bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxico‐kinetics, recovery efficiency and microsomal changes following administration of deltamethrin to black Bengal goats
Authors: Juliet Sanis , Chakraborty Animesh K , Koley Kishori M , Mandal Tapan K , Bhattacharyya Anjan
Published: August 2002

A study of the toxico‐kinetics, recovery percentage from different substrates, cytotoxicity and role of cytochrome P450 and b5 of liver microsome in the metabolism of deltamethrin were carried out in female black Bengal goat. The ALD50 value of deltamethrin in goat by intravenous route lies between 0.2 and 0.6 mg kg−1. Intravenous disposition kinetics using a dose of 0.2 mg kg−1 showed that the maximum blood concentration of deltamethrin was recorded at 0.5 min, followed by rapid decline, and a minimum concentration was detected at 6 min after administration. The following values were obtained : Vdarea 0.148 (± 0.02) litre kg−1; t1/2 (α) 0.22 (± 0.02) min; t1/2 (β) 2.17 (± 0.37) min; Kel 1.05 (± 0.24) min−1; AUC 4.30(± 0.45) µg min ml−1; ClB 0.05 (± 0.006) litre kg−1 min−1; T∼B 1.93 (± 0.58); fc 0.40(± 0.05). After 10 min, liver retained the maximum residue, and heart, adrenal gland, kidney, spleen, fat and brain also held the insecticide; liver, fat, heart and spleen retained residue after 30 min, and bone, liver and fat retained residue after 60 min of intravenous administration. Oral absorption of deltamethrin was poor and inconsistent, and approximately 65% of administered dose was recovered from faeces and gastrointestinal contents. The excretion of deltamethrin through urine was meagre, and only 0.01 and 0.013% of the administered dose was recovered after 3 and 5 days of oral administration respectively. All the tissues retained the residue after 3 days; while fat, rumen, reticulum, omasum, abomasum, large and small intestine and bone retained the residue after 5 days of oral administration; and the percentage recoveries were 1.73 and 0.027 respectively. Deltamethrin reduced the level of cytochrome P450 content of liver microsomal pellet of goat after 5 days of oral administration. Histopathological examination of liver, kidney, heart, spleen brain and lung sections of treated goats did not reveal any pathological changes.

© 2001 Society of Chemical Industry
Evaluation of uncalibrated preferential flow models against data for isoproturon movement to drains through a heavy clay soil
Authors: Beulke Sabine , Brown Colin D , Dubus Igor G , Harris Graham
Published: August 2002

The uncalibrated predictive ability of four preferential flow models (CRACK‐NP, MACRO/MACRO_DB, PLM, SWAT) has been evaluated against point rates of drainflow and associated concentrations of isoproturon from a highly structured and heterogeneous clay soil in the south of England. Data were available for four plots for a number of storm events in each of three successive growing seasons. The mechanistic models CRACK‐NP and MACRO generally gave reasonable estimates of drainflow over the three seasons, but under‐estimated concentrations of isoproturon over a prolonged period in the first season and over‐estimated them in the two remaining seasons. CRACK‐NP simulated maximum concentrations of isoproturon over the first two events of each of the three seasons of 156, 527 and 24.4 µg litre−1, respectively, and matched the observed data (465, 65.1 and 0.65 µg litre−1) slightly better than MACRO (69.1, 566 and 58.5 µg litre−1). Automatic selection of parameters from soils information within MACRO_DB reduced the emphasis on preferential flow relative to the stand‐alone version of MACRO. This gave a poor simulation of isoproturon breakthrough and simulated maximum concentrations were 0, 50.1 and 35.1 µg litre−1, respectively. The capacity model PLM gave the best overall simulation of total drainflow for the first two events in each season, but over‐estimated concentrations of isoproturon (967, 808 and 51.3 µg litre−1). The simple model SWAT represented total drainflow reasonably well and gave the best simulation of maximum isoproturon concentrations (140, 80.2 and 8.2 µg litre−1). There was no clear advantage here in using the mechanistic models rather than the simpler models. None of the models tested was able to simulate consistently the data set, and uncalibrated modelling cannot be recommended for such artificially drained heavy clay soils.

© 2001 Society of Chemical Industry
Corrosion fatigue reliability of aging aircraft structures
Authors: Mahadevan Sankaran , Shi Pan
Published: August 2002

Structural integrity evaluation methods for aging aircraft are surveyed. Design approaches and programmes adopted by the aircraft industry to ensure structural safety are reviewed. Corrosion fatigue is the major failure mechanism affecting airframe integrity. Therefore, corrosion fatigue reliability analysis and life prediction methods are emphasized in detail. Probabilistic methods to simulate the total corrosion fatigue damage process and to estimate the reliability, considering both single‐site and multiple‐site damage, are studied. Application examples that illustrate the reliability evaluation of aircraft fuselage lap joints under corrosion and fatigue are discussed.
Compatibilized Ny6‐based blends as ­innovative packaging materials: ­determination of some important properties ­relevant to food contact application
Authors: Laurienzo P. , Malinconico M. , Volpe M. G. , Luongo D. , Ranieri V. , Scoponi M.
Published: August 2002

