bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topographic forcing of flow partition and flow structures at river bifurcations
Authors: Miori Stefano , Hardy Richard J. , Lane S. N. 
Published: January 2012

ABSTRACTThis paper presents the predicted flow dynamics from the application of a Reynolds‐averaged Navier–Stokes model to a series of bifurcation geometries with morphologies measured during previous flume experiments. The topography of the bifurcations consists of either plane or bedform‐dominated beds which may or may not possess discordance between the two bifurcation distributaries. Numerical predictions are compared with experimental results to assess the ability of the numerical model to reproduce the division of flow into the bifurcation distributaries. The hydrodynamic model predicts: (1) diverting fluxes in the upstream channel which direct water into the distributaries; (2) super‐elevation of the free surface induced at the bifurcation edge by pressure differences; and (3) counter‐rotating secondary circulation cells which develop upstream of the apex of the bifurcation and move into the downstream channels, with water converging at the surface and diverging at the bed. When bedforms are not present, weak transversal fluxes characterize the upstream channel for almost its entire length, associated with clearly distinguishable secondary circulation cells, although these may be under‐estimated by the turbulence model used in the solution. In the bedform dominated case, the same hydrodynamic conditions were not observed, with the bifurcation influence restricted and depth scale secondary circulation cells not forming. The results also demonstrate the dominant effect bed discordance has upon flow division between the two distributaries. Finally, results indicate that in bedform dominated rivers. Consequently, we suggest that sand‐bed river bifurcations are more likely to have an influence that extends much further upstream and have a greater impact upon water distribution. This may contribute to observed morphological differences between sand‐bedded and gravel‐bedded braided river networks. Copyright © 2012 John Wiley & Sons, Ltd.
Local moving least square‐one‐dimensional integrated radial basis function networks technique for incompressible viscous flows
Authors: Ngo‐Cong D. , Mai‐Duy N. , Karunasena W. , Tran‐Cong T. 
Published: January 2012

SUMMARYThis paper presents a local moving least square‐one‐dimensional integrated radial basis function networks method for solving incompressible viscous flow problems using stream function‐vorticity formulation. In this method, the partition of unity method is employed as a framework to incorporate the moving least square and one‐dimensional integrated radial basis function networks techniques. The major advantages of the proposed method include the following: (i) a banded sparse system matrix which helps reduce the computational cost; (ii) the Kronecker‐δproperty of the constructed shape function which helps impose the essential boundary condition in an exact manner; and (iii) high accuracy and fast convergence rate owing to the use of integration instead of conventional differentiation to construct the local radial basis function approximations. Several examples including two‐dimensional (2D) Poisson problems, lid‐driven cavity flow and flow past a circular cylinder are considered, and the present results are compared with the exact solutions and numerical results from other methods in the literature to demonstrate the attractiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Non‐destructive evaluation of ripening and quality traits in apples using a multiparametric fluorescence sensor
Authors: Betemps Débora L , Fachinello José Carlos , Galarça Simone P , Portela Nicácia M , Remorini Damiano , Massai Rossano , Agati Giovanni 
Published: January 2012

AbstractBACKGROUND: The detection of pigments and colourless flavonoids in apples can provide a useful indication of fruit quality. Optical methods are preferable because they are fast and non‐destructive. In this study, a fluorescence‐based portable sensor was used in order to non‐invasively determine the content of chlorophylls, anthocyanins and flavonols in Fuji, Granny Smith and Golden Delicious apple cultivars. The aim was to define new non‐destructive optical indices of apple quality.RESULTS: The anthocyanin index (ANTH) in Fuji was higher in the sunny (i.e. sun‐exposed) side of the fruit compared to the shady side. For all cultivars, the flavonol index (FLAV) was higher in the sunny side compared with the shady side. The chlorophyll index (CHL) for the shady sides of Granny Smith and Golden Delicious was significantly higher than for the sunny sides. Fine linear regressions were found between the ANTH, FLAV and CHL indices and the actual anthocyanin, flavonol and chlorophyll concentrations, respectively, which were determined destructively on the apple peel extracts. A negative correlation was found between the apple sugar content and the chlorophyll fluorescence in the far‐red spectral band.CONCLUSION: Our results indicate that a single multiparametric fluorescence‐based sensor can provide valuable non‐destructive markers of ripening and quality in apples. Copyright © 2012 Society of Chemical Industry
Combining stir‐bar sorptive extraction and large volume injection‐gas chromatography‐mass spectrometry for the determination of benzotriazole UV stabilizers in wastewater matrices
Authors: Carpinteiro Inma , Ramil Maria , Rodríguez Isaac , Nogueira José Manuel F. 
Published: January 2012

