bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric analysis of chlorophyll pigments in canola and rapeseed oils
Authors: Daun James K. 
Published: June 2012

AbstractOf all the vegetable oils commonly in production, rapeseed and canola oil have the highest level of undesirable chlorophyll pigments. Chlorophyll is desirable as a flavour and colour agent in olive oil, the other species with significant levels. In canola and rapeseed oils, chlorophyll is not desired because it imparts an undesirable colour, especially in North America where consumers are accustomed to colourless oils. It also makes the processed oils more susceptible to oxidation, even after the chlorophyll components have been removed. The content and role of chlorophyll in canola seed and oil have been well reviewed recently [1].
Regularized Dirac delta functions for phase field models
Authors: Lee Hyun Geun , Kim Junseok 
Published: June 2012

SUMMARYThe phase field model is a highly successful computational technique for capturing the evolution and topological change of complex interfaces. The main computational advantage of phase field models is that an explicit tracking of the interface is unnecessary. The regularized Dirac delta function is an important ingredient in many interfacial problems that phase field models have been applied. The delta function can be used to postprocess the phase field solution and represent the surface tension force. In this paper, we present and compare various types of delta functions for phase field models. In particular, we analytically show which type of delta function works relatively well regardless of whether an interfacial phase transition is compressed or stretched. Numerical experiments are presented to show the performance of each delta function. Numerical results indicate that (1) all of the considered delta functions have good performances when the phase field is locally equilibrated; and (2) a delta function, which is the absolute value of the gradient of the phase field, is the best in most of the numerical experiments. Copyright © 2012 John Wiley & Sons, Ltd.
A hybridized discontinuous Petrov–Galerkin scheme for scalar conservation laws
Authors: Moro D. , Nguyen N. C. , Peraire J. 
Published: June 2012

SUMMARYWe present a hybridized discontinuous Petrov–Galerkin (HDPG) method for the numerical solution of steady and time‐dependent scalar conservation laws. The method combines a hybridization technique with a local Petrov–Galerkin approach in which the test functions are computed to maximize the inf‐sup condition. Since the Petrov–Galerkin approach does not guarantee a conservative solution, we propose to enforce this explicitly by introducing a constraint into the local Petrov–Galerkin problem. When the resulting nonlinear system is solved using the Newton–Raphson procedure, the solution inside each element can be locally condensed to yield a global linear system involving only the degrees of freedom of the numerical trace. This results in a significant reduction in memory storage and computation time for the solution of the matrix system, albeit at the cost of solving the local Petrov–Galerkin problems. However, these local problems are independent of each other and thus perfectly scalable. We present several numerical examples to assess the performance of the proposed method. The results show that the HDPG method outperforms the hybridizable discontinuous Galerkin method for problems involving discontinuities. Moreover, for the test case proposed by Peterson, the HDPG method provides optimal convergence of order k + 1. Copyright © 2012 John Wiley & Sons, Ltd.
Floating stress‐point integration meshfree method for large deformation analysis of elastic and elastoplastic materials
Authors: Onishi Y. , Amaya K. 
Published: June 2012

SUMMARYA new meshfree formulation of stress‐point integration, called the floating stress‐point integration meshfree method, is proposed for the large deformation analysis of elastic and elastoplastic materials. This method is a Galerkin meshfree method with an updated Lagrangian procedure and a quasi‐implicit time‐advancing scheme without any background cell for domain integration. Its new formulation is based on incremental equilibrium equations derived from the incremental virtual work equation, which is not generally used in meshfree formulations. Hence, this technique allows the temporal continuity of the mechanical equilibrium to be naturally achieved. The details of the new formulation and several examples of the large deformation analysis of elastic and elastoplastic materials are presented to show the validity and accuracy of the proposed method in comparison with those of the finite element method. Copyright © 2012 John Wiley & Sons, Ltd.
Dynamic failure simulation of quasi‐brittle material in dual particle dynamics
Authors: Sanchez J.J. , Randles P.W. 
Published: June 2012