Chemical physical analysis, photo‐oxidative stability and lipid oxidation of innovative polymeric films based on blends of nylon 6 and ethylene‐co‐vinyl alcohol for use in food packaging have been investigated. Thermal mechanical analysis showed that the presence of an interfacial agent in the blend stabilized the films towards the action of permeants. Synergistic effects of the interfacial agent are reported with respect to UV photostability. Peroxide value (PV) was used to follow the oxidation of the olive oil, and for this parameter also the influence of the interfacial agent was clearly detected. Copyright © 2001 John Wiley & Sons, Ltd.
Simulated experimental design used to define the characteristic curves of car shock‐absorbers
Authors: Arcidiacono G. , Capitani R. , Vianello M.
Published: August 2002

This paper introduces a special ‘quality’ parameter on automotive perspective, i.e. the quality index in order to measure the customer satisfaction with car manoeuvrability. In particular, it describes how the characteristic setting curves of a car shock‐absorber can be optimized using subjective customer assessment of three categories of perception: handling, steering quality and ride‐comfort. These, called manoeuvrability indices, were used to represent the assessment of customer satisfaction with car manoeuvrability. The characteristic curves for each shock‐absorber setting were defined using parameters which uniquely determined their shape. Subsequent analysis was carried out using simulated experimental design which adopts a numeric model of vehicle simulation thereby enabling experimental costs to be reduced. This analysis made it possible to ascertain which setting parameter values provided the best compromise among the three categories of required performance. A codified method of optimization was then developed. This method, which includes the three categories of perception, will be extended to all new projects. Copyright © 2001 John Wiley & Sons, Ltd.
Phase I control charts for independent Bernoulli data
Authors: Borror Connie M. , Champ Charles W.
Published: August 2002

Phase I Shewhart p, np and runs of conforming charts are investigated. The performance of these charts are assessed using the probability of a false alarm. As with other Phase I Shewhart charts, the probability of a false alarm increases as the number, m, of samples increases for a fixed sample size, n. For a fixed value of m, the probability of at least one signal decreases as the sample size n increases. The probability of a signal for a runs of conforming chart depends on the number of samples m. Like the p and np charts, as m increases the probability of a false alarm increases. Unlike the p and np charts, the false alarm rate for a runs of conforming chart does not depend on the in‐control value of p. Copyright © 2001 John Wiley & Sons, Ltd.
High level ab initio and density functional theory calculations of the dissociation energies, ionization energies, geometrical variations, and vibrational modes of ground and excited CO2, CO2+, and CO22+
Authors: Jalbout Abraham F.
Published: August 2002

The potential energy surface of CO22+ ( 3Σg−) is investigated with HF, MP2, MP4, CBS‐Q, G1, G2MP2, G2, G3B3, and B3LYP/6‐311++G(3df,3pd) methods. Density functional theory shows the lowest dissociation channel of this compound to be the formation of CO+ ( 2Σ+)+O+ ( 4Su) and to have a barrier of around 2 eV as well as a dissociation energy of around −3.2 eV. Thus we propose that with enough correlation it is possible to accurately predict the energies of dissociation and barrier widths and heights to test for the stability of a particular molecular species. We also propose a refinement of current understanding by observing HOMO–LUMO gaps, Lowdin and Mulliken bond orders (to test for bond orbital overlap and hence qualitatively describe bonding and fragmentation in these complexes) and predicted spectrum for such studies as ZEKE spectroscopy (to study cationic states) and REMPI (to study the first excited states) of these class of molecules and, we hope, provide future insight into larger and more interesting systems. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Using theozymes for designing transition‐state analogs for the intramolecular aldol reaction of δ‐diketones
Authors: Arnó Manuel , Domingo Luis R.
Published: August 2002

Two theozymes for the intramolecular aldol reaction of δ‐diketones have been studied using ab initio methods. The presence of both acid/base residues favors several steps of the aldol reaction. The appropriate positioning of these residues can accelerate one of two diastereromeric reaction pathways, the catalyzed aldol reaction being highly stereoselective. Analysis of the geometrical parameters, charge distribution, and the shape of molecular electrostatic potential for the corresponding acid/base catalyzed transition structure allows us to design adequate transition‐state analogs to favor a reactive channel of this intramolecular aldol reaction. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 338–347, 2001
Density functional study of small Nin clusters, with n=2–6, 8, using the generalized gradient approximation
Authors: Michelini M. C. , Pis Diez R. , Jubert A. H.
Published: August 2002

Results of a systematic study of the geometry, electronic structure, magnetic, and vibrational properties of small nickel clusters Nin, with n=2–6, 8, within the framework of the generalized gradient approximation of the density functional theory are presented in this work. Emphasis is on the increasing number of stable conformers found when the cluster size increases. Some discussion on how the lower vibrational frequencies could help in the experimental elucidation of the ground states is provided. Finally, a comparison between experimental and calculated average magnetic moments per atom is presented. © 2001 John Wiley & Sons, Inc. Int J Quant Chem, 2001
Theoretical studies on heats of formation for cubylnitrates using density functional theory B3LYP method and semiempirical MO methods
Authors: Zhang Ji , Xiao Jijun , Xiao Heming
Published: August 2002

