bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and properties of chlorogenic acid lipophilic esters
Authors: Pencreac'h Gaëlle , Lorentz Cécile , Ergan Françoise , Soultani‐Vigneron Samia 
Published: May 2012

AbstractChlorogenic acid is a dietary polyphenol with important bioactivities. However, its high hydrophilicity prevents its applications as an antioxidant for lipid protection in a complex matrix such as food. Grafting an aliphatic chain onto chlorogenic acid, so‐called lipophilisation, via lipase‐catalysed esterification represents an efficient means of increasing its lipophilicity. A series of alkyl esters with various chain lengths were produced and used to explore the structure‐antioxidant activity relationship of amphiphilic antioxidants. Data obtained from complex systems (oil‐in‐water emulsion and cell culture) concluded that short or medium chain lengths enhance the antioxidant activity while longer chains tend to decrease the antioxidant ability of chlorogenic acid. This phenomenon remains to be fully explained. Acyl esters, in which the carboxylic acid group remains free were also produced and were shown to be interesting antioxidant candidates as well as useful tools for the understanding of antioxidant activities.
Optimum shape design for surface of a thermohydrodynamic lubrication slider bearing
Authors: Alyaqout Sulaiman F. , Elsharkawy Abdallah A. 
Published: May 2012

ABSTRACTThis paper utilises a thermohydrodynamic model of bearing to optimise the shape of slider bearing. Friction is minimised subject to load and centre of pressure requirements using a sequential quadratic programming algorithm. A generalised Reynolds equation is solved simultaneously with an energy equation using the finite volume method to obtain bearing characteristics, such as friction, load and centre of pressure. Results show that the coefficient of friction is reduced by the optimisation approach. Results also show that larger temperature–viscosity coefficient and inlet viscosity tend to yield smaller optimal friction, whereas larger thermal conductivity tends to yield larger optimal friction. Copyright © 2012 John Wiley & Sons, Ltd.
Materials and Corrosion 5/2012
Authors: Li Q. , Turhan M. C. , Rottmair C. A. , Singer R. F. , Virtanen S. 
Published: May 2012

Cover: The main image was taken by optical microscopy and shows a polished 0.1 wt% well‐dispersed MWCNT/AZ91 sample after 1 day immersion in 3.5% NaCl. The inset presents a SEM image of pristine MWCNTs, which we postulate to act as electrodes in the AZ91 composites. The evenly distributed corrosion pattern in the main image indicates that with well‐dispersed MWCNTs in AZ91, formation of galvanic couples takes place everywhere on the composite surface. The corrosion rate of the AZ91 composites with well dispersed MWCNTs is therefore strongly increased compared to the composites with less well dispersed MWCNTs and pure AZ91.More detailed information can be found in: Q. Li, M. C. Turhan, C. A. Rottmair, R. F. Singer, S. Virtanen, Influence of MWCNT Dispersion on Corrosion Behaviour of their Mg Composites, Materials and Corrosion 2012, 63, 384.
Ceramic Filament Fibers – A Review
Authors: Schawaller Dirk , Clauß Bernd , Buchmeiser Michael R. 
Published: May 2012

AbstractCeramic fibers are essential components of new high‐temperature‐resistant lightweight materials. The production routes of ceramic filament fibers are complex and in most cases polymeric components or structures are key factors for fiber spinning. Either organic polymers are used as additives in the spinning dopes for oxide ceramic fibers or inorganic polymers are the precursors for the production of non‐oxide fibers. This paper gives an up‐to‐date overview about different ceramic fibers and the chemistry behind the fiber development and production.magnified image
Proteine auf medizinischen und technischen Substraten
Authors: Ziegler Christiane , Müller Christine 
Published: May 2012

AbstractBevor sich auf einer festen Oberfläche ein Biofilm bildet, adsorbieren in der Regel Proteine. Ein solches Adsorbat zu charakterisieren, erfordert die Kombination mehrerer oberflächenanalytischer Methoden, die alle ihre spezifischen Grenzen haben. Oft gelingt es nur in kleinen Schritten und über Modellsysteme, ein Proteinadsorbat auf einer realen Oberfläche zu beschreiben.
Flüchtige Substanzen in Wasser
Authors: Meletis Panos 
Published: May 2012