SUMMARYThe feasibility of simulating dynamic fracture in quasi‐brittle material using a dual particle computational method with a smeared‐crack representation of material failure is explored. The computational approach utilized is dual particle dynamics, which incorporates a moving least squares interpolation of field variables between two sets of particles that discretize the spatial domain, and a Lagrangian description of the moving least squares weight function. Material failure is represented by an inelastic continuum strain contribution obtained from smearing the effect of a cohesive failure model over a discrete volume of material. A three‐dimensional simulation of the initiation and development of a dynamic mode I failure is performed for the case of approximate plane wave propagation. Post failure wave interaction with the resulting global failure surface replicates the behavior of a stress‐free boundary condition. The computational material failure approach is applied to problems of spalling in split Hopkinson pressure bar tests. Experimental failure trends are reproduced successfully.Copyright © 2012 John Wiley & Sons, Ltd.
Partitioned vibration analysis of internal fluid‐structure interaction problems
Authors: González José A. , Park K.C. , Lee I. , Felippa C.A. , Ohayon R. 
Published: June 2012

SUMMARYA partitioned, continuum‐based, internal fluid–structure interaction (FSI) formulation is developed for modeling combined sloshing, acoustic waves, and the presence of an initial pressurized state. The present formulation and its computer implementation use the method of localized Lagrange multipliers to treat both matching and non‐matching interfaces. It is shown that, with the context of continuum Lagrangian kinematics, the fluid sloshing and acoustic stiffness terms originate from an initial pressure term akin to that responsible for geometric stiffness effects in solid mechanics. The present formulation is applicable to both linearized vibration analysis and nonlinear FSI transient analysis provided that a convected kinematics is adopted for updating the mesh geometry in a finite element discretization. Numerical examples illustrate the capability of the present procedure for solving coupled vibration and nonlinear sloshing problems. Copyright © 2012 John Wiley & Sons, Ltd.
Embedded kinematic boundary conditions for thin plate bending by Nitsche's approach
Authors: Harari Isaac , Shavelzon Evgeny 
Published: June 2012

SUMMARYA stabilized variational formulation, based on Nitsche's method for enforcing boundary constraints, leads to an efficient procedure for embedding kinematic boundary conditions in thin plate bending. The absence of kinematic admissibility constraints allows the use of non‐conforming meshes with non‐interpolatory approximations, thereby providing added flexibility in addressing the C1‐continuity requirements typical of these problems. Work‐conjugate pairs weakly enforce kinematic boundary conditions. The pointwise enforcement of corner deflections is key to good performance in the presence of corners. Stabilization parameters are determined from local generalized eigenvalue problems, guaranteeing coercivity of the discrete bilinear form. The accuracy of the approach is verified by representative computations with bicubic C2 B‐splines, exhibiting optimal rates of convergence and robust performance with respect to values of the stabilization parameters. Copyright © 2012 John Wiley & Sons, Ltd.
A sub‐grid scale finite element agglomeration multigrid method with application to the Boltzmann transport equation
Authors: Buchan A.G. , Pain C.C. , Umpleby A.P. , Smedley‐Stevenson R.P. 
Published: June 2012

SUMMARYThis article describes a new element agglomeration multigrid method for solving partial differential equations discretised through a sub‐grid scale finite element formulation. The sub‐grid scale discretisation resolves solution variables through their separate coarse and fine scales, and these are mapped between the multigrid levels using a dual set of transfer operators. The sub‐grid scale multigrid method forms coarse linear systems, possessing the same sub‐grid scale structure as the original discretisation, that can be resolved without them being stored in memory. This is necessary for the application of this article in resolving the Boltzmann transport equation as the linear systems become extremely large. The novelty of this article is therefore a matrix‐free multigrid scheme that is integrated within its own sub‐grid scale discretisation using dual transfer operators and applied to the Boltzmann transport equation.The numerical examples presented are designed to show the method's preconditioning capabilities for a Krylov space‐based solver. The problems range in difficulty, geometry and discretisation type, and comparisons made with established methods show this new approach to perform consistently well. Smoothing operators are also analysed and this includes using the generalized minimal residual method. Here, it is shown that an adaptation to the preconditioned Krylov space is necessary for it to work efficiently. Copyright © 2012 John Wiley & Sons, Ltd.
H1‐Galerkin expanded mixed finite element methods for nonlinear pseudo‐parabolic integro‐differential equations
Authors: Che Haitao , Zhou Zhaojie , Jiang Ziwen , Wang Yiju 
Published: June 2012