AbstractStir‐bar sorptive extraction and liquid desorption followed by large volume injection‐gas chromatography coupled to mass spectrometry under selected ion monitoring mode acquisition (SBSE‐LD/LVI‐GC‐MS(SIM)) was applied for the determination of six benzotriazole UV stabilizers (Tinuvin P, Allyl‐bzt, Tinuvin 320, Tinuvin 326, Tinuvin 327 and Tinuvin 328) in wastewater matrices. Parameters affecting the performance of extraction and desorption steps were thoroughly evaluated using uni‐ and multivariate optimization strategies, based on the use of experimental factorial designs. Assays performed with stir bars, coated with 24 μL of polydimethylsiloxane, on 25 mL of ultra‐pure water samples spiked at the 0.5 ng/mL level, yielded recoveries ranging from 47.9±1.4% (Tinuvin P) to 103.1±3.6% (Tinuvin 326), under optimized experimental conditions. When applied to complex matrices (e.g. wastewater), the methodology showed also excellent linear dynamic ranges (0.02–10.00 ng/mL) for the six benzotriazole UV stabilizers studied with correlation coefficients higher than 0.9970, limits of quantification in between 0.004 and 0.015 ng/mL, suitable repeatability (RSD<12.7%) and reproducibility (RSD<4.5%). The application of the proposed methodology to urban sewage waters from Spain and Portugal wastewater plants revealed the presence of low contents of some benzotriazole UV stabilizers.
Fit‐for‐purpose in veterinary drug residue analysis: Development and validation of an LC‐MS/MS method for the screening of thirty illicit drugs in bovine urine
Authors: Leporati Marta , Capra Pierluigi , Brizio Paola , Ciccotelli Valentina , Abete Maria Cesarina , Vincenti Marco 
Published: January 2012

AbstractA selective and sensitive method for screening 31 analytes (nine corticosteroids, eight β‐agonists, seven anabolic steroids, six promazines and zeranol) in bovine urine was validated according to 2002/657/EC guidelines. Upon optimization of sample treatment conditions, the extraction was performed by diethylether at pH 9, after deconjugation. Extraction yields (R%) proved higher than 70% for 19 analytes, 50<R%<70 for 5 analytes, lower than 50% but reproducible for the remaining six analytes. The analyses were carried out using HPLC‐ESI‐MS/MS. The method sensitivity proved high enough to largely exceed the CCβ requirements of the Italian residue detection plan, ranging from 1 to 3 ng/mL (20 ng/mL for promazines). The present method allowed the simultaneous analysis of most drugs for which the European legislation prescribes official controls. Its practical applicability was verified on 494 real samples as an alternative to the traditional screening protocols based on multiple immunometric analysis, demonstrating high efficiency and comprehensive investigation capacity, allowing epidemiological assessment of the current trends in cattle breeding drug abuse. Among non‐compliant results, nine borderline cases of growth‐promoters illegal treatments, making use of long‐term low‐dosage administrations and typically yielding urine residues below the cut‐off value for immunochemical methods, were detected by using the present LC‐MS/MS method.
Investigation of brush‐type chiral stationary phases based on O,O′‐diaroyl tartardiamide and O,O′‐bis‐(arylcarbamoyl) tartardiamide
Authors: Wu Haibo , Ji Shuying , Yang Bing , Yu Hui , Jin Yu , Ke Yanxiong , Liang Xinmiao 
Published: January 2012

AbstractFour chiral organosilanes based on O,O′‐dibenzoyl tartardiamide, O,O′‐bis‐(3,5‐dimethylbenzoyl) tartardiamide, O,O′‐bis‐(phenylcarbamoyl) tartardiamide and O,O′‐bis‐[(3,5‐dimethylphenyl)carbamoyl] tartardiamide were synthesized and immobilized on silica to afford corresponding brush‐type chiral stationary phases (CSPs) with well‐defined structures. Using 54 compounds containing a wide variety of structures as analytes, the enantioselectivities of the four CSPs were evaluated under normal‐phase modes. 3,5‐Dimethyl substituent in the aryl group was found to significantly affect the enantioselectivity of CSPs containing aryl ester moieties. Aryl carbamate moieties in CSPs were observed more beneficial for enantioseparation than aryl ester moieties. The additional hydrogen‐bond donors (NH) present in the carbamate groups contributed greatly to the enantioselectivity of CSPs, which is contrary to the results that have been found in network‐polymeric CSPs.
Materials and Corrosion 1/2012
Authors: Yang Z.‐G. , Gong Y. , Yuan J.‐Z. 
Published: January 2012

