bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling of Self‐Induced Oscillations in the Mixing Head of a RIM Machine
Authors: Li Xiaojin , Santos Ricardo J. , Lopes José Carlos B.
Published: July 2010

In this paper, the self‐induced oscillations in the mixing head of a RIM machine were modelled. An analytical and simple correlation was derived between the Strouhal number and the averaged pressure drop along the amplitude of the oscillation in the mixing chamber. This correlation theoretically identified that the frequency of the oscillations could be well correlated by the jet Reynolds number, Red, and the dimensionless distance between the two jets as proposed by Denshchikov et al., Fluid Dyn. 3, 460‐462 (1983). The flow field dynamics in the mixing head was simulated successfully by Fluent and the computed pressure fluctuations were used to calculate the frequencies of the oscillations in the mixing head. The calculated Strouhal numbers are in good agreement with the dominant frequency from the power spectra of the measured velocity component ux (Santos, 2003). Finally, the effect of Red and Froude number, Fr, on the Strouhal number was investigated in the impingement region. The average Strouhal number showed a decrease with the Reynolds numbers, due to the increasing randomness of flow field in the impingement region. It was also found that the operations at lower values of Fr presented an increasing stability up to the point where the system is unable to present dynamic evolution. The model in this paper provides a theoretical starting point towards understanding of the quantities of the oscillatory flow in the mixing head, as well as a numerical approach to evaluate the dominant frequency in the mixing chamber.
On the Effect of Non‐Linearity on Linear Quadratic Regulator Stability and Performance
Authors: Guay Martin , Forbes J. Fraser
Published: July 2010

In this paper, two new local measures of non‐linearity are introduced to quantify the sensitivity of controller stability and performance for linear controllers operating on a non‐linear plant. The measure quantifies the departures from optimality of locally linear quadratic regulators. The main difference between this technique and all other techniques presented in the literature is that the analysis can be used directly in the control design step. If a linear controller can be shown to operate as intended, despite the non‐linearity, then a practitioner can apply a linear controller to the non‐linear systems with the guarantee that a certain degree of performance can be assured, at the design step.
A Novel Data‐Driven Bilinear Subspace Identification Approach
Authors: Yang Hua , Li Shaoyuan
Published: July 2010

Subspace identification methods for bilinear systems perform computation with data matrix exploding. Huge computational burdens have been the biggest problem that prohibits real applications of bilinear subspace identification. In this paper, we propose a novel approach with the identification of bilinear predictor model from input‐output data with enhanced computational efficiency. Based on the displacement structure theory, the QR factorization is replaced with a fast Cholesky factorization, which deals with the curse of huge dimensionality and therefore reduces the computation cost. These improvements make the bilinear subspace approach more computationally efficient with good prediction ability. Finally, the proposed control approach is illustrated with a simulation of the non‐linear continuously stirred tank reactor (CSTR) system.
Experimental Tests and Modelling of an Electrodeionization Cell for the Treatment of Dilute Copper Solutions
Authors: Mahmoud Akrama , Muhr Laurence , Grévillot Georges , Lapicque François
Published: July 2010

The paper presents the results of experimental and theoretical investigations of an electrodeionization process for the removal of metal cations from dilute solutions. The ability of this technique to treat 100 ppm copper solutions using cationic membranes and ion‐exchange resins between the membranes was studied. Fair abatement yields were obtained in the 100 mm high resin bed in long‐term runs, and solutions of an appreciable copper ion concentration could be produced in the cathode chamber. The process capacity was limited by significant deposition of copper at the cathode, non‐even distribution of current density, and side‐diffusion to the anode chamber. Additional tests were then carried out using a 15 mm resin bed. The more even current distributions allowed the effect of the resin stiffness and the current density on the removal yield to be thoroughly observed. Steady‐state operation of the resin bed was modelled using generalized expressions of the various transport rates. Results of the model clearly showed the significance of solid‐liquid interactions on the transport processes.
Removal of SO2 by Activated Carbon Fibre Impregnated with Transition Metals
Authors: Gaur Vivekanand , Sharma Ashutosh , Verma Nishith
Published: July 2010

Phenolic resin based activated carbon fibres (ACF) impregnated with oxides of various transition metals were investigated for the catalytic oxidation of SO2 into H2SO4. Oxidation was carried out in the packed bed tubular reactor in the presence of O2 and H2O. The activity of the various metals impregnated on ACF was observed to be in the order, Cu>Ni>Co>Cr. It was found that the metal oxides were dispersed as monolayer on ACF up to ∼5% (w/w) loading, beyond which crystallites formation occurred. A kinetic mechanism for the catalytic oxidation of SO2 into H2SO4 was proposed and incorporated in a transport model developed to explain the experimental breakthrough data.
A Modified Simplex Method for Solving 1‐Norm Minimization Problem in Model Predictive Control
Authors: Gupta Yash P.
Published: July 2010

Since the simplex method requires the polyhedron to be in the positive domain, the 1‐norm minimization problems are formulated by substantially increasing the size of the LP problems. This paper presents a simple modification that enables the simplex method to be directly applicable to a polyhedron, which extends into the negative domain. That is, instead of requiring the problem to change, the method is changed to fit the problem. The modification eliminates the need to increase the size of the problem and thus eliminates the associated computational effort. The proposed method skips iterations and Phase 1 of the simplex method. Its computational advantage is verified in two examples.
Hydrodynamic Modelling of Internal Loop Airlift Reactor Applying Drift‐Flux Model in Bubbly Flow Regime
Authors: Chriastel L. , Kawase Y. , Znad H.
Published: July 2010

