bluuebunny/crossref_metadata_2025 huggingface dataset:
Sorption of NaOH and NaOC6H5 on quaternary ammonium resin in a fixed‐bed adsorber
Authors: Wu Ho‐Shing , Wang Chih‐Ta
Published: March 2009

The sorption behaviours of NaOH and NaOC6H65 on quaternary ammonium resin with functional groups of ‐NMe+4CI− (hydrophilicity) and ‐NBu+4Cl− (lipophilicity) in an aqueous fixed‐bed adsorber were investigated. The types of resins and salts, salt concentration, and operating temperature were evaluated to achieve the optimum sorption conditions. The probability distribution function of the breakthrough curve was employed to describe the sorption system. The parameters of probability distribution function, sorption rate, exchange capability, height of mass‐transfer zone and degree of saturation were also obtained. The effective exchange capacities for hydrophilic resins were found to be smaller than those for lipophilic resins. The sorption capability of NaOC6H5 in the resin was larger than that of NaOH.
The role of the vapour phase in fluid coker cyclone fouling: Part 2. Liquid and vapour yields and compositions
Authors: Mallory Donald G. , Mehta S. A. (Raj) , Moore R. Gordon
Published: March 2009

The vapours derived from thermally cracked Athabasca bitumen were exposed to temperatures phase 490°C and 560°C in order to investigate the effects of vapour phase thermal cracking on product yields and campositiom. Raising the vapour phase temperature above the temperature at which the vapours were derived increased both the yield of non‐condensable vapours and the amount of olefins in the produced gas. In addition, the liquid yield decreased with increasing vapour phase temperature and changes in liquid product composition were also observed. The H/C ratio of the liquid product decreased with increasing vapour phase temperature.
Performance of symmetric polygonal fins with and without tip loss — A comparison of different methods of prediction
Authors: Kundu Balaram , Das Prasanta K.
Published: March 2009

No analytical solution exists for estimating the efficiency of symmetric polygonal fins (SPFs) circumscribing circular tubes. Performance of such fins is conventionally determined from either of the two approximate techniques, namely, the equivalent annulus method and the sector method. The present work aims to judge the relative merits and applicability of these two methods critically. To this end, the results obtained from the approximate techniques have compared with those obtained from a semi‐analytical technique. It has been noted that, with the increase of the tip heat loss, the accuracy of prediction from any of the approximate methods decreases. For the sector method, a modification has been suggested. The prediction from the modified version of the sector method is always more accurate than that from the equivalent annulus method. It has been further illustrated that though the approximate techniques can be employed for the prediction of efficiency, they cannot be used to predict the tip temperatures accurately.
Evaluation of an artificial neural network for NOX emission prediction from a transient diesel engine as a base for NOX control
Authors: Krijnsen H. C. , Van Kooten1 W. E. J. , Calis H. P. A. , Verbeek R. P. , Van Den Bleek C. M.
Published: March 2009

For an adequate control of the reductant flow in selective catalytic reduction of NOx in diesel exhaust, a tool has to be available to predict accurately and fast the engine's NOx emission. In this article the application of a neural network is proposed. Measurements were performed on a transient diesel engine. The average absolute deviation between the measured NOx emission and the emission predicted by the neural network is 6.7%. The high accuracy of the neural network predictions, combined with the short computation times (0.2 ms/data point), makes the neural network a very promising tool in automotive NOx control.
Transient multi gas—solid reactions in a bubbling fluidized bed
Authors: Hastaoglu M. A. , Hilal N. , Abdulkarim M. , El‐Naas M.
Published: March 2009

A “multimodel” for gas‐solid reactions in a reacting particle has been applied to a bubbling fluidized bed reactor. The particle is tracked and bed and particle variables are determined continuously. The conservation equations of mass and heat with auxiliary relations are solved in an accelerating particle, which may rise or fall. The effects of bulk pressure, velocity and temperature, and particle diameter are studied. Heat and mass transfer coefficients may fluctuate up to 75% and 148% respectively. Doubling the pressure changes hc by 75% and kc by −45%. Increase in pellet diameter reduces both hc and kc.
Modélisation du traitement de purification de l'acide phosphorique de voie humide par la méthylisobutylcétone
Authors: Feki Mongi , Ayedi Hassine Ferid
Published: March 2009

Les performances de l'étape d'extraction du procédé de purification de l'acide phosphorique de voie humide par extraction liquide—liquide avec la méthyl isobutyl cétone ont été déterminées en faisant appel à la méthodologie des plans d'expériences. Pour ce faire, un plan factoriel complet 24 avec comme variables, la concentration de l'acide d'alimentation, le taux de solvant, la température et le nombre d'étages théoriques d'extraction a été réalisé. Les modèles obtenus ont permis de prédire les performances de l'extraction en terme aussi bien de rendement en P2O5 que de facteur de décontamination de l'acide produit et ce quelle que soit la teneur en eau du solvant recyclé. Le recours à la fonction désirabilité a permis de déterminer l'optimum multiréponse réalisant le meilleur compromis entre aussi bien un rendement en P2O5 de l'extraction élevé que des facteurs de décontamination de l'acide désextrait acceptables.
Estimation of diffusivity of alkaline metals in graphite lattice from oxidation rate measurements
Authors: Shimizu Akira , Akuzawa Noboru
Published: March 2009

