bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue Life Prediction for Cord-Rubber Composite Tires Using a Global-Local Finite Element Method
Authors: Han Y. H. , Becker E. B. , Fahrenthold E. P. , Kim D. M.
Published: June 2006

A failure analysis, based on fracture mechanics, may be useful for predicting the lifetime of a cord-reinforced rubber composite pneumatic tire. This paper presents a new three-dimensional Finite Element (FE) local model to calculate the energy release rate at the belt edge region. The new local model uses a three-dimensional (3D) Finite Element Modeling (FEM) fracture analysis based on a steady-state rolling assumption, in conjunction with a global-local technique in ABAQUS. Within the local model, a J-integral variation study is performed in the crack region. This consists of a prediction of the crack propagation direction and a mesh density analysis of the crack model. Furthermore, the study is used to determine the crack growth rate analysis. This study assumes that a flaw exists inside the tire, in the local model, due to a mechanical inhomogeneity introduced in the manufacturing of the tire. This paper also considers how different driving conditions, such as free-rolling, braking and traction, contribute to the detrimental effects of belt separation in tire failure.
Evaluation of a Pseudo-Elastic Model for the Mullins Effect
Authors: Mars W. V.
Published: June 2006

Typically, the stress-strain response in filled rubbers depends strongly on the maximum loading previously encountered. The phenomenon, known as the Mullins effect, can be idealized for many purposes as an instantaneous and irreversible softening of the stress-strain curve that occurs whenever the load increases beyond its prior all-time maximum value. At times when the load is less than a prior maximum, nonlinear elastic behavior prevails. Ogden and Roxburgh proposed an empirical model capable of describing this phenomenon, based on a pseudo-elastic concept. Their model, with minor adaptations, has recently been implemented in a commercial finite element program. This paper demonstrates the effectiveness of the implemented model for several benchmark cases including uniform hydrostatic loading, simple tension, pure shear, and equibiaxial tension. The paper also compares model predictions with experimental results for a series of experiments conducted with various combinations of axial tension/compression and torsion loading.
Tire Non-Uniformities And Steering Wheel Vibrations
Authors: Dorfi H. R.
Published: June 2006

Steering wheel vibrations are frequently related to non-uniformities of the tire/wheel system. While steering system design is a major factor in the sensitivity of the vehicle, the excitation of steering wheel vibrations is due in general to non-uniformities of the tire/wheel system. However, tire non-uniformities are to some extent unavoidable and result in rolling force variation at the spindle during steady state rolling. Therefore, limiting and managing these non-uniformities is of great economic importance to tire manufacturers.

The present work demonstrates the tire's role in generating non-uniformity induced dynamic force variations due to 1st order geometric imperfections. Both analytical and numerical approaches are studied. Numerical experiments of the effects of non-uniformities are investigated with the physics based tire model FTIRE. The effects of tire resonance on the non-uniformity force amplitudes are demonstrated through modeling and simulation. The model is then verified using experimental data and the distribution of geometric non-uniformities is studied in a large tire sample based on force measurement data and the model fit.

A MSC.ADAMS model of a light truck is combined with non-uniform FTIRE models to study the effect of geometric non-uniformities on steering wheel vibrations. The simulations show that the angular acceleration of the steering wheel around its steer-axis is primarily dependent on force variations in the longitudinal direction (T1H). The effects of phasing, increase in inertia and tire position on the steering wheel vibrations are also discussed.
Computing self‐organisation: environmentally sensitive growth modelling
Authors: Hensel Michael
Published: June 2006

The self‐organisation processes underlying the growth of living organisms can provide important lessons for architects. Natural systems display higher‐level integration and functionality evolving from a dynamic feedback relation with a specific host environment. Biologists, biomimetic engineers and computer scientists have begun to tackle research in this field and there is much to learn from their work. Here, Michael Hensel examines the work undertaken by Professor Przemyslaw Prusinkiewicz and his collaborators at the Department of Computer Science at the University of Calgary in Alberta, Canada,1 outlining its potential application for architectural design. Copyright © 2006 John Wiley & Sons, Ltd.
(Synthetic) life architectures: ramifications and potentials of a literal biological paradigm for architectural design
Authors: Hensel Michael
Published: June 2006

Biology is the science of life. It concerns itself with the living. The long‐proclaimed biological paradigm for architectural design must for this reason go beyond using shallow biological metaphors or a superficial biomorphic formal repertoire. The consequence is a literal understanding of the design product as a synthetic life‐form embedded within dynamic and generative ecological relations. Michael Hensel examines the repercussions of this proposition and surveys current developments in biology and biochemistry with respect to synthetic‐life research, gathering insights into their potential application in architectural design. Copyright © 2006 John Wiley & Sons, Ltd.
Instrumental geometry
Authors: Menges Achim
Published: June 2006

For two decades, the individual members of the SmartGeometry Group have pioneered innovative computer‐aided design (cad) techniques and technologies. Now that they are situated in key positions in internationally renowned companies, the group is involved in developing a new generation of parametric design software. Here, Robert Aish (Director of Research at Bentley Systems), Lars Hesselgren (Director of Research and Development, kpf London), J Parrish (Director of ArupSport) and Hugh Whitehead (Project Director of the Specialist Modelling Group, Foster and Partners, London) discuss with Achim Menges the group's instrumental approach to geometry and their unique collaboration spanning the world of practice and software development. Copyright © 2006 John Wiley & Sons, Ltd.
Australian wildlife health centre, Healesville Sanctuary, Melbourne
Authors: van Schaik Leon
Published: June 2006