AbstractH1‐Galerkin mixed finite element method combined with expanded mixed element method is discussed for nonlinear pseudo‐parabolic integro‐differential equations. We conduct theoretical analysis to study the existence and uniqueness of numerical solutions to the discrete scheme. A priori error estimates are derived for the unknown function, gradient function, and flux. Numerical example is presented to illustrate the effectiveness of the proposed scheme. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Posterior brain in fetuses with trisomy 18, trisomy 13 and triploidy at 11 to 13 weeks' gestation
Authors: Ferreira Ana Fatima A. , Syngelaki Argyro , Smolin Anna , Vayna Ana‐Maria , Nicolaides Kypros H. 
Published: June 2012

ABSTRACTObjectiveTo measure changes in the posterior fossa of first‐trimester fetuses with trisomy 18, trisomy 13 and triploidy.MethodsBrain stem (BS) diameter and BS to occipital bone (BSOB) diameter were measured in images of the midsagittal view of the face at 11+0 to 13+6 weeks from 45 trisomy 18, 21 trisomy 13 and 15 triploid fetuses and compared with values in 162 euploid fetuses.ResultsIn euploid fetuses BS and BSOB diameters increased significantly with crown–rum length and the BS to BSOB ratio decreased. In all three aneuploidies BSOB diameter was significantly higher than in euploid fetuses. In trisomy 18 and trisomy 13, the BS diameter and BS to BSOB ratio were decreased. The BS to BSOB ratio was below the 5th percentile in 16 (35.6%), 17 (81.0%) and 5 (33.3%) of trisomy 18, trisomy 13 and triploidy, respectively. In 7 (8.6%) of the aneuploid fetuses there was open spina bifida and in all these cases the BS to BSOB ratio was above the 95th percentile.ConclusionsAt 11 to 13 weeks' gestation many fetuses with trisomy 18, trisomy 13 and triploidy have measurable abnormalities in the posterior brain. © 2012 John Wiley & Sons, Ltd.
Service users and care providers' experiences of tertiary combined fetal medicine clinics
Authors: Miller Sarah , Liao Lih‐Mei , Warner Deborah , Chitty Lyn S. 
Published: June 2012

ABSTRACTObjectiveTo explore service users and care providers' experiences of combined fetal medicine and specialist paediatric clinics.MethodA brief survey of service users and care providers at combined fetal medicine clinics, which bring together multiple specialists and expertise for the management of pregnancies complicated by fetal cardiac, renal, neurological or surgical abnormalities.ResultsTwo hundred and sixty‐one patients and 22 health professionals participated. More than 85% of women rated the clinic highly, 61% reported that the service had changed how they viewed the abnormality, and 53% reported that they would welcome further visits to the combined clinic. The majority of health professionals reported that combined clinics improved the accuracy of parental counselling and enhanced communication between specialties involved in the management of complicated pregnancies. The clinics are generally regarded as being useful for the training of junior staff.ConclusionA service model that combines fetal medicine and paediatric specialists in a single clinic can efficiently modify parental perspective on fetal anomalies and enhance professional communication and training. Condition‐specific information leaflets could further enhance service quality. A larger study involving a socio‐demographically stratified sample of service users is needed to provide more authoritative data. © 2012 John Wiley & Sons, Ltd.
Implications for CdTe and CIGS technologies production costs of indium and tellurium scarcity
Authors: Candelise Chiara , Winskel Mark , Gross Robert 
Published: June 2012

