bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling of isotropic double negative media for microwave applications
Authors: Vendik I. , Vendik O. , Kolmakov I. , Odit M. 
Published: September 2006

AbstractA composite medium consisting of two sublattices of dielectric spherical particles of high permittivity and different radii embedded in a dielectric matrix of smaller permittivity are considered. It has been shown that such a composite medium reveals properties of an isotropic double negative media (DNG) in a limited frequency range, when resonance oscillations of HIII mode in one kind of particles and EIII mode in another kind of particles are excited simultaneously. The EIII resonance and the HIII resonance give rise to the magnetic dipole momentum and the electric dipole momentum correspondingly. Averaging the magnetic momentum and the electric momentum over the cells belonging to the appropriate spherical particles gives the negative permittivity and permeability. The model of diffraction of a plane electromagnetic wave on a dielectric sphere is presented and compared with the mixing rule based consideration. The results obtained are rather close. Distribution of the electromagnetic wave outside the sphere is calculated. Influence of the dispersion of the sphere size and the dielectric permittivity on the effective parameters of the DNG material is estimated.
A review of size and geometrical factors influencing resonant frequencies in metamaterials
Authors: Johnson N. , Khokhar A. , Chong H. , Rue R. , Antosiewicz T. , McMeekin S. 
Published: September 2006

AbstractAlthough metamaterials and so-called left-handed media have originated from theoretical considerations, it is only by their practical fabrication and the measurement of their properties that they have gained credibility and can fulfil the potential of their predicted properties. In this review we consider some of the more generally applicable fabrication methods and changes in geometry as they have progressed, exhibiting resonant frequencies ranging from radio waves to the visible optical region.
Identifying magnetic response of split-ring resonators at microwave frequencies
Authors: Aydin K. , Ozbay E. 
Published: September 2006

AbstractIn this study we provide experimental methods to identify the magnetic resonance of split ring resonantors (SRR) at the microwave frequency regime. Transmission measurements were performed on both single SRR unit cell and periodic arrays of SRRs. The magnetic response of the SRR structure was demonstrated by comparing the transmission spectra of SRRs with closed ring resonators (CRR). Effects of the changes in the effective dielectric constant of the SRR medium on the band-gaps of SRR are investigated experimentally. SRRs not only exhibit a magnetic resonance band gap but also a band gap due to the electric resonance. Finally, we present the effect of electric coupling to the magnetic resonance of bianisotropic SRRs by utilizing SRRs with different orientations, and incident electromagnetic wave polarizations.
Photonic band structure of oxidized macroporous silicon
Authors: Glushko A. , Karachevtseva L. 
Published: September 2006

AbstractWe investigated theoretically the effect of surface silicon oxide layer on the photonic band structure of a macroporous silicon photonic crystal. Using the plain wave method we have shown that the bandgap in oxidized structure is shifted to the higher frequencies relative to non-oxidized case. We also demonstrate that comparatively wide absolute bandgap can be obtained for low air filling fractions by using thick SiO2 layer. As an example of possible application of such three-component systems, we have shown the concept of a selector of electromagnetic modes based on our calculations.
Optical bistability of planar metal/dielectric nonlinear nanostructures
Authors: Noskov R. , Zharov A. 
Published: September 2006

AbstractWe study theoretically a nonlinear response of the planar metal/dielectric nanostructures constituted from periodical array of ultra thin silver layers and the layers of Kerr-like nonlinear dielectric. We predict hysteresis-type dependences of the components of the tensor of effective dielectric permittivity on the field intensity allowing the change in material transmission properties from transparent to opaque and back at extremely low intensities of the light. It makes possible to control the light by light in all-optical nanoscale devices and circuits.
Optical guided dispersions and subwavelength transmissions in dispersive plasmonic circular holes
Authors: Kim K. , Cho Y. , Tae H. , Lee J. 
Published: September 2006