Leon van Schaik places Minifie Nixon's experimental Australian Wildlife Health Centre at Healesville Sanctuary, just outside Melbourne, within the wider context of the city's architectural culture. Copyright © 2006 John Wiley & Sons, Ltd.
Tuning the Dimensions and Periodicities of Nanostructures Starting from the Same Polystyrene‐block‐poly(2‐vinylpyridine) Diblock Copolymer
Authors: Krishnamoorthy S. , Pugin R. , Brugger J. , Heinzelmann H. , Hinderling C.
Published: June 2006

The controlled tuning of the characteristic dimensions of two‐dimensional arrays of block‐copolymer reverse micelles deposited on silicon surfaces is demonstrated. The polymer used is polystyrene‐block‐poly(2‐vinylpyridine) (91 500‐b‐105 000 g mol–1). Reverse micelles of this polymer with different aggregation numbers have been obtained from different solvents. The periodicity of the micellar array can be systematically varied by changing copolymer concentration, spin‐coating speeds, and by using solvent mixtures. The profound influence of humidity on the micellar film structure and the tuning of the film topography through control of humidity are presented. Light scattering, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy were used for characterization. As possible applications, replication of micellar array topography with polydimethylsiloxane and post‐loading of the micelles to form iron oxide nanoparticle arrays are presented.
Shaping Carbon Nanotubes and the Effects on Their Electrical and Mechanical Properties
Authors: Wang M. S. , Peng L.‐M. , Wang J. Y. , Chen Q.
Published: June 2006

A method is developed and shown to be able to shape a carbon nanotube (CNT) into a desired morphology while maintaining its excellent electrical and mechanical properties. Single, freestanding nanotubes are bent by a scanning tunneling microscopy probe, and their morphology is fixed by electron‐beam‐induced deposition (inside a transmission electron microscope) of amorphous carbon on the bent area. It is shown that the mechanical strength of the bent CNT may be greatly enhanced by increasing the amount of carbon glue or the deposition area, and the electrical conduction of the nanotube shows hardly any dependence on the bending deformation or on the deposition of amorphous carbon. Our findings suggest that CNTs might be manipulated and processed as interconnections between electronic devices without much degradation in their electrical conductance, and be used in areas requiring complex morphology, such as nanometer‐scale transport carriers and nanoelectromechanical systems.
Anisotropic Optical Properties of Semitransparent Coatings of Gold Nanocaps
Authors: Liu J. , Cankurtaran B. , Wieczorek L. , Ford M. J. , Cortie M.
Published: June 2006

An ordered array of cap‐shaped gold nanoparticles has been prepared by vapor deposition onto polystyrene nanospheres supported on a glass substrate. The method of fabrication used imparts a significant anisotropy to the geometric and optical properties of the coating. The optical‐absorption properties of these deposits have been measured using UV‐vis spectrometry and simulated using a code based on the discrete dipole approximation. Because the nanocaps are not interconnected, they interact with incident light as individual particles with a plasmon resonance that depends upon wavelength and the polarization vector of the light. The resulting extinction peaks manifest in the upper visible and near‐infrared regions of the electromagnetic spectrum. Surprisingly, varying the angle of incidence of the light (for a fixed polarization) has no effect on the optical properties of individual nanocaps. Calculations show that these phenomena may be readily interpreted in terms of dipole resonances excited across the longitudinal, transverse, and short‐transverse directions of the nanocaps. Coatings comprised of arrays of these particles have the potential to serve as angularly and spectrally selective filters.
Quantitative Measurement of the Local Surface Potential of π‐Conjugated Nanostructures: A Kelvin Probe Force Microscopy Study
Authors: Liscio A. , Palermo V. , Gentilini D. , Nolde F. , Müllen K. , Samorì P.
Published: June 2006

We describe a systematic study on the influence of different experimental conditions on the Kelvin probe force microscopy (KPFM) quantitative determination of the local surface potential (SP) of organic semiconducting nanostructures of perylene‐bis‐dicarboximide (PDI) self‐assembled at surfaces. We focus on the effect of the amplitude, frequency, and phase of the oscillating voltage on the absolute surface potential value of a given PDI nanostructure at a surface. Moreover, we investigate the role played by the KPFM measuring mode employed and the tip–sample distance in the surface potential mapping by lift‐mode KPFM. We define the ideal general conditions to obtain a reproducible quantitative estimation of the SP and we find that by decreasing the tip–sample distance, the area of substrate contributing to the recorded SP in a given location of the surface becomes smaller. This leads to an improvement of the lateral resolution, although a more predominant effect of polarization is observed. Thus, quantitative SP measurements of these nanostructures become less reliable and the SP signal is more unstable. We have also devised a semi‐quantitative theoretical model to simulate the KPFM image by taking into account the interplay of the different work functions of tip and nanostructure as well as the nanostructure polarizability. The good agreement between the model and experimental results demonstrates that it is possible to simulate both the change in local SP at increasing tip–sample distances and the 2D potential images obtained on PDI/highly oriented pyrolytic graphite samples. These results are important as they make it possible to gain a quantitative determination of the local surface potential of π‐conjugated nanostructures; thus, they pave the way towards the optimization of the electronic properties of electroactive nanometer‐scale architectures for organic (nano)electronic applications.
Synthesis, structure and cytotoxic activity of 2‐acetyl‐5‐trimethylsilylthiophene(furan) and their oximes
Authors: Lukevics Edmunds , Ignatovich Luba , Sleiksha Ilze , Muravenko Velta , Shestakova Irina , Belyakov Sergey , Popelis Jury
Published: June 2006