ABSTRACTScarcity of indium and tellurium has been highlighted as a potential barrier for cadmium telluride (CdTe) and copper indium gallium (di)selenide (CIGS) thin film technologies to achieve both large‐scale deployment and reduction in production costs. With the aim of assessing the relative weight of the aforementioned concerns, this paper looks at indium and tellurium availability and implications for CIGS and CdTe production costs of their price increases. A breakdown of CdTe and CIGS module production costs is provided, accounting for the relative share of each component materials over total module cost. Conditions affecting usage of the key materials in CdTe and CIGS technologies are weighted against potential future indium and tellurium price escalation to provide a fuller picture of production cost implications for the thin film photovoltaics technologies. This includes exploring and quantifying the potential for innovation and technological developments (including efficiency increases, reduced absorber layer, higher material utilisation during deposition process) to ease the impact of possible future indium and tellurium supply constraints and price increases. Copyright © 2012 John Wiley & Sons, Ltd.
A new access to polypyrrole‐based functionalized magnetic core‐shell nanoparticles
Authors: Karsten Sebastian , Nan Alexandrina , Turcu Rodica , Liebscher Jürgen 
Published: June 2012

AbstractMagnetic nanoparticles (NP) have found various important applications in nanotechnology and nanomedicine, because they can be manipulated by external magnetic field and can be functionalized on their surface. Although a variety of magnetic core shell NP are known present research focuses on new NP with better properties (reduced toxicity, high colloidal and chemical stability, wide scope of application) and more straightforward and reproducible syntheses. In this work, we report the synthesis of azido‐functionalized polypyrrole (PPy)‐based superparamagnetic core shell NP by surface initiated polymerization wherein miniemulsion technique have been applied in this field for the first time. The new NP are attractive for biomedical applications because the PPy is biocompatible, the shell can easily be functionalized by Cu‐catalyzed click‐reaction as shown by the introduction of biotin and the material exhibits superparamagnetic behavior. The surface initiated polymerization is carried out at new magnetite NP, which are stabilized by pyrrol‐containing fatty acids. Although these starting NP lack a polymer shell, they show a remarkable stability and thus have the potential for further functionalization. The magnetic NP are characterized by various methods such as FTIR, X‐ray photoelectron spectroscopy, magnetic measurements, thermal gravimetric analysis, and dynamic light scattering. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Benzooxadiazaole‐based D–A–D co‐oligomers: Synthesis and electropolymerization
Authors: Pati Palas Baran , Das Soumyajit , Zade Sanjio S. 
Published: June 2012

AbstractFour D–A–D type co‐oligomers have been synthesized by Stille condensation between monostannyl derivatives of furan/thiophene/selenophene/3,4‐ethylenedioxythiophene (EDOT) and 4,7‐dibromo‐benzo[1,2,5]oxadiazole. All these co‐oligomers were successfully electrochemically polymerized in dichloromethane and characterized by spectroelectrochemistry. All four polymers possess narrow optical band gap. Spectroelectrochemical studies of polymer films on indium tin oxide revealed that the replacement of donor EDOT with furan/thiophene/selenophene has affected the low‐energy charge‐carrier (bipolaron) formation significantly. Kinetic studies based on chronoamperometry show that the polymer P5 (EDOT‐capped benzo[1,2,5]oxadiazole system) possess better electrochromic property with high transmittance (66%) in visible region than the other copolymers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Negative cancer stereotypes and disease‐specific self‐concept in head and neck cancer
Authors: Wong Janice C. , Payne Ada Y. M. , Mah Kenneth , Lebel Sophie , Lee Ruth N. F. , Irish Jonathan , Rodin Gary , Devins Gerald M. 
Published: June 2012