The heats of formation (HOF) have been calculated for all the 21 cubylnitrate compounds using the semiemprical molecular orbital (MO) methods (MINDO/3, MNDO, AM1, and PM3) and for 8 of 21 cubylnitrates containing 1–4 ONO2 groups using the density functional theory (DFT) method at the B3LYP/6‐31G* level by means of designed isodesmic reactions. The cubane cage skeletons in cubylnitrate molecules have been kept in setting up isodesmic reactions to produce more accurate and reliable results. It is found that there are good linear relationships between the HOFs of the 8 cubylnitrates calculated using B3LYP/6‐31G* and two semiempirical MO (PM3 and AM1) methods, and the linear correlation coefficients of PM3 and AM1 methods are 0.9901 and 0.9826, respectively. Subsequently, the accurate HOFs at B3LYP/6‐31G* level of other 13 cubylnitrates containing 4–8 ONO2 groups are obtained by systematically correcting their PM3‐calculated HOFs. Compared with noncaged nitrates, all the 21 cubylnitrates have high heats of formation implying that they may be very powerful energetic materials and have highly exploitable value. The relationship between the HOFs and the molecular structures of cubylnitrates has been discussed. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Neural network modeling of physical properties of chemical compounds
Authors: Kozioł J.
Published: August 2002

Three different models relating structural descriptors to normal boiling points, melting points, and refractive indexes of organic compounds have been developed using artificial neural networks. A newly elaborated set of molecular descriptors was evaluated to determine their utility in quantitative structure–property relationship (QSPR) studies. Applying two data sets containing 190 amines and 393 amides, neural networks were trained to predict physical properties with close to experimental accuracy, using the conjugated gradient algorithm. Obtained results have shown a high predictive ability of learned neural networks models. The fit error for the predicted properties values compared to experimental data is relatively small. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 84: 117–126, 2001
Third‐order nonlinear optical properties of dendritic molecular aggregates: Effects of fractal architecture
Authors: Nakano M. , Fujita H. , Takahata M. , Kiribayashi S. , Yamaguchi K.
Published: August 2002

We investigate the microscopic third‐order nonlinear optical properties, i.e., the second hyperpolarizabilities (γ), of two different sizes of molecular aggregates with a dendritic, i.e., Bethe‐lattice, structure. One possesses a nonfractal structure, while the other has a fractal structure. The aggregate is treated in a two‐exciton model composed of two‐state monomers coupled to each other by the dipole–dipole interaction. The off‐resonant γ of the aggregates are calculated by the numerical Liouville approach, including relaxation effects. The total γ value is partitioned into the contribution of virtual exciton generation, and its spatial contribution to γ is analyzed in relation to the virtual excitation processes in the perturbation theory. It is found that the intermolecular‐interaction effect enhances both one‐ and two‐exciton‐generation contributions, while the relaxation effect reduces those, although the one‐ and two‐exciton‐generation contributions have mutually opposite signs. From the comparison of spatial contributions to γ between the nonfractal and fractal aggregates, an enhancement of the contribution to γ from the periphery to the core is observed in the fractal structure, while such a feature is not observed in the nonfractal structure. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Theoretical study on dependence of hyperpolarizability of one‐dimensional ring system on the delocalization transition
Authors: Nagao Hidemi , Ohta Yasuhito , Yoshimoto Takashi , Saito Hiroaki , Maki Jun , Kawabe Hiroyuki , Ohta Koji , Nishikawa Kiyoshi
Published: August 2002

We calculate the optical properties such as the polarization, the (hyper)polarizabilities, the critical vector potential, etc., in terms of the non‐Hermitian Anderson model of a 6‐site ring model. The dependence of the optical properties on the delocalization transition is investigated. It is found that all the total optical properties nonlinearly increase with the increase of the delocalization. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Reaction mechanisms between methylamine and a few Schiff bases: Ab initio potential energy surfaces of a catalytic step in semicarbazide sensitive amino oxidases (SSAO)
Authors: Alagona Giuliano , Ghio Caterina
Published: August 2002

The potential energy surfaces for the transamination reaction catalyzed by SSAO were explored for some of the possible reactants considered in a preliminary investigation (Comput Chem 2000, 24, 311). The proton transfer to methylamine (as a model of the catalytic base belonging to the enzyme active site)—either from the keto or enol form of the reactant Schiff bases with one of the possible cofactors, pyridoxal phosphate, PLP (using as a model the pyridoxal ring protonated at N)—was investigated. The enol form seems to be preferred in the region of the neutral intermediate, because even the keto form undergoes a spontaneous rearrangement to the enol form once the Cα proton is delivered to methylamine, producing methylammonium. When the proton is returned back to the Schiff base (on C1), the adduct is about 1.4 kcal/mol more stable than the reactants, while a canonical electron distribution is obtainable only for the enol form. The proton transfer to methylamine was also studied in the presence of the other possible cofactor (para or ortho) topaquinone, TQ. A steep uphill pathway, similar to the keto‐pyridoxal Schiff base one, is obtained using the Schiff base with pTQ, which requires a rearrangement to the final intermediate. On the contrary, using the oTQ structures with the quinonoid O on the same side of methylamine, the proton abstracted from the Schiff base goes spontaneously onto the other quinonoid oxygen. The effect on the barrier heights produced by the presence of a variety of functional groups in the vicinity of the pyridoxal ring nitrogen was also examined. © 2001 John Wiley & Sons, Inc. Int J Quant Chem, 2001
Solvent effect on DNA base stacked dimers: An isodensity polarizable continuum model approach
Authors: Sivanesan D. , Subramanian V. , Nair B. U.
Published: August 2002