5‐Trimethylsilylderivatives of 2‐acetylthiophene and ‐furan have been regioselectively prepared by a one‐pot procedure from the corresponding 2‐acetylfuran or 2‐acetylthiophene using lithium N‐methylpiperazide (LNMP)–butyllithium–trimethylchlorosilane–water as the sequence of reagents. The ketones obtained were converted to the corresponding oximes. The structure of 2‐acetyl‐5‐trimethylsilylthiophene oxime (E‐isomer) has been studied by X‐ray diffraction. Formation of centrosymmetric dimers by means of H‐bonds has been observed. The intermolecular hydrogen bond O9H…N8 length is 2.842(5) Å [H…N8 = 1.87 (6) Å, O9H…N8 = 157(4)°]. Copyright © 2006 John Wiley & Sons, Ltd.
α‐Amino boronates as cyanoborane complexes: crystal structure and inhibition properties for the serine proteases: α‐chymotrypsin and trypsin
Authors: Shibli Amal , Smoum Reem , Goldberg Israel , Rubinstein Abraham , Srebnik Morris
Published: June 2006

The first examples of α‐amino boronate complexes stabilized by amino cyanoborane complexation were tested as trypsin and chymotrypsin inhibitors, and they showed moderate inhibition. The structure of compound 1 that contains two different boron atoms reveals that the geometry around the boron atom in the cyano group is tetrahedral, whereas a trigonal planar geometry exists around the boron atom attached to two oxygen atoms and a carbon atom. Copyright © 2006 John Wiley & Sons, Ltd.
Management of an unexpected appendiceal neoplasm
Authors: Murphy E M A , Farquharson S M , Moran B J
Published: June 2006

Background

Appendiceal neoplasms are rare and most present unexpectedly as acute appendicitis. The classification and management are confusing, and there are few substantial reports in the literature.

Methods

A systematic literature review was performed to access relevant publications on the presentation, pathology and management of appendiceal tumours.

Results

Appendiceal tumours account for 0·4 to 1 per cent of all gastrointestinal tract malignancies and are found in 0·7 to 1·7 per cent of appendicectomy specimens. Carcinoid tumours are most common. Most are cured by simple appendicectomy if the tumour is less than 2 cm in size and does not involve the resection margin or mesoappendix. Epithelial tumours may present with, or in time develop, pseudomyxoma peritonei, the optimal management of which involves complete tumour resection and intraperitoneal chemotherapy, usually available only in specialized centres.

Conclusion

Suggested algorithms for the management of unexpected appendiceal tumours are provided. Recommendations are made for follow-up of patients with a perforated appendiceal epithelial tumour.
Systematic review and meta-analysis of the use of fibrin sealant to prevent seroma formation after breast cancer surgery
Authors: Carless P A , Henry D A
Published: June 2006

Background

The use of fibrin sealant has been proposed as a means of preventing seroma formation following breast cancer surgery. Conflicting trial results require the efficacy of fibrin sealant to be reviewed critically.

Methods

A systematic review of randomized controlled trials was conducted to examine the efficacy of fibrin sealants in reducing postoperative drainage and seroma formation after breast cancer surgery. Studies were identified by computer searches of Medline, Embase, the Cochrane Central Register of Controlled Trials and manufacturer websites (to June 2005), and bibliographic searches of published articles. Trials were eligible for inclusion if they reported data on postoperative drainage and the number of patients who developed a seroma.

Results

Eleven trials met the criteria for inclusion. Generally, the trials were small and of poor methodological quality. Fibrin sealant did not reduce the rate of postoperative seroma (relative risk 1·14, 95 per cent confidence interval (c.i.) 0·88 to 1·46), the volume of drainage (weighted mean difference − 117·7, 95 per cent c.i. − 259·2 to 23·8 ml), or the length of hospital stay (weighted mean difference − 0·38, 95 per cent c.i. − 1·58 to 0·83 days).

Conclusions

The current evidence does not support the use of fibrin sealant in breast cancer surgery to reduce postoperative drainage or seroma formation.
Randomized clinical trial comparing axillary padding with closed suction drainage for the axillary wound after lymphadenectomy for breast cancer
Authors: Classe J-M , Berchery D , Campion L , Pioud R , Dravet F , Robard S
Published: June 2006

Background

After axillary lymphadenectomy for breast cancer, a suction drain is routinely inserted into the axilla to prevent seroma formation. This drain is an obstacle to reducing hospital stay after breast-conserving surgery. This was a prospective randomized clinical trial to assess the safety and results of axillary padding without the use of a drain.

