bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permethylpentalene Chemistry
Authors: Ashley Andrew E. , Cowley Andrew R. , O'Hare Dermot 
Published: March 2007

AbstractA rational solution‐phase synthesis of a permethylpentalene (Pn*) ligand precursor for use in organometallic chemistry has been devised through the novel peripheral alkylation of the bicyclo[3.3.0]octane ring system. Tetramethylation of tetramethyl 3,7‐dihydroxybicyclo[3.3.0]octa‐2,6‐diene‐2,4,6,8‐tetracarboxylate (1) forms sterically encumbered 2 which exhibits fluxionality. Decarboxylation to 3 followed by facile double dehydrogenation using Br2 affords 4. Nucleophilic addition of the final two methyl groups necessitates the use of an organocerium reagent and work‐up yields the hexamethylated hydroxy‐fulvene 5. Dehydration is achieved using aprotic conditions (LiCl/DMSO) to afford the tetraene 6, an exocyclic isomer of Pn*. 6 incorporates a bicyclic vinyl‐fulvene unit, avoiding an 8π anti‐aromatic structure. Both 3 and 4 have been structurally characterised.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Determination of medroxyprogesterone acetate residues by CE immunoassay with chemiluminescence detection
Authors: Peng Chi‐Fang , Huo Tie‐Ming , Liu Li‐Qiang , Chu Xiao‐Gang , Xu Chuan‐Lai 
Published: March 2007

AbstractA rapid and simple method is developed for the determination of medroxyprogesterone acetate (MPA) by CE immunoassay with chemiluminescence (CL). This method is based on the competitive reactions between horseradish peroxidase (HRP)‐labeled MPA (MPA‐HRP) and free MPA with anti‐MPA antiserum. The influencing factors on the electrophoresis and CL detection were studied completely and the optimal conditions of separation and determination were obtained. The linear range was 2.0–50 nmol/L and the LOD for MPA was 0.9 nmol/L. The present method was applied to the analysis of pork tissues.
Data processing in metabolic fingerprinting by CE‐UV: Application to urine samples from autistic children
Authors: Soria Ana C. , Wright Barry , Goodall David M. , Wilson Julie 
Published: March 2007

AbstractMetabolic fingerprinting of biofluids such as urine can be used to detect and analyse differences between individuals. However, before pattern recognition methods can be utilised for classification, preprocessing techniques for the denoising, baseline removal, normalisation and alignment of electropherograms must be applied. Here a MEKC method using diode array detection has been used for high‐resolution separation of both charged and neutral metabolites. Novel and generic algorithms have been developed for use prior to multivariate data analysis. Alignment is achieved by combining the use of reference peaks with a method that uses information from multiple wavelengths to align electropherograms to a reference signal. This metabolic fingerprinting approach by MEKC has been applied for the first time to urine samples from autistic and control children in a nontargeted and unbiased search for markers for autism. Although no biomarkers for autism could be determined using MEKC data here, the general approach presented could also be applied to the processing of other data collected by CE with UV–Vis detection.
CE microchips: An opened gate to food analysis
Authors: Escarpa Alberto , González María Cristina , Crevillén Agustín González , Blasco Antonio Javier 
Published: March 2007

AbstractCE microchips are the first generation of micrototal analysis systems (μ‐TAS) emerging in the miniaturization scene of food analysis. CE microchips for food analysis are fabricated in both glass and polymer materials, such as PDMS and poly(methyl methacrylate) (PMMA), and use simple layouts of simple and double T crosses. Nowadays, the detection route preferred is electrochemical in both, amperometry and conductivity modes, using end‐channel and contactless configurations, respectively. Food applications using CE microchips are now emerging since food samples present complex matrices, the selectivity being a very important challenge because the total integration of analytical steps into microchip format is very difficult. As a consequence, the first contributions that have recently appeared in the relevant literature are based primarily on fast separations of analytes of high food significance. These protocols are combined with different strategies to achieve selectivity using a suitable nonextensive sample preparation and/or strategically choosing detection routes. Polyphenolic compounds, amino acids, preservatives, and organic and inorganic ions have been studied using CE microchips. Thus, new and exciting future expectations arise in the domain of food analysis. However, several drawbacks could easily be found and assumed within the miniaturization map.
Evidence that 4‐aminobiphenyl, benzidine, and benzidine congeners produce genotoxicity through reactive oxygen species
Authors: Makena Patrudu S. , Chung King‐Thom 
Published: March 2007