The role of solvent on the base stacking properties of various stacked dimers has been analyzed. Ab initio calculations have been performed on the various stacked dimers using the isodensity polarizable continuum model (IPCM), in the framework of the HF/6‐31G** level. It is observed that the stacked dimers undergo different levels of stabilization for different rotated conformations, and the total energy of stacked dimers depends on the twist angle. The results reveal that DNA stacked dimers prefer the twisted (rotated conformation) conformation in water environment, so as to escape from water, due to their hydrophobic nature. In addition, the presence of solvent stabilizes the stacking interaction between bases. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Facile sequencing of oligosaccharides by matrix‐assisted laser desorption/ionisation on a hybrid quadrupole orthogonal acceleration time‐of‐flight mass spectrometer
Authors: Hanrahan Sarah , Charlwood Joanne , Tyldesley Richard , Langridge James , Bordoli Robert , Bateman Robert , Camilleri Patrick
Published: August 2002

N‐Linked oligosaccharide mixtures released from a number of standard glycoproteins were derivatised with 3‐acetylamino‐6‐acetylaminoacridine (AA‐Ac) using reductive amination. Analysis of these mixtures using an experimental matrix‐assisted laser desorption/ionisation (MALDI) hybrid quadrupole orthogonal acceleration time‐of‐flight (Q‐TOF) mass spectrometer provided detailed information about the mass distribution of the glycan derivatives. Collision‐induced dissociation of the singly protonated [M + H]+ ions also gave rise to a number of product ions produced by the sequential cleavage of the glycosidic linkages. As fragmentation of the positively charged species occurred predominantly in one direction, i.e., from the non‐reducing end of the glycan to the AA‐Ac moiety, a considerable amount of information could be obtained with ease about the sequence in which the sugar residues were attached to one another. This derivatisation procedure and mass spectrometric methodology were applied successfully to neutral and acidic glycans released from proteins separated by gel electrophoresis. Copyright © 2001 John Wiley & Sons, Ltd.
Simultaneous assessment of cholesterol absorption and synthesis in humans using on‐line gas chromatography/ combustion and gas chromatography/pyrolysis/isotope‐ratio mass spectrometry
Authors: Gremaud G. , Piguet C. , Baumgartner M. , Pouteau E. , Decarli B. , Berger A. , Fay L. B.
Published: August 2002

A number of dietary components and drugs are known to inhibit the absorption of dietary and biliary cholesterol, but at the same time can compensate by increasing cholesterol synthesis. It is, therefore, necessary to have a convenient and accurate method to assess both parameters simultaneously. Hence, we validated such a method in humans using on‐line gas chromatography(GC)/combustion and GC/pyrolysis/isotope‐ratio mass spectrometry (IRMS). Cholesterol absorption was measured using the ratio of [13C]cholesterol (injected intravenously) to [18O]cholesterol (administered orally). Simultaneously, cholesterol synthesis was measured using the deuterium incorporation method. Our methodology was applied to 12 mildly hypercholesterolemic men that were given a diet providing 2685 ± 178 Kcal/day (mean ± SD) and 255 ± 8 mg cholesterol per day. Cholesterol fractional synthesis rates ranged from 5.0 to 10.5% pool/day and averaged 7.36% ± 1.78% pool/day (668 ± 133 mg/day). Cholesterol absorption ranged from 36.5–79.9% with an average value of 50.8 ± 15.4%. These values are in agreement with already known data obtained with mildly hypercholesterolemic Caucasian males placed on a diet similar to the one used for this study. However, our combined IRMS method has the advantage over existing methods that it enables simultaneous measurement of cholesterol absorption and synthesis in humans, and is therefore an important research tool for studying the impact of dietary treatments on cholesterol parameters. Copyright © 2001 John Wiley & Sons, Ltd.
Structural elucidation of monoterpene oxidation products by ion trap fragmentation using on‐line atmospheric pressure chemical ionisation mass spectrometry in the negative ion mode
Authors: Warscheid Bettina , Hoffmann Thorsten
Published: August 2002

Based on ion trap mass spectrometry, an on‐line method is described which provides valuable information on the molecular composition of structurally complex organic aerosols. The investigated aerosols were generated from the gas‐phase ozonolysis of various C10H16‐terpenes (α‐pinene, β‐pinene, 3‐carene, sabinene, limonene), and directly introduced into the ion source of the mass spectrometer. Negative ion chemical ionisation at atmospheric pressure (APCI(−)) enabled the detection of multifunctional carboxylic acid products by combining inherent sensitivity and molecular weight information. Sequential low‐energy collision‐induced product ion fragmentation experiments (MSn) were performed in order to elucidate characteristic decomposition pathways of the compounds. Dicarboxylic acids, oxocarboxylic acids and hydroxyketocarboxylic acid products could be clearly distinguished by multistage on‐line MS. Furthermore, sabinonic acid and two C9‐ether compounds were tentatively identified for the first time by applying on‐line APCI(−)‐MSn. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of selected sulfonamide antibiotics and trimethoprim in manure by electrospray and atmospheric pressure chemical ionization tandem mass spectrometry
Authors: Pfeifer Thomas , Tuerk Jochen , Bester Kai , Spiteller Michael
Published: August 2002