Cover: Hydrogen blistering, which was induced by the interaction of galvanic corrosion and crevice corrosion within the 0.5mm gap between titanium tube and carbon steel tube sheet, occurred at 35∼40°C on the outside wall of the tube used in the RCW (recirculating cooling water) heat exchanger of Qinshan Nuclear Power Plant in China. Afterwards, the tube wall was bulged inwards to the inside wall, and then localizedly thinned by oriented eddy erosion from the seawater containing sediment particles inside the tube until being ruptured.More detailed information can be found in: Z.‐G. Yang, Y. Gong, J.‐Z. Yuan, Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant. Part I: Electrochemical corrosion, Materials and Corrosion 2012, 63, page 7.
Clinical application of pharmacokinetic analysis as a biomarker of solitary pulmonary nodules: Dynamic contrast‐enhanced MR imaging
Authors: Mamata Hatsuho , Tokuda Junichi , Gill Ritu R. , Padera Robert F. , Lenkinski Robert E. , Sugarbaker David J. , Butler James P. , Hatabu Hiroto 
Published: January 2012

AbstractThe purpose of this study is to evaluate perfusion indices and pharmacokinetic parameters in solitary pulmonary nodules (SPNs). Thirty patients of 34 enrolled with SPNs (15–30 mm) were evaluated in this study. T1 and T2‐weighted structural images and 2D turbo FLASH perfusion images were acquired with shallow free breathing. B‐spline nonrigid image registration and optimization by χ2 test against pharmacokinetic model curve were performed on dynamic contrast‐enhanced MRI. This allowed voxel‐by‐voxel calculation of kep, the rate constant for tracer transport to and from plasma and the extravascular extracellular space. Mean transit time, time‐to‐peak, initial slope, and maximum enhancement (Emax) were calculated from time–intensity curves fitted to a gamma variate function. After blinded data analysis, correlation with tissue histology from surgical resection or biopsy samples was performed. Histologic evaluation revealed 25 malignant and five benign SPNs. All benign SPNs had kep < 1.0 min−1. Nineteen of 25 (76%) malignant SPNs showed kep > 1.0 min−1. Sensitivity to diagnose malignant SPNs at a cutoff of kep = 1.0 min−1 was 76%, specificity was 100%, positive predictive value was 100%, negative predictive value was 45%, and accuracy was 80%. Of all indices studied, kep was the most significant in differentiating malignant from benign SPNs. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Isotropic submillimeter fMRI in the human brain at 7 T: Combining reduced field‐of‐view imaging and partially parallel acquisitions
Authors: Heidemann Robin M. , Ivanov Dimo , Trampel Robert , Fasano Fabrizio , Meyer Heiko , Pfeuffer Josef , Turner Robert 
Published: January 2012

AbstractEcho‐planar imaging is the most widely used imaging sequence for functional magnetic resonance imaging (fMRI) due to its fast acquisition. However, it is prone to local distortions, image blurring, and signal voids. As these effects scale with echo train length and field strength, it is essential for high‐resolution echo‐planar imaging at ultrahigh field to address these problems. Partially parallel acquisition methods can be used to improve the image quality of echo‐planar imaging. However, partially parallel acquisition can be affected by aliasing artifacts and noise enhancement. Another way to shorten the echo train length is to reduce the field‐of‐view (FOV) while maintaining the same spatial resolution. However, to achieve significant acceleration, the resulting FOV becomes very small. Another problem occurs when FOV selection is incomplete such that there is remaining signal aliased from the region outside the reduced FOV. In this article, a novel approach, a combination of reduced FOV imaging with partially parallel acquisition, is presented. This approach can address the problems described above of each individual method, enabling high‐quality single‐shot echo‐planar imaging acquisition, with submillimeter isotropic resolution and good signal‐to‐noise ratio, for fMRI at ultrahigh field strength. This is demonstrated in fMRI of human brain at 7T with an isotropic resolution of 650 μm. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Comparing Gait Performance of People with Charcot‐Marie‐Tooth Disease Who Do and Do Not Wear Ankle Foot Orthoses
Authors: Ramdharry Gita M. , Pollard Alexander J. , Marsden Jonathan F. , Reilly Mary M. 
Published: January 2012

