bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Coating of Laser Mirrors for the Generation of Ultrashort Laser Pulses
Authors: Brunk Jochen , Morgner Uwe , Rieder Andreas 
Published: December 2005

AbstractUltrashort laser pulses play an important role in various scientific and industrial applications. For instance, they allow studying the dynamics in fast molecular processes or improve the power of imaging techniques in medical technology, as in optical coherence tomography.The generation of such short pulses requires techniques for dispersion compensation over an enormous bandwidth. Therefore laser cavities with so‐called double chirped mirrors are used. These mirrors consist of a series of alternating high‐ and low‐index layers. The optical properties of the laser cavity depend on the material, the thickness and the number of the layers. So the generation of ultrashort laser pulses can be formulated as an inverse problem:How have the mirrors to be coated to design laser cavities with prescribed spectral properties?Mathematically, the coating of a mirror is described by a space (time) dependent refractive index n . The spectral properties of the mirror are modeled by its complex, frequency dependent reflection coefficient r . Now, the inverse problem reads: given r find n . We suggest to solve the inverse problem relying on its relation to an one‐dimensional Schrödinger equation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An inverse medium problem for scanning acoustic microscopy
Authors: Clason Christian , Beilina Larisa 
Published: December 2005

AbstractFor nondestructive testing of materials, the scanning acoustic microscope is commonly used for the qualitative visualization of elastic properties. However, especially for medical applications, quantitative evaluation of the measured data is of considerable interest.Based on a mathematical model of the process of scanning acoustic microscopy, the problem of recovering elastomechanical parameters of human bone can be cast into the form of identifying the unknown space‐dependent speed of sound in the three‐dimensional acoustic wave equation. Specific methods have to be devised for this kind of inverse medium problem due to the reduced set of measured data available. Here, an optimal control approach is used. We discuss uniqueness and stability of the reconstruction and present a numerical example. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pre‐Tensioned Belts Overhanging Elastic Rollers
Authors: Daxner T. , Luxner M. H. , Rammerstorfer F. G. 
Published: December 2005

AbstractSubject of this paper are deformation mechanisms in pre‐tensioned elastic belts, which are wrapped around rollers carrying elastic layers that support the belts over part of their width. By means of analytical models and the finite element method the corresponding deformations of the belts are predicted. Special emphasis is put on the effects of the nonlinear (contact) boundary conditions in the vicinity of the lateral edges of the roller. The continuum finite element simulations provide reference solutions, and, furthermore, serve as an accurate means for predicting the contact stress distribution, whereas the semi‐analytical solutions allow for an inexpensive and quick investigation of several parameter combinations. The high quality of the semi‐analytical model can be judged by the excellent agreement of the obtained results with the reference finite element results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active control laws for aeroelasticity
Authors: Dumitrache Alexandru , Botez Ruxandra 
Published: December 2005

AbstractThe objective of this paper is to describe a methodology to design control laws in the context of a computational aeroelasticity environment. The technical approach involves employing a systems identification technique to develop an explicit state‐space model for control law design from the output of a computational aeroelasticity code. As a control law design techniques, the standard LQG technique is employed. The computational aeroelasticity code is modified to accept control laws and perform closed‐loop simulations. Numerical results for flutter suppression of the BACT wind‐tunnel model are given. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Arnoldi‐Type Algorithm for Parametric Finite Element Modelling of Microwave Components
Authors: Farle O. , Hill V. , Nickel P. , Dyczij‐Edlinger R. 
Published: December 2005

AbstractIn this paper, we present an efficient model order reduction (MOR) technique for computing the solution of a linear equation system depending on a multivariate polynomial of scalar parameters. We propose a moment‐matching projection method based on the concept of multivariate Krylov spaces of higher order. The new method exhibits greater stability and allows to build models of higher order than previous approaches. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamical Particle Simulation with Parallel Cache‐Aware Domain Decomposition Strategies
Authors: Fleissner Florian , Eberhard Peter 
Published: December 2005

AbstractThe simulation of large particle systems with the Discrete Element Method can be very time consuming. This is due to the necessity for collision detection between the disordered particles. Various methods, originating from different areas such as computer science, are well established and have been used in various applications. For parallel computations the simulation domain needs to be divided into subdomains to be distributed among the different nodes or machines within a supercomputer or a computer‐cluster. The strategy for this domain decomposition has a significant influence on the performance of the calculation. In this paper we discuss some aspects of the development of a hierarchical domain decomposition algorithm that provides flexible adaption of the decomposition pattern to the changing structure of the particle system during the simulation. Thus an even load distribution among the different machines can be maintained. Moreover, the same method is also used to deal with the computational bottleneck caused by the presence of unstructured data. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Control for non–isothermal crystallization of polymers
Authors: Götz Thomas , Pinnau Rene , Struckmeier Jens 
Published: December 2005