Abstract4‐Aminobyphenyl (4‐Ab), benzidine (Bz), and Bz congeners were evaluated for their ability to induce genotoxicity through an oxidative mechanism. The mutagenicity of these compounds was tested in the presence and absence of Aroclor 1254‐induced rat S9 mix using Salmonella typhimurium tester strain TA102, which is sensitive to agents producing reactive oxygen species (ROS). In the presence of S9, 4‐Ab, Bz, N‐acetyl‐benzidine, and 3,3′‐dimethoxybenzidine were strongly mutagenic in TA102, whereas, 3,3′,5,5′‐tetra‐methylbenzidine, 3,3′‐dimethylbenzidine (O‐tolidine), and N,N′‐diacetylbenzidine were not mutagenic. In addition, 3,3′‐dichlorobenzidine and 4,4′‐dinitro‐2‐biphenylamine were directly mutagenic in TA102. Incorporation of the free radical and metal scavengers, catalase, superoxide dismutase (SOD), butylated hydroxytolune (BHT), and ethylenediamine tetraacetic acid (EDTA) reduced the mutagenic responses of 4‐Ab and Bz, whereas heat‐inactivated catalase and SOD had no effect. 4‐Ab and Bz also induced lipid peroxidation in the presence of S9 mix as shown using the thiobarbituric acid reactive substances assay. The results of this study indicate that 4‐Ab and Bz induce mutations through the induction of ROS. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Recovering information from synthetic air quality indices
Authors: Bruno Francesca , Cocchi Daniela 
Published: March 2007

AbstractSynthetic indices are often used to condense complex situations into a single figure. However, this condensing process risks losing potentially useful information, especially when the index is to be utilised by public decision‐making bodies. The present study proposes a general strategy, combining a number of different methods, designed to recover information from air‐quality indices: graphical methods to reconstruct the composition of pollution, multinomial logit analysis to study the influence of meteorological covariates on air‐quality indices, and finally, a probability distribution for the index itself as a basic tool with which to interpret the index's crucial values. Copyright © 2007 John Wiley & Sons, Ltd.
Aseismic strength of kolkewadi dam
Authors: Saini S. S. , Krishna Jai , Chandrasekaran A. R. 
Published: March 2007

AbstractKolkewadi Dam, a masonry gravity dam in India, is under construction at a'site which was considered to be non‐seismic at the time of planning and design. Subsequently, some major and minor earthquake shocks have occurred in the area. In view of the earthquake activity in the region, it was necessary to estimate the seismic resistance of the dam. A dynamic analysis of the two highest monoliths of the dam has been carried out, based on the probable ground motion expected at the site, including a simplified analysis, treating the dam as a cantilever beam and a detailed analysis considering two‐dimensional behaviour by the finite element method. It is concluded that the dam will be able to safely withstand the severest shock that has occurred in the region. The behaviour of models of one monolith has also been studied experimentally using a shake table. The experimental behaviour of the models compares favourably with the behaviour obtained theoretically, indicating the applicability of the theoretical method of analysis.
Finite strip analysis of the dynamic response of beam and slab highway bridges
Authors: Smith J. W. 
Published: March 2007

AbstractThis paper presents a method of analysis for the dynamic response of a simply supported beam and slab bridge under the action of a moving vehicle. The bridge is idealized as an orthotropic plate and, in the analysis, is subdivided into a number of finite strips. The vehicle is idealized as a moving sprung mass. Viscous damping is taken into account for both bridge and vehicle.The results show that there is significant variation of response across transverse sections of the bridge. Furthermore the dynamic magnification is considerably greater than that predicted by a more approximate method in which the bridge is idealized as a simple prismatic beam.
Dynamic properties of planar, coupled shear walls
Authors: Jennings Paul C. , Skattum Knut S. 
Published: March 2007