AbstractThe light transmission through a dispersive plasmonic circular hole is numerically investigated with an emphasis on its subwavelength guidance. For a better understanding of the effect of the hole diameter on the guided dispersion characteristics, the guided modes, including both the surface plasmon polariton mode and the circular waveguide mode, are studied for several hole diameters, especially when the metal cladding has a plasmonic frequency dependency. A brief comparison is also made with the guided dispersion characteristics of a dispersive plasmonic gap [K.Y. Kim, et al., Opt. Express 14, 320–330 (2006)], which is a planar version of the present structure, and a circular waveguide with perfect electric conductor cladding. Finally, the modal behaviour of the first three TM-like principal modes with varied hole diameters is examined for the same operating mode.
Electromagnetic modelling of 3D periodic structure containing magnetized or polarized ellipsoids
Authors: Koledintseva M. 
Published: September 2006

AbstractCoupling matrix and coupling coefficient concepts are applied to the interaction of an incident plane wave with a regular array of small magnetized or polarized ellipsoids, placed in a homogeneous surrounding medium. In general case, the angle of incidence and polarization of the plane wave upon an array of ellipsoids can be arbitrary. In this model, it is assumed that all the ellipsoids are the same, and the direction of their magnetization is also the same. The direction of magnetization is arbitrary with respect to the direction of the propagation of the incident wave and to the boundary plane between the first medium, where the incident wave comes from, and the array material under study. Any magnetized or polarized ellipsoid is represented as a system of three orthogonal elementary magnetic radiators (EMR) and/or three orthogonal elementary electric radiators (EER). Mutual interactions of individual radiators in the array through the incident plane wave and corresponding scattered electromagnetic fields are taken into account. The electrodynamic characteristics — reflection from the surface of the semi-infinite array (in particular, containing uniaxial hexagonal ferrite resonators), transmission through the array, and absorption are analyzed.
Experimental Techniques for the Investigation of the Elasto‐Plastic Transition Zone of Foamed Materials
Authors: Öchsner A. , Fiedler T. , Grácio J. , Kuhn G. 
Published: September 2006

AbstractThe classical assumption in solid materials, i.e. that the plastic behaviour is incompressible, does no longer hold in the case of cellular materials. The plastic behaviour is pressure‐sensitive due to the cellular structure even when the pure base material is independent of the hydrostatic pressure in the plastic range. Therefore, the yield criterion needs to incorporate the hydrostatic pressure. In many cases, the yield criterion can be simplified to an additive form where an arbitrary scalar function weights the influence of the hydrostatic stress. The yield stress can be obtained from uniaxial tests but the determination of the weighting function for the hydrostatic stress requires the realisation of multi‐axial stress states. This work presents two experimental procedures, i.e. an experiment under plane strain conditions and the axial compression, for the determination of the parameters of the yield criterion in the elasto‐plastic transition zone. Furthermore, both experiments aim to determine a second elastic constant if for example Young's modulus is known from uniaxial compression tests. The proposed procedures are numerically applied to a material obeying the Deshpande‐Fleck yield criterion.[1,2]
Density‐Graded Cellular Aluminum
Authors: Brothers A. H. , Dunand D. C. 
Published: September 2006

AbstractOpen‐cell metallic foams with controlled, continuous density gradients were created from polyurethane foam precursors using an investment casting method. This method, designed to improve mass‐efficiency in load‐bearing metallic foams and facilitate bonding of foams to dense materials in higher‐order structures, is described in detail, and demonstrated through pure aluminum foams with model relative density gradients. Methods for structural characterization, including non‐destructive local density mapping, are also illustrated.
Replication Processing of Highly Porous Materials
Authors: Conde Y. , Despois J.‐F. , Goodall R. , Marmottant A. , Salvo L. , San Marchi C. , Mortensen A. 
Published: September 2006

AbstractThere exist several methods for the production of highly porous materials; among these, replication processing is well‐adapted for open‐pore microcellular structures. The process begins by making a porous preform, open pores of which are filled with the foam material. Thereafter the preform is removed, generally by shaking or by dissolution, leaving an interconnected porous network within the foam material. We give here a general description of the process and its variants. We then give a brief overview of its fundamentals, placing particular focus on pathways it offers for microstructural tailoring and control.
The Structure of Random Foam
Authors: Kraynik A. M. 
Published: September 2006