Methods

Between May 2001 and August 2003, 100 women were randomly allocated axillary padding without a drain or with the use of an axillary suction drain. Prospective assessments were made of morbidity, pain, shoulder mobility, quality of life and medical costs including length of hospital stay.

Results

Using axillary padding significantly reduced the mean (s.d.) length of hospital stay (1·8(1) versus 4·5(2) days, P < 0·001). Postoperative complications, pain, shoulder mobility and quality of life were similar in the two groups. There was no difference in the duration of the two procedures.

Conclusion

Axillary padding after axillary lymphadenectomy was feasible and safe, without a drain, and shortened hospital stay.
Laparoscopic surgery today
Authors: Slim K , Chipponi J
Published: June 2006

Not always the best approach
A kaleidoscope as a cyberworld and its animation: linear architecture and modeling based on an incrementally modular abstraction hierarchy
Authors: Kunii Tosiyasu L. , Ohmori Kenji
Published: June 2006

An incrementally modular abstraction hierarchy is known to effectively linearize cyberworlds and virtual worlds, which are combinatorially exploding and hardly managed. It climbs down from general level to specific model preserving the higher level modules as invariants. It not only prevents the combinatorial explosion but also benefits the reuse, development, testing and validation of cyberworld resources. By applying this incrementally modular abstraction hierarchy to a kaleidoscope animation, its architecture and modeling is also specified in this paper as a typical case of cyberworlds. In particular, a homotopy lifting property and a homotopy extension property, which satisfy a duality relation, are also described to show how a kaleidoscope world is systematically created top‐down from the whole system and bottom‐up from the components. Copyright © 2006 John Wiley & Sons, Ltd.
Optimized motion simplification for crowd animation
Authors: Ahn Junghyun , Oh Seungwoo , Wohn Kwangyun
Published: June 2006

Simulating a huge number of articulate figures in a real‐time application is one of the challenging research topics in character animation. Several researchers have tried to improve the performance of animation using the image‐based technique such as ‘impostor.’ This method improved the speed of the animation; however, the accuracy, memory, and interactivity problems related to motion remain to be resolved. In this regard, a ‘motion simplification’ framework for an articulate figure is proposed, which not only improves the speed of the animation but also conserves the features of the original motion. First, the motion sequence is analyzed using mean shift clustering for the purpose of extracting key postures and automatically generating the priority of joint reductions. These motion analysis results are directly utilized as the input of the proposed posture optimization. The least square method is applied in order to minimize the error between the original and the simplified posture. Finally, how to apply the proposed simplified motion in a real‐time application without decreasing the visual quality of the scene is shown. The experimental result shows that the proposed motion simplification can be successfully applied in a real‐time animation system. Copyright © 2006 John Wiley & Sons, Ltd.
Motion synthesis and editing in low‐dimensional spaces
Authors: Shin Hyun Joon , Lee Jehee
Published: June 2006

Human motion is difficult to create and manipulate because of the high dimensionality and spatiotemporal nature of human motion data. Recently, the use of large collections of captured motion data has added increased realism in character animation. In order to make the synthesis and analysis of motion data tractable, we present a low‐dimensional motion space in which high‐dimensional human motion can be effectively visualized, synthesized, edited, parameterized, and interpolated in both spatial and temporal domains. Our system allows users to create and edit the motion of animated characters in several ways: The user can sketch and edit a curve on low‐dimensional motion space, directly manipulate the character's pose in three‐dimensional object space, or specify key poses to create in‐between motions. Copyright © 2006 John Wiley & Sons, Ltd.
Key‐styling: learning motion style for real‐time synthesis of 3D animation
Authors: Wang Yi , Liu Zhi‐Qiang , Zhou Li‐Zhu
Published: June 2006

In this paper, we present a novel real‐time motion synthesis approach that can generate 3D character animation with required style. The effectiveness of our approach comes from learning captured 3D human motion as a self‐organizing mixture network (SOMN); of parametric Gaussians.The learned model describes the motion under the control of a vector variable calledstyle variable, and acts as a probabilistic mapping from the low‐dimensional style values to the high‐dimensional 3D poses. We design a pose synthesis algorithm to allow the user to generate poses by specifying new style values. We also propose a novel motion synthesis method, the key‐styling, which accepts a sparse sequence of key style values and interpolates a dense sequence of style values to synthesize an animation. Key‐styling is able to produce animations that are more realistic and natural‐looking than those synthesized with the traditional key‐keyframing technique. Copyright © 2006 John Wiley & Sons, Ltd.
Multimodal expression in virtual humans
Authors: de Melo Celso , Paiva Ana
Published: June 2006

This work proposes a real‐time virtual human multimodal expression model. Five modalities explore the affordances of the body: deterministic, non‐deterministic, gesticulation, facial, and vocal expression. Deterministic expression is keyframe body animation. Non‐deterministic expression is robotics‐based procedural body animation. Vocal expression is voice synthesis, through Festival, and parameterization, through SABLE. Facial expression is lip‐synch and emotion expression through a parametric muscle‐based face model. Inspired by psycholinguistics, gesticulation expression is unconventional, idiosyncratic, and unconscious hand gestures animation described as sequences of Portuguese Sign Language hand shapes, positions and orientations. Inspired by the arts, one modality goes beyond the body to explore the affordances of the environment and express emotions through camera, lights, and music. To control multimodal expression, this work proposes a high‐level integrated synchronized markup language—expressive markup language. Finally, three studies, involving a total of 197 subjects, evaluated the model in storytelling contexts and produced promising results. Copyright © 2006 John Wiley & Sons, Ltd.
As‐consistent‐As‐possible compositing of virtual objects and video sequences
Authors: Zhang Guofeng , Qin Xueying , An Xiaobo , Chen Wei , Bao Hujun
Published: June 2006