AbstractDie deutsche Trinkwasserverordnung fordert, gesundheitsschädliche flüchtige organische Substanzen wie Benzol oder Vinylchlorid zu überwachen. Um Spuren der Substanzen mit Headspace‐GC‐MS zu identifizieren und zu quantifizieren, hilft eine Kühlfalle am Säulenanfang direkt unter dem Injektor. Sie fokussiert den Analyten, so dass die Peaks schärfer werden und die Empfindlichkeit des Messverfahrens steigt.
Steepest descent preconditioning for nonlinear GMRES optimization
Authors: Sterck Hans De 
Published: May 2012

SUMMARYSteepest descent preconditioning is considered for the recently proposed nonlinear generalized minimal residual (N‐GMRES) optimization algorithm for unconstrained nonlinear optimization. Two steepest descent preconditioning variants are proposed. The first employs a line search, whereas the second employs a predefined small step. A simple global convergence proof is provided for the N‐GMRES optimization algorithm with the first steepest descent preconditioner (with line search), under mild standard conditions on the objective function and the line search processes. Steepest descent preconditioning for N‐GMRES optimization is also motivated by relating it to standard non‐preconditioned GMRES for linear systems in the case of a standard quadratic optimization problem with symmetric positive definite operator. Numerical tests on a variety of model problems show that the N‐GMRES optimization algorithm is able to very significantly accelerate convergence of stand‐alone steepest descent optimization. Moreover, performance of steepest‐descent preconditioned N‐GMRES is shown to be competitive with standard nonlinear conjugate gradient and limited‐memory Broyden–Fletcher–Goldfarb–Shanno methods for the model problems considered. These results serve to theoretically and numerically establish steepest‐descent preconditioned N‐GMRES as a general optimization method for unconstrained nonlinear optimization, with performance that appears promising compared with established techniques. In addition, it is argued that the real potential of the N‐GMRES optimization framework lies in the fact that it can make use of problem‐dependent nonlinear preconditioners that are more powerful than steepest descent (or, equivalently, N‐GMRES can be used as a simple wrapper around any other iterative optimization process to seek acceleration of that process), and this potential is illustrated with a further application example. Copyright © 2012 John Wiley & Sons, Ltd.
Efficient non‐linear proper orthogonal decomposition/Galerkin reduced order models with stable penalty enforcement of boundary conditions
Authors: Kalashnikova I. , Barone M. F. 
Published: May 2012

SUMMARYAn efficient, stability‐preserving model reduction technique for non‐linear initial boundary value problems whose solutions exhibit inherently non‐linear dynamics such as metastability and periodic regimes (limit cycles) is developed. The approach is based on the ‘continuous’ Galerkin projection approach in which the continuous governing equations are projected onto the reduced basis modes in a continuous inner product. The reduced order model (ROM) basis is constructed via a proper orthogonal decomposition (POD). In general, POD basis modes will not satisfy the boundary conditions of the problem. A weak implementation of the boundary conditions in the ROM based on the penalty method is developed. Asymptotic stability of the ROM with penalty‐enforced boundary conditions is examined using the energy method, following linearization and localization of the governing equations in the vicinity of a stable steady solution. This analysis, enabled by the fact that a continuous representation of the reduced basis is employed, leads to a model reduction method with an a priori stability guarantee. The approach is applied to two non‐linear problems: the Allen–Cahn (or ‘bistable’) equation and a convection‐diffusion‐reaction system representing a tubular reactor. For each of these problems, bounds on the penalty parameters that ensure asymptotic stability of the ROM solutions are derived. The non‐linear terms in the equations are handled efficiently using the ‘best points’ interpolation method proposed recently by Peraire, Nguyen et al. Numerical experiments reveal that the POD/Galerkin ROMs with stability‐preserving penalty boundary treatment for the two problems considered, both without as well as with interpolation, remain stable in a way that is consistent with the solutions to the governing continuous equations and capture the correct non‐linear dynamics exhibited by the exact solutions to these problems. Published 2012. This article is a US Government work and is in the public domain in the USA.
Biquadratic finite volume element method based on optimal stress points for second order hyperbolic equations
Authors: Yu Changhua , Li Yonghai 
Published: May 2012