A reaction model has been developed for the estimation of diffusivity of the intercalated species in graphite on the basis of a material balance expressed in terms of cylindrical coordinates, where the species in the layered structural cylinder diffuse radially from the center to the surface and react with gas. The resultant kinetic equations are used to analyze the experimental data for the oxidation rate of potassium atoms intercalated in natural graphite powder of initially different sizes intercalated at the first stage.
Turbulence decay behind expanded metal screens
Authors: Oshinowo Lanre , Kuhn David C. S.
Published: March 2009

An experiment study of the turbulent flow behind expanded metal screens has been carried out in a low‐turbulence wind tunnel using an X‐probe hot‐wire anemometer system. The expanded metal screens turn flow due to a complex array of vaned elements. The flow turning was found to vary accordingly with the dimensions of the strands that make up the screen. The turbulence generated by the screens decays at a rate proportional to the downstream distance to the power ‐ 5/7, consistent with studies in the literature of conventional screens types, and was found to scale with the thickness of the screen strands. The mean velocity, pressure drop and turbulence characteristics of expanded metal screens are presented.
Hydrodynamics and mass transfer in a pulsed packed column
Authors: Jie Yu , Weiyang Fei
Published: March 2009

The hydrodynamics and mass transfer characteristics of a pulsed packed column (PPC) filled with a stainless steel super mini ring (SMR), ceramic and stainless steel Raschig rings have been studied using a 30% tributyl phosphate‐kerosene (dispersed phase)/acetic acid/water (continuous phase) system. Experiments were performed in a 100 mm internal diameter column with 1.0 m height of packing. The mass transfer and axial mixing parameters were estimated simultaneously from the measured concentration profiles of two‐phase based on the backflow model. It was found that pulsation has great influence on hydrodynamics and mass transfer characteristics of PPC with the SMR. Hoxp and Hox decrease significantly with pulsation, whereas flooding velocity decreases only slightly. Comparison among the three types of packing showed that the SMR has superior characteristics both in terms of capacity and mass transfer efficiency. The influence of mass transfer on characteristics of PPC was also studied. New empirical equations of characteristic velocity, Hoxand Hoxd were proposed and good agreement between calculated and experimental data was obtained.
Heat transfer in a reciprocating plate column
Authors: Rao Nadella V. Rama , Baird Malcolm H. I.
Published: March 2009

A pilot‐scale (5.08 cm internal diameter) reciprocating plate column has been modified by the insertion of a brass test section for heat transfer measurements. Heat is supplied to liquid (water or a glucose solution) in the column from an electrical heating tape wound round the brass section, the walls of which contain thermocouples. Reciprocation of the plates in the column results in up to a seven‐fold improvement In heat transfer coefficient, to single phase liquids. Conditions are turbulent with oscillatory Reynolds numbers up to 20000. The effect of plate reciprocation is much less pronounced when the liquids are agitated by a stream of gas bubbles. The single‐phase heat transfer coefficients have been correlated for 5 different types of plates using approaches already available in the literature for turbulent systems in steady flow. The best‐fit oscillatory flow correlation differs slightly from the existing correlations for steady flow.
Removal of trace quantities of co from H2 using temperature‐swing‐adsorption
Authors: Sadhankar Ramakant R. , Aelick Christopher R. , Burns Deborah L. , Marcinkowska Krystyna
Published: March 2009

A method for the removal of trace quantities (0.2 to 10 ppm) of carbon monoxide in commercial hydrogen using a temperature‐swing‐adsorption system with 0.5 wt% Pt/Al2O3, adsorbent has been investigated. The adsorbent could be regenerated by treatment with air at 200°C to 250°C or by treatment with hydrogen at 270°C. The breakthrough curves have been described by a model which considers both the external‐film resistance and the intraparticle diffusion resistance. The model has been validated at the high gas velocities expected in a commercial plant.
Liquid‐solid mass transfer from horizontal woven screen packing in bubble column reactors
Authors: Zaki M. M. , Nirdosh I. , Sedahmed G. H.
Published: March 2009

The effect of gas sparging on the rate of mass transfer at horizontal single screen and stacks of closely packed horizontal screens was studied by an electrochemical technique which involved measuring the limiting current of the cathodic reduction of potassium ferricyanide. Variables studied were: distance between the sparger and the screen, screen characteristics, e.g., mesh number and wire diameter, physical properties of the solution and superficial gas velocity. Screen characteristics were found to have little effect on the rate of mass transfer.

The mass transfer measurement at beds of closely packed screens revealed that the mass transfer coefficient decreased below the single screen value with increasing the number of screens per bed. Comparison of the present data with previous results showed that screens produce higher rates of mass transfer than other geometries under otherwise the same conditions. The importance of the present work to the design and operation of catalytic and electrochemical reactors was highlighted.
A theoretical investigation of enhancement of mass transfer from a packed bed using acoustic oscillations
Authors: Sujith Raman I. , Zinn Ben T.
Published: March 2009

This paper describes a theoretical investigation of the possibility of improving the performance of packed bed dryers using acoustic oscillations. It was motivated by the increasing interest in the use of acoustic oscillations to improve the performance of energy‐intensive, industrial processes. Sound propagation in a packed bed was modelled as propagation through a porous medium. The effect of acoustic oscillations on the drying rate was then investigated by numerically integrating the heat and mass transfer equations. The model used quasi‐steady correlations for heat and mass transfer. The results show that threshold values for void fractions and sound pressure levels exist, above which significant increase in drying rate can be obtained. The increase in mass transfer decreases with effective particle diameter.
Solubilities of anthracene, fluoranthene and pyrene in organic solvents: Comparison of calculated values using UNIFAC and modified UNIFAC (Dortmund) models with experimental data and values using the mobile order theory
Authors: Hansen Henrik K. , Riverol Carmen , Acree William E.
Published: March 2009

