bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of Interfacial Complexation of Samarium(III) and its Fluorescence Lifetime by Micro-two-phase Sheath Flow/Fluorescence Microscopy
Authors: Tokimoto Takahira , Tsukahara Satoshi , Watarai Hitoshi 
Published: September 2003

Abstract
The micro-two-phase sheath flow/fluorescence microscopy was used for the fluorescence lifetime measurement for the first time. An inner micro-flow of the toluene solution of samarium(III) complex was flowed in an aqueous phase stream. From the fluorescence decay images observed in the inner flow just after the excitation point, the fluorescence lifetime of the complex was observed. By flowing a toluene solution of ligands into the Sm(III) aqueous stream, the interfacial formation of the fluorescent complex was observed.
New Copper(II) Complexes Connected by NH···O=C and NH···S=C Intermolecular Hydrogen Bonds
Authors: Kondo Mitsuru , Shimizu Emi , Horiba Tomonori , Tanaka Hirokazu , Fuwa Yumiko , Nabari Keiko , Unoura Kei , Naito Tetsuyoshi , Maeda Kenji , Uchida Fumio 
Published: September 2003

Abstract
Two new copper(II) complexes with imidazole-4-carboxylate and imidazole-4-dithiocarboxylate have been synthesized. The monomeric units are connected by NH···O=C and NH···S=C intermolecular hydrogen bonds, respectively, yielding one-dimensional chains that stack with unusually short π–π distances.
Rotational Isomerism and Structure of the 1-Butyl-3-methylimidazolium Cation in the Ionic Liquid State
Authors: Ozawa Ryosuke , Hayashi Satoshi , Saha Satyen , Kobayashi Akiko , Hamaguchi Hiro-o 
Published: September 2003

Abstract
The crystal structures of 1-butyl-3-methylimidazolium chloride [bmim]Cl and 1-butyl-3-methylimidazolium bromide [bmim]Br show that two rotational isomers, the TT form and the GT form, of the [bmim]+ cation exist in the crystalline state. A vibrational analysis based on a DFT calculation indicates that two characterstic Raman bands of crystalline [bmim]Cl and three of crystalline [bmim]Br can be used as marker bands of the rotational isomerism around the C7–C8 bond of the n-butyl group. The Raman spectra of liquid [bmim]BF4, in which both sets of marker bands are simultaneously observed, then prove that at least two rotational isomers of the [bmim]+ cation coexist in the ionic liquid state.
Synthesis of Highly Ordered Hybrid Mesoporous Material Containing Etenylene (–CH=CH–) within the Silicate Framework
Authors: Nakajima Kiyotaka , Lu Daling , Kondo Junko N , Tomita Ikuyoshi , Inagaki Shinji , Hara Michikazu , Hayashi Shigenobu , Domen Kazunari 
Published: September 2003

Abstract
A hybrid mesoporous material containing etenylene in a two-dimensional, hexagonally arranged mesoporous silicate framework with long-range symmetry is successfully synthesized. Quantitative analysis of the reactive etenylene groups within the silicate framework indicates that approximately 30% of the etenylene is exposed at the surface and is available for further modification.
A Novel Double-helical Assembly in Inclusion Crystals of Fumaropimaric Acid
Authors: Kato Kazuaki , Aburaya Kazuaki , Matsumoto Masatake , Tohnai Norimitsu , Miyata Mikiji 
Published: September 2003

Abstract
A crystal structure of the inclusion compound of fumaropimaric acid (FPA), a new host material, with 2-butanone reveals that the host framework is composed of novel double-helical supramolecular aggregates without hydrogen bonds between the intertwined helices.
Dependence of the Electrochemical Response of Ferritin on the Number of Iron Atoms at the Ferritin Core
Authors: Tominaga Masato , Taniguchi Isao 
Published: September 2003