A method for the determination of sulfonamides and trimethoprim in the complex matrix liquid manure has been developed using reversed‐phase liquid chromatography and atmospheric pressure chemical ionization (APCI) tandem mass spectrometry. A comparison was made between electrospray and atmospheric pressure chemical ionization. APCI proved to be more robust and less sensitive to matrix effects. High‐performance liquid chromatographic (HPLC) separation of the analytes was achieved in less than 7 min. The compounds were extracted with ethyl acetate and the extracts were cleaned up by solid‐phase extraction on an aminopropyl column. Recoveries were not dependent on the concentration level. The mean recoveries were as follows: trimethoprim 79.0%, sulfadiazine 80.5%, N4‐acetylsulfadiazine 91.0%, sulfamerazine 78.6%, sulfadimidine 77.2% and sulfamethoxazole 82.8%. Linearity was established over a concentration range of 5 to 5000 µg/kg with correlation coefficients greater than 0.99. The method had a limit of quantitation (LOQ) of 5 µg/kg manure. Copyright © 2002 John Wiley & Sons, Ltd.
Electrospray mass spectrometric studies of L‐carnosine (β‐alanyl‐L‐histidine) complexes with copper(II) or zinc ions in aqueous solution
Authors: Mineo P. , Vitalini D. , La Mendola D. , Rizzarelli E. , Scamporrino E. , Vecchio G.
Published: August 2002

Electrospray ionization mass spectrometry (ESI‐MS) was used for the speciation of supramolecular assemblies formed between equimolar amounts of carnosine and copper or zinc ions in dilute aqueous solutions. In the case of pure carnosine and carnosine/copper systems, the effect of pH changes, in the range 2–9, on the complexes surviving in solution was also explored. ESI data, besides supporting previous reported results on the formation of dimeric carnosine/copper and carnosine/zinc complexes, allowed a more complete speciation of the examined systems, bringing to light the existence of bis‐complex species and, in the zinc case, the formation of oligomeric species. The data obtained for the systems investigated show that ESI‐MS is not only a reliable and fast technique for the analysis of the metal/ligand systems, but also an interesting tool to obtain stoichiometric information on metal complexes formed in very low concentration solutions. Copyright © 2002 John Wiley & Sons, Ltd.
Short capillary ion‐pair high‐performance liquid chromatography coupled to electrospray (tandem) mass spectrometry for the simultaneous analysis of nucleoside mono‐, di‐ and triphosphates
Authors: Tuytten R. , Lemière F. , Dongen W. Van , Esmans E. L. , Slegers H.
Published: August 2002

A liquid chromatography/mass spectrometry (LC/MS) method for the analysis of complex mixtures of nucleoside mono‐, di‐ and triphosphates has been developed. A short capillary column (35mm × 0.3mm i.d.) was operated under ion‐pair high‐performance liquid chromatography conditions and hyphenated to (negative) electrospray (tandem) mass spectrometry. As such, the separation of 12 nucleotides was performed by a binary gradient elution using CH3OH/H2O and N,N‐dimethylhexylamine (N,N‐DMHA) as ion‐pairing agent. The influence of different N,N‐DMHA concentrations on the chromatographic and mass spectrometric performance was evaluated to achieve optimal LC/MS conditions. In addition it was demonstrated that a controlled admission of ammonium dihydrogen phosphate (NH4H2PO4) improved both chromatographic performance and mass spectrometric detection. Because the system was hyphenated to an orthogonal designed electrospray interface (Z‐spray™), long acquisition times were possible without loss of sensitivity. Copyright © 2002 John Wiley & Sons, Ltd.
Dynamic positioning of a turret moored FPSO using sliding mode control
Authors: Tannuri E. A. , Donha D. C. , Pesce C. P.
Published: August 2002

This paper presents the application of a sliding mode control technique to the dynamic positioning of a turret moored FPSO. The proposed controller is robust with respect to modelling errors and variations in the intensity and direction of environmental forces. Since the system is strongly non‐linear, the sliding mode methodology is appropriate because it does not require linearization and uses the complete model for the controller design. Furthermore, the design of the controller term that guarantees robustness is very simple, and can be generalized to any adopted model of dynamic and environmental forces. The main drawback of the sliding controller, related to the high oscillatory control action, is avoided by the definition of a “boundary layer” near the sliding surface. The controller was tested through numerical simulations of a moored VLCC under several environmental conditions, confirming the stability and performance robustness. Copyright © 2001 John Wiley & Sons, Ltd.
A dexterous humanoid shoulder mechanism
Authors: Stanišić M. M. , Wiitala J. M. , Feix J. T.
Published: August 2002

This paper presents a mechanism that has the potential to serve as a simple humanoid shoulder joint. Unlike the
ball‐in‐socket joint or universal joint, this mechanism can replicate the range of dexterous shoulder
motion found in humans. The mechanism's kinematic equations of motion are studied for singular configurations
and a prototype system is presented. © 2001 John Wiley & Sons, Inc.
A generic approach for the unranking of labeled combinatorial classes
Authors: Martínez Conrado , Molinero Xavier
Published: August 2002