The solubility of anthracene in 43 organic solvents, fluoranthene (45 solvents) and pyrene (30 solvents) has been calculated using UNIFAC and Modified UNIFAC (Dortmund) models to estimate the activity coefficient of the solute. It was found that both UNIFAC and Modified UNIFAC described better the solubilities in polar solvents like alcohols, ketones, esters and ethers than in nonpolar solvents like alkanes and aromatic hydrocarbons. UNIFAC and the Mobile Order Theory supplement each other well in calculating the solubilities, which means that one can choose the right model depending on the solvent one is using.
An experimental investigation of the cross‐flow of power law liquids past a bundle of cylinders and in a bed of stacked screens
Authors: Prasad D. V. N. , Chhabra R. P.
Published: March 2009

The steady flow of power‐law polymer solutions normal to arrays of cylinders and in a bed of screens has been investigated experimentally. Extensive pressure drop measurements have been made for three different test cells (two tube bundles and one bed made of screens) of different voidages for a series of inelastic carboxymethyl cellulose and sodium alginate aqueous solutions. The resulting values of friction factor correlate well with a modified definition of the Reynolds number based on the capillary bundle representation of the bed. The new data extend considerably the range of voidage values from ∼0.6 to ∼0.87. Extensive comparisons have also been made between the present experimental data and our previous calculations based on the use of simple cell models. The close correspondence between the two demonstrates the utility of such idealized analyses. All in all, the present results embrace the following ranges of physical and kinematic conditions: Reynolds number: 0.01 to ∼1200; power‐law flow behaviour index: 0.38 to 1; and three values of voidage, namely, 0.74, 0.78 and 0.87.
The jet shape of concentric mixers
Authors: Giorges Aklilu T. G. , Wang Xiaodong , Forney Larry J.
Published: March 2009

In this paper, we present an analytical and experimental study of the mixing region and jet shape in concentric mixers. Based on a simple but effective analytical model, we are able to predict the growth of the mixing region with respect to downstream distance. An experimental study is conducted on the concentric mixing of paper fibre stock and water. By comparing with experimental results, we confirm that the shape of the mixing region is a practical indicator of mixing efficiency with the consideration of jet velocity and geometry including the nozzle wall thickness.
The effect of non‐ideal mixing on the number of steady states and dynamic behaviour for autocatalytical reactions in a CSTR
Authors: Chien Yu‐Shu
Published: March 2009

In this paper, we analyze the concentration multiplicity and dynamic behavior for an autocatalytical reaction, A + R → (n + 1)R + products with an overall rate expression given by – γa= kcapcrr(p > 0 and r > 0) in a imperfectly mixed (Cholette's model) CSTR. We proved that non‐ideal mixing had an effect on the number of steady states and dynamic behavior for the reaction orders r > 1 and r = 1. However, the above‐mentioned effect does not happen for the reaction order r < 1. Furthermore, a simulated example was used to demonstrate our results.
A Re‐Examination of heat transfer in laminar divergent flow between two parallel fixed discs
Authors: Fahidy Thomas Z. , Cóuret François
Published: March 2009

Upon a critical review of pertinent literature, new theoretical expressions for dimensionless heat transfer rates between two parallel fixed circular discs and a fluid in radial divergent laminar flow are established and compared to previously published theory and experimental data. Based on the logarithmic mean temperature difference, the new analytical relationships are shown to adequately predict dimensionless heat transfer rates, and it is recommended that they be used in preference to certain earlier expressions which are either erroneous or of strongly limited applicability.
Modelling oxygen solubility in bleaching solutions
Authors: Tromans Desmond
Published: March 2009

A general thermodynamics‐related model of oxygen solubility, previously developed for water and aqueous inorganic solutions, has been applied to bleaching solutions. The model allows estimations of dissolved oxygen concentrations to be made for different combinations of temperature, oxygen partial pressure and inorganic solute concentrations likely to be encountered during oxygen bleaching of pulp. Combination of the model with oxygen diffusion kinetics allows optimum temperatures for transport‐controlled oxygen delignification rates to be estimated.
Diffusion and reactivity of gas oil in FCC catalysts
Authors: Al‐Khattaf Sulaiman , de Lasa Hugo I.
Published: March 2009

This study considers the effects of diffusion and intrinsic catalytic reactivity for the cracking of gas oil on FCC catalysts. A four‐lump kinetic model, initially developed in a novel CREC Simulator, is employed to estimate the unconverted gas oil, the gasoline, the light gases and the coke fractions. The model incorporates a modified Thiele modulus, based on zeolite crystal properties, and an effectiveness factor. The calculated effectiveness factor is found to increase with the gas oil conversion and to decrease with the intrinsic rate constant and the zeolite crystal size. The proposed model predicts that crystal size changes in the 0.13 to 1.3 μm range affect both primary and secondary cracking reactions and the yields of gasoline, coke and light gas yields.
Modelling of trickle‐bed reactors in foaming regime
Authors: Turco Francesco , Hudgins Robert R. , Silveston Peter L. , Sicardi Silvio , Manna Luigi , Banchero Mauro
Published: March 2009