AbstractThe paper is a study of the natural frequencies and mode shapes of planar, coupled shear walls, a common lateral resistive element in building construction. The equations of motion are derived for the general case, and the eigenvalue problem associated with free vibrations of equal, constant shear walls is solved, both with and without the inclusion of the inertia of vertical motion. Explicit solutions are presented for the characteristic equation and the mode shapes and the results are illustrated with figures, including an example calculation based on the shear walls of the Mt. McKinley Building, damaged by the Alaskan earthquake of 1964. The results affirm the necessity of including vertical displacement of the shear walls in the analysis of such systems, and suggest that the inertia of vertical motion also must be considered in the analysis for certain ranges of the parameters.
Damped vibration mode superposition method for dynamic response analysis
Authors: Itoh Tetsuji 
Published: March 2007

AbstractIn the dynamic response analysis of extremely complex structural systems in which the damping characteristics of each element are independent, the damping matrix is not always diagonalized by the use of undamped free vibration mode shapes. In the present paper, a mode‐superposition method by the use of damped free vibration mode shapes is developed for such structural systems. It is also shown that the Fast Fourier Transform (FFT) procedures, that are available for the dynamic response analysis of linear structural systems, are used effectively in this mode‐superposition method with good accuracy.
Calculation of selected ordinates of fourier spectra
Authors: Jennings Paul C. 
Published: March 2007

AbstractA method is presented for calculating single or, by repeated use, selected ordinates of Fourier spectra rapidly and efficiently. The approach differs from standard methods in that any frequency consistent with the interval of digitization may be chosen and records of arbitrary length may be analysed. The method is based on the relation between Fourier spectra of an accelerogram and the final response of an undamped oscillator to the same accelerogram. This relation is reviewed and extended to aid the development of the computing method and to assist in the interpretation of Fourier spectrum techniques in earthquake engineering. Because only the terminal values of the response of an undamped oscillator are required to define the Fourier spectra, repeated application of superposition is used to form equivalent excitations with durations of only one‐quarter of the period of the oscillator.
Earthquake response analysis of the olive view hospital psychiatric day clinic
Authors: Selna L. G. , Morrill K. B. , Ersoy O. K. 
Published: March 2007

AbstractThe collapse of the Olive View Hospital Psychiatric Day Clinic is studied using three biaxial force‐deflection models to represent the columns of the building. These models are: shear collapse, elastic and inelastic. The biaxial models for shear and inelastic behaviour are new developments and are useful for non‐linear structural dynamic studies. In the present study, the shear collapse model is intended to represent the actual prototype behaviour. The inelastic model, which is based on a hardening rule of plasticity, is used to study the performance of a hypothetical structure with the same storey shear capacity as the prototype but which exhibits ductile behaviour.The prototype structure had a base storey shear capacity of 25 per cent, and actually failed by shearing of all of the first floor columns. In the present study, the shear collapse model predicted this behaviour even with the El Centro accelerogram as input. This result may have far‐reaching significance because many low‐rise reinforced concrete buildings which were designed according to recent codes have similar storey shear capacity coefficients and column properties. According to this study, such buildings may collapse even in a moderate earthquake.In the inelastic representation, the structure was found to have a base storey shear capacity of 80 per cent when moment hinging was assumed to occur at the top and bottom of the columns. Even with this high strength capacity, the permanent offset computed from the inelastic model corresponded to a ductility factor of 5 when the Pacoima Dam accelerogram was used as input. On the basis of damage to other structures observed on the site, it seems likely that ground motion of about the Pacoima Dam intensity occurred at Olive View. From this it is concluded that a low‐rise ductile frame concrete building, even with this high shear force capacity, may not prove satisfactory for hospital use when subjected to strong ground motion.
Free vibration and transient response of thick and thin plates using the finite element method
Authors: Rock T. , Hinton E. 
Published: March 2007