A new model for the liquid circulation rates in airlift reactor (ALR) is presented. The model is based on the energy balance for the flow loop (riser, turn riser‐downcomer, downcomer, and turn downcomer‐riser) coupled with a drift flux theory of two‐phase flow gas‐liquid system, considering a bubbly flow regime. The predicted values of the liquid circulation rates by the developed model are compared with experimental results performed in a 22 dm3 internal loop airlift reactor and with the results obtained in the literatures. The proposed model predicted the experimental results very well. Slip velocity relationship based on the drift flux model was proposed; including the gas holdup, bubble size and the liquid physical properties. The predicted slip velocity was similar to that obtained from the literature. The study revealed that appropriate arrangements of internal bioreactor parts can positively influence the liquid circulation velocity at the same energy consumption. The proposed models are useful in the design; scale up and characterization of the internal loop airlift reactors, and provides a direct method of predicting hydrodynamic behaviour in gas‐liquid airlift reactors.
Experimental Investigations of Regimes of Bubble Formation on Submerged Orifices Under Constant Flow Condition
Authors: Badam V. K. , Buwa V. , Durst F.
Published: July 2010

Regimes of bubble formation on a submerged orifice under constant flow conditions were investigated experimentally. The effects of orifice diameter, surface characteristics (contact angle and roughness) and surface tension on the regimes of bubble formation were studied for a wide range of gas flow rates. In particular, the transitions of period‐1 to period‐2 bubbling regime, with pairing or with coalescence at the orifice, and period‐2 to chaotic bubbling were investigated in detail. An attempt is made to provide a generalized bubble formation regime map constructed using appropriate dimensionless numbers. The physical understanding of various bubbling regimes and the experimental data on the effects of various system parameters are expected to contribute to the development and validation of analytical and CFD models
Bifurcation Analysis on Pt and Ir for the Reduction of NO by CO
Authors: Mantri Dinesh , Mehta Viral , Aghalayam Preeti
Published: July 2010

Due to the importance of the NO‐CO reaction in current catalytic converters, reduction of NO by CO on Pt group catalysts is important to study. Various reaction mechanisms have been proposed for the NO‐CO reaction on Pt(100), which shows bifurcations, kinetic oscillations and multiple steady states under ultra high vacuum (UHV) conditions due to complex surface dynamics. Some experiments on supported Pt group catalysts reported in literature show oscillations and bistability under atmospheric conditions as well. Industrially relevant conditions require the modelling and detailed analysis of the system at atmospheric pressure. We have proposed a reaction mechanism for the NO‐CO system on Pt group catalysts and coupled it with an isothermal PSR model to obtain solutions at atmospheric conditions with the continuation software CONTENT 1.5, at different operating conditions. Simulation results suggest that Pt(111) shows bifurcations at certain operating conditions while Ir(111) shows stable solutions at all the operating conditions studied here.
Relationship on Stabilizability of LTI Systems by P and PI Controllers
Authors: Zhang Zhiping , Wang Qing‐Guo , Zhang Yong
Published: July 2010

This paper investigates the relationship on stabilizability of linear time‐invariant (LTI) systems by P and PI controllers. Elementary tools such as the Routh stability criterion and Root‐Locus method are employed in the analysis. It is found that PI can stabilize all the systems that P stabilizes but in general the converse is not true. The cases with the equivalence of stabilizability by P and PI are established and they are in general low‐order systems with few zeros. The cases with non‐equivalence are also identified.
Transition from Batch to Continuous Operation in Bio‐Reactors: A Model Predictive Control Approach and Application
Authors: Mhaskar Prashant , Aumi Siam
Published: July 2010

This work considers the problem of determining the transition of ethanol‐producing bio‐reactors from batch to continuous operation and subsequent control subject to constraints and performance considerations. To this end, a Lyapunov‐based non‐linear model predictive controller is utilized that stabilizes the bio‐reactor under continuous mode of operation. The key idea in the predictive controller is the formulation of appropriate stability constraints that allow an explicit characterization of the set of initial conditions from where feasibility of the optimization problem and hence closed‐loop stability is guaranteed. Additional constraints are incorporated in the predictive control design to expand on the set of initial conditions that can be stabilized by control designs that only require the value of the Lyapunov function to decay. Then, the explicit characterization of the set of stabilizable initial conditions is used in determining the appropriate time for which the reactor must be run in batch mode. Specifically, the predictive control approach is utilized in determining the appropriate batch length that achieves stabilizable values of the state variables at the end of the batch. Application of the proposed method to the ethanol production process using Zymomonas mobilis as the ethanol producing micro‐organism demonstrates the effectiveness of the proposed model predictive control strategy in stabilizing the bio‐reactor.
Characteristics‐Based Model Predictive Control of a Catalytic Flow Reversal Reactor
Authors: Fuxman A. M. , Forbes J. F. , Hayes R. E.
Published: July 2010