AbstractIn this paper an optimal control problem for polymer crystallization is investigated. The crystallization is described by a non–isothermal Avrami–Kolmogorov model. The boundary temperature serves as control variable. The cost functional takes the spatial variation of the crystallinity and the final degree of crystallization into account. The resulting boundary control problem for a parabolic equation coupled with two ordinary differential equations is treated by an adjoint variable approach. A steepest descent algorithm is used to solve the problem numerically. Simulations illustrate the applicability and performance of the optimization algorithm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling of Systems of Hyperbolic Equations
Authors: Herty Michael 
Published: December 2005

AbstractWe consider the Aw‐Rascle system of hyperbolic equations which describes traffic flow phenomena on a single road. The model consists of two coupled nonlinear conservation laws in a single space dimension. We study an extension of the Aw/Rascle system to a network of roads. We derive necessary coupling conditions and introduce an obvious definition of a solution. We prove the existence of a solution to the road network problem. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of moment functions for parabolic PDEs with random parameters
Authors: Kandler Anne , vom Scheidt Jürgen 
Published: December 2005

AbstractThis paper deals with different approaches for the computation of stochastic characteristics (such as mean, variance, correlation function, …) of the solution to parabolic PDEs with random parameters, in particular with a random Neumann boundary conditions and a random initial condition. Thereby Finite‐Element discretisation of the spatial variables is used for the construction of pathwise solutions. The random influences are assumed to beε‐correlated (cp. [4]) that means the correlation functions vanish if the difference of the arguments exceeds a given correlation lengthε. So an asymptotic expansion of higher order with respect to the correlation length for the correlation function of the approximative solution is given. A second possibility is the so called explicit calculation. Examples which compare the different methods can be found in [2]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐linear modelling and statistical anlaysis of multi‐stage high‐pressure inactivation of lactic acid bacteria
Authors: Kilimann Klaus Valentin , Hartmann Christoph , Gänzle Michael , Delgado Antonio 
Published: December 2005

AbstractIt was the aim of this work to determine the combined effects of pressure, temperature, and co‐solvents on Lactococcus lactis , and to detect correlations between culture‐dependent and culture‐independent methods for assessment of cellular viability and sublethal injury. Therefore, the pressure induced inactivation of L. lactis MG 1363 was investigated in 21 buffer systems at a pressure range of 0.1 MPa to 600 MPa and a temperature range of 5 to 50 Grad Celsius. The inactivation was characterised by viable cell counts, stress resistant cell counts, membrane integrity, metabolic activity, and LmrP activity. By using Principal Component Analysis, correlations were detected between viable cell counts and metabolic activity as well as stress resistant cell counts and LmrP activity. Based on these correlations, a fuzzy logic model was formulated. The model uses two of the five physiological states as autonomous output variables. Input variables are pressure, temperature, application time and food systems. Latter fully describe the inactivation process of L. lactis correctly. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐temperature mastication of raw natural rubber: Changes in macrostructure and mesostructure
Authors: Ehabe E.E. , Bonfils F. , Sainte‐Beuve J. , Collet A. , Schué F. 
Published: December 2005

AbstractRaw natural rubber samples of different Mooney viscosity values and inherent molar mass distributions (MMD) were used to characterize changes occurring during high‐temperature mastication and to identify the structural components conditioning mastication‐induced degradation. The macrogel degraded rapidly to essentially microgel, the latter of which was also continuously degraded, and at times completely. Mastication provoked decreases in the average molar mass of polyisoprene chains and changes in their MMD. The MMDs evolved differently as mastication progressed, differences that could be linked to the inherent MMD of each rubber. The non‐viscosity stabilized grade rubber (TSR 10) of monomodal MMD was progressively degraded by mastication, whereas rubber of the same grade but with a bimodal MMD was degraded much slowly and even stagnated on prolonged mastication. The stage at which stagnation occurred was characterized by an offset of the balance between long and short polyisoprene chains due to increases in the quantity of short chains, which facilitate the sliding of the longer ones. POLYM. ENG. SCI., 46:222–227, 2006. © 2005 Society of Plastics Engineers
Effect of heat‐sealing temperature on the failure criteria of oriented polypropylene/cast polypropylene heat seal
Authors: Hashimoto Yasuo , Ishiaku U.S. , Leong Y.W. , Hamada Hiroyuki , Tsujii Tetsuya 
Published: December 2005

