bluuebunny/crossref_metadata_2025_split huggingface dataset:
GRECP/5e‐MRD‐CI calculation of the electronic structure of PbH
Authors: Isaev T. A. , Mosyagin N. S. , Titov A. V. , Alekseyev A. B. , Buenker R. J. 
Published: August 2002

AbstractThe correlation calculation of the electronic structure of PbH is carried out with the generalized relativistic effective core potential (GRECP) and multireference single‐ and double‐excitation configuration interaction (MRD‐CI) methods. The 22‐electron GRECP for Pb is used and the outer core 5s, 5p, and 5d pseudospinors are frozen using the level‐shift technique, so only five external electrons of PbH are correlated. A new configuration selection scheme with respect to the relativistic multireference states is employed in the framework of the MRD‐CI method. The [6, 4, 3, 2] correlation spin–orbit basis set is optimized in the coupled cluster calculations on the Pb atom using a recently proposed procedure, in which functions in the spin–orbital basis set are generated from calculations of different ionic states of the Pb atom and those functions are considered optimal that provide the stationary point for some energy functional. Spectroscopic constants for the two lowest‐lying electronic states of PbH (2Π1/2, 2Π3/2) are found to be in good agreement with the experimental data. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Theoretical analysis on TiO2(110)/V surface
Authors: Sambrano J. R. , Martins J. B. L. , Andres J. , Longo Elson 
Published: August 2002

AbstractTheoretical analysis based on the Hartree–Fock method were performed in order to study the stoichiometric TiO2 (110) surface and the vanadium substituted system. The Pople with polarization 3‐21G* basis set level was used. The TiO2 (110) surface was modeled using a (TiO2)15 cluster model. In order to take into account the finite size of the cluster, we have studied two different models: the point charge and the hydrogen saturated methodologies. The charge values used in the point charge calculations were optimized. The density of states, orbital self‐consistend field (SCF) energies, and Mulliken charge values were analyzed. The method and model's dependence on the analyzed results are discussed. The theoretical results are compared with available experimental data. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Gas chromatography/combustion/isotope‐ratio‐monitoring mass spectrometric analysis of methylboronic derivatives of monosaccharides: a new method for determining natural 13C abundances of carbohydrates
Authors: van Dongen Bart E. , Schouten Stefan , Damsté Jaap S. Sinninghe 
Published: August 2002

AbstractMonosaccharides were derivatized using methylboronic acid and N,O‐bis(trimethylsilyl)trifluoroacetamide (BSTFA), and the δ13C values of these derivatives measured by gas chromatography/combustion/isotope‐ratio‐monitoring mass spectrometry to determine the original 13C‐content of the monosaccharides. Comparison with the measured off‐line δ13 values of the monosaccharides shows that no fractionation in 13C takes place during derivatization. The methylboronic derivatization method has proven to be a new method for natural abundance isotopic analysis of intact monosaccharides (arabinose, xylose, fucose, fructose and glucose). The method is rapid, does not involve isotopic fractionation during derivatization, and gives more precise δ13C values than other methods reported. The method was successfully applied to determine the δ13C value of glucose of the freshwater alga Scenedesmus communis. Copyright © 2001 John Wiley & Sons, Ltd.
Coupling of a supercritical fluid chromatography system to a hybrid (Q‐TOF 2) mass spectrometer: on‐line accurate mass measurements
Authors: Garzotti Marco , Rovatti Luca , Hamdan Mahmoud 
Published: August 2002

AbstractThis note describes a simple and economical method to couple a supercritical fluid chromatography (SFC) system (Berger Instruments, US) with a high‐resolution hybrid mass spectrometer (Q‐TOF 2; Micromass, UK). This experimental arrangement has three distinct advantages: (1) coupling between the two systems can be effected without the need for an interface or hardware modifications of either system, (ii) this experimental arrangement provides on‐line accurate mass SFC/MS measurements which are indispensable for the characterisation of new chemical entities and unknown metabolites, and (iii) the characteristically fast spectral acquisition rate of the time‐of‐flight (TOF) analyser renders the present arrangement an important contribution to future semipreparative fraction collection setups which use mass spectrometry as a detector. Copyright © 2001 John Wiley & Sons, Ltd.
Screening for anabolic steroids and related compounds in illegal cocktails by liquid chromatography/time‐of‐flight mass spectrometry and liquid chromatography/quadrupole time‐of‐flight tandem mass spectrometry with accurate mass measurement
Authors: Nielen Michel W. F. , Vissers Johannes P. C. , Fuchs Regine E. M. , Velde Jan W. van , Lommen Arjen 
Published: August 2002