Hydrogenation of α‐methyl styrene (AMS) to cumene at 40°C in a downflow trickle bed was used as a test reaction for an investigation of the prediction of the performance of trickle‐bed reactors. Dynamic and static saturation are well predicted by several models but pressure drop cannot be accurately estimated by correlations now in the literature. This raises doubts about the use of mass transfer models which employ pressure drop taken from the literature. The simple film model for predicting conversion fails in the high‐interaction regime at least with foaming liquids. A correction to the model to allow for the effect of foam on mass transfer characteristics is proposed but was not independently tested.
An investigation of the effect of air addition during oil sand conditioning
Authors: Flynn Morris , Bara Barry , Czarnecki Jan , Masliyah Jacob
Published: March 2009

Bitumen aeration was studied by flooding samples of medium grade oil sand with de‐ionized water under both ambient and high vacuum conditions. The samples were then agitated on a shaker table. Subsequent analysis revealed the presence or absence of an air gap in the sample container was the single most important factor in determining the overall bitumen recovery. Furthermore, samples that were flooded while under high vacuum produced slightly less bitumen compared to samples flooded at atmospheric pressure. This suggests that oil sand that is not under high vacuum when flooded with water contains some amount of indigenous air (see introduction) that would aid in bitumen flotation.
Effect of particle tethering and Scale‐Up on solid–liquid mass transfer in Three‐Phase fluidized beds of light particles
Authors: Song Jiasen , Hyndman Caroline L. , Kantzas Apostolos
Published: March 2009

Solid–liquid mass transfer in three‐phase fluidized beds with low‐density particles was studied using a tethered benzoic acid particle dissolution technique. Two columns with air, water and polypropylene cylinders were used for experiments. The solid–liquid mass transfer coefficient was found to increase with column diameter but decrease with tether length. The effect of tethering on solid particle movements was also evaluated using radioactive particle tracking (RPT) technique. RPT showed that tethered particles exhibited slower movements. Statistical analysis suggests that tether lengths 3 times the column radius are sufficient to reduce the effects of tethering.
Use of ultrasound for phase holdup measurements in multiphase systems
Authors: Macchi Arturo , Grace John R. , Bi Hsiaotao
Published: March 2009

This study evaluates ultrasound as a non‐invasive technique for determining the cross‐sectional holdups of multiphase systems. Experiments are performed in a column of 292 mm inner diameter with air, water and uniform glass beads of 1.3 mm diameter as the particles. In a bubble column, the signal intensity decayed exponentially with increasing gas holdup. In a liquid–solid fluidized bed, the wave time‐of‐flight decreased linearly when the solids holdup increased from 25% to 60% (fixed bed), while the signal intensity increased. Signal attenuation limits the use of this method for three‐phase fluidized beds. When large particles (mm range) are used, it is difficult to operate at a wavelength that permits transmission through both dispersed phases. For three‐phase systems, slurry bubble columns with low dispersed phases holdups and smaller particles present a less attenuative media and are better suited to this technique.
Cysteine Oxidation by the Superoxide Radical: A Theoretical Study
Authors: Cardey Bruno , Enescu Mironel
Published: March 2009

Active molecular environment: Oxidation of the cysteine residue by the superoxide radical (see picture) is studied in the gas phase and in aqueous solution using the integrated molecular orbital+molecular orbital. It is shown that the molecular environment plays an important role in the oxidation of biologically relevant thiol compounds by the superoxide radical.

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The cysteine residue oxidation by the superoxide radical in the gas phase and in aqueous solution is studied using the integrated molecular orbital+molecular orbital (IMOMO) method combining the quadratic configuration interaction [QCISD(T)] and density functional (DFT) methods. The molecular environment effects are systematically investigated by considering two alternative directions of attack of the superoxide radical on the thiol and two different cysteine residue conformations. It is found that hydrogen bonding and the electrostatic interactions between the superoxide radical and cysteine side chain significantly affect the reaction energy barrier, as compared to that derived for the simple thiol model methanethiol. Among the two possible reaction channels, the one involving the sulfinyl radical formation is predicted to be the dominant channel in aqueous solution. In a highly hydrophobic environment the thiyl radical formation channel becomes the main cysteine oxidation channel.
Chromatin immunoprecipitation in early Xenopus laevis embryos
Authors: Blythe Shelby A. , Reid Christine D. , Kessler Daniel S. , Klein Peter S.
Published: March 2009

Chromatin immunoprecipitation (ChIP) is a powerful method for analyzing the interaction of regulatory proteins with genomic loci, but has been difficult to apply to studies on early embryos due to the limiting amount of genomic material in these samples. Here, we present a comprehensive technique for performing ChIP on blastula and gastrula stage Xenopus embryos. We also describe methods for optimizing crosslinking and chromatin shearing, verifying antibody specificity, maximizing PCR sensitivity, and quantifying PCR results, allowing for the use of as few as 50 early blastula stage embryos (approximately 5×104 cells) per experimental condition. Finally, we demonstrate the predicted binding of endogenous β‐catenin to the nodal‐related 6 promoter, binding of tagged Fast‐1/FoxH1 to the goosecoid promoter, and binding of tagged Tcf3 to the siamois and nodal‐related 6 promoters as examples of the potential application of ChIP to embryological investigations. Developmental Dynamics 238:1422–1432, 2009. © 2009 Wiley‐Liss, Inc.
Evaluation of the PESERA model in two contrasting environments
Authors: Licciardello F. , Govers G. , Cerdan O. , Kirkby M. J. , Vacca A. , Kwaad F. J. P. M.
Published: March 2009