This paper describes the formulation and tuning of a model‐based controller for a catalytic flow reversal reactor (CFRR). A plug flow non‐linear pseudo‐homogeneous mathematical representation of the process is used to model the mass and energy transport phenomena for the model‐based controller. A combination of the method of characteristics and model predictive control (MPC) technology is used to formulate the controller (Shang et al., Ind. Eng. Chem. Res. 43(9) 2140–2149 (2004)). Mass extraction from the midsection of the reactor is used as the manipulated variable. Numerical simulations are used to show the performance of the formulated controller. The performance of the controller is evaluated on a simulated catalytic flow reversal reactor unit for combustion of lean methane streams for reduction of greenhouse gases emissions.
Dependence of the Error in the Optimal Solution of Perturbation‐Based Extremum Seeking Methods on the Excitation Frequency
Authors: Chioua Moncef , Srinivasan Bala , Guay Martin , Perrier Michel
Published: July 2010

In perturbation‐based extremum‐seeking methods, an excitation signal is added to the input, and the gradient, computed from the correlation between the input and output variations, is forced to zero. The main drawback of the method is that the speed of convergence, which is linked to the dither frequency, is slow due to the low value of dither frequency typically chosen. Increasing the excitation frequency may cause instability, but that could be corrected by phase compensation. In this paper, it is shown that an additional problem exists, i.e., the distance between the optimum and solution reached by the perturbation method is proportional to the square of the frequency of excitation and does not go to zero even when the amplitude of the excitation goes to zero. However, for Wiener/Hammerstein approximations, the error will indeed go to zero with the excitation amplitude. Simulation results on a distributed reaction system are used to illustrate the concepts presented in this work.
Detection, Diagnosis and Root Cause Analysis of Sheet‐Break in a Pulp and Paper Mill with Economic Impact Analysis
Authors: Imtiaz S. A. , Shah S. L. , Patwardhan R. , Palizban H. A. , Ruppenstein J.
Published: July 2010

Sheet‐break is a long standing problem in the pulp and paper industry. This study is concerned with the analysis of process data to diagnose causes of sheet‐breaks and therefore significant down times. PCA was used to model the process and a combined index based on the Hotelling's T2 and Squared Prediction Error (SPE) was developed as a sheet‐break detection indicator. As the process is subject to external disturbances, changes and frequent interruptions, pre‐processing of the data played an important role in getting consistent results. We used several novel techniques for data selection, scaling and modelling. The models were validated using a large validation data set with known fault conditions. The developed model, data visualization tool and engineering judgement was used for off‐line diagnosis of root causes of sheet‐breaks. Several operational changes were recommended and implemented on the process resulting in significantly reduced sheet‐breaks. Key Performance Indicators calculated before and after the changes shows the significant economic gain as a result of this 'data‐mining' project.
Enhanced Performance Assessment of Subspace Model‐Based Predictive Controller with Parameters Tuning
Authors: Zhang Qiang , Li Shaoyuan
Published: July 2010

This study focuses on performance assessment of model predictive control. An MPC‐achievable benchmark for the unconstrained case is proposed based on closed‐loop subspace identification. Two performance measures can be constructed to evaluate the potential benefit to update the new identified model. Potential benefit by tuning the parameter can be found from trade‐off curves. Effect of constraints imposed on process variables can be evaluated by the installed controller benchmark. The MPC‐achievable benchmark for the constrained case can be estimated via closed‐loop simulation provided that constraints are known. Simulation of an industrial example was done using the proposed method.
Synthesis of Gold Nanoplates in Lecithin Lamellar Liquid Crystals
Authors: Wang Luyan , Chen Xiao , Sun Zhenwen , Chai Yongcun
Published: July 2010

Gold nanoplates mixed with spherical nanoparticles were prepared in lecithin lamellar liquid crystals containing non‐ionic surfactants as reductant. The effects of the concentrations of surfactants, reactants and salt on the formation of the nano‐products are discussed. The selective adsorption of lecithin headgroups on metal surfaces plays an important role in nanoplate formation. However, this effect is weakened by the large volume of the headgroups and only a few plates can be observed. Using biological liquid crystals as a template to synthesize the anisotropic noble metal nanoparticles will be helpful for better understanding the formation of nanostructures with controllable morphologies in biomimetic systems.
Surface Characteristics of Kaolinite and Other Selected Two Layer Silicate Minerals
Authors: Miller Jan D. , Nalaskowski Jakub , Abdul Baseer , Du Hao
Published: July 2010

The electrokinetic features and interfacial water structure, as revealed from molecular dynamics simulations (MDS) are considered with respect to the anisotropic features of selected two layer silicate minerals. Planar structures of kaolinite and antigorite are compared to the, compositionally equivalent, tubular structures of halloysite and chrysotile with respect to the pH dependency of zeta potential as determined from the electrophoretic mobility measurements. The importance of the atomic mismatch between the tetrahedral and octahedral sheets in a particular bilayer is discussed in order to explain the electrokinetic behaviour of these two layer silicate minerals. Interfacial water structure from MDS suggests that the silica tetrahedral surface is not wetted by water. In the case of planar silicates structural imperfections are considered to explain wetting characteristics. The possibility of polarity reversal (domain inversion) within a tetrahedral/octahedral layer and an out‐of‐order layer (inserted layer) within the tetrahedral/octahedral stack are considered in order to explain electrokinetic behaviour and wetting characteristics.
Liquid Transport in a Coalescing Froth
Authors: Ireland Peter M. , Jameson Graeme J.
Published: July 2010