In this article, we design and analyze algorithms that solve the unranking problem (i.e., generating a combinatorial structure of size, n given its rank) for a large collection of labeled combinatorial classes, those that can be built using operators like unions (+), products (⋆), sequences, sets, cycles, and substitutions. We also analyze the performance of these algorithms and show that the worst‐case is 𝒪(n2) (𝒪(n log n) if the so‐called boustrophedonic order is used), and provide an algebra for the analysis of the average performance and higher‐order moments together with a few examples of its application. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 19: 472–497, 2001
Martingales and large deviations for binary search trees
Authors: Jabbour‐Hattab Jean
Published: August 2002

We establish an almost sure large deviations theorem for the depth of the external nodes of binary search trees (BSTs). To achieve this, a parametric family of martingales is introduced. This family also allows us to get asymptotic results on the number of external nodes at deepest level. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 19: 112–127, 2001
A class of systematic m‐ary single‐symbol error correcting codes
Authors: Namba Kazuteru , Fujiwara Eiji
Published: August 2002

Nowadays, m‐ary information such as postal numbers, ID numbers, telephone numbers, and book numbers is being widely used. Increasing the reliability of such information is very important. Single‐symbol error correcting codes for such m‐ary information (m>2) proposed in the past have some limitations. For example, AN codes are nonsystematic, and Hamming codes cannot be constructed over integer rings in which the base is other than prime numbers or power multiples of prime numbers. This paper presents a new class of systematic m‐ary single‐symbol error correcting codes whose check symbols are determined under integer ring of modulo 2m and prime field, and then transformed into m‐ary symbols. This also shows that the proposed codes are superior to existing codes in terms of the code length when the base number m is not a prime or a power multiple of prime. In addition, the detection probabilities with respect to errors greater than the code function such as double symbol errors have been clarified. © 2001 Scripta Technica, Syst Comp Jpn, 32(6): 21–28, 2001
Evaluation of exchanging time for mechanism of exchanging parts of programs during execution
Authors: Taniguchi Hideo , Goto Masataka
Published: August 2002

The authors describe the relationship with program characteristics for a method of exchanging the parts of a program during execution. They then formulate the exchanging time and the thread stoppage time during which the thread is stopped so it can be exchanged. In application programs that share execution units (threads) allocated in a processor or in the case of operating system programs that can be preempted, parts of several programs must be exchanged at the same time. These program parts are shared among many threads. The exchanging time rises along with the processing time for the program part to be exchanged, and the impact on the number of threads which a program shares is minimal. The thread stoppage time during which a thread is stopped so it can be exchanged rises along with the number of shared threads and the processing time for the program parts to be exchanged. The formulation for the exchanging time and the thread stoppage time is shown to have results similar to real measurements. © 2001 Scripta Technica, Syst Comp Jpn, 32(8): 53–62, 2001
The control of goods transportation growth by modal share re‐planning: the role of a carbon tax
Authors: Piattelli Mauro L. , Cuneo Marta A. , Bianchi Nicola P. , Soncin Giuseppe
Published: August 2002

A simple model is proposed, at the macrolevel of variables aggregation, as a support for policy choice making in the control of goods transportation growth by possible alternative modes. The impact of feasible changes in the levying of “carbon tax” can be investigated with the proposed model, as well as the effects of investments in infrastructure and of the coverage of operational costs. Based on some transport externalities, various cost indices are identified and suitably minimized using optimization techniques, so that a quantitative definition of public policies can be derived. As an example, the model is used to evaluate application of alternative policies in Germany. This case study shows that the model system of goods transportation has a slight sensitivity to the public interventions considered. The application of the carbon tax shows significant effects on the increase of fiscal revenues rather than on the reduction of carbon dioxide emissions and on the share of road transportation. Reductions in carbon dioxide emissions and in transportation by road are best achieved by higher investment in the infrastructures of alternative modes of transport, together with a reduction in fuel taxation. Copyright © 2002 John Wiley & Sons, Ltd.
Adhesion properties on nanometric scale of silicon oxide and silicon nitride surfaces modified by 1‐octadecene
Authors: Pignataro B. , Grasso G. , Renna L. , Marletta G.
Published: August 2002

Silicon oxide and silicon nitride surfaces have been treated with 1‐octadecene at ∼200°C . The resulting film topography has been inspected by atomic force microscopy (AFM), showing a densely packed organic coating with a corrugation of some tenths of a nanometre. High‐mass‐resolution time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) spectra from such surfaces display octadecene‐ as well as substrate‐related peaks. Furthermore, peaks diagnostic of the formation of SiOC or SiC linkages are observed in the case of silicon oxide, whereas the same peaks and those due to SiNC species have been observed in the case of silicon nitride. These results suggest that 1‐octadecene molecules are chemisorbed on the substrate. Contact angle measurements and AFMforce spectroscopy measurements allow comparison upon the macroscopic and nanoscopic scale, respectively, of the surface free energy modification due to the formation of the organic coating. Copyright © 2002 John Wiley & Sons, Ltd.
Uses of SIMS three dimensional imaging to understand the relationships between grain boundary chemistry, orientation and intergranular degradation
Authors: McIntyre N. S. , Huctwith C. M. , Taylor K. F. , Keating E. , Petersen N. O. , Brennenstühl A. M.
Published: August 2002