The performance of the Pan‐European Soil Erosion Risk Assessment (PESERA) model was evaluated by comparison with existing soil erosion data collected in plots under different land uses and climate conditions in Europe. In order to identify the most important sources of error, the PESERA model was evaluated by comparing model output with measured values as well as by assessing the effect of the various model components on prediction accuracy through a multistep approach. First, the performance of the hydrological and erosion components of PESERA was evaluated separately by comparing both runoff and soil loss predictions with measured values. In order to assess the performance of the vegetation growth component of PESERA, the predictions of the model based on observed values of vegetation ground cover were also compared with predictions based on the simulated vegetation cover values. Finally, in order to evaluate the sediment transport model, predicted monthly erosion rates were also calculated using observed values of runoff and vegetation cover instead of simulated values. Moreover, in order to investigate the capability of PESERA to reproduce seasonal trends, the observed and simulated monthly runoff and erosion values were aggregated at different temporal scale and we investigated at what extend the model prediction error could be reduced by output aggregation.

PESERA showed promise to predict annual average spatial variability quite well. In its present form, short‐term temporal variations are not well captured probably due to various reasons. The multistep approach showed that this is not only due to unrealistic simulation of cover and runoff, being erosion prediction also an important source of error. Although variability between the investigated land uses and climate conditions is well captured, absolute rates are strongly underestimated. A calibration procedure, focused on a soil erodibility factor, is proposed to reduce the significant underestimation of soil erosion rates. Copyright © 2009 John Wiley & Sons, Ltd.
Wolken, Wind und Niederschlag
Authors: Hense Andreas
Published: March 2009

Wettervorhersagen sind ein komplexes Unterfangen. Neben immer präziseren Daten fließt auch viel Grundlagenforschung in die Prognosen ein. Die Meteorologen wollen dabei vor allem die Naturerscheinungen in der Atmosphäre noch besser verstehen
Medical students' recognition of elder abuse
Authors: Thompson‐McCormick Jonas , Jones Lisa , Cooper Claudia , Livingston Gill
Published: March 2009

Objectives

To determine the proportion of fourth‐year medical students who correctly recognise abusive and not abusive care of older people and whether recognition is related to sociodemographic factors and education.

Design

A cross‐sectional self‐report questionnaire study, using the Caregiving Scenario Questionnaire; measuring recognition of elder abuse according to the Department of Health's definition.

Participants

Fourth‐year medical students at University College London and the University of Birmingham, UK.

Results

Two hundred and two of 207 students (97.6%) responded. Twenty‐nine of 201 (14.4%) identified accepting someone was not clean; 113/200 (56.5%) locking someone in alone; and 160/200 (80.0%) trapping someone in an armchair as abusive. All medical students correctly identified four out of five not abusive responses. Twelve (6.0%) incorrectly identified camouflaging the door to prevent wandering as abusive. Logistic regression analysis found the independent predictors of recognising that locking in alone was abusive were working as a professional carer (OR = 3.33, 95% CI = 1.25–8.89, p < 0.05) and reporting being taught to look for elder abuse (OR = 0.46, 95% CI = 0.24–0.89, p < 0.05). Similarly, the independent predictors of recognising that restraint in an armchair was abusive were attending university A versus university B (OR = 2.38, 95% CI = 1.09–5.26, p < 0.05); being of White British versus Asian ethnicity (OR = 4.00, 95% CI = 1.75–9.09, p < 0.01).

Conclusions

Medical students are good at recognising not abusive care, but not as successful at recognising elder abuse. Working as a professional carer was associated with better recognition of abuse, while personal contact with a person with dementia and recalling formal education about abuse were not. Copyright © 2009 John Wiley & Sons, Ltd.
Temporal characteristics and variability of point rainfall: a statistical and wavelet analysis
Authors: Beecham S. , Chowdhury R. K.
Published: March 2009

Rainfall characteristics at different temporal resolutions play a significant role in sustainable urban water management. In this study we attempted to identify the temporal characteristics and variability of point rainfall measured in Melbourne, Australia. Statistical moments, lag1 autocorrelation, the Buishand's Q test for homogeneity, the Mann–Kendall (MK) test for trend and wavelet analyses for temporal variability were carried out for rainfall intensities at resolutions of 0.1, 0.5, 1, 3, 6, 12 h and for the monthly rainfall depths and proportion dry ratios. Series of rainfall intensities at different temporal scales and the monthly rainfall depths and proportion dry ratios were accumulated from the high resolution rainfall dataset for the period from 1925 to 2002. Homogeneity of rainfall intensity was found to increase as the temporal scale increases. Both rainfall intensities and monthly rainfall depths were found to be serially correlated. The 2nd, 3rd and 4th statistical moments of rainfall intensities increased as the resolution increased. While no statistically significant trends were found using the MK test, there were indications that trends are more likely as the temporal scale increases. Wavelet power spectra identified a dominant frequency scale (0.25–1 year) in the 3, 6 and 12 h rainfall intensities that were periodically observed in a 5 to 10–year cyclic order. This phenomenon could be influenced by the inter‐annual variability of the El Niño Southern Oscillation (ENSO). Copyright © 2009 Royal Meteorological Society
Impacts of Pacific and Indian Ocean coupling on wintertime tropical intraseasonal oscillation: a basin‐coupling CGCM study
Authors: Weng Shu‐Ping , Yu Jin‐Yi
Published: March 2009