A previous study (Ireland and Jameson, J. Colloid Interface Sci., 314 207‐213 (2007)) demonstrated that a “drift‐flux” model could describe liquid transport in a stable rising froth with added “wash water.” In the present study, a drift‐flux model was used to describe a rising coalescing froth. This model incorporated the effect of liquid released into the froth by coalescence. Vertical profiles of liquid fraction and bubble size were obtained in a laboratory cell; a novel technique was used for measuring bubbles deep within the cell. These data were consistent with the predictions of the drift‐flux model.
Early Events in the Precipitation Fouling of Calcium Sulphate Dihydrate under Sensible Heating Conditions
Authors: Fahiminia Feridoun , Watkinson A. Paul , Epstein Norman
Published: July 2010

Supersaturated aqueous solutions of calcium sulphate, an inverse solubility salt, were circulated through a 9 mm i.d. stainless steel tube in which they were subjected to a constant and uniform heat flux at Reynolds numbers ranging from 2100 to 36 000. Precipitation fouling of the tube surface, which was monitored and measured thermally, resulted in calcium sulphate dihydrate (gypsum) scales. Measured delay times decreased with increasing bulk solute concentration, Cb, in accord with classical nucleation kinetics, decreased with increasing surface temperature Ts, its reciprocal correlating with Ts in the Arrhenius manner, and decreased with increasing fluid velocity V up to V ≈ 0.5 m/s before flattening out. Initial linear fouling rates,Rfo, at Cb = 3400 ppm, also yielded Arrhenius plots, with fouling activation energies increasing almost eight‐fold over the 0.1–1.6 m/s velocity range. This result implies a shift in the mechanism of fouling rate control with increasing velocity from mass transfer, which is weakly temperature dependent, to surface integration, which is strongly temperature dependent. The “Initial Fouling Rate Model,” which simulates this mechanistic shift with a unique dependence of the surface‐integration step on the residence time of the fluid at the tube wall, was used to represent, by least‐squares fitting, 84 fouling rate data points at different values of V and Ts, with three adjustable parameters. Observed trends of Rfo with V and clean wall Ts were qualitatively captured by the model, but quantitative agreement was imperfect. Substantial quantitative improvement was effected by introducing into the model an additional temperature dependence of the surface‐integration term—resulting in one additional adjustable parameter—rationalized as a method of accounting for the previously neglected temperature‐dependent nucleation that accompanies crystal growth. The fouling investigation was supplemented by an experimental study of crystal growth kinetics.
Interpretation of Bitumen Recovery Data from Batch Extraction Tests
Authors: Omotoso O. , Friesen W. I. , Mikula R. J.
Published: July 2010

Small‐scale batch tests are often used to compare oil sand samples and to understand processing trends for process variables such as temperature, water chemistry, and ore properties. The uncertainty associated with the value of bitumen recovery determined from a carefully performed batch test is approximately 4%, a level that can have significant economic implications when commercial production rates are considered. This paper discusses several methods for determining bitumen recovery and shows the preferred, although seldom used, method for calculating this value.
The Stability of Water‐in‐Crude and Model Oil Emulsions
Authors: Sullivan Andrew P. , Zaki Nael N. , Sjöblom Johan , Kilpatrick Peter K.
Published: July 2010

The critical electric field (cef) technique has been utilized to measure the stabilities of a variety of water‐in‐model oil and petroleum emulsions. The cef method allows for a fast, reproducible, and quantitative gauge of emulsion stability. Here, we have used cef to measure the stability of water‐in‐heptane‐toluene‐asphaltene emulsions and confirmed the importance of solvation of asphaltenes and the state of asphaltene aggregation to emulsion stability. Emulsion stability increased with the concentration of soluble asphaltenes near the point of precipitation. Droplet sizes were measured with optical microscopy in order to calculate interfacial areas and film thicknesses. It was found that film thickness increased with asphaltene concentration up to the solubility limit, above which increased concentration had little effect, and cef increased with interfacial film thickness up to a monolayer coverage of asphaltene aggregates, above which film thickness had a much smaller effect. These findings were applied to a cef investigation of water‐in‐ppetroleum emulsions to develop correlations of the stability of water‐in‐ccrude oil emulsions. A strong correlation (coefficient = 0.95) was found for cef with the product of asphaltene concentration and the difference in hydrogen to carbon atomic ratios of the asphaltenes and petroleum solvent. The development of a kinetic model and its fit to experimental data revealed the effects of asphaltene chemistry, solvency, and resin concentration on the adsorption and consolidation of emulsion stabilizing interfacial films.
Effects of Viscous Dissipation on Heat Transfer between an Array of Long Circular Cylinders and Power Law Fluids
Authors: Chhabra R. P. , Soares A. A. , Ferreira J. M. , Caramelo L.
Published: July 2010