We present an efficient approach that merges the virtual objects into video sequences taken by a freely moving camera in a realistic manner. The composition is visually and geometrically consistent through three main steps. First, a robust camera tracking algorithm based on key frames is proposed, which precisely recovers the focal length with a novel multi‐frame strategy. Next, the concerned 3D models of the real scenes are reconstructed by means of an extended multi‐baseline algorithm. Finally, the virtual objects in the form of 3D models are integrated into the real scenes, with special cares on the interaction consistency including shadow casting, occlusions, and object animation. A variety of experiments have been implemented, which demonstrate the robustness and efficiency of our approach. Copyright © 2006 John Wiley & Sons, Ltd.
Integrating physically based sound models in a multimodal rendering architecture
Authors: Avanzini Federico , Crosato Paolo
Published: June 2006

This paper presents a multimodal rendering architecture that integrates physically based sound models with haptic and visual rendering. The proposed sound modeling approach is compared to other existing techniques. An example of implementation of the architecture is presented, that realizes bimodal (auditory and haptic) rendering of contact stiffness. It is shown that the proposed rendering scheme allows tight synchronization of the two modalities, as well as a high degree of interactivity and responsiveness of the sound models to gestures and actions of a user. Finally, an experiment on the relative contributions of haptic and auditory information to bimodal judgments of contact stiffness is presented. Experimental results support the effectiveness of auditory feedback in modulating haptic perception of stiffness. Copyright © 2006 John Wiley & Sons, Ltd.
Real‐time navigating crowds: scalable simulation and rendering
Authors: Pettré Julien , Ciechomski Pablo de Heras , Maïm Jonathan , Yersin Barbara , Laumond Jean‐Paul , Thalmann Daniel
Published: June 2006

This paper introduces a framework for real‐time simulation and rendering of crowds navigating in a virtual environment. The solution first consists in a specific environment preprocessing technique giving rise to navigation graphs, which are then used by the navigation and simulation tasks. Second, navigation planning interactively provides various solutions to the user queries, allowing to spread a crowd by individualizing trajectories. A scalable simulation model enables the management of large crowds, while saving computation time for rendering tasks. Pedestrian graphical models are divided into three rendering fidelities ranging from billboards to dynamic meshes, allowing close‐up views of detailed digital actors with a large variety of locomotion animations. Examples illustrate our method in several environments with crowds of up to 35 000 pedestrians with real‐time performance. Copyright © 2006 John Wiley & Sons, Ltd.
Structure and Bonding in First‐Row Transition‐Metal Dicarbides: Are They Related to the Stability of Met‐cars?
Authors: Rayón Víctor M. , Redondo Pilar , Barrientos Carmen , Largo Antonio
Published: June 2006

First‐row transition‐metal dicarbides MC2(M=Sc–Zn) have been investigated by using quantum‐mechanical techniques. The competition between cyclic and linear isomers in these systems has been studied and the bonding scheme for these compounds is discussed through topological analysis of electron density. All of the systems have been found to prefer aC2v‐symmetric arrangement, although for ZnC2the energy difference between this and the linear isomer is rather small. In most cases theC2v‐symmetric structure corresponds to a T‐shaped structure, with the exceptions of TiC2, CoC2, and NiC2which have been shown to be true rings. A detailed analysis of the variation of the energy of the system with geometry has been carried out. An analysis of the bonding, taking into account the main interactions between the valence orbitals of both fragments, the M atom and the C2molecule, has allowed the main features of these compounds to be interpreted. A clear correlation between the dissociation energies of the first‐row transition‐metal dicarbides and the bonding energies of the corresponding met‐cars was observed.
Iterative Deoxypropionate Synthesis Based on a Copper‐Mediated Directed Allylic Substitution: Formal Total Synthesis of Borrelidin (C3–C11 Fragment)
Authors: Herber Christian , Breit Bernhard
Published: June 2006

A new iterative strategy for the flexible preparation of any oligodeoxypropionate stereoisomer is presented which relies on an o‐DPPB‐directed copper mediated allylic substitution employing enantiomerically pure Grignard reagents; the reaction is working with perfect control over all aspects of the reaction selectivity. This key CC bond‐forming step features reversed polarity compared with established enolate alkylation methodology. It thus avoids existing problems of enolate alkylation strategies such as enolate reactivity as well as costs and problems associated with the chiral auxiliary. Practicability of this new method is demonstrated through application in natural product syntheses. Thus, an efficient synthesis of the northern part of the angiogenesis inhibitor borrelidin (28), the deoxypropionate building block 27, could be devised, representing a formal total synthesis.
Pentafluorosulfanyl (SF5) Containing Energetic Salts
Authors: Gao Haixiang , Ye Chengfeng , Winter Rolf W. , Gard Gary L. , Sitzmann Michael E. , Shreeve Jean’ne M.
Published: June 2006