This study examines the respective influences of Pacific and Indian Ocean couplings on tropical intraseasonal oscillation (ISO) in boreal winter (November–April). Three basin‐coupling experiments are performed with a coupled atmosphere‐ocean general circulation model (CGCM), in which air‐sea coupling is limited respectively to the Indian Ocean, the Pacific Ocean, and both the oceans. The modelling results show that zonal ISO propagations can be found in the Indo‐Pacific region with or without the ocean coupling; however, the propagation signals are enhanced by the coupling. In this particular model the Pacific Ocean coupling has a stronger influence on the ISO propagation than the Indian Ocean coupling. Without the Pacific coupling, the ISO propagation signal is weakened significantly when it enters the Pacific Ocean sector. Without the Indian Ocean coupling, the simulated ISO intensity is weakened less in the Indain Ocean, and significant zonal propagations of ISO can still be simulated in the sector. The relative importance of the ocean coupling is likely related to the smaller ISO‐related sea surface temperature (SST) anomalies in the Indian Ocean than in the Pacific Ocean. In this particular CGCM, the ocean coupling affects the ISO propagation mainly through a wind‐evaporation‐SST feedback rather than a cloud‐radiation‐SST feedback, while in observations both processes are equally important. To further confirm the importance of the ocean coupling, forced atmospheric GCM experiments are performed with SSTs prescribed from the climatologies produced in the basin‐coupling experiments. It is found that the eastward propagating feature seen in the CGCM experiments is weakened and dominated by the strong standing feature in the forced AGCM runs. The difference demonstrates the contribution of the ocean coupling to the ISO propagation, and also confirm that biases in the mean SST and low‐level wind caused by the ocean coupling are responsible for the spurious standing ISO oscillation feature in the central Pacific and Indian Oceans. Copyright © 2009 Royal Meteorological Society
Joint‐preserving limb salvage surgery under navigation guidance
Authors: Cho Hwan Seong , Oh Joo Han , Han Ilkyu , Kim Han‐Soo
Published: March 2009

Background

Recently, the navigation system has been introduced to orthopedic oncology. It can apply MRI and/or CT images to intraoperative visualization. We performed navigation‐assisted limb salvage surgeries on patients with a malignant bone tumor of the metaphysis of the long bone or the iliac bone while preserving the adjacent joint.

Methods

When preoperative chemotherapy was estimated to be effective by imaging studies and the residual remaining epiphysis was expected to be more than 1 cm long after tumor resection with 1–2 cm of surgical margin, joint‐preserving surgery was performed under navigation guidance. We carried out CT and MRI data fusion to use MR images as an intraoperative guide. A deep frozen strut allograft was placed in the defect for the restoration of anatomical continuity.

Results

Resection margin measured on pathological examination was in accordance with that of the preoperative plan. The functional scores of all patients were satisfactory. There was no evidence of recurrence on the regional radiographs and CT on the chest until the last follow‐up.

Conclusion

Navigation‐assisted surgery can be indicated for limb salvage and it can help to preserve the adjacent joint in selected cases. J. Surg. Oncol. 2009;100:227–232. © 2009 Wiley‐Liss, Inc.
Direkte und indirekte Gefahren von Laserstrahlung (Teil II)
Authors: Foth Hans‐Jochen
Published: March 2009

Um den erneuten Einstieg in das Thema zu erleichtern, hier zunächst eine kurze Wiederholung der Punkte, die im ersten Teil des Artikels (LTJ 5/2008) beschrieben wurden:
Polymer Brushes by Nitroxide‐Mediated Polymerization
Authors: Brinks Marion K. , Studer Armido
Published: March 2009

This review article describes the preparation of polymer brushes by nitroxide‐mediated radical polymerization using either the ‘grafting to’ or the ‘grafting from’ approach. The use of TEMPO as a classical initiator is intensively described. More sophisticated nitroxides are also included in the discussion. Brush formation on flat surfaces such as wafers and also on particles is reported. Finally, some applications of polymer brushes are presented.

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Self‐assembly of Sulfonated Polystyrene Ionomers in Chloroform
Authors: Lezov A. V. , Polushina G. E. , Mikhailova M. E. , Rjumtsev E. I.
Published: March 2009

Light scattering and electric birefringence were used to determine the dimensions and extent of aggregation of dilute solutions of sodium sulfonated polystyrene ionomers with sulfonation levels of 0.5, 1.35, 2.6 and 5.8 mol% in chloroform. It was found that in solutions of ionomers with sulfonation level 1.35 and more the equilibrium between single chains and aggregates consisting of two and more chains is observed. These data were analyzed using the “open” association model. It was shown that an increase in the sulfonation level of ionomers results in a decrease in the hydrodynamic radius of single chain. On the other hand, it was established that an increase in sulfonation level leads to increase in the size of aggregate consisting of two chains. More pronounced expansion of ionomer chains incorporated into aggregate was found for ionomers with high sulfonation level.
Synthesis, characterization, thermal stability, conductivity, and band gaps of substitute oligo/polyamines or polyphenol
Authors: Kaya İsmet , Aydın Aysel
Published: March 2009