AbstractFindings of illegal hormone preparations such as syringes, bottles, cocktails, and so on, are an important information source for the nature of the current abuse of anabolic steroids and related compounds as growth‐promoting agents in cattle. A new screening method for steroids in cocktails is presented based on liquid chromatography (LC) with diode‐array UV‐absorbance detection and electrospray ionization time‐of‐flight mass spectrometry (ESI‐TOFMS). Accurate mass measurements were performed at a mass resolution of 4000 using continuous introduction of a lock mass through a second (electro)sprayer. Similar experiments were carried out using dual‐sprayer quadrupole time‐of‐flight mass spectrometry (ESI‐QTOFMS/MS) at a mass resolution of 10 000 with data‐dependent MS/MS acquisition; i.e. beyond an intensity threshold for the [M + H]+ ions, MS/MS spectra were automatically acquired at three different collision energies. Elemental compositions were calculated for precursor and product ions and it is shown that the combined information from LC retention behavior, UV spectra, elemental compositions, and accurate mass MS/MS spectra yield a fast impression of the steroids present in the complex mixture. Using a new software tool for structure elucidation of MS/MS spectra, an additional non‐steroidal additive was identified as well. Copyright © 2001 John Wiley & Sons, Ltd.
A combined linear ion trap time‐of‐flight system with improved performance and MSn capabilities
Authors: Collings B. A. , Campbell J. M. , Mao Dunmin , Douglas D. J. 
Published: August 2002

AbstractA detailed description of a linear ion trap time‐of‐flight (TOF) mass spectrometer system, capable of sequential mass spectrometry (MSn), is given. Many improvements have been incorporated since the initial description of this system (Rapid Commun. Mass Spectrom. 1998; 12: 1463–1474). The pressure in the trap has been lowered from 7.0 to 1.8 mTorr, resulting in an increase in the mass resolution of ion excitation from 75 to 240. Use of the system for MS3 is demonstrated. Dipole excitation of the n = 1 harmonic, instead of the n = 0 fundamental frequency of ion motion, is shown to have a higher frequency resolution, f/Δf, but lower mass resolution, m/Δm. Both experiments and modeling demonstrate that at the lower pressure there is less collisional cooling of ions in the axial and radial directions of the trap. The efficiency of trapping is shown to be nearly 100% for periods up to 5 s. The demonstrated mass range for mass analysis has been extended to greater than m/z 16 250. To avoid the formation of adduct ions when trapping protein ions for extended times requires ultra‐high vacuum cleanliness conditions, even though the trap operates in the mTorr‐pressure range. Upgrading the TOF to a reflectron with higher quality ion optics results in an increase in the mass resolution of the TOF mass spectrometer to about 5000 at m/z 750. Copyright © 2001 John Wiley & Sons, Ltd.
Rapid monitoring assay of congenital adrenal hyperplasia with microbore high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry from dried blood spots
Authors: Lai Chien‐Chen , Tsai Chang‐Hai , Tsai Fuu‐Jen , Lee Cheng‐Chun , Lin Wei‐De 
Published: August 2002