AbstractFailure criteria of the heat‐sealed part of oriented polypropylene (OPP) and cast polypropylene (CPP) heat seals made by an impulse type heat‐sealing machine were investigated. Circular notches and precracks were introduced to direct failure to specific areas such as inside the seal, at the border, or at the unsealed part. The notched strength as a function of heat‐sealing temperature revealed that the seals were stronger in the transverse direction (TD) as compared with the machine direction (MD). Tensile failure that occurred inside the heat seal is more sensitive to sealing temperature, whereas that at the unsealed part is immune. The stress intensity factor (K1) is generally higher along the TD. At high sealing temperatures, i.e. above 150°C, orientation in the OPP film is relaxed and this results in consistently low mechanical properties at this temperature range. This morphology was revealed by studies of crystalline orientation state and FTIR imaging. POLYM. ENG. SCI., 46:205–214, 2006. © 2005 Society of Plastics Engineers
Hydrothermal effects on the thermomechanical properties of high performance epoxy/clay nanocomposites
Authors: Wang Lei , Wang Ke , Chen Ling , He Chaobin , Zhang Yongwei 
Published: December 2005

AbstractThe effects of hydrothermal ageing on the thermomechanical properties of high performance epoxy and its nanocomposite were studied. The epoxy–clay nanocomposite was prepared through a recently developed “slurry‐compounding” approach. The cured samples were immersed in distilled water at 60°C for different periods of time before subjecting to characterization. The storage modulus, relaxation behavior, fracture toughness, and tensile properties were investigated. It was found that the storage modulus and α‐relaxation were strongly affected by water uptake, while the fracture toughness and Young's modulus were less influenced. Dependence of tensile strength and strain at break on water uptake was found to be different in neat epoxy and epoxy–clay systems. POLYM. ENG. SCI., 46:215–221, 2006. © 2005 Society of Plastics Engineers
QoS Model of a Router with Feedback Control
Authors: Yang Zhibin , Ye Nong , Lai Ying‐Cheng 
Published: December 2005

AbstractThe Internet has evolved into a shared, integrated platform of a broad range of applications with different Quality‐of‐Service (QoS) requirements. Routers are an important part of the Internet and play a critical role in assuring QoS. A router is usually placed between two networks to receive data packets from one network and then transmit those data packets to another network if necessary. Data packets are the actual units of data traveling on computer networks. A data packet has two parts: header and data. The data carries messages, such as e‐mail text, from computer applications. The header carries information that is required to control and manage the transmission of the data packet on computer networks. Existing approaches for providing QoS involve prediction or estimation for traffic characterization to determine parameters required of static traffic admission control. However, prediction or estimation inaccuracy in traffic characterization can result in inappropriate parameter settings for static admission control and, in turn, compromise QoS or resource utilization. This study presents a QoS model of a router with feedback control that monitors the state of resource usage and adaptively adjusts parameters of traffic admission control to overcome prediction or estimation inaccuracy and achieve a balance between QoS and resource utilization. The QoS model of a router with feedback control is simulated to test its performance on QoS and resource utilization in both heavy and light traffic conditions. The performance of the QoS model of a router with feedback control is also compared with that of two basic QoS models of a router with static admission control using admission control parameters resulting from over‐ and under‐characterization of traffic, respectively. The simulation results show that the QoS model of a router with feedback control achieves a better balance between QoS and resource utilization than the basic QoS models with over‐ and under‐characterizations of traffic in the heavy traffic condition. This study also shows that the three models of routers demonstrate similar QoS performances and resource utilization in the light traffic condition. Copyright © 2005 John Wiley & Sons, Ltd.
Availability Demonstration Testing
Authors: Usher John S. , Taylor G. Don 
Published: December 2005

AbstractThis paper presents a procedure for conducting an availability demonstration test (ADT) under the assumption that time to failure and time to repair are both exponentially distributed. The procedure yields a test plan consisting of the required number of failures that must be observed, and the required ratio of total observed repair time to total observed failure time. The test is designed to meet stated levels of producer and consumer risk. Solutions require the use of numerical integration, but can easily be implemented using mathematics software or spreadsheets. The approach should be useful to both producers and consumers who want to define a system test for which availability is the primary performance measure of interest. Copyright © 2005 John Wiley & Sons, Ltd.
Performance Measures for ―X Charts with Asymmetric Control Limits
Authors: Marcellus Richard L. 
Published: December 2005

AbstractTheoretical and empirical justification is given for using asymmetric control limits for certain types of production processes. The following are also discussed: the sensitivity of the performance measures to the process and control parameters, the advantages and disadvantages of using asymmetric control limits, and the construction of tradeoff curves to characterize performance. The justification is given in terms of a collection of quantitative performance measures for ―X charts with asymmetric control limits. The performance measures quantify the false‐alarm frequency, the sensitivity to out‐of‐control conditions, and the resources required for sampling. Copyright © 2005 John Wiley & Sons, Ltd.
Parameter Selection for a Robust Tracking Signal
Authors: Brence John R. , Mastrangelo Christina M. 
Published: December 2005