In this study, the oxidative polycondensation reaction conditions of 3,5‐dichloroaniline (DCA), 3,4,5‐trimethoxyaniline (TMA), 3,5‐bis(trifluoromethyl)aniline (BTFMA), and 4‐{[(3,5‐dichlorophenyl)imino]methyl}phenol (DCPIMP) were studied by using NaOCl oxidant in an aqueous alkaline medium between 40 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FT‐IR, Ultraviolet–visible (UV–vis), 1H‐NMR, and 13C‐NMR and elemental analysis. The characterization was made by TGA–DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yields of oligo‐3,5‐dichloroaniline (ODCA), poly‐3,4,5‐trimethoxy aniline (PTMA), oligo‐3,5‐bis(trifluoromethyl)aniline (OBTFMA), and poly‐4‐{[(3,5‐dichlorophenyl) imino]methyl} phenol (PDCPIMP) were found to be 98, 48, 80, and 83% in using NaOCl oxidant. According to the SEC analysis, the number‐average molecular weight (Mn), weight‐average molecular weight (Mw) and polydispersity index (PDI) values of ODCA, PTMA, and OBTFMA were found to be 2200, 3800 g mol−1, and 1.727; 4700, 7500 g mol−1, and 1.596; and 1690, 1950 g mol−1, and 1.154, respectively. According to TG analysis, the weight losses of ODCA, PTMA, OBTFMA, and PDCPIMP were found to be 78.55, 54.18, 99.38, and 59.70% at 1000°C, respectively. PTMA showed higher stability against thermal decomposition. Electrical conductivity of the polymers was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical band gaps ($E'_{\rm g} $) of ODCA, PTMA, OBTFMA, and PDCPIMP were calculated from their absorption edges of cyclic voltammograms. The optical band gaps (Eg) values of all compounds were calculated from UV–vis measurements. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and characterization of linseed oil‐based nanocomposites
Authors: Sharma Vinay , Banait J.S. , Larock R.C. , Kundu P.P.
Published: March 2009

The nanocomposites from conjugated linseed oil, acrylic acid, and divinylbenzene are synthesized using modified montmorillonite clay and characterized for thermal properties. The wide angle X‐ray diffraction results clearly show the distortion of the platy nanolayers of the nanofiller in the polymer matrix as the peak due to the clay disappears in the nanocomposite samples. The dynamic mechanical analysis results show the enhanced storage modulus and transition temperature compared with the pristine polymer. At the glass transition temperature, the storage modulus of nanocomposites is in the range of 17–79 MPa, whereas the pristine polymer shows a storage modulus of 2.1 MPa. The melting peak temperature ranges from 230 to 260°C, which is further confirmed by thermogravimetric analysis (TGA) results. The samples are stable up to 200°C and show a two‐stage degradation. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Selective laser sintering of clay‐reinforced polyamide
Authors: Jain Prashant K. , Pandey Pulak M. , Rao P.V.M.
Published: March 2009

An experimental investigation has been carried out to study the feasibility of processing blended powder of polyamide (PA) and organically modified nanoclay using selective laser sintering. The effect of nanoclay on the sintering parameters and mechanical properties of the sintered specimen have been studied. This article presents the details of preprocessing studies required and conducted to find suitability of the blended powder material to be processed on SLS machine. A suitable part bed temperature has also been found to avoid curling as well as to ensure the powder reusability. In this work, laser power, beam speed, scan spacing have been considered as influential operating process parameters and are explored using Taguchi's L9 orthogonal array. Tensile specimens of PA and PA/clay composite have been fabricated as per ASTM D638 standard and tested for ultimate tensile strength, elongation at break, and Young's modulus using universal testing machine. Ultimate tensile strength and elongation at break are found to be decreased in case of PA/clay composite when compared with virgin polyamide. To understand the sintering insight and to explain the behavior of obtained mechanical properties, further investigations have been carried out using material characterization techniques like X‐ray diffraction and scanning electron microscopy. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Synthesis and characterization of fluorinated poly(etherimide)s toughening for carbon fiber‐reinforced epoxy composites
Authors: Chen Weiming , Tao Zhiqiang , Fan Lin , Yang Shiyong , Jiang Wenge , Wang Junfeng , Xiong Yanli
Published: March 2009

Novel‐fluorinated poly(etherimide)s (FPEIs) with controlled molecular weights were synthesized and characterized, which were used to toughen epoxy resins (EP/FPEI) and carbon fiber‐reinforced epoxy composites (CF/EP/FPEI). Experimental results indicated that the FPEIs possessed outstanding solubility, thermal, and mechanical properties. The thermally cured EP/FPEI resin showed obviously improved toughness with impact strength of 21.1 kJ/m2 and elongation at break of 4.6%, respectively. The EP/FPEI resin also showed outstanding mechanical strength with tensile strength of 91.5 MPa and flexural strength of 141.5 MPa, respectively. The mechanical moduli and thermal property of epoxy resins were not affected by blending with FPEIs. Furthermore, CF/EP/FPEI composite exhibited significantly improved toughness with Mode I interlaminar fracture toughness (GIC) of 899.4 J/m2 and Mode II interlaminar fracture toughness (GIIC) of 1017.8 J/m2, respectively. Flexural properties and interlaminar shear strength of the composite were slightly increased after toughening. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Stationary cuvette: a new approach to obtaining analytical curves by UV–VIS spectrophotometry
Authors: Silva K. G. H. , Júnior F. H. Xavier , Farias I. E. G. , Silva A. K. A. , Neto J. A. Caldas , Souza L. C. A. , Santiago R. R. , Júnior F. Alexandrino , Júnior T. Nagashima , Soares L. A. L. , Santos‐Magalhães N. S. , Egito E. S. T.
Published: March 2009

Background

Investigations in the field of pharmaceutical analysis and quality control of medicines require analytical procedures that achieve suitable performance. An analytical curve is one of the most important steps in the chemical analysis presenting a direct relationship to features such as linearity.