AbstractBased on optimal stress points, we develop a full discrete finite volume element scheme for second order hyperbolic equations using the biquadratic elements. The optimal order error estimates in L∞(H1), L∞(L2) norms are derived, in addition, the superconvergence of numerical gradients at optimal stress points is also discussed. Numerical results confirm the theoretical order of convergence. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
Life‐sustaining treatment decisions in the ICU for patients with ESLD: A prospective investigation
Authors: Hansen Lissi , Press Nancy , Rosenkranz Susan J. , Baggs Judith Gedney , Kendall Judith , Kerber Amanda , Williamson Angel , Chesnutt Mark S. 
Published: May 2012

AbstractWe conducted a prospective study in the ICU of life‐sustaining treatment and comfort care decisions over time in patients with end‐stage liver disease (ESLD) from the perspectives of patients, family members, and healthcare professionals. Six patients with ESLD, 19 family members, and 122 professionals participated. The overarching theme describing the decision‐making process was “on the train.” Four sub‐themes positioned patients and family members as passengers with limited control, unable to fully understand the decision‐making process. Findings suggest that including patients and family members in non‐immediate life‐saving decisions and verifying early on their understanding may help to improve the decision‐making process. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:518–532, 2012
Personality disorders with over‐regulation of emotions and poor self‐reflectivity—The case of a man with avoidant and not‐otherwise specified personality disorder and social phobia treated with Metacognitive Interpersonal Therapy
Authors: Dimaggio Giancarlo , Attinà Giovanna , Popolo Raffaele , Salvatore Giampaolo 
Published: May 2012

ABSTRACTTreating patients with personality disorders (PD) with significant over‐regulation of affects, poor metacognition and a restricted interpersonal schema repertoire requires specialized procedures. We present here the case of a man in his 30s suffering from Avoidant PD and overall 21 PD criteria met, with co‐occurring axis I disorders. Metacognitive Interpersonal Therapy was used, and after 1 year of therapy, outcome was good, although therapy is still continuing. First, a more nuanced understanding of mental states and then attempts at change began, which led to a modification of the patient's negative self‐image and a reduction of social avoidance. The possible relevance and generalization of formalized procedures, applied with a careful case formulation, is discussed to successfully treat persons with this type of complex PD. Copyright © 2012 John Wiley & Sons, Ltd.
Physiotherapy after stroke: More is better?
Authors: Langhorne Peter , Wagenaar Robert , Partridge Cecily 
Published: May 2012

AbstractPhysiotherapy is an established component of stroke rehabilitation but uncertainties remain about the most appropriate intensity of therapy input. We conducted a systematic review of the randomised trials of physiotherapy after stroke where qualitatively similar therapy regimens were provided at different levels of intensity. A heterogeneous group of seven randomised trials (597 patients) was identified. Dichotomous outcomes (death or the combined poor outcome of death or deterioration) were analysed by use of the odds ratio and 95% confidence interval. Patients subjected to more intensive physiotherapy input showed a non‐significant reduction in case fatality (odds ratio 0.60; 95% CI 033–1.09) and a significant reduction (OR 0.54; 95% CI 0.34–0.85; p<0.01) in the combined poor outcome of death or deterioration by the end of follow‐up. Two statistical techniques were used to identify patterns within the continuous data. Firstly, impairment and disability scores were converted to a standardised measure of 0–100 and the weighted mean difference (WMD) between the scores in the intensive and conventional physiotherapy groups were then calculated. Modest improvements were observed in both the impairment (WMD+5; 95% CI–1–11) and disability scores (WMD+5; 95% CI 0–10) recorded at the initial review (median 3 months post‐stroke), but not at the final review (median 1 year post‐stroke). Secondly, Fisher's inverse chi‐squared test was used to combine the p values from individual trials; this confirmed the above findings (p<0.05 at initial review; p>0.05 at final review). More intensive physiotherapy input was associated with a reduction in the combined poor outcome of death or deterioration and may enhance the rate of recovery. These observations warrant further investigation.
Physiotherapy in knee osteoarthrosis: Effect on pain and walking
Authors: Börjesson M , Robertson E , Weidenhielm L , Mattsson E , Olsson E 
Published: May 2012