New quaternary salts of pentafluorosulfanyl‐substituted (SF5)N‐methylimidazole (1), 4‐amino‐1,2,4‐triazole (3) or pyridine (5) were prepared and characterized. Most of the salts exhibit good thermal stabilities and low melting points placing them in the ionic liquid class. Their densities range between 1.4 and 1.8 g/cm3. The standard enthalpies of formation for the new salts were calculated by the use of computationally feasible DFT(B3LYP) and MP2 methods in conjunction with an empirical approach based on densities of salts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Electrochemical Behavior of MCF‐7 Cells on Carbon Nanotube Modified Electrode and Application in Evaluating the Effect of 5‐Fluorouracil
Authors: Chen Kun , Chen Jinhua , Guo Manli , Li Zhenfeng , Yao Shouzhuo
Published: June 2006

The electrochemical behavior of human breast cancer cells (MCF‐7) suspension on multiwalled carbon nanotube (MWCNT) modified graphite electrode was studied by using cyclic voltammetry (CV) and potentiometric stripping analysis (PSA). Compared with bare graphite electrode, the MWCNTs‐modified electrode showed electrocatalytic property to the oxidation of electroactive species in the cell suspension. One oxidative peak at about +0.74 V was observed in the cyclic voltammogram. PSA was proved to be more sensitive than CV for investigation of the electrochemical behavior of cells. And it was found that ultrasonication treatment of the cell suspension can significantly enhance the PSA signal. Factors influencing the PSA signal of cells, including deposition time, deposition potential and stripping current, were investigated in detail and the optimum conditions were obtained. The baseline corrected PSA signal was found to be related to the viability of cells and the technique was used for monitoring the growth of MCF‐7 cells. The effect of anticancer drug 5‐fluorouracil (5‐FU) on the growth of MCF‐7 cells was also investigated by PSA.
Speciation of Antimony by Adsorptive Stripping Voltammetry Using Pyrogallol Red
Authors: González M. Jesús Gómez , Domínguez Renedo Olga , Arcos Martínez M. Julia
Published: June 2006

This paper proposes a procedure for the speciation of antimony by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV) using pyrogallol red (PGR) as a complexing agent. It employs a Partial Least Squares regression (PLS) in the resolution of strongly overlapping voltammetric signals obtained from mixtures of Sb(III) and Sb(V) in the presence of pyrogallol red. The absolute value of the relative error was less than 3.5% when concentrations of several mixtures were calculated, the minimum concentrations being 9.98×10−9 mol dm−3and 4.87×10−8 mol dm−3for Sb(III) and Sb(V), respectively. Any undue effects caused by the presence of foreign ions in the solution were also analyzed. The procedure was successfully applied to the speciation of antimony in pharmaceutical preparations.
Anti‐radical power gives insight into early lipid oxidation events during frying
Authors: van Loon Wil AM , Linssen Jozef PH , Legger Aagje , Voragen Alphons GJ
Published: June 2006

The aim of this research was to use anti‐radical power (ARP) to study early lipid oxidation events during frying. The 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH•) test was used to determine the ARP. As oil does not dissolve completely in methanol, which is generally used for the DPPH• test, butanol was used instead. Changing the solvent did not influence the value of the ARP. The decrease of the ARP highly correlated with the increase of the peroxide value for soybean oil heated at 110 °C (R2 = 0.99). Sensory analysis showed that rancidity of soybean oil and frying oil, heated at 180 °C, was perceived before the ARP decreased. Once the oil was perceived as rancid, the intensity of rancidity did not change significantly upon further heating. The ARP of soybean oil was found to decrease faster at 110 °C than at 180 °C, suggesting different mechanisms of radical formation. The total polar compounds of frying oil in which French fries were fried did not differ significantly from frying oil that was heated alone. However, frying of French fries caused more hydrolysis of the oil, while the ARP decreased faster when the oil was heated alone. Copyright © 2006 Society of Chemical Industry
The economics of nonprofit organizations
Authors: Hughes Patricia
Published: June 2006

This article presents an economic view of Nonprofit institutions and insight into what the discipline can offer Nonprofit practitioners. I review the theories and assumptions behind economic models, then give an overview of the major areas of economic research in the Nonprofit sector. I then discuss various factors to consider when judging the quality of economic research. The discussion then turns to a brief overview of the major statistical tool used by economists: regression analysis. The point is not to teach practitioners to become expert econometricians but to provide a framework to judge the quality of economic research. The article concludes with suggestions for economic research that may be undertaken at the firm level.
Historical research for the nonprofit sector
Authors: Hammack David C.
Published: June 2006

Because there are many possible uses of history and conceptions of what constitutes historical inquiry, there can be no single description of “historical research for the nonprofit sector.” Nonprofit researchers, like all nonprofit leaders, cannot avoid having views of historical development; neither can they avoid the necessity of drawing conclusions from incomplete and indeterminate evidence, just as all historians must do. Students of the Nonprofit sector might want to pay particular attention to questions raised by legal and economic history (others have made much of the relevance of social and intellectual history). Most generally, historical materials and perspectives are especially relevant to the education of nonprofit leaders.
The catalyst process: What academics provide to practitioners
Authors: Milofsky Carl
Published: June 2006