Abstract
The well-defined redox reaction of ferritin was observed at an indium oxide electrode with a fully hydrophilic surface at a low concentration of ferritin solution (0–7 μmol dm−3). This was a diffusion-controlled electrode reaction process. Conversely, at a higher concentration of ferritin (7 μmol dm−3 &lt;), ferritin was weakly adsorbed on the electrode surface. The electrochemical redox response of ferritin was strongly affected by the number of iron atoms at the core of the ferritin molecule.
In Situ X-ray Absorption Fine Structure Studies on the Structure of Nickel Phosphide Catalyst Supported on K-USY
Authors: Kawai Toshihide , Sato Shinsuke , Suzuki Shushi , Chun Wang-Jae , Asakura Kiyotaka , Bando Kyoko K , Matsui Takashi , Yoshimura Yuji , Kubota Takeshi , Okamoto Yasuaki , Lee Yong-Kul , Oyama Shigeo Ted 
Published: September 2003

Abstract
Local structure around Ni in a nickel phosphide catalyst supported on K-USY was investigated by an in situ X-ray absorption fine structure (XAFS) method during the reduction process of the catalyst and the hydrodesulfurization (HDS) reaction of thiophene. In the passivated sample, Ni phosphide was partially oxidized but after the reduction, 1.1 nm diameter Ni2P particles were formed with Ni–P and Ni–Ni distances at 0.218 and 0.261 nm, respectively, corresponding to those of bulk Ni2P. In situ XAFS clearly revealed that the Ni2P structure was stable under reaction conditions and was an active structure for the HDS process.
Evaluation of controller performance—use of models derived by subspace identification
Authors: Bezergianni S. , Georgakis C. 
Published: September 2003

AbstractA new approach is presented for the estimation of the controller, process, and disturbance models necessary for the calculation of the relative variance index, which was introduced in an earlier paper (Control Eng. Practice2000;8:791–797), for the performance of SISO controllers. It involves the use of dynamically, sufficiently rich segments from the normal operating data and the use of the subspace identification technique to estimate the systems mentioned above. This approach improves the estimation accuracy of the performance index in relation to the method presented previously. The estimated models enable the comparison of the present controller performance with that of optimally tuned PI or IMC controllers. This helps identify the potential benefits of either retuning or redesigning the assessed controller. Copyright © 2002 John Wiley & Sons, Ltd.
Determining controller benefits via probabilistic optimization
Authors: Zhou Y. , Forbes J. F. 
Published: September 2003

AbstractFor the most part, process control research has focussed on the synthesis and tuning of controllers, which has provided a plethora of techniques that can address virtually any application. With each new control technique, a steady stream of ‘successful’ application results are generated and reported. Recently, a considerable number of control researchers have turned their attention to assessing the performance of installed control systems and to the diagnosis of controller performance problems. Despite successes in the areas of controller synthesis, tuning and performance analysis, almost no research has addressed the fundamental issue of determining whether the economic performance gains that are expected accrue from a proposed process control project are sufficient to justify its execution. The work presented here proposes an optimization‐based technique for calculating the expected economic performance of a given control system; a method, which is analogous to analysis of variance, for determining the expected economic benefit that will arise from a particular controller improvement effort; and a sensitivity analysis approach for determining the effect of specific assumptions on control system improvement decisions. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of multivariable controllers using degree of freedom data
Authors: Harris T. J. , Yu W. 
Published: September 2003

AbstractMost approaches for monitoring, diagnosis and performance analysis of multivariable control loops employ time series methods and use non‐parametric statistics to analyse the process inputs and outputs. In this paper, we explore the use of a discrete variable that summarizes the status of the constraint set of the controller to analyse the long run behaviour of control systems. We introduce a number of waiting and holding time statistics that describe the status of this data, which we call the degree of freedom data. We demonstrate how Markov Chains might be used to model the status of the degree of freedom data. This model‐based approach has the potential to provide considerable insight into the behaviour of a model based control scheme with relative ease. We demonstrate the methodologies on simulated and industrial data. Copyright © 2003 John Wiley & Sons, Ltd.
A comparison of two feedforward control structure assessment methods
Authors: Petersson M. , Årzén K.‐E. , Hägglund T. 
Published: September 2003