AbstractPatients with knee osteoarthrosis are often referred for physiotherapy and many different types of treatment are given. The value of many of these treatments has been questioned. This study was intended to evaluate the effect of commonly used physiotherapy treatments in a training programme on patients with medial knee osteoarthrosis, scheduled for surgery. The results from this study also provide useful data for further evaluation of different physiotherapy treatments to this patient group. Thirty‐four patients were randomised to physiotherapy three times a week for 5 weeks and the other 34 received no treatment. The training programme is described in detail. The patients were evaluated by clinical examination, step test, gait analysis and isokinetic measurements of thigh muscle strength before and after treatment. The patients in the treatment group experienced a feeling of overall improvement in the knee and the ability to descend steps improved when compared to the control group. There were no significant differences in gait, range of motion or isokinetic measurements of muscle strength between the groups. We conclude that physiotherapy as given here made our patients feel better and their ability to descend stairs improved. These improvements are beneficial to the patients and support the positive effects of exercises and activity. Whilst the objective improvements were small, suggesting that this treatment may not be justified, patients in the treatment group believed that they were improved.
The reliability of measuring quadriceps cross‐sectional area with compound B ultrasound scanning
Authors: Howe Tracey E , Oldham Jackie A 
Published: May 2012

AbstractMany therapists use thigh circumference as a measure of quadriceps size to evaluate the effect of an injury or effectiveness of an intervention. However, this technique has been shown to be unreliable, thus more accurate methods of measuring muscle size are required. The purpose of this study was to investigate the validity and reliability of measuring quadriceps cross‐sectional area (CSA) with static compound B ultrasound scanning at the level of the mid‐thigh. Repeated measures of known linear distances and CSAs were made with a planimetry device. Both face and criterion validity were demonstrated indicating that the device is reliable when measuring CSAs. A single rater located quadriceps muscle borders and measured CSAs on a series of ultrasound scans. A mean coefficient of variation (%CV = 1.7) was observed, signifying high intra‐rater reliability. Two raters performed six scans on each of 15 subjects. Initial observation of these results suggest that the measurement of quadriceps CSA with compound B ultrasound scanning is reliable, mean %CVs = 2.8 and 1.9 for the two raters and 2.4 when their results were combined. When raters performed scans on 18 subjects on two occasions on the same day intra‐class correlation coefficients (ICC) were high, 0.991 and 0.980 for raters A and B, respectively. Paired Student's t‐tests revealed a significant difference (p<0.05) for Rater B between CSAs measured for initial and relocated scans. However, this difference was calculated as 1.4–2.9% and was not of clinical importance. A significant difference (p<.0.05) was observed between measurements of CSAs made by both raters on the same subject. A calibration factor was calculated for transforming the measurements of Rater B, the use of which gave comparable values. ICCs using a fixed model for inter‐rater reliability were 0.963 and 0.974 for actual and trans' formed values, respectively. This study observed differences between measures obtained by different raters and recommends that the calculation and employment of a calibration factor may be useful when comparing sequential measures made by different raters.
Data assimilation for state and parameter estimation: application to morphodynamic modelling
Authors: Smith P. J. , Thornhill G. D. , Dance S. L. , Lawless A. S. , Mason D. C. , Nichols N. K. 
Published: May 2012