AbstractTracking signals use past forecast errors to monitor and control a forecasting process. In this study, the cumulative‐sum tracking signal and the smoothed‐error tracking signal are evaluated on their ability to aid in shift (process upset) detection. The moving‐centerline EWMA control chart technique is coupled with these tracking signals to enhance the monitoring of autocorrelated processes. The analysis characterizes two prevalent time series models: AR(1) and ARMA(1,1). The goal of this paper is to explore the capabilities of the tracking signals and the moving‐centerline EWMA when the smoothing constants are varied and a shift is introduced into the process. The tracking signals are evaluated based on average run length (ARL) and false alarm rate (FA). Copyright © 2005 John Wiley & Sons, Ltd.
Temperature dependence of the mean autodetachment lifetime of the p‐benzoquinone molecular radical anion
Authors: Pshenichnyuk S. A. , Lomakin G. S. , Fokin A. I. , Pshenichnyuk I. A. , Asfandiarov N. L. 
Published: December 2005

AbstractExperimental data previously published from this laboratory (Asfandiarov NL, Pshenichnyuk SA, Fokin AI, Nafikova EP. Chem. Phys. 2004; 298: 263), on the temperature dependence of the mean autodetachment lifetime of the p‐benzoquinone molecular radical anion, were analyzed in the framework of a simple statistical model. This model is a simplification of the well‐known semiempirical approach elaborated by Christophorou et al. (Christophorou LG, Hadjiantoniou A, Carter JG. J. Chem. Soc., Faraday Trans. II 1973; 69: 1722). Evaluation of the vibrational energy storage of the target molecule and anion was made in a quantum approximation following a published procedure (Matejčik Š, Märk TD, Španěl P, Smith D, Jaffke T, Illenberger E. J. Chem. Phys. 1994; 102: 2516). The results obtained are in reasonable agreement with the experimental data. Copyright © 2005 John Wiley & Sons, Ltd.
Desorption electrospray ionization mass spectrometry for the analysis of pharmaceuticals and metabolites
Authors: Kauppila Tiina J. , Wiseman Justin M. , Ketola Raimo A. , Kotiaho Tapio , Cooks R. Graham , Kostiainen Risto 
Published: December 2005

AbstractThe performance of desorption electrospray ionization (DESI) in the analysis of a group of pharmaceuticals and their glucuronic acid conjugates is reported. The suitability of different sprayer solvents and different surfaces was examined. In the positive ion mode, water/methanol/trifluoroacetic acid performed best, whereas, in the negative ion mode, water/methanol/ammonium hydroxide was found to be the most suitable spray solvent. Of the surfaces investigated, polymethylmethacrylate (PMMA) was found to give the best performance in terms of sensitivity. Spray solution flow rate and the distance of the sprayer tip from the surface were also found to have significant effects on the signal intensity. Analytes with basic groups efficiently formed the corresponding protonated molecules in the positive ion mode, whereas acidic analytes, such as the glucuronic acid conjugates, formed intense signals due to the deprotonated molecules in the negative ion mode. Ionization of neutral compounds was less efficient and in many cases it was achieved through adduct formation with simple anions or cations. Copyright © 2005 John Wiley & Sons, Ltd.
An ion‐pairing liquid chromatography/tandem mass spectrometric method for the determination of ethephon residues in vegetables
Authors: Marín José M. , Pozo Óscar J. , Beltrán Joaquín , Hernández Félix 
Published: December 2005

AbstractA rapid, sensitive and selective method has been developed for the direct determination of ethephon residues in vegetables (apple, cherry and tomato). Given the anionic character of ethephon, the use of ion‐pairing liquid chromatography (LC) in combination with tandem mass spectrometry (MS/MS, triple quadrupole) allowed its direct determination in these matrices avoiding a derivatisation step and favouring the automation of the method. Samples were extracted with a mixture of dichloromethane/aqueous formic acid (pH 3) (1:1). Then, tetrabutylammonium acetate (TBA) was added as an ion‐pairing reagent, and an aliquot of the aqueous extract was directly injected into the LC/MS/MS system. Quantification was performed with matrix‐matched standards prepared from blank sample extracts. MS/MS measurements were made in the selected reaction monitoring (SRM) mode, using the most sensitive transition (m/z 107 > 79) for quantification, and up to four additional transitions for confirmation. Quantitative recoveries were obtained for all matrices (between 83% and 96%) at two concentration levels tested (0.05 and 0.5 mg/kg), with relative standard deviations lower than 9% in all cases. The addition of TBA directly into the sample extract contained in the injection vial was found sufficient to obtain satisfactory LC retention for the analyte. Under these conditions, the absence of ion‐pairing reagent in the mobile phase minimised the ionisation suppression for ethephon in the MS source, leading to an increase in the sensitivity of the method and reaching limits of detection of 0.02 mg/kg for all matrices investigated. The acquisition of five specific MS/MS transitions for ethephon allowed the simultaneous and reliable quantification and confirmation of the analyte in the samples. Copyright © 2006 John Wiley & Sons, Ltd.