In this article, I explore what academics may offer community groups and practitioners by suggesting that scholars serve as catalysts that make community projects possible. One goal is to propose the catalyst model as a way of refocusing the action research paradigm. Action research is an established paradigm for scholars who wish to combine their research agenda with a desire to partner with community leaders on change projects. Discussions of action research tend to focus on the value of the approach for academics and methodological strategies that allow them to produce research their university colleagues consider legitimate. In the catalyst approach, we explore what university people provide in pragmatic terms that allows community movements and projects to move ahead. I deemphasize expert knowledge and focus instead on institutional resources. Scholars provide a gateway to a rich resource environment. The organization of professional work also allows scholars to give continuity to projects and to provide a framework that allows projects that otherwise might stall to move toward completion. The catalyst model eliminates the notion that scholars and practitioners belong to fundamentally different intellectual cultures and thereby removes one of the perceived barriers to effective action research. The model also indicates some organizational strategies for university people to use should they wish to set up long‐term university‐community partnerships..
Step by step to more effective programs
Authors: Hopkins Karen M.
Published: June 2006

Designing and Planning Programs for Nonprofit and Government Organizations, by Edward J. Pawlak and Robert D. Vinter. San Francisco: Jossey‐Bass, 2004. 288 pp., $67.00 cloth.
How to create a mentoring program
Authors: Brescia William
Published: June 2006

Mentoring the Next Generation of Nonpro.t Leaders: A Practical Guide for Managers, by Ken Williams. Washington, D.C.: AED Center for Leadership Development, Academy for Educational Development, 2005. 36 pp., $15.00 paper or available online (http://newvoices.aed.org/MentoringNext Generation.pdf).
Inhibitory activity on HIV‐1 reverse transcriptase and integrase of a carmalol derivative from a brown Alga, Ishige okamurae
Authors: Ahn M.‐J. , Yoon K.‐D. , Kim C. Y. , Kim J. H. , Shin C.‐G. , Kim J.
Published: June 2006

The bioassay‐directed isolation of a marine brown alga, Ishige okamurae, afforded a carmalol derivative, diphlorethohydroxycarmalol. This compound exhibited inhibitory effects on HIV‐1 reverse transcriptase and integrase with IC50 values of 9.1 µm and 25.2 µm, respectively. However, diphlorethohydroxycarmalol did not show an inhibitory activity against HIV‐1 protease. Moreover, diphlorethohydroxycarmalol nonaacetate obtained by acetylation and fucosterol failed to show any inhibitory activity against these viral enzymes. Copyright © 2006 John Wiley & Sons, Ltd.
Anticonvulsant effect of Persea americana Mill (Lauraceae) (Avocado) leaf aqueous extract in mice
Authors: Ojewole John A. O. , Amabeoku George J.
Published: June 2006

Various morphological parts of Persea americana Mill (Lauraceae) (avocado) are widely used in African traditional medicines for the treatment, management and/or control of a variety of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant effect of the plant's leaf aqueous extract (PAE, 50–800 mg/kg i.p.) against pentylenetetrazole (PTZ)‐, picrotoxin (PCT)‐ and bicuculline (BCL)‐induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, Persea americana leaf aqueous extract (PAE, 100–800 mg/kg i.p.) significantly (p < 0.05–0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)‐induced seizures. The plant's leaf extract (PAE, 100–800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)‐induced seizures, but only weakly antagonized bicuculline (BCL)‐induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that ‘avocado’ leaf aqueous extract (PAE) produces its anticonvulsant effect by enhancing GABAergic neurotransmission and/or action in the brain. The findings of this study indicate that Persea americana leaf aqueous extract possesses an anticonvulsant property, and thus lends pharmacological credence to the suggested ethnomedical uses of the plant in the management of childhood convulsions and epilepsy. Copyright © 2006 John Wiley & Sons, Ltd.
Quantitative Structure–Activity Relationship of the 4,5α‐Dihydrotestosterone Steroid Family
Authors: Alvarez‐Ginarte Yoanna María , Crespo‐Otero Rachel , Marrero‐Ponce Yovani , Montero Luis Alberto , Ruiz‐García José Alberto , Padrón‐García Alexander , Zaragoza Francisco Torrens
Published: June 2006