AbstractAn isoparametric quadrilateral plate bending element is used for the free and forced vibration analysis of both thick and thin plates. Plates of rectangular, circular and triangular planform are analysed and excellent results are obtained. The element performance is assessed by comparison with analytical solutions based on Mindlin's thick plate theory, three‐dimensional elasticity solutions and solutions based on thin plate theory.
Earthquake response analysis of multistorey buildings including foundation interaction
Authors: Chopra Anil K. , Gutierrez Jorge A. 
Published: March 2007

AbstractAn efficient method, based on the Ritz concept, for dynamic analysis of response of multistorey buildings including foundation interaction to earthquake ground motion is presented. The system considered is a shear building on a rigid circular disc footing attached to the surface of a linearly elastic halfspace. In this method, the structural displacements are transformed to normal modes of vibration of the building on a rigid foundation. The analysis procedure is developed and numerical results are presented to demonstrate that excellent results can be obtained by considering only the first few modes of vibration. As the number of unknowns are reduced by transforming to generalized co‐ordinates, the method presented is much more efficient than direct methods.
Effect of soil on structural response to wind and earthquake
Authors: Novak Milos 
Published: March 2007

AbstractAn approximate analytical approach is presented which makes it possible to consider soil properties and footing embedment in the analysis of the response of structures to external excitation such as wind and earthquake. The approach is based on modal analysis and the definition of stiffness and damping due to soil pertinent to each vibration mode. The approach also facilitates the analysis of coupled motions of a footing alone. The analysis of a tall chimney for the effects of gusting wind, vortex shedding and earthquake is used as an example.
Some ground motion and intensity relations for the central united states
Authors: Necioglu Altan , Nuttli Otto W. 
Published: March 2007

AbstractBecause of low absorption of seismic wave energy in the central United States, as compared to the western part, relations between ground motion and intensity differ for the two regions. This paper presents some empirical relations between magnitude, intensity and perceptibility that are applicable to the central United States. In general, the areas of perceptibility and of damage are one to two orders greater for earthquakes in the central area than for western earthquakes of equal magnitude or of equal maximum Modified Mercalli intensity.
Hysteretic response of a nine‐storey reinforced concrete building
Authors: Iemura H. , Jennings P. C. 
Published: March 2007

AbstractThe Millikan Library on the campus of the California Institute of Technology was strongly shaken during the San Fernando earthquake of 9 February 1971. The building was not damaged structurally, but the observed E‐W response of the building showed a fundamental period of about 1.0 sec, significantly longer than the 0.66 sec observed in pre‐earthquake vibration tests. In this study, the response of the fundamental mode was treated as that of a single‐degree‐of‐freedom hysteretic structure, and four simple models, two stationary and two with changing properties, were examined to see if they could describe the observed response. It was found that an equivalent linear model and a bilinear hysteretic model both could match the response, provided their properties were changed during the earthquake. (Four changes were used.) A linear model with constant properties and a stationary, bilinear hysteretic model did not give nearly as good agreement as the non‐stationary models. The results indicated, in general, a degrading of the stiffness and energy dissipation capacity of the building, with the suggestion that the changes were sudden rather than gradual.
Torsional vibrations in boxgirder suspension bridges
Authors: Irvine Max 
Published: March 2007

AbstractA linear theory is developed for the free, torsional vibrations of the single‐span, boxgirder suspension bridge. Both symmetric and antisymmetric modes are considered. For the symmetric modes, which induce additional cable tension, it is shown that it is imperative to include the elasticity of the cables if correct solutions are to be obtained. Three examples of bridges with widely differing properties are presented to illustrate the applicability of the theory. Orthogonality of the torsional modes of vibration is proved in Appendix I and the modification to the analysis, required when rigid centre ties are present, is outlined in Appendix II. The theories presented herein can be readily extended to the three‐span bridge.
Characteristics of 3‐dimensional earthquake ground motions
Authors: Penzien Joseph , Watabe Makoto 
Published: March 2007