The free surface model has been combined with the equations of motion and of thermal energy to investigate the role of viscous dissipation on heat transfer between banks of long cylinders and power law (shear‐thinning and shear‐thickening) fluids. The equations of motion cast in the stream function/vorticity formulation have been solved numerically using a second‐order accurate finite difference method to obtain extensive information on the behaviour of local and surface‐averaged Nusselt numbers over a range of Reynolds numbers 1 – 500, for a wide range of power law indices (0.4 ≤ n ≤ 2.0), Brinkman numbers (0 ≤ Br ≤ 5) and Prandtl numbers (Pr = 1, 1000) at two representative solid volume fractions corresponding to the porosities of e = 0.4 and 0.9. Two different thermal boundary conditions are considered at the cylinder surface: constant temperature (CT) and constant heat flux (CHF). The results presented herein provide a fundamental knowledge about the influence of viscous dissipation on the heat transfer characteristics. The results reported herein further show that the effect of Brinkman number on heat transfer is strongly conditioned by the thermal boundary condition, Prandtl number and the power law index.
New Attraction Term for the Soave‐Redlich‐Kwong Equation of State
Authors: Chouaieb O. , Bellagi A.
Published: July 2010

A new 3‐parameter attraction term for the Soave‐Redlich‐Kwong equation of state, that ensures a correct physical behaviour, is proposed to improve its predictive capabilities, particularly in the supercritical region and in the gas phase. Vapour pressure and second virial coefficient data for a set of eight pure fluids with a low acentric factor ω (Ar, Ne, Kr, O2, N2, C‐H4, CO and C2‐H6) are used to determine the equation's adjustable parameters. When only vapour pressure data are considered the supercritical region is poorly described. An extension of the data base by including for instance the second virial coefficient data leads to a significant improvement in the description of the sub and supercritical regions of the considered fluids and particularly in the prediction of the Joule‐Thomson inversion curves. The new attraction term is shown to be suitable for other pratical fluids like hydrocarbons as well as their mixtures.
Effect of Reaction Solvent on the Hydrogenation of Isophthalonitrile for Meta‐Xylylendiamine Preparation
Authors: Row Sung Wook , Chae Tae Young , Yoo Kye Sang , Lee Sang Duek , Lee Do Weon , Shul Yonggun
Published: July 2010

This study focused on the effects of reaction solvent on the hydrogenation of isophthalonitrile (IPN) to produce m‐Xylylenediamine (MXDA) over Ni‐based commercial catalyst. The hydrogenation was carried out using various reaction solvents such as 1‐methylimidazole, mesitylene, benzyl ether and isopropanol under various reaction conditions. It was observed that 1‐methylimiazole outperformed the other reaction solvent, exhibiting a high MXDA yield and producing a low concentration of undesirable products.
Modeling capping protein FRAP and CALI experiments reveals in vivo regulation of actin dynamics
Authors: Kapustina Maryna , Vitriol Eric , Elston Timothy C. , Loew Leslie M. , Jacobson Ken
Published: July 2010

To gain insights on cellular mechanisms regulating actin polymerization, we used the Virtual Cell to model fluorescence recovery after photobleaching (FRAP) and chromophore‐assisted laser inactivation (CALI) experiments on EGFP‐capping protein (EGFP‐CP). Modeling the FRAP kinetics demonstrated that the in vivo rate for the dissociation of CP from actin filaments is much faster (∼0.1 s−1) than that measured in vitro (0.01–0.0004 s−1). The CALI simulation revealed that in order to induce sustainable changes in cell morphology after CP inactivation, the cells should exhibit anticapping ability. We included the VASP protein as the anticapping agent in the modeling scheme. The model predicts that VASP affinity for barbed ends has a cooperative dependence on the concentration of VASP‐barbed end complexes. This dependence produces a positive feedback that stabilizes the complexes and allows sustained growth at clustered filament tips. We analyzed the range of laser intensities that are sufficient to induce changes in cell morphology. This analysis demonstrates that FRAP experiments with EGFP‐CP can be performed safely without changes in cell morphology, because, the intensity of the photobleaching beam is not high enough to produce the critical concentration of free barbed ends that will induce filament growth before diffusional replacement of EGFP‐CP occurs. © 2010 Wiley‐Liss, Inc.
The formin FRL1 (FMNL1) is an essential component of macrophage podosomes
Authors: Mersich Akos T. , Miller Matthew R. , Chkourko Halina , Blystone Scott D.
Published: July 2010

Podosomes are highly dynamic actin‐rich adhesion structures in cells of myeloid lineage and some transformed cells. Unlike transformed mesenchymal cell types, podosomes are the sole adhesion structure in macrophage and thus mediate all contact with adhesion substrate, including movement through complex tissues for immune surveillance. The existence of podosomes in inflammatory macrophages and transformed cell types suggest an important role in tissue invasion. The proteome, assembly, and maintenance of podosomes are emerging, but remain incompletely defined. Previously, we reported a formin homology sequence and actin assembly activity in association with macrophage β‐3 integrin. In this study we demonstrate by quantitative reverse transcriptase polymerase chain reaction and Western blotting that the formin FRL1 is specifically upregulated during monocyte differentiation to macrophages. We show that the formin FRL1 localizes to the actin‐rich cores of primary macrophage podosomes. FRL1 co‐precipitates with beta‐3 integrin and both fixed and live cell fluorescence microscopy show that endogenous and overexpressed FRL1 selectively localize to macrophage podosomes. Targeted disruption of FRL1 by siRNA results in reduced cell adhesion and disruption of podosome dynamics. Our data suggest that FRL1 is responsible for modifying actin at the macrophage podosome and may be involved in actin cytoskeleton dynamics during adhesion and migration within tissues. © 2010 Wiley‐Liss, Inc.
A computational model to detect and quantify a primary blast lung injury using near‐infrared optical tomography
Authors: Kannan R. , Przekwas A.
Published: July 2010