Predictive Quantitative Structure–Activity Relationship (QSAR) models of Anabolic/Androgenic (A/A) activities for the 4,5α‐dihydrotestosterone steroid family were obtained by means of multilinear regression using quantum and physicochemical Molecular Descriptors (MDs) as well as a genetic algorithm for the selection of the best subset of MDs. MDs included in our QSAR models allow the structural interpretation of the biological process, evidencing the main role of the shape of molecules, hydrophobicity, and electronic properties. Attempts were made to include lipophilicity (octanol–water partition coefficient) as well as electronic (lowest unoccupied molecular orbital properties and dipole moment) values of the whole molecules in the multivariate relations. It was found from the study that the calculated net charges by semiempirical methods of different atoms in the steroid nucleus [atoms 4 (ring A), 8 (bridgeheads of rings B and C), 11 (ring C) 13 (fusion points of rings C and D), and 16 (ring D)] contribute significantly to binding affinity. The found MDs can also be efficiently used in similarity studies based on cluster analysis. Our model for the A/A ratio (expressed by the weights of the levator ani muscle/ventral prostate in mice) predicts that 2α, 3α‐difluoro‐methylene‐17α‐methyl‐5α‐androstan‐17β‐ol (13) is the most potent anabolic steroid. By contrast, the 17α‐methyl‐2β, 17β‐dihydroxy‐5α‐androstane (16) is flagged as the least potent anabolic steroid. The approach described in this report is an alternative for the discovery and optimization of leading anabolic compounds among steroids and analogues. It also gives an important role to electron exchange terms of molecular interactions to this kind of steroid activity.
Ultra‐fast tandem mass spectrometry scanning combined with monolithic column liquid chromatography increases throughput in proteomic analysis
Authors: Batycka Mariola , Inglis Neil F. , Cook Ken , Adam Alex , Fraser‐Pitt Douglas , Smith David G. E. , Main Laura , Lubben Anneke , Kessler Benedikt M.
Published: June 2006

Liquid chromatography combined with electrospray ionization mass spectrometry (LC/ESI‐MS) has been used successfully for the characterization of biomolecules in proteomics in the last few years. This methodology relied largely on the use of reversed‐phase chromatography, in particular C18‐based resins, which are suitable for separation of peptides. Here we show that polymeric [polystyrene divinylbenzene] monolithic columns can be used to separate peptide mixtures faster and at a higher resolution. For 500 fmol bovine serum albumin, up to 68% sequence coverage and Mascot Mowse scores of >2000 were obtained using a 9 min gradient on a monolithic column coupled to an ion trap mass spectrometer with ultra‐fast MS/MS scan rates. In order to achieve similar results using C18 columns, it was necessary to extend gradient times to 30 min. In addition, we demonstrate the utility of this approach for the analysis of whole Escherichia coli cell lysates by one‐dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D‐SDS‐PAGE) in combination with LC/MS/MS using 4 min gradients on monolithic columns. Our results indicate higher throughput capabilities of monolithic columns (3‐fold gain in time or more) for conventional proteomics applications, such as protein identification and high sequence coverage usually required for detection of post‐translational modifications (PTMs). Further optimization of sensitivity and quality of sequence information is discussed, in particular when combined with mass spectrometers that have very fast MS‐MS/MS switching and scanning capabilities. Copyright © 2006 John Wiley & Sons, Ltd.
New surfaces for desorption electrospray ionization mass spectrometry: porous silicon and ultra‐thin layer chromatography plates
Authors: Kauppila Tiina J. , Talaty Nari , Salo Piia K. , Kotiaho Tapio , Kostiainen Risto , Cooks R. Graham
Published: June 2006

The performance of nanoporous silicon (pSi) and ultra‐thin layer chromatography (UTLC) plates as surfaces for desorption electrospray ionization (DESI) was compared with that of polymethyl methacrylate (PMMA) and polytetrafluoroethylene (PTFE), both popular surfaces in previous DESI studies. The limits of detection (LODs) and other analytical characteristics for six different test compounds were determined using all four surfaces. The LODs for the compounds were in the fmol–pmol (pg–ng) range. The LODs with the pSi surface were further improved for each of the compounds when heat was applied to the surface during sample application which gave LODs as low as or lower than those achieved with PMMA and PTFE. The UTLC plates were successfully used as a rapid means of chromatographic separation prior to DESI‐MS analysis. Another advantage achieved using the newer pSi and UTLC surfaces was increased speed of analysis, associated with drying of solution‐phase samples. This took place immediately at the UTLC surface and it could be achieved rapidly by gently heating the pSi surface. The presence of salts in the sample did not cause suppression of the analyte signal with any of the surfaces. Copyright © 2006 John Wiley & Sons, Ltd.
State modelling of self‐excited induction generator for wind power applications
Authors: Wamkeue R. , Songia L. , Lakehal M. , Viarouge P.
Published: June 2006

The increase in wind power production with self‐excited induction generators (SEIGs) has led to new kinds of protection and stability problems. Suitable state models of a wind plant with SEIGs must accurately simulate balanced and unbalanced transient phenomena for adequate calibration and control of protection devices. However, the SEIG models currently available are unable to simulate the neutral current following unbalanced faults for forecasting the SEIG insulation and protection needed against some network stresses. In addition, the saturation model commonly used is not flexible when deriving a state model. This article presents an effective electromechanical state model for transient analysis of a saturated SEIG for wind power applications. A neutral connection through impedance is included for exact modelling of a Park wye‐connected SEIG. Simple‐shunt and short‐shunt (series) configurations are explored. A comparative analysis of the effects of these two types of configuration on the steady state and transient performances of an SEIG is presented. Numerical and experimental data obtained with a 380V, 5·5kVA, 11·9A, 50Hz induction generator are presented to attest to the effectiveness of the proposed SEIG modelling framework. Among the results obtained, simulations show that the simple‐shunt configuration produces poor voltage regulation, possible voltage collapse and inherent protection against short‐circuit faults, while the short‐shunt connection provides better voltage variation but needs to be well protected against short‐circuit faults. Copyright © 2006 John Wiley & Sons, Ltd.