AbstractAn orthogonal set of principal axes is defined for earthquake ground motions along which the component variances have maximum, minimum and intermediate values and the covariances equal zero. Corresponding axes are defined which yield maximum values for the covariances. The orthogonal transformations involved are identical in form to those used in the transformation of stress. Examination of real accelerograms reveals that the major principal axis points in the general direction of the epicentre and the minor principal axis is nearly vertical. It is concluded that artificially generated components of ground motion need not be correlated statistically provided they are directed along a set of principal axes.
Seismic analysis of long multiple‐span highway bridges
Authors: Tseng W. S. , Penzien J. 
Published: March 2007

AbstractMathematical models and three‐dimensional non‐linear dynamic analysis procedures are described for determining the seismic response of long, curved (or straight), multiple‐span, reinforced concrete highway bridges. Under the action of strong earthquakes, the columns (or piers) of such structures may experience large cyclic inelastic deformations of a coupled form. Also, cyclic slippage of the Coulomb type can take place in the expansion joints of the deck causing multiple impacts and separations to occur. These separations may be sufficiently large to cause tensile yielding of the longitudinal expansion joint restrainer bars (or cables) and, if not controlled, can permit deck spans to fall off their supports resulting in partial or total collapse of the structure. In this paper, a three‐dimensional elasto‐plastic mathematical model suitable for representing the coupled inelastic flexural behaviour of reinforced concrete columns under cyclic deformations is presented along with a non‐linear mathematical model for simulating the non‐linear discontinuous behaviour of expansion joints. The procedures used for non‐linear seismic response analysis are described and a numerical example is given to illustrate the method.
Ground‐motion modelling at regional distances for earthquakes in a continental interior, II. Effect of focal depth, azimuth and attenuation
Authors: Herrmann Robert B. , Nuttli Otto W. 
Published: March 2007

AbstractMultiple‐mode surface‐wave signals are used to model ground motion at distances of 50 to 500 km for an earthquake source in a continental interior. Motion on a thrust fault is used as the earthquake model. Theoretical ground‐motion time histories are generated for this source for various focal depths, receiver azimuths and medium‐attenuation models. A shallow source will generate greater values for the ground motion than the same source at a greater depth. Two anelastic attenuation models are considered, one appropriate to the central and eastern United States and the other to southern California. The effects of the difference in the attenuation models are seen at distances greater than 100 km for periods greater than 1.5 sec.
Measuring water velocity in highly turbulent flows: field tests of an electromagnetic current meter (ECM) and an acoustic Doppler velocimeter (ADV)
Authors: MacVicar B. J. , Beaulieu E. , Champagne V. , Roy A. G. 
Published: March 2007

AbstractTwo field tests were completed to compare the performance of an electromagnetic current meter (ECM) with that of an acoustic Doppler velocimeter (ADV) in gravel‐bed rivers. Research was particularly motivated by the need to measure flow properties in highly energetic turbulent flows. Measurements were made at two field sites, one at moderate velocities (up to 70 cm/s) and with moderate turbulence intensities (10–20% of mean flow), and the other in an area of non‐uniform flow that included locations with fast mean velocities (up to 1.75 m/s) and high turbulent intensities (up to 50% of mean flow). Comparison of means, standard deviations, turbulent kinetic energy and Reynolds shear stress confirm the general agreement between the ECMs and ADVs. The general agreement is subject to limitations associated with the sample volume and frequency response of the instruments, and only applies within restricted velocity (up to ≈1.25 m/s) and turbulence intensity ranges (up to ≈0·125 m/s). At higher turbulence intensities, spectral analysis showed anomalous behavior of the ADV signal, especially in the vertical velocity component. Quadrant analysis of the Reynolds stress suggests that these problems occur predominantly in quadrants 1 and 3. Errors in ADV measurements were estimated using four different methods: one that utilized the characteristic noise floor in spectral plots, one based on internal ADV measurements of signal correlation and two techniques that aggregate errors related to various sub‐factors. Estimates were divergent at high flows. Techniques that rely on sub‐factors appeared to underestimate the impact of high turbulence on signal quality. The key conclusion for future field applications is that the older ECM technology provides the more reliable estimates of flow parameters in high turbulence. Copyright © 2007 John Wiley & Sons, Ltd.