy; Action Editor: Emilie Phillips Smith
Corrosion Inhibition by Some Cationic Surfactants in Oil Fields
Authors: Tawfik Salah M. , Sayed Atef , Aiad Ismail 
Published: March 2012

AbstractTwo cationic surfactants, namely, tetradecyl dimethyl benzyl ammonium chloride (TDBAC) and tributyl tetradecyl phosphonium chloride (TTPC) were supplied from the local market and characterized. The adsorption tendency of the two surfactants was estimated from the values of the depression of surface tension of the water at the critical micelle concentration. The studied surfactants were evaluated as antimicrobial agents against sulfate‐reducing bacteria. These cationic surfactants showed good antimicrobial activities against the tested microorganisms. It was also found that these compounds are good corrosion inhibitors for carbon steel in 0.5 M HCl at doses of 25–600 ppm.
Drops in the bucket? A review of onshore responses to Somali piracy
Authors: Bueger Christian 
Published: March 2012

AbstractThat piracy needs to be addressed onshore is a widely shared assumption. While the majority of counter-piracy measures focus on the sea, a number of onshore counter-piracy initiatives have been launched. We can observe the seeds of an alternative land-based policy approach. One set of land-based programs aims at strengthening the legal and security state apparatus to better deter and punish pirates. The other set of programs aims at addressing local populations on regional, clan or village levels. Such projects aim at increasing surveillance, sensitizing populations for the consequences of piracy, and providing rehabilitation or alternative livelihood opportunities. In this article, I review the latter type of projects and discuss the promises and difficulties of addressing piracy by such measures. I discuss five major problems: knowledge problems, implementation problems, counterintuitive consequences, tensions towards other parts of counter-piracy strategy, and the securitization of aid.
Total losses and the peril of piracy in English law of marine insurance
Authors: Gauci Gotthard 
Published: March 2012

Abstract
Whereas the Marine Insurance Act 1906 provides substantial detail about total losses, very little is provided in relation to piracy in the said statute. The recent judgments in Masefield v Amlin by Steel J ([2010] 1Lloyd's Rep. IR 345) and then by the English Court of Appeal ([2011] EWCA Civ 24) have highlighted the difficulties associated with determining whether a seizure of the subject-matter of insurance, in this case cargo, by pirates, demanding a ransom, can give rise to a claim for a total loss. This is a very important matter which also raises issues of legality and public policy. This article examines the implications of this judgment against the backdrop of the English marine insurance definition of piracy and the intricacies of the law relating to constructive and actual total losses. The article concludes with the suggestion that possibly the marine insurance definition of piracy should tally with that in the domain of public international law, and further, that legislative intervention should be considered for the purpose of ascertaining the point in time whether and when seizure by pirates can constitute a total loss.
Managing Female Foreign Domestic Workers in Singapore: Economic Pragmatism, Coercive Legal Regulation, or Human Rights?
Authors: Tan Eugene KB 
Published: March 2012

Singapore's immigration discourse is deeply influenced by its need to “right-size” its population. As a society that has and remains in need of immigration, contemporary immigration and globalization have rigorously challenged the conventional thinking and understanding of citizenship, as well as notions of who belongs and who does not. Nevertheless, international marriages and pervasive in-and out-migration for purposes of employment, study, and family, conspire to make more pronounced the decoupling of citizenship and residence in Singapore. This transnational dimension sits uncomfortably with the policy makers' desire for, and the imperatives of, state sovereignty, control, and jurisdiction.Although one quarter of people living in Singapore are foreigners, concerns of human rights and justice are largely peripheral, if not absent from the immigration discourse. This is seen most clearly in employment issues pertaining to foreign female domestic workers (FDWs), most of who come from other parts of Southeast Asia. ‘Rights talk’ is largely absent even as activists seek to engage the key stakeholders through the subtle promotion of rights for such workers.The government, however, has resisted framing the FDW issues as one of rights but instead has focused on promotional efforts that seek to enhance the regulatory framework. This dovetails with the reality that immigration law also functions as quasi-family law in which the freedom of FDWs and other foreign menial workers to marry Singapore citizens and permanent residents are severely restricted. As such, the immigration regime's selectivity functions as a draconian gatekeeper. Justice and human rights are but tangential concerns.