Objective

This study has the aim of developing a new methodology, the stationary cuvette, to derive analytical curves by spectroscopy for drug analysis.

Methodology

The method consists basically of the use of a cuvette with a path length of 10 cm, containing a constant volume of solvent in which increasing amounts of a stock solution of the sample are added, droplet by droplet. After each addition, the cuvette is stirred and the absorbance is measured. This procedure was compared with the currently used methodology, which requires a labour‐intensive dilution process, and possible sources of variation between them were evaluated.

Results

The results demonstrated that the proposed technique presented high sensitivity and similar reproducibility compared with the conventional methodology. In addition, a number of advantages were observed, such as user‐friendliness, cost‐effectiveness, accuracy, precision and robustness.

Conclusion

The stationary cuvette approach may be considered to be an appropriate alternative to derive analytical curves for analysing drug content in raw materials and medicines through UV–VIS spectrophotometry. Copyright © 2009 John Wiley & Sons, Ltd.
Isothermal crystallization kinetics of silk fibroin fiber‐reinforced poly(ε‐caprolactone) biocomposites
Authors: Qiao Xiuying , Li Wei , Sun Kang , Xu Shi , Chen Xiaodong
Published: March 2009

BACKGROUND: Poly(ε‐caprolactone) (PCL) has attracted great attention due to its wide applications for pharmaceutical controlled released systems and implanted polymer devices. In this study, silk fibroin fiber (SF) obtained from degumming treatment of silk was used to prepare novel reinforced PCL biocomposites. The isothermal crystallization behavior of these composites was investigated using differential scanning calorimetry measurements.

RESULTS: With a decrease of isothermal crystallization temperature (Tc) and an increase of fiber filler, the crystallization time of the SF/PCL composites becomes shorter, the crystallization rate constant (K) increases and the Avrami exponent (n) gradually decreases (being between 1 and 2). The crystallization of PCL and SF/PCL composites occurs in the same regime. With the gradual addition of fiber, lateral surface free energy (σ) is nearly unchanged, but fold surface free energy (σe) decreases.

CONCLUSION: Heterogeneous nucleation is dominant and different growth morphologies coexist during the isothermal crystallization process of the SF/PCL hybrid systems. Although the introduction of SF obviously increases the overall crystallization rate of PCL, the growth rate constant and nucleation constant of PCL are reduced because of the confinement effect of fiber network structures on the molecular mobility of polymer molecular chains. Copyright © 2009 Society of Chemical Industry
A survey of once‐daily dosage tobramycin therapy in patients with cystic fibrosis
Authors: Van Meter Daniel J. , Corriveau Michele , Ahern John W. , Lahiri Thomas
Published: March 2009

The purpose of this study was to quantify the prevalence of once‐daily dosage of tobramycin (ODDT) among Cystic Fibrosis Foundation‐accredited care centers and affiliated programs (CFFACCs) and characterize the ODDT approaches used by these institutions. An anonymous cross‐sectional survey of CFFACCs was performed using an electronic survey tool. This tool was electronically mailed to the program directors. Eighty‐four out of 195 institutions completed the survey (response rate = 43%). Fifty‐one (61%) of 84 centers reported using ODDT. Of those 51 institutions, 34 (67%) use a dosage of 10 mg/kg/dose. Serum creatinine was measured routinely in 51 centers (100%) with weekly monitoring being used in 40 centers (78%). Audiometric evaluation was performed routinely in 22 (43%) centers with annual assessment performed in 14 (64%) of these 22 centers. In conclusion, a majority of responding institutions use ODDT. The most common reported dosage is 10 mg/kg. Serum creatinine was routinely measured in all institutions with weekly assessment being the most common frequency. Audiometic assessment is routinely performed in <50% of centers. Of the institutions performing audiograms routinely, annual assessment is the most common frequency. Pediatr Pulmonol. 2009; 44:325–329. © 2009 Wiley‐Liss, Inc.
The thermo‐ and acido‐stable ORF‐99 from the archaeal virus AFV1
Authors: Goulet Adeline , Spinelli Silvia , Blangy Stéphanie , van Tilbeurgh Herman , Leulliot Nicolas , Basta Tamara , Prangishvili David , Cambillau Christian , Campanacci Valérie
Published: March 2009

Acidianus Filamentous Virus 1 (AFV1), isolated from acidic hot springs, is an enveloped lipid‐containing archaeal filamentous virus with a linear double‐stranded DNA genome. It infects Acidianus, which is a hyperthermostable archaea growing at 85°C and acidic pHs, below pH 3. AFV1‐99, a protein of 99 amino acids of unknown function, has homologues in the archaeal virus families Lipothrixviridae and Rudiviridae. We determined the crystal structure of AFV1‐99 at 2.05 Å resolution. AFV1‐99 has a new fold, is hyperthermostable (up to 95°C) and resists to extreme pH (between pH 0 and 11) and to the combination of high temperature (95°C) and low pH (pH 0). It possesses characteristics of hyperthermostable proteins, such as a high content of charged residues.