AbstractThe most common loop in an industrial plant is a SISO‐loop with a PI(D) controller. If the loop is affected by disturbances, these can be handled by adding a feedforward control action. In an industrial control system there are many measured signals, apart from those of the loop, available. The question we address in this article is how to select the feedforward variable out of the available measurements. A comparison is made of two methods for feedforward control structure assessment. The first is a method based on comparing the actual variance with the minimum achievable variance, and thus the contribution to the overall variance. The second is a method for evaluating deterministic additive disturbances and estimate where they enter in the process. The methods complement each other and show that assessment methods should be handled with care, since they are mostly designed for different control objectives. Copyright © 2003 John Wiley & Sons, Ltd.
A segmentation‐based method for detection of stiction in control valves
Authors: Stenman A. , Gustafsson F. , Forsman K. 
Published: September 2003

AbstractA method for detecting static friction (stiction) in control valves is proposed. The method is model‐based and is inspired by ideas from the fields of change detection and multi‐model mode estimation. Opposed to existing methods only limited process knowledge is needed and it is not required that the loop has oscillating behaviour. The advantage of the method is illustrated in both numerical simulations and evaluations on real loop data. Copyright © 2003 John Wiley & Sons, Ltd.
Process and controller performance monitoring: overview with industrial applications
Authors: Hoo K. A. , Piovoso M. J. , Schnelle P. D. , Rowan D. A. 
Published: September 2003

AbstractComplex processes depend on regulatory control systems to operate. Changes made to the sensor system and the process itself as well as the natural degradation over time of the equipment may cause some controllers' and process performance to suffer. Since there are hundreds of controllers in most complex processes, it is virtually impossible to monitor their performance manually. This work reviews the state‐of‐the‐art in controller performance monitoring including both feedforward and feedback control. The experiences of the DuPont Company in the deployment of a system for performance monitoring are presented. Information as to how such a monitoring system is implemented in the operation of a chemical process and examples of its operation are included. Copyright © 2003 John Wiley & Sons, Ltd.
Performance assessment of level controllers
Authors: Horton E. C. , Foley M. W. , Kwok K. E. 
Published: September 2003

AbstractA variety of techniques have been developed for the assessment of industrial control loops. These involve computation of an index which compares some measure of controlled variable performance (e.g. variance of distillate impurity) to the best achievable. Such methods are generally not suitable for the assessment of surge tank level controllers, for which the behaviour of the manipulated effluent flowrate is of greater concern. This paper introduces a flow smoothing performance index for the assessment of surge tank level loops against an averaging level control standard. Several control schemes were evaluated as potential flow smoothing benchmarks through application to simulated, pilot‐plant and industrial data sets. An optimal PI regulator was recommended as the default performance standard for industrial level control loops. A novel feature of this assessment technique is that it not only measures the performance of the installed controller, but also specifies new settings for the PI tuning parameters. Copyright © 2003 John Wiley & Sons, Ltd.
A relative performance monitor for process controllers
Authors: Li Q. , Whiteley J.R. , Rhinehart R.R. 
Published: September 2003

AbstractA monitor is developed to automatically detect poor control performance. It provides a measure (relative performance index—RPI) of a control‐loop performance relative to a reference model of acceptable control. The reference model simulates the controlled variable output of a user‐defined, acceptably tuned control loop. The inputs to the reference model are the setpoints (same as the true plant) and the disturbances (estimated from the measurements). The monitor uses routine plant operation data only. Pending ability to obtain temporally accurate process models, and the validity of process measurements, simulations and experiments show that the monitor can detect the poor control performance caused by improper controller parameter values or changes in plant characteristics, and can distinguish it from poor performance caused by external disturbances. Copyright © 2003 John Wiley & Sons, Ltd.
Controller performance assessment in set point tracking and regulatory control
Authors: Thornhill N.F. , Huang B. , Shah S.L. 
Published: September 2003

AbstractRecent critiques of minimum variance benchmarking for single‐input–single‐output (SISO) control loops have focused on the need for assessment of performance during set point changes and also on the need to pay attention to the movements in the manipulated variable. This paper examines factors that influence the minimum variance performance measure of a SISO control loop. It discusses the reasons why performance during set point changes differs from the regulatory performance during operation at a constant set point. The results demonstrate how regulatory performance is influenced by the nature of a disturbance, and that correlation of signals within a control loop can indicate whether the disturbance is random or deterministic. The paper is illustrated with simulated, experimental and industrial examples. Copyright © 2003 John Wiley & Sons, Ltd.
Computing Fibers: A Novel Fiber for Intelligent Fabrics?
Authors: Clemens F. , Wegmann M. , Graule T. , Mathewson A. , Healy T. , Donnelly J. , Ullsperger A. , Hartmann W. , Papadas C. 
Published: September 2003