AbstractBackgroundLife‐threatening diseases, such as head and neck cancer (HNCa), can stimulate the emergence of a new disease‐specific self‐concept. We hypothesized that (i) negative cancer‐stereotypes invoke distancing, which inhibits the adoption of a disease‐specific self‐concept and (ii) patient characteristics, disease and treatment factors, and cancer‐related stressors moderate the phenomenon.MethodsHead and neck cancer outpatients (N = 522) completed a semantic‐differential measure of disease‐specific self‐concept (perceived similarity to the ‘cancer patient’) and other self‐report measures in structured interviews. Negative cancer‐stereotypes were represented by the number of semantic‐differential dimensions (0–3) along which respondents evaluated the stereotypic ‘cancer patient’ negatively (i.e., negative valence). We tested the two‐way interactions between negative valence and hypothesized moderator variables.ResultsWe observed significant negative valence × moderator interactions for the following: (i) patient characteristics (education, employment, social networks); (ii) disease and treatment factors (cancer‐symptom burden); and (iii) cancer‐related stressors (uncertainty, lack of information, and existential threats). Negative cancer stereotypes were consistently associated with distancing of self from the stereotypic ‘cancer patient,’ but the effect varied across moderator variables. All significant moderators (except employment and social networks) were associated with increasing perceived similarity to the ‘cancer patient’ when respondents maintained negative stereotypes; perceived similarity decreased when people were employed or had extensive social networks. Moderator effects were less pronounced when respondents did not endorse negative cancer stereotypes.DiscussionWhen they hold negative stereotypes, people with HNCa distance themselves from a ‘cancer patient’ identity to preserve self‐esteem or social status, but exposure to cancer‐related stressors and adaptive demands may attenuate these effects. Copyright © 2012 John Wiley & Sons, Ltd.
Introduction of Basic Functionalities on the Surface of Granular Adsorbers by Low Pressure Plasma Processes
Authors: De Vietro Nicoletta , d'Agostino Riccardo , Fracassi Francesco 
Published: June 2012

AbstractLow pressure plasma, generated in a radio frequency reactor under rotation, was utilized to modify the ability of granular substrates to adsorb volatile acid compounds. Carbon black granules were treated with NH3 or allylamine containing feeds, while sepiolite granules were processed only in allylamine fed discharges. The chemical modifications induced by plasma treatments were evaluated by means of X‐ray photoelectron spectroscopy studies and water contact angle measurements, while scanning electron microscope and Brunauer, Emmet, Teller analyses were performed to study the surface morphological changes caused by plasma processes. The ability of the treated materials to adsorb acids, in gas or vapour phase, was estimated with hydrochloric, acetic and propanoic acid, employing a home‐made test system. The results show that the optimized plasma treatments are able to improve the adsorption ability of carbon black and sepiolite granules for the three acids investigated.magnified image
Electrospray ionization and matrix‐assisted laser desorption/ionization mass spectrometric analysis of extrapolysaccharides of Escherichia coli
Authors: Gedda Gangaraju , Gopal Judy , Wu Hui‐Fen 
Published: June 2012

RATIONALEConventional studies of extracellular polymeric substances (EPS) typically require elaborate separation procedures or complicated sample pretreatment processes such as purification by dialysis and lyophilization. The objective of this study is to demonstrate the use of electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry (MS) as powerful techniques for direct analysis of EPS secreted by E. coli.METHODSWe have compared the extraction efficiency of two widely used extraction methods including physical extraction (room‐temperature centrifugation and high‐speed centrifugation) and chemical extraction using EDTA and formaldehyde. We specify the most favorable extraction method and the analyte to extractant concentration with respect to mass spectrometric analysis of EPS, based on the results obtained from ESI‐MS and MALDI‐MS analysis.RESULTSChemical extraction methods were found to be more efficient than physical extraction methods. Of the chemical extractants, EDTA was found more effective compared to formaldehyde and gave more EPS peaks during ESI‐ and MALDI‐MS analysis. We report the classification of E. coli EPS into loosely bound, bound and tightly bound EPS based on a simple modification of an existing methodology. Our studies showed that ESI‐MS was very effective for <300 Da EPS studies and MALDI‐MS more suitable for rapid analysis of EPS above mass range 400 Da.CONCLUSIONSThis is a preliminary study reporting for the first time the feasibility of ESI‐MS and MALDI‐MS techniques for the analysis of bacterial EPS without prior complicated purification and separation methodologies. Copyright © 2012 John Wiley & Sons, Ltd.