Near‐infrared (NIR) tomography is an imaging technique, in which the optical properties of tissues are reconstructed from the measurements obtained from the sensors located on the boundary. In this paper, we describe a computational method for rapid non‐invasive detection/quantification of blast lung injury using the above. The Near‐infrared spectroscopy (NIRS) technique is simulated using computational models and thus in principle mimics an actual NIRS procedure which penetrates non‐invasively through the thoracic wall, pleural region and the lungs to detect (and subsequently reconstruct their properties) the presence of water, oxygenated and de‐oxygenated blood. These ‘pseudo’ measurements can then be used to predict the extent and severity of the lung injury. The paper also discusses ideas to obtain the location, radius and the severity of a localized injury. Simulations are performed as a proof of concept for NIRS being feasible for the above‐mentioned detection/quantification. Copyright © 2010 John Wiley & Sons, Ltd.
Traveling wave solutions of the Schrödinger map equation
Authors: Lin Fanghua , Wei Juncheng
Published: July 2010

We first construct traveling wave solutions for the Schrödinger map in ℝ2

of the form m(x1, x2 − ϵ t), where m has exactly two vortices at approximately
$\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}(\pm {{1}\over{2 \epsilon}}, 0) \in \R^2$
of degree ±1. We use a perturbative approach that gives a complete characterization of the asymptotic behavior of the solutions. With a few modifications, a similar construction yields traveling wave solutions of Schrödinger map equations in higher dimensions. © 2010 Wiley Periodicals, Inc.
Random matrix model with external source and a constrained vector equilibrium problem
Authors: Bleher P. , Delvaux S. , Kuijlaars A. B. J.
Published: July 2010

We consider the random matrix model with external source in the case where the potential V(x) is an even polynomial and the external source has two eigenvalues ±a of equal multiplicity. We show that the limiting mean eigenvalue distribution of this model can be characterized as the first component of a pair of measures (μ1, μ2) that solve a constrained vector equilibrium problem. The proof is based on the steepest‐descent analysis of the associated Riemann‐Hilbert problem for multiple orthogonal polynomials.

We illustrate our results in detail for the case of a quartic double‐well potential
$V(x) = {1 \over 4} x^4 - {t \over 2} x^2$. We are able to determine the precise location of the phase transitions in the ta‐plane, where either the constraint becomes active or the two intervals in the support come together (or both). © 2010 Wiley Periodicals, Inc.
Environmental assessment in the british planning system
Authors: Stone Chris , Walker Sue
Published: July 2010

It is commonly held that the most effective environmental protection policies address the prevention rather than the cure of the effects of pollution. Chris Stone and Sue Walker discuss the nature of environmental impact assessment, a major preventative tool in environmental policy, and offer practical insights from an appraisal of a new ski development in the Scottish Highlands.
Sedimentary and faunal events revealed by a revised correlation of post‐glacial Hirnantian (Late Ordovician) strata in the Welsh Basin, UK
Authors: Davies Jeremy R. , Waters Richard A. , Williams Mark , Wilson David , Schofield David I. , Zalasiewicz Jan A.
Published: July 2010

The discovery of a previously unrecognized unconformity and of new faunas in the type Llandovery area underpins a revised correlation of Hirnantian strata in mid Wales. This has revealed the sedimentary and faunal events which affected the Lower Palaeozoic Welsh Basin during the global rise in sea level that followed the end‐Ordovician glacial maximum and has allowed their interpretation in the context of local and global influences.

In peri‐basinal shelfal settings the onset of post‐glacial deepening is recorded by an unfossiliferous, transgressive shoreface sequence (Cwm Clyd Sandstone and Garth House formations) which rests unconformably on Rawtheyan rocks, deformed during an episode of pre‐Hirnantian tectonism. In the deep water facies of the basin centre, this same sequence boundary is now recognized as the contact between fine‐grained, re‐sedimented mudstones and an underlying regressive sequence of turbidite sandstones and conglomerates; it is at a level lower than previously cited and calls into question the established lithostratigraphy.

In younger Hirnantian strata, graptolites associated with the newly recognized Ystradwalter Member (Chwefri Formation) demonstrate that this distal shelf unit correlates with the persculptus graptolite‐bearing Mottled Mudstone Member of the basinal succession. Together these members record an important macrofaunal recolonization of the Welsh Basin and mark a key event in the post‐glacial transgression. Further deepening saw the establishment of a stratified water column and the imposition of anoxic bottom water conditions across the basin floor.