AbstractThis communication describes a possible path for transition from a wearable computer to a fiber computer in which digital processing power is integrated directly into textiles via circuits on individual fibers. Three different classes of computing fiber substrate (active, passive, and intermediate) are discussed and some technologies for their manufacture are reviewed. It is shown here that with two of these techniques it is possible to develop new substrates for the semiconductor industry. Using an silicon‐on‐insulator (SOI) process, polycrystalline silicon fibers with a length of 42 mm have been successfully produced at NMRC in Ireland. These fibers are 35 μm wide and 1 μm thick. Silicon carbide (SiC) and silicon dioxide (SiO2) endless fibers (subsequently cut in to 20 cm lengths) have also been produced by extrusion. After sintering, this method yielded polycrystalline SiC fibers and pure amorphous SiO2 glass fibers. For many future applications, fiber computing appears to be a possible key to success. The computing power offered by such fibers may be combined with additional in‐ and output functions by weaving fiber‐based sensors and piezoelectric materials into textiles.
Ductility in Intermetallic Compounds
Authors: Russell A.M. 
Published: September 2003

AbstractIntermetallic compounds are comprised of two or more metallic elements, but unlike ordinary metals, they have bonding that is part metallic, part covalent, and part ionic. Because of their mixed bonding, they are often lighter, stronger, stiffer, and more corrosion‐resistant than ordinary metals, particularly at high temperatures. Yet their uses are limited because they are usually brittle at room temperature (RT), making them difficult to fabricate and vulnerable to fracture. These materials hold great promise to improve efficiency in the transportation, electric power generation, and chemical process industries; however, persistent problems with low ductility and poor fracture toughness have severely limited their use in engineering systems. This article presents an overview of the progress in improving the RT ductility and fracture toughness of intermetallic compounds and describes prospects for their near‐term engineering use.
Advanced New Lightweight Materials: Hollow‐Sphere Composites (HSCs) for Mechanical Engineering Applications
Authors: Baumeister E. , Klaeger S. 
Published: September 2003

Abstract“Lightweight” is a major trend in machine tool design to ensure higher speed and higher acceleration of elements, which results from state‐of‐the‐art technology, such as the new linear drive and the control system.[1] Research is being carried out in institutes worldwide into lightweight construction by either design and/or choice of material. One type of advanced lightweight engineering material to reduce the mass of the moving parts of machine tools is hollow‐sphere composites. Investigations of their thermal and mechanical properties show the superior quality of HSCs compared with alternative materials. Example applications of hollow‐sphere composites include the table of a milling machine and robot arms.
Progress in Polypropylene Nanocomposite Development
Authors: Leuteritz A. , Pospiech D. , Kretzschmar B. , Willeke M. , Jehnichen D. , Jentzsch U. , Grundke K. , Janke A. 
Published: September 2003

AbstractThis article summarizes some of the highlights of newest developments in polypropylene (PP) clay nanocomposite research. Different property improvements, including mechanical performance enhancements, achieved by melt compounding of organoclay materials with PP and/or PP‐g‐MA are presented.
Naturstoffhybride als neue Leitstrukturen bei der Wirkstoffsuche
Authors: Tietze Lutz F. , Bell Hubertus P. , Chandrasekhar Srivari 
Published: September 2003

AbstractBei der Entwicklung neuer Wirkstoffe spielen Naturstoffe eine wichtige Rolle. Besondere Bedeutung kommt ihnen auf den Gebieten Antiinfektiva, Krebstherapeutika und Immunsuppressiva zu. Die Zahl der natürlich vorkommenden Substanzen ist jedoch begrenzt, wohingegen durch die Kombination von Teilen unterschiedlicher Naturstoffe Millionen von Naturstoffhybriden mit vielfältigen und verschiedenartigen Eigenschaften zugänglich sein sollten. Dieser Ansatz ist für die Entwicklung neuer Leitstrukturen für sowohl medizinische als auch agrochemische Anwendungen sehr vielversprechend, da die biologische Aktivität dieser Hybride in vielen Fällen diejenige der entsprechenden Mutterverbindungen übersteigt. Der Vorteil dieses Konzepts gegenüber einem auf dem Zufall beruhenden kombinatorischen Ansatz besteht in der Vielfalt und der inhärenten biologischen Aktivität der gebildeten Hybride.
Natural Product Hybrids as New Leads for Drug Discovery
Authors: Tietze Lutz F. , Bell Hubertus P. , Chandrasekhar Srivari 
Published: September 2003