Abstract17‐Hydroxyprogesterone (17OHP) is the most important plasma parameter for diagnosing and monitoring congenital adrenal hyperplasia (CAH) caused by 21‐hydroxylase deficiency. A rapid, simple, and specific method based on microbore high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (µ‐HPLC/ESI‐MS/MS) was developed to determine the presence of 17OHP on dried filter‐paper blood samples from patients with CAH caused by 21‐hydroxylase deficiency. 17OHP from dried blood spots formed by the action of Girard reagent P (GirP) turned out to be a water‐soluble hydrazone complex. Derivatization with GirP led to higher ESI sensitivity for 17OHP. The LC/MS/MS detection of GirP‐derivatized 17OHP (GirP‐17OHP) was rapid (<3 min). The method is repeatable and reproducible, with CVs <7% and 12%, respectively. This new method was used for direct determination of 17OHP in dried blood specimens obtained from abnormal children and infants of various ages with a detection limit of 10 ng/mL (∼12 µL blood). The method described allows for rapid and reliable measurements of 17OHP in dried blood specimens from patients affected by CAH. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of flow rate on high‐throughput quantitative analysis of protein‐precipitated plasma using liquid chromatography/tandem mass spectrometry
Authors: Murphy Anthony T. , Berna Michael J. , Holsapple Jeffrey L. , Ackermann Bradley L. 
Published: August 2002

AbstractThe effects of flow rate and column length on analyte response (peak area and height), total cycle time, column backpressure, and elution volume are presented. Rapid chromatographic separations and tandem mass spectrometric (MS/MS) detection are applied to the supernatant of protein‐precipitated plasma standards containing four compounds from a drug discovery screen. The plasma samples were injected onto three C‐18 columns (2 × 10,2.1 × 30 and 2.1 × 50 mm) at flow rates of 0.25, 0.50, 1.00 and 1.50 mL/min. The plasma samples were detected using a Sciex API 3000 tandem mass spectrometer operated in the Turbo Ionspray mode. A post‐column split was used to maintain a flow rate of 0.25 mL/min into the mass spectrometer source to avoid differences in nebulization efficiency. The data show that diluted protein‐precipitated plasma supernatants show average matrix effects (i.e. suppression) of 60.0% (2 × 10 mm), 89.3% (2 × 30 mm), and 76.7% (2 × 50 mm) of expected response at 10 ng/mL. Average matrix effects of 70.2% (2 × 10 mm), 88.9% (2 × 30 mm), and 81.2% (2 × 50 mm) of expected response at 1000 ng/mL plasma. The data also show if peak widths remain relatively constant, analytes are less sensitive as flow rates are increased. These data are consistent with the concentration‐dependent relationship of ionspray in the range of flow rates studied. The data show that, while analyte response decreased proportionately to increases in flow rate, the analysis cycle times did not decrease proportionately. Copyright © 2002 John Wiley & Sons, Ltd.
Stable isotope compositions of CO2 in background air and at polluted sites in Hungary
Authors: Demény Attila , Haszpra László 
Published: August 2002

AbstractCO2 samples were collected from air at three sites in Hungary for comparison of polluted and background areas. In order to reduce the uncertainties caused by the varying amount of N2O, a gas chromatography (GC)‐based vacuum separation was applied. The reliability of the procedure was demonstrated by careful standardization and comparison with global network data. The stable isotope data show complex diurnal and seasonal variations that can be explained by fractionations during photosynthesis and respiration. The isotopic characteristics of pollution‐derived (anthropogenic) and biogenic CO2 appear to be indistinguishable at the study sites. However, the sites at unpolluted areas reveal a seasonal variation in the carbon isotope composition of biogenic CO2 that may be related to changes in soil biogenic activities. The atmospheric background CO2 shows constant δ13C in the region. Finally, the study demonstrates the need for careful standardization of sampling in order to make the data obtained from different sampling systems comparable. Copyright © 2002 John Wiley & Sons, Ltd.
Methodology and model for performance and cost comparison of innovative treatment technologies at wood preserving sites
Authors: Evans Mark L. , Porges Robert E. , Coghlan Gunarti H. , Eilers Richard G. , Glazer Art G. 
Published: August 2002