Secondary ion mass spectrometry (SIMS) image depth profiles have been made through grain structures on nickel alloy material that had displayed differing levels of intergranular stress corrosion cracking. The distributions of trace impurities, both within and outside the grain boundaries, are documented qualitatively through three‐dimensional imaging, and quantitatively through the use of cross‐correlation spectroscopy. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative surface chemical analysis of stainless steel 1.4301 using Surface Science Instruments XPS spectrometers: report on an interlaboratory comparison
Authors: Gross Th. , Unger W. E. S. , Patscheider J.
Published: August 2002

Results of an interlaboratory comparison of XPS data obtained with stainless steel are presented. Only one photoelectron spectrometer model was used. The stainless‐steel sample surfaces were analysed in different states by XPS: ‘as received’, after sputtering to I(C 1s)/I(Fe 2p3/2) ∼0.025 and after removing a chromium‐enriched oxide layer following a certain protocol. The Fe, Cr and Ni elemental concentrations were evaluated from the respective XPS data submitted by the participants of the interlaboratory test experiment. Total means, repeat standard deviations (sr) and reproducibility standard deviations (sR) are presented. The best reproducibility standard deviations were obtained for the XPS analysis after removal of a chromium‐enriched oxide layer and quantification of the XPS intensities without taking the contamination elements of carbon and oxygen into account. The absolute reproducibility standard deviation of the elemental concentrations in that case is as small as 1.1–1.5 at.%. This gives 2%, 6% and 16% for the relative reproducibility standard deviation of the concentrations of iron, chromium and nickel, respectively. The total means of the iron, chromium and nickel concentrations finally obtained agree within 2sR with bulk values determined by wavelength‐dispersive x‐ray fluorescence spectroscopy. Comparison to an earlier interlaboratory test experiment shows that using only one model of photoelectron spectrometer reduces the reproducibility standard deviations efficiently. Copyright © 2002 John Wiley & Sons, Ltd.
Silicon wafer cleaning processes and ozone oxide growth as studied by angle‐resolved x‐ray photoelectron spectroscopy (ARXPS) and ellipsometry
Authors: Ermolieff A. , Marthon S. , Rochet X. , Rouchon D. , Renault O. , Michallet A. , Tardif F.
Published: August 2002

Knowledge of silicon oxide layer thickness and stoichiometry is essential for the integration of new dielectric materials. Among the various ways of obtaining ultrathin silicon oxides, chemically grown oxides are a promising choice. Different cleaning processes of silicon wafer for microelectronic integrated‐circuit‐scale application were investigated by XPS and ellipsometry. In this work, overlayer thicknesses were deduced from XPS intensity photoelectron lines and ellipsometric measurements. A comparison between these techniques was carried out. Chemical compositions of the overlayers were deduced from XPS measurements, and an ellipsometric calibration is proposed according to the relative oxygen atomic concentration. Copyright © 2002 John Wiley & Sons, Ltd.
Auger electron spectroscopy and ion scattering spectroscopy studies of altered layer formation in AlN thin film prepared by post‐irradiation with N2+ ions
Authors: Mizuhara Y. , Mitsuhashi R. , Nagatomi T. , Takai Y. , Inoue M.
Published: August 2002

Thin AlN films prepared by post‐irradiation with N2+ ions were examined using Auger electron spectroscopy (AES) and ion scattering spectroscopy (ISS) measurements. The AES spectra clearly indicate the existence of nitrogen in an aluminium substrate that had been irradiated by N2+ ions, forming AlN layers in the subsurface region, whereas ISS revealed only a tiny peak of nitrogen atoms on the topmost surface. The in‐depth composition of the AlN in the surface region was speculated by using a series of chemical compositions assessed from AES and ISS measurements, leading to the proposal of an altered layer formation that is quite similar to those observed in alloy surfaces under ion bombardment. Copyright © 2002 John Wiley & Sons, Ltd.
Non‐parametric methods for recurrent event data with informative and non‐informative censorings
Authors: Wang Mei‐Cheng , Chiang Chin‐Tsang
Published: August 2002

Recurrent event data are commonly encountered in health‐related longitudinal studies. In this paper time‐to‐events models for recurrent event data are studied with non‐informative and informative censorings. In statistical literature, the risk set methods have been confirmed to serve as an appropriate and efficient approach for analysing recurrent event data when censoring is non‐informative. This approach produces biased results, however, when censoring is informative for the time‐to‐events outcome data. We compare the risk set methods with alternative non‐parametric approaches which are robust subject to informative censoring. In particular, non‐parametric procedures for the estimation of the cumulative occurrence rate function (CORF) and the occurrence rate function (ORF) are discussed in detail. Simulation and an analysis of data from the AIDS Link to Intravenous Experiences Cohort Study is presented. Copyright © 2002 John Wiley & Sons, Ltd.
Does EBM offer the best opportunity yet for teaching medical statistics?
Authors: Morris Richard W.
Published: August 2002