AbstractNatural products play an important role in the development of drugs, especially for the treatment of infections and cancer, as well as immunosuppressive compounds. However, the number of natural products is limited, whereas millions of hybrids as combinations of parts of different natural products can be prepared. This new approach seems to be very promising in the development of leads for both medicinal and agrochemical applications, as the biological activity of several new hybrids exceeds that of the parent compounds. The advantage of this concept over a combinatorial chemistry approach is the high diversity and the inherent biological activity of the hybrids.
Use of some plant wastes as fillers for polypropylene
Authors: Eboatu A. N. , Akpuaka M. U. , Ezenweke L. O. , Afiukwa J. N. 
Published: September 2003

AbstractPalm kernel shell and the palm fruit pulp fiber were used as additives for polypropylene. The mechanical properties of the polymer, namely, tensile strength, impact strength, surface hardness, and flexural modulus were remarkably enhanced. This was attributed to the fact that these solid wastes functioned as reinforcing fillers through bonding interactions and stress‐sharing mechanisms. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1447–1452, 2003
Rate and amount of cellulose synthesis in developing fibers of Gossypium arboreum and Gossypium hirsutum cotton
Authors: Moharir A. V. , Bodas Manish , Vashisth Ananta 
Published: September 2003

AbstractCotton fiber cellulose synthesis and cellulose content at various post anthesis maturity stages of boll' development were studied in sixteen cotton varieties of Gossypium arboreum and Gossypium hirsutum species, grown in the 2001 crop year in New Delhi, under identical agro‐climatic conditions. Cellulose content was estimated using Updegraff's method. Field matured seed cotton was harvested at the end of the crop season and ginned fibers were subjected to physical testing in an AFIS‐HVI facility. X‐ray orientation parameters were computed from the normalized azimuthal diffracted X‐ray intensity scans of (002) reflections. Simple correlations were worked out among various parameters measured. Cotton varieties were indeed observed to vary in their synthesized cellulose content and such differences are genetically inherent. Varieties of Gossypium arboreum synthesized less cellulose compared to the Gossypium hirsutum cultivars, although the rate of cellulose synthesis within each variety, regardless of species, was observed to be practically uniform at any five‐day interval. The range of variation in cellulose content was observed to be more than 260%. Uniformity ratio, HVI tenacity and average leaf area were positively correlated with cellulose content. X‐ray angles of 40% and 50% correlated significantly with a negative cellulose content, (thereby) indicating an increased orientation of cellulose crystallites to the fiber axis, with a greater amount of cellulose synthesized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1453–1462, 2003
Fractal approach for modeling the morphology evolution of olefin polymerization with heterogeneous catalysts
Authors: Huo C. , Ren X. H. , Liu B. P. , Yang Y. R. , Rong S. X. 
Published: September 2003

AbstractFractal theory and methodology were used to investigate the morphology of titanium–magnesium‐supported polyethylene catalysts and their relevant polymer particles. Through an analysis of the submicrostructures using scanning electron microscopy images, the surface fractal dimensions of the related particles were estimated with the box‐counting method. With consideration given to the fact that the growth process of a polymer is an evolving fractal process, which is controlled on the one hand by the initial conditions, including the initial fractal dimensions of the catalysts and the initial reaction conditions, and on the other hand by the previous morphology characteristics of the system, a novel polymerization fractal growth model was constructed. The simulation results showed good agreement with the experiment data. Moreover, the morphology evolution with the prepolymerization technique was predicted, and it was suggested that the duration of polymerization was 10–30 min. It was proven that the use of the surface fractal dimension as an important parameter describing the surface morphologies of the particles, either of catalysts or polymers, was real and effective. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1463–1470, 2003