AbstractWood preserving facilities have used a variety of compounds, including pentachlorophenol (PCP),
creosote, and certain metals, to extend the useful life of wood products. Past operations and waste management
practices resulted in soil and water contamination at a portion of the more than 700 wood preserving sites in the
United States (EPA, 1997). Many of these sites are currently being addressed under federal, state, or
voluntary cleanup programs. The U.S. Environmental Protection Agency (EPA) National Risk Management
Research Laboratory (NRMRL) has responded to the need for information aimed at facilitating remediation
of wood preserving sites by conducting treatability studies, issuing guidance, and preparing reports. This article
presents a practical methodology and computer model for screening the performances and comparing the costs of
seven innovative technologies that could be used for the treatment of contaminated soils at user‐specified
wood preserving sites. The model incorporates a technology screening function and a cost‐estimating
function developed from literature searches and vendor information solicited for this study. This article also
provides background information on the derivation of various assumptions and default values used in the model,
common contaminants at wood preserving sites, and recent trends in the cleanup of such sites. © 2001 John
Wiley & Sons, Inc.
Iowa's land recycling program: A case study
Authors: Quast Cynthia L. 
Published: August 2002

AbstractVoluntary cleanup programs for contaminated sites have been developed in several states over the last few years.
Some of the advantages of these programs include developing a collaboration between site owners and regulators,
implementing cleanup standards based upon site‐specific current and future risks, and enhancing the market
conditions that can lead to development of properties to their highest productive use. This article offers a case
study of the first site in Iowa to proceed through the state's voluntary cleanup program, the Land Recycling
Program. It offers the step‐by‐step progress toward the client's goal of a site classification
requiring no further action. © 2001 John Wiley & Sons, Inc.
Using integrated food‐web and population‐based models for environmental monitoring, remediation decisions, and long‐term planning
Authors: Burger Joanna , Hunter John , Cooper Keith 
Published: August 2002

AbstractWhile ecologists have used food‐web models to understand how ecosystems function, the potential role
of integrated food‐web and population‐based models in environmental monitoring and decision making
has been ignored. Sound ecological principles should be integrated with state‐of‐the‐art
monitoring and management practices. This article presents the ways in which population‐based models can
answer basic ecological questions necessary for decision making about remediation and restoration, and for
monitoring to ensure long‐term stewardship. Discussed are the uses of food‐web and
population‐based models for understanding the movement of chemicals through different trophic levels.
Three examples, including global warming, tributyltin, and monomethylmercury scenarios, are presented to
illustrate how such models are useful. The responses of the component parts varies, depending on parameters such
as birth, death, and respiration, as well as feeding rates, predator‐prey rates, and uptake and
elimination rates. There are several different models available for decision making, with different levels of
complexity, based on the specific hypothesis or question being asked and the amount of current information
available. Therefore, it is recommended to use deterministic‐based, population‐based
food‐web models for ecological risk assessment. © 2001 John Wiley & Sons, Inc.
A team algorithm for robust stability analysis and control design of uncertain time‐varying linear systems using piecewise quadratic Lyapunov functions
Authors: Almeida H. L. S. , Bhaya A. , Falcão D. M. , Kaszkurewicz E. 
Published: August 2002

AbstractA team algorithm based on piecewise quadratic simultaneous Lyapunov functions for robust stability analysis and control design of uncertain time‐varying linear systems is introduced. The objective is to use robust stability criteria that are less conservative than the usual quadratic stability criterion. The use of piecewise quadratic Lyapunov functions leads to a non‐convex optimization problem, which is decomposed into a convex subproblem in a selected subset of decision variables, and a lower‐dimensional non‐convex subproblem in the remaining decision variables. A team algorithm that combines genetic algorithms (GA) for the non‐convex subproblem and interior‐point methods for the solution of linear matrix inequalities (LMI), which form the convex subproblem, is proposed. Numerical examples are given, showing the advantages of the proposed method. Copyright © 2001 John Wiley & Sons, Ltd.
Robust and non‐fragile PID controller design
Authors: Ho Ming‐Tzu , Datta Aniruddha , Bhattacharyya S. P. 
Published: August 2002

AbstractThis paper provides a solution to the problem ofrobustlystabilizing a given interval plant family using P, PI and PID controllers. This solution is derived by combining some recent results on P, PI and PID stabilization of fixed plants with some standard results from the parametric robust control literature. The paper also develops a technique for designing PID controllers which are not only robust with respect to plant parameter perturbations but are also ‘non‐fragile’ in the space of the controller coefficients. Copyright © 2001 John Wiley & Sons, Ltd.
Redesign of backstepping for robustness against unmodelled dynamics
Authors: Arcak Murat , Kokotovic Petar 
Published: August 2002