AbstractBackground and PurposeAnkle foot orthoses (AFOs) are commonly prescribed for people with Charcot‐Marie‐Tooth (CMT) disease. Scant evidence exists to guide the type and timing of orthotic prescription. This study explores the latter issue by investigating the differences in presentation and gait function of people with CMT disease who wore AFOs for daily mobility (n = 11) and a group who did not (n = 21). The aim was to see if there was a difference in the characteristics in people who regularly wear AFOs.MethodsPrimary measures of gait function were a 10‐m timed walk (comfortable and maximum speed) and a 6‐minute walk test. Means of the variables were compared using independent t‐tests. Secondary measures included disease severity, lower limb muscle strength, sensory impairment, walking effort, fatigue severity and perceived walking ability.ResultsAFO wearers walked slower with higher effort. They also had greater disease severity, weaker leg muscles and perceived greater walking difficulty. Subjects not wearing AFOs showed significant relationships between gait variables and muscle strength, whereas AFO wearers showed significant relationships between gait variables and perceived walking ability, fatigue severity and effort.ConclusionsPeople who regularly wore AFOs were more severely affected, had a slower maximum walking speed, higher energy cost of walking and worse perceived walking ability. Walking ability in this group was related to fatigue, perceived exertion during walking and perceived walking ability. Gait function of people not using AFOs was determined by lower limb muscle function. People prescribed AFOs, those who do not wear them and those not prescribed AFOs were similar in presentation, suggesting that people choose to wear orthoses when their condition becomes sufficiently severe. Copyright © 2012 John Wiley & Sons, Ltd.
Crystal structure and fluorescence studies reveal the role of helical dimeric interface of staphylococcal fabg1 in positive cooperativity for NADPH
Authors: Dutta Debajyoti , Bhattacharyya Sudipta , Das Amit Kumar 
Published: January 2012

AbstractCrystal structure of Staphylococcal β‐ketoacyl‐ACP reductase 1 (SaFabG1) complexed with NADPH is determined at 2.5 Å resolution. The enzyme is essential in FAS‐II pathway and utilizes NADPH to reduce β‐ketoacyl‐ACP to (S)‐β‐hydroxyacyl‐ACP. Unlike the tetrameric FabGs, dimeric SaFabG1 shows positive homotropic cooperativity towards NADPH. Analysis of FabG:NADPH binary crystal structure endorses that NADPH interacts directly with the helices α4 and α5 those are present on a dimerization interface. A steady shift in tryptophan (of α4 helix) emission peak upon steady increment of NADPH concentration reveals that the dimeric interface is formed by α4‐α4′ and α5‐α5′ helices. This dimeric interface imparts positive homotropic cooperativity towards NADPH. PEG, a substrate mimicking molecule is also found near the active site of the enzyme. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Photoprotection for deltamethrin using chitosan‐coated beeswax solid lipid nanoparticles
Authors: Nguyen Hiep Minh , Hwang In‐Cheon , Park Jae‐Won , Park Hyun‐Jin 
Published: January 2012

AbstractBACKGROUND: In the natural environment, photodegradation is one of the most common degradative processes of pesticides. In order to reduce the photodegradation of pesticides, and so increase their killing activity against target pests, chitosan‐coated beeswax solid lipid nanoparticles (CH‐BSLNs) were prepared by a combination of hot homogenization and sonication, with deltamethrin as an active ingredient.RESULTS: Under optimal conditions, the highest encapsulation efficiency (95%) and a high payload of deltamethrin (approximately 12.5%) were achieved. In direct photolysis, in the case of CH‐BSLNs after UV irradiation for 24 h, 37.3% of deltamethrin remained, as opposed to only 14.6% of the free‐form deltamethrin. In addition, in indirect photolysis, in the case of CH‐BSLNs after UV irradiation for 2 h in 2% acetone solution, approximately 74.5% of deltamethrin remained, as opposed to only 37.6% of the free‐form deltamethrin.CONCLUSION: CH‐BSLNs showed good protection for deltamethrin against photodegradation. This novel nanocarrier may be useful in crop protection as an economical strategy to enhance the effect of pesticides in the field and protect the environment as well. Copyright © 2012 Society of Chemical Industry
Acaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two‐spotted spider mite (Tetranychus urticae)
Authors: Attia Sabrine , Grissa Kaouthar L , Mailleux Anne C , Heuskin Stéphanie , Lognay Georges , Hance Thierry 
Published: January 2012