AbstractData assimilation is predominantly used for state estimation, combining observational data with model predictions to produce an updated model state that most accurately approximates the true system state whilst keeping the model parameters fixed. This updated model state is then used to initiate the next model forecast. Even with perfect initial data, inaccurate model parameters will lead to the growth of prediction errors. To generate reliable forecasts, we need good estimates of both the current system state and the model parameters. This article presents research into data assimilation methods for morphodynamic model state and parameter estimation. First, we focus on state estimation and describe implementation of a three‐dimensional variational (3D‐Var) data assimilation scheme in a simple 2D morphodynamic model of Morecambe Bay, UK. The assimilation of observations of bathymetry derived from synthetic aperture radar (SAR) satellite imagery and a ship‐borne survey is shown to significantly improve the predictive capability of the model over a 2‐year run. Here, the model parameters are set by manual calibration; this is laborious and is found to produce different parameter values depending on the type and coverage of the validation dataset. The second part of this article considers the problem of model parameter estimation in more detail. We explain how, by employing the technique of state augmentation, it is possible to use data assimilation to estimate uncertain model parameters concurrently with the model state. This approach removes inefficiencies associated with manual calibration and enables more effective use of observational data. We outline the development of a novel hybrid sequential 3D‐Var data assimilation algorithm for joint state‐parameter estimation and demonstrate its efficacy using an idealised 1D sediment transport model. The results of this study are extremely positive and suggest that there is great potential for the use of data assimilation‐based state‐parameter estimation in coastal morphodynamic modelling. Copyright © 2012 Royal Meteorological Society
An improved representation of the raindrop size distribution for single‐moment microphysics schemes
Authors: Abel S. J. , Boutle I. A. 
Published: May 2012

AbstractWe analyse observations of the size distribution of raindrops from a variety of cloud types and precipitation rates. The measurements show a transition from large raindrops observed in convective showers and frontal rainbands to higher concentrations of much smaller drizzle drops observed in stratocumulus clouds. The observations are used to develop an improved parametrization of the raindrop size distribution that better captures the observed transition for use in single‐moment microphysics schemes. Sensitivity tests are performed in both climate and numerical weather prediction versions of the Met Office Unified Model to demonstrate that the new parametrization leads to improvements in various precipitation and cloud‐related metrics. Copyright © 2012 British Crown copyright, the Met Office. Published by John Wiley & Sons Ltd.
Extending the forecast range of the UK storm surge ensemble
Authors: Flowerdew Jonathan , Mylne Ken , Jones Caroline , Titley Helen 
Published: May 2012

AbstractFlooding due to coastal storm surges presents a significant threat to life and property. The UK has long had a storm surge forecasting system based on a single ‘deterministic’ simulation. This was augmented with an operational storm surge ensemble in December 2009. By producing several simulations sampling the forecast uncertainty, the ensemble estimates the probability of reaching critical water levels and thus supports a more risk‐based approach to civil protection.The original storm surge ensemble provided forecasts out to T + 54 h, limited by the forecast range of the driving MOGREPS‐R atmospheric ensemble. Longer‐range forecasts could provide advance notice of the potential for a significant event, allowing suitable preparatory actions to be taken. This study investigates the possibility of extending the storm surge ensemble to between 5 and 7 days using atmospheric data from the lower‐resolution Met Office 15‐day ensemble (MOGREPS‐15).Both case studies and statistical verification indicate the potential for useful forecasts out to the full 7.25 days tested. The best performance is obtained by extending the existing surge ensemble products with output from separate runs of the storm surge model, which have been driven by MOGREPS‐15 meteorology from T + 0 h. An attempt to create a single surge history for each member by switching from MOGREPS‐R to MOGREPS‐15 input at T + 54 h led to spurious oscillations in some cases, and poorer performance on several statistical measures. These issues might be improved by smoothing the discontinuity in atmospheric forcing.Following this successful trial, the separate‐runs extension to the surge ensemble was implemented operationally in summer 2011. The study also demonstrates the benefit of online bias correction and ‘dressing’ the forecast members to account for errors which the system does not otherwise sample. The operational implementation of these features is left for future work. Copyright © 2012 British Crown copyright, the Met Office Published by John Wiley & Sons Ltd.