These post‐glacial Hirnantian events are consistent with the re‐establishment of connections between a silled Welsh Basin and the open Iapetus Ocean. However, a comparison with other areas suggests that each event records a separate deepening episode within a pulsed glacio‐eustatic transgression, while also reflecting changes in post‐glacial climate and patterns of oceanic circulation and associated biotic flux. British Geological Survey © NERC 2009. All rights reserved.
Intraformational conglomerates and scoured surfaces in the lower old red sandstone of the Anglo‐Welsh cuvette
Authors: Allen J. R. L.
Published: July 2010

Scoured surfaces occur in the upper part of the Lower Old Red Sandstone of the Anglo‐Welsh cuvette between cyclothems consisting of intraformational conglomerate→sandstone→siltstone. The conglomerates are formed chiefly of rocks which can be matched in the deposits of the cuvette, and contain little or no gravel from more distant sources. The scoured surfaces persist laterally and are preserved typically as casts. They discordantly cut earlier beds, and show a variety of discordantly‐filled minor structures (sole marks) due to current scour: flute‐like and lobate forms, current crescents, sack‐like bulges, terraces and small flat‐bottomed channels. Large channels are also known. Scoured surfaces occur also in the Lower Old Red Sandstone amongst sandstones, within which they may delineate major groups of sedimentation units as well as individual units in trough cross‐stratified compilations.

The basal features of the cyclothems (scoured surfaces, intraformational conglomerates) record periods when sediments of the cuvette were reworked. This probably took place as the rivers instrumental in deposition of the Lower Old Red Sandstone underwent major changes in their courses, perhaps as the result of crevassing directly onto their floodplains. By reference to modern river sands, the trough cross‐stratified sandstones appear to have accumulated on sandbanks in the stream channels of the cuvette through the action of megaripples.
Correlation of the upper purbeck beds of england with the German Wealden
Authors: Anderson F. W.
Published: July 2010

Certain ostracod species in the Upper Purbeck of England show a succession of morphological changes which correspond to those described by Wolburg from the Wealden of North‐West Germany. Thus stage by stage correlation is possible between the deposits in the two countries, and it is shown that the Upper Purbeck Beds in England correspond to most of the German Wealden W3 together with all of W4.
Palaeontological and physical evidence of the palaeoecology of some early species of non‐marine lamellibranchs
Authors: Bennison G. M.
Published: July 2010

Using techniques applied by Eagar and by Broadhurst to investigate sedimentary environments of Westphalian non‐marine shell beds, an attempt is made to assess the palaeoecology of the earliest recorded Carboniferous non‐marine lamellibranchs. The latter pose a special problem of ecology by virtue of their antiquity and presumed closeness in time to a marine ancestry. Since the species under discussion occur with few other fossils the usual recourse to a study of faunal relationships provides only limited evidence of ecology.
Chomatichnus, a new Ichnogenus, and other trace‐fossils of Wegber quarry
Authors: Donaldson Douglas , Simpson Scott
Published: July 2010

A group of alternating shale and limestone beds in the Dibunophyllum Zone of the Carboniferous Limestone at a quarry near Carnforth, Lancashire, shows an interesting variety of well‐preserved trace‐fossils. These include exceptionally large tracks of Helminthopsis type, burrows of a tubular character which give rise to the characteristic “Stick Bed” structures, “cauda‐galli” markings and piles of worm castings. The new ichnogenus Chomatichnus is proposed for the last of these.
The glaciology of the coniston basin
Authors: Gresswell R. Kay
Published: July 2010

Much of the lower hill‐country of the Lake District had a continuous ice‐cover during the Main Irish Sea glaciation, as probably also in the earlier glaciations, and there are many indications of ice‐action at considerable altitudes. The later phases of the Newer glaciation, however, made a great contribution to the present topography, in respect both of valley erosion and lowland deposition. The main Coniston glacier bifurcated south of Coniston town, and the eastern portion itself divided into three at Blawith and Lowick Green. A further triple sub‐division also occurred north of Ulverston. The drumlin display formed by the piedmont glaciers is correlated with the Scottish re‐advance, and with an end moraine at Kirkham, Lancashire. They are very similar to drumlins forming an extensive field of the same age between the Antrim and Kells moraines in Ireland. A substantial terminal moraine was formed at Haverthwaite and a multiple one at Nibthwaite. These are correlated with terminal moraines at Newby Bridge and Church Town, and with the Highland re‐advance and the Antrim coast glaciation. The sculpturing of the cirques to the form seen today belongs to the last, post‐Alleröd phase, the Cirque glaciation.
Holocene mollusca from Saltend, Hull, Yorkshire
Authors: Shdllitoe J. S.
Published: July 2010

The marine Mollusca are named and their relative numbers given in the stratigraphical section, which is described. From known facts of their habitat and resistance to changes of salinity in their environment, the geological history of the Holocene strata at this locality is attempted.
On the torridonian sediments of colonsay and their relationship to the main outcrop in north‐west Scotland
Authors: Stewart A. D.
Published: July 2010

Colonsay is a small island in the Inner Hebrides, about 100 km. south of Skye. The main part of the succession, which is about 2 km. thick, consists of phyllites, fine dark sandstones and flags, occasionally graded, with major intercalations of coarse current‐bedded arkose and, near the top, dolomitic limestone horizons. This series rests with a sharp contact (probably a slight unconformity) on a sequence of graded greywackes and mudstones, not less than 2 km. thick, most of which outcrops to the south in Oronsay, and in Islay, where it rests unconformably on the Lewisian basement. The greywackes and arkoses indicate that currents moved mainly northeastwards.