Trends in the teaching of statistics to medical undergraduates since the 1970s are traced. I conclude that the aim of enabling doctors to evaluate statistical information relevant to their practice preceded the arrival of evidence‐based medicine (EBM). However this aim was not well realized before 1990. EBM has given an enormous opportunity for statisticians to teach critical appraisal and to orientate future doctors towards evidence‐based practice. This advantage should outweigh any disadvantage of loss of our discipline's identity in modern curricula. Copyright © 2002 John Wiley & Sons, Ltd.
A sensitivity analysis for subverting randomization in controlled trials
Authors: Marcus Sue M.
Published: August 2002

In some randomized controlled trials, subjects with a better prognosis may be diverted into the treatment group. This subverting of randomization results in an unobserved non‐compliance with the originally intended treatment assignment. Consequently, the estimate of treatment effect from these trials may be biased. This paper clarifies the determinants of the magnitude of the bias and gives a sensitivity analysis that associates the amount that randomization is subverted and the resulting bias in treatment effect estimation. The methods are illustrated with a randomized controlled trial that evaluates the efficacy of a culturally sensitive AIDS education video. Copyright © 2001 John Wiley & Sons, Ltd.
Compiler to interpreter: experiences with a distributed programming language
Authors: Gebala Robert M. , McNamee Carole M. , Olsson Ronald A.
Published: August 2002

One interpretive approach for handling concurrency is to provide an interpreter instance for each executing language‐level process. Such an approach has mainly been applied to concurrent implementations of logic and functional languages. This paper describes the use of this approach in constructing an interpreter for an imperative, distributed programming language from an existing compiler and run‐time support system (RTS). Primary design goals were to exploit the existing compiler to the extent possible as well as to have minimal impact on the RTS used to support concurrency. We have been successful in meeting these goals. Additionally, performance results show our interpreter's execution times compare favorably to the times required for compilation, linkage, and execution of small programs or programs with a significant number of calls to the RTS; on such programs, our interpreter's performance also compares favorably to that of the standard Java implementation. However, for larger programs and programs with fewer calls to the underlying RTS, the conventional compiler‐based implementation outperforms the interpreter implementation. For many distributed programs in which network costs dominate, the performances of the two implementations differ little. Copyright © 2001 John Wiley & Sons, Ltd.
Object‐oriented design of the subsumption architecture
Authors: Butler Greg , Gantchev Andrea , Grogono Peter
Published: August 2002

The subsumption architecture is a layered mediator invented by Rodney Brooks for behaviour‐based control of robots. The layers are minimally dependent and use minimal communication. We develop an object‐oriented software design for the subsumption architecture, and demonstrate that each layer can be used as a slot for a set of plug‐and‐play components that implement different microstrategies for achieving a particular goal. Guidelines for the development of specific layers and components of a subsumption architecture are also presented. Copyright © 2001 John Wiley & Sons, Ltd.
Supporting configurability and real time in RTD channels
Authors: Das Rajsekhar , Hiltunen Matti A. , Schlichting Richard D.
Published: August 2002

Network communication services that can be configured to customize functionality provide significant advantages over monolithic versions, but can be difficult to construct if the services must also provide real‐time guarantees on message delivery. This paper describes how practical issues related to the combination of configurability and real time have been addressed in real‐time dependable (RTD) channels, a communication abstraction that has been prototyped using the Cactus system. The architecture and implementation of RTD channels are described, including facilities for translating an application's quality of service requirements into configuration‐specific resource requirements, and an admission control architecture that uses system‐wide information to determine whether sufficient resources exist to create new channels. In addition, the results of experiments that demonstrate that the desired channel properties—including real‐time guarantees—are provided for various configurations are presented. Finally, practical problems and lessons learned from implementing RTD channels on the general‐purpose MK 7.3 Mach operating system are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
In vivo assessment of adenoviral vector‐mediated gene expression of dopamine D2 receptors in the rat striatum by positron emission tomography
Authors: Umegaki Hiroyuki , Ishiwata Kiichi , Ogawa Osamu , Ingram Donald K. , Roth George S. , Yoshimura Juri , Oda Keiichi , Matsui‐Hirai Hisako , Ikari Hiroyuki , Iguchi Akihisa , Senda Michio
Published: August 2002

For functional assessment of gene therapy in experimental animals, in vivo assessment of transferred genes will provide a major advance over an in vitro analysis which must be done post‐hoc. In the current study we conducted positron emission tomography (PET) analysis in rats following injection of the adenoviral vector encoding the cDNA for the rat dopamine D2 receptors (D2R) (AdCMV.DopD2R) into rat brain to provide a quantitative evaluation of D2R overexpression. Quantitative measurements as well as images by PET and ex vivo autoradiography demonstrated the significant increase of D2R binding of [11C]raclopride, a specific D2R radioligand, in the AdCMV.DopD2R‐injected rat striatum 2 or 3 days after vector injection. Longitudinal in vivo assessment of the gene expression by PET demonstrated decreased binding of [11C]raclopride with time, which was in agreement with the observation in a cross‐sectional autoradiographic study. The results of the current study demonstrate that PET can be used for longitudinal in vivo assessment of D2R expression mediated by adenoviral vector in rat brain. Synapse 43:195–200, 2002. © 2002 Wiley‐Liss, Inc.