AbstractBACKGROUND: Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in the world.RESULTS: The chemical composition of the two oils was characterised by GC‐MS. The most abundant component in the Santolina africana (Jord. & Fourr) oil was terpinen‐4‐ol (54.96%), while thymol (61%) was prevalent in the Hertia cheirifolia (L.) oil. Mortality and fecundity were measured upon treatment with oil concentrations ranging from 0.07 to 6.75 mg L−1 with a Potter spray tower. Mite mortality increased with oil concentration, with LC50 values of 2.35 mg L−1 for S. africana and 3.43 mg L−1 for H. cheirifolia respectively. For both oils, a reduction in fecundity was observed at concentrations of 0.07, 0.09 and 0.29 mg L−1. Artificial blends of constituents of oils were also prepared and tested with individual constituents missing from the mixture. The results showed that the presence of all constituents was necessary to equal the toxicity of the two natural oils.CONCLUSION: S. africana and H. cheirifolia oils can provide valuable acaricide activity with significantly lower LC50 values. Thus, these oils cause important mortality and reduce the number of eggs laid by females. Copyright © 2012 Society of Chemical Industry
Self‐assembled GaN nanostructures by dry etching and their optical properties
Authors: Haab Anna , Mikulics Martin , Winden Andreas , Voigt Sally , von der Ahe Martina , Moers Jürgen , Wirtz Konrad , Stoica Toma , Grützmacher Detlev , Hardtdegen Hilde 
Published: January 2012

AbstractThe influence of process parameters and template characteristics on the morphology and optical properties of self‐assembled nanostructures produced by dry etching from GaN/sapphire templates was investigated. It was found that the chemical component in the etching gas–chlorine supports the formation of nanostructures and that a minimum amount of RF and ICP power (i.e., energy) is necessary. Additionally the crystalline imperfection and the doping concentration of the template greatly affect the nanostructure morphology. All nanostructures exhibit higher luminescence intensity than the templates they are fabricated from and exhibit a red‐shift of the luminescence with respect to the epilayer. The results indicate effective strain relaxation as well as more efficient absorption of the incoming photons the smaller the nanostructures become.
Crystal growth and spectroscopic properties of Er3+‐doped CaYAlO4
Authors: Zhou Dahua , Xu Xiaodong , Chen Xueyuan , Zhu Haomiao , Li Dongzhen , Di Juqing , Xia Changtai , Wu Feng , Xu Jun 
Published: January 2012

AbstractA single crystal of 1% Er3+‐doped CaYAlO4 has been grown by the traditional Czochralski method. The as‐grown crystal showed optical transparency and developed two planes along the (001) direction. The absorption spectra showed a marked difference in the 4I15/2 → 4I13/2 and 4I15/2 → 4F9/2 transitions with different polarizing direction. Due to the disordered crystal structure, broad absorption, and emission spectra around 1550 nm were obtained. In our experiments, the lifetime of the 4I13/2 excited state of Er3+ was determined to be 3.46 ms by the powder method, while it was 4.95 ms in the bulk samples. In addition, the upconversion spectrum in the green and red regions was observed pumped by a laser diode (LD) at 970 nm.
Synthesis of Nanoamorphous Germanium and Its Transformation to Nanocrystalline Germanium
Authors: Dag Ömer , Henderson Eric J. , Ozin Geoffrey A. 
Published: January 2012

AbstractA simple reaction between a mild reducing agent such as a trialkoxysilane and GeIV species such as germanium tetraalkoxides in a room‐temperature water/alcohol solution produces silica‐coated ultrasmall (2–3 nm) amorphous germanium nanoparticles (na‐Ge/SiO2). The initial reaction involves the straightforward hydrolysis and condensation of the precursors, Ge(OCH2CH3)4 and (CH3CH2O)3SiH, where the reaction rate depends on the water concentration in the reaction medium. These processes can be further accelerated by adding acid to the reaction medium or carrying out the reaction at higher temperatures. At low water contents (up to 50% water/ethanol) and low acid concentrations, the reaction proceeds as a clear solution, and no precipitation is observed. The initially colorless clear solution progressively changes to pale yellow, yellow, orange, red, and finally dark red as the na‐Ge particles grow. Evaporation of the solvent yields a reddish‐brown powder/monolith consisting of na‐Ge, embedded in an encapsulating amorphous silica matrix, na‐Ge/SiO2. The formation of na‐Ge proceeds extremely slowly and follows a first‐order dependence on both water concentration and diameter of the na‐Ge particles under the reaction conditions used. Annealing of the na‐Ge/SiO2 powder under an inert atmosphere at 600 °C produces ultrasmall germanium nanocrystals (nc‐Ge) embedded in amorphous silica (nc‐Ge/SiO2). Freestanding, colloidally stable nc‐Ge is obtained by chemical etching of the encapsulating silica matrix.