A comparison of the Torridonian rocks to the north with those in Colonsay suggests the equivalence of the beds above the greywackes with at least part of the Diabaig in Skye. Three major fades are distinguished in the Torridonian; the greywacke, Diabaig and arkose fades, and it is tentatively suggested that they mark stages in the infilling of a major sedimentary basin or trough of which the present Torridonian outcrop forms only the western margin.
Notes on a temporary section in the ordovician at Conway, north Wales
Authors: Wood D. S. , Harper J. C.
Published: July 2010

Black graptolitic shales of approximately D. clingani age were seen resting on flaggy beds with an Upper Longvillian fauna, which are taken to belong to the Upper Ash Group of Elles. This section conflicts with the details published concerning the nearby Conway railway cutting and an attempt is made to correlate the two sections. The work shows that volcanism at Conway ended within the same stage of the Caradoc as in Snowdonia, not earlier as formerly supposed.
The borrowdale volcanic rocks of the Seathwaite Fells, Lancashire
Authors: Mttchell G. H.
Published: July 2010

The Borrowdale Volcanic Rocks of the Seathwaite Fells, northwest of Coniston, Lancashire, consist of up to 13550 ft of lavas and tuffs, mainly andesitic in composition, but including some rhyolitic rocks among which are welded tuffs. They occupy a position in the lower part of the Borrowdale Volcanic succession and dip steeply to the southeast with little folding. A number of northerly trending faults and others with a trend between east‐northeast and east‐southeast traverse the area. Volcanic vents filled with agglomerate have been found at two places.
The occurrence of the Branchiopod Crustacean euestheria in the Keuper Sandstone of alderley edge, Cheshire
Authors: Warrington G.
Published: July 2010

The specimens of Euestheria originally found at Alderley Edge were given inadequate descriptions and their horizon is confused by conflicting statements. A revised account is given, incorporating information from newly collected material.
Boring algae, micrite envelopes and lithification of molluscan biosparites
Authors: Bathurst R. G. C.
Published: July 2010

The preservation of molluscan shells as calcite casts is commonly a result of their centripetal replacement, while on the sea floor, by a stable micrite envelope. This grows in three stages: (1) algae bore into the shell wall, (2) the algal filaments die and decay, (3) micritic aragonite fills the tubes. Later, if the skeletal sand is exposed to fresh water as a result of uplift or a fall in sea level, or to a suitable brine deep under the sea floor, the residual molluscan shell is dissolved but the envelope remains intact. It forms an empty mould that is subsequently filled with drusy calcite. Complete replacement of skeletal grains by micritic aragonite yields cryptocrystalline grains like Ming's “grains of aragonite matrix” and the grains in Beales's “bahamite”. Through a study of compaction fabrics it may be possible to decide whether an envelope‐bearing limestone was cemented above sea level or below the sea floor.
The magnetic fabric of some Irish Granites
Authors: King R. F.
Published: July 2010

Magnetic anisotropy measurements have been made on fifty‐four oriented samples from the Carna and Screeb areas of the Galway Granite, and from the Ardara pluton and the Main Granite (including the Trawenagh Bay Granite) in Donegal. The origin of magnetic anisotropy in plutonic magnetic rocks is discussed, and it is concluded that it is probably due to grain alignment of inequant magnetite, which may occur either as free grains or as secondary inclusions in ferromagnesian minerals. The grain alignment may occur either whilst the magma is essentially fluid, giving a magnetic lineation transverse to the flow, or at a much later stage of consolidation during plastic deformation, in which case the magnetic lineation parallels the direction of greatest elongation.

The results of the measurements are consistent with macroscopic foliations and lineations where these have been observed, but also indicate the existence of fabrics too weak to observe by conventional methods. This is because the magnetic method assesses the alignment of a very large number of grains, and is therefore much more sensitive than conventional fabric analysis. The weak fabrics can be qualitatively explained in terms consistent with other evidence relating to the emplacement of the granites, and experimental work now in progress may make possible a more quantitative interpretation.
New carboniferous Polyzoa from Derbyshire
Authors: Owen D. E.
Published: July 2010

The highly fossiliferous fore‐reef limestones of B2 age from near Castleton, Derbyshire are rich in Polyzoa. Ten species are described, six of them new.
A study of the relation between jointing and structural evolution
Authors: Roberts J. C.
Published: July 2010

This paper records the results of a regional jointing survey in the country adjacent to a part of the Neath disturbance, South Wales, in an area of Old Red Sandstone and Carboniferous Strata. A well developed joint system exists which is comprised of up to six sets of joints striking at 350°, 330°, 290°, 270°, 240° and 210°. The joint patterns undergo stratigraphical and areal variation, which can be correlated with lithology and tectonic setting. A comparison of the joint trends with the faults and folds shows that a genetic relationship exists between the structures. It is suggested that the joint sets formed early in the tectonic evolution of the area, and that these and the faults can be attributed to a general N‐S compressive force, and its related first and second order shear regimes.
The glaciation of the Langdale fells
Authors: Walker D.
Published: July 2010

The detailed distribution of glacial features in the Langdale Fells is described and the uncertainties attending their explanation discussed. Although it cannot be shown that all the kettle moraines are of a single age, two of them have been dated to Zone III of the pollen‐analytical chronology.