AbstractWe present a redesign method to robustify backstepping control laws against linear unmodelled dynamics at the input of the plant. The admissible unmodelled dynamics are relative degree zero and minimum phase. We prove that the redesign ensures global boundedness and convergence of the closed‐loop solutions to an arbitrarily small compact set around the origin. Copyright © 2001 John Wiley & Sons, Ltd.
Structured singular value approach for systems with parametric uncertainty
Authors: Young Peter M. 
Published: August 2002

AbstractThis paper provides a tutorial introduction and overview of analysis and design techniques for systems with both parametric uncertainty and unmodelled dynamics, using the structured singular value, orμ, family of techniques. This includes the analysis/design framework, stability and performance problems, frequency sweeps and state‐space tests, continuous‐time and discrete‐time systems, and computational issues and methods for both analysis and design. The paper also includes connections between the structured singular value and polynomial approaches to handling parametric uncertainty, as well as several examples which illustrate how to cast typical (including polynomial) problems into theμframework. Copyright © 2001 John Wiley & Sons, Ltd.
Robust ℋ︁∞filtering for uncertain Markovian jump linear systems
Authors: de Souza Carlos E. , Fragoso Marcelo D. 
Published: August 2002

AbstractThis paper investigates the problem of ℋ︁∞filtering for a class of uncertain Markovian jump linear systems. The uncertainty is assumed to be norm‐bounded and appears in all the matrices of the system state‐space model, including the coefficient matrices of the noise signals. It is also assumed that the jumping parameter is available. We develop a methodology for designing a Markovian jump linear filter that ensures a prescribed bound on the ℒ︁2‐induced gain from the noise signals to the estimation error, irrespective of the uncertainty. The proposed design is given in terms of linear matrix inequalities. Copyright © 2002 John Wiley & Sons, Ltd.
On Horowitz's contributions to reset control
Authors: Chait Yossi , Hollot C. V. 
Published: August 2002

AbstractHistory shows that Prof. Isaac Horowitz was often ahead of the curve in his feedback control research, especially in developing quantitatively driven design procedures. In some topics, his work was so out of line with the main stream that it has received virtually no recognition from the control community until a few decades later. In this paper, we present recent research that was directly motivated by Horowitz's pioneering work on reset controllers in the 1970s. Reset controllers are linear controllers that reset some of their states to zero when their inputs reach a threshold. Horowitz motivated their use by showing that with qualitative design, they can exhibit better performance trade‐offs than those in linear, time‐invariant systems. This paper supports and advances his thinking by presenting recent theoretical and experimental results on reset control. Copyright © 2002 John Wiley & Sons, Ltd.
Interval QFT: a mathematical and computational enhancement of QFT
Authors: Nataraj P. S. V. 
Published: August 2002

AbstractThe paper presents an overview of a mathematical and computational enhancement of Horowitz's QFT design procedure. The enhancement uses methods of interval analysis and is called as interval QFT, or IQFT. IQFT addresses and solves some of the fundamental issues in QFT, concerning selection of design frequencies, selection of controller phases in bound generation, approximation of plant templates with finite plant sets, and generation of plant templates and controller bounds with reliability and to a prescribed accuracy. An example is presented to illustrate the key features of IQFT. Copyright © 2002 John Wiley & Sons, Ltd.
Plant zero structure and further order reduction of a singular H∞ controller
Authors: Watanabe Takao , Stoorvogel Anton A. 
Published: August 2002

AbstractA new class of reduced‐order controllers is obtained for the H∞ problem. The reduced‐order controller does not compromise the performance attained by the full‐order controller. Algorithms for deriving reduced‐order H∞ controllers are presented in both continuous and discrete time. The reduction in order is related to unstable transmission zeros of the subsystem from disturbance inputs to measurement outputs. In the case where the subsystem has no infinite zeros, the resulting order of the H∞ controller is lower than that of the existing reduced‐order H∞ controller designs which are based on reduced‐order observer design. Furthermore, the mechanism of the controller order reduction is analysed on the basis of the two‐Riccati equation approach. The structure of the reduced‐order H∞ controller is investigated. Copyright © 2002 John Wiley & Sons, Ltd.