AbstractSurface Evolver models of soap froth with a wide range of cell‐size distributions are used to investigate random cellular morphology. Geometric properties of foams and foam cells are analyzed. A simple, accurate theory relates the total suface area of foam to the cell‐size distribution. The total surface area is approximately equal to the total edge length when both quantities are scaled by average cell volume. Voronoi structures are significantly different from foams, which raises questions over their use for predicting structure‐property relationships.
Cover Picture: The Structure of Random Foam (Adv. Eng. Mater. 9/2006)
Authors: Kraynik A. M. 
Published: September 2006

AbstractThe cover picture shows some results of simulated metal foam structures. To learn more about the structure of random foams, read the article by Andrew M. Kraynik on page 900.Surface Evolver models of soap froth with a wide range of cell‐size distributions are used to investigate random cellular morphology. Geometric properties of foams and foam cells are analyzed. A simple, accurate theory relates the total suface area of foam to the cell‐size distribution. The total surface area is approximately equal to the total edge length when both quantities are scaled by average cell volume. Voronoi structures are significantly different from foams, which raises questions over their use for predicting structure‐property relationships.
Asymmetric oxidation of sulfides catalyzed by chiral (salen)Mn(III) complexes with a pyrrolidine backbone
Authors: Gao Aiping , Wang Mei , Shi Jicheng , Wang Dongping , Tian Wei , Sun Licheng 
Published: September 2006

AbstractCatalytic properties of a series of chiral (pyrrolidine salen)Mn(III) complexes for asymmetric oxidation of aryl methyl sulfides were evaluated. Moderate activity, good chemical selectivity and low enantioselectivity were attained with iodosylbenzene as a terminal oxidant. Enantioselectivity of sulfide oxidation was affected slightly by polar solvent and the sulfoxidation carried out in THF for thioanisole and in CH3CO2Et for electron‐deficient sulfides gave better enatioselctivities. The addition of the donor ligand PPNO (4‐phenylpyridine N‐oxide) or MNO (trimethylamine N‐oxide) only has a minor positive effect on the enantioselectivity. Also explored was the steric effect of the Naza‐substituent in the backbone of (pyrrolidine salen)Mn(III) complexes on the enantioselectivity of sulfide oxidation. The sulfides' access pathway is discussed based on the catalytic results. Copyright © 2006 John Wiley & Sons, Ltd.
Work roles, tasks, and the information behavior of dentists
Authors: Landry Carol Fay 
Published: September 2006

AbstractThe purpose of this study was to determine the effects work roles (patient management/service provider, administrator/manager, researcher, educator, and student) and their associated tasks have on the choice of information sources used to meet private practice dentists' information needs. Additionally, the study investigated how the Internet has affected the information seeking of dentists. Using Leckie, Pettigrew, and Sylvain's (1996) model of the information seeking of professionals as the conceptual framework, vignette‐based, in‐depth interviews were conducted with 12 dentists in the metropolitan areas of Seattle, Tacoma, and Everett, Washington. Follow‐up interviews were used to investigate dentists' use of the Internet. Findings revealed that the type of work role‐related task significantly shapes dentists' choices of information sources; the Internet emerged as a significant information source because it provides up‐to‐date information in a convenient and timely manner; the Internet is a complement to traditional information sources, not a replacement for them; and the Leckie and associates (1996) general model of professional information seeking is supported by this study.
Role of blood flow on RF exposure induced skin temperature elevations in rabbit ears
Authors: Jia Fu , Ushiyama Akira , Masuda Hiroshi , Lawlor George F. , Ohkubo Chiyoji 
Published: September 2006

AbstractIn this in vivo study, we measured local temperature changes in rabbit pinnae, which were evoked by radiofrequency (RF) exposure for 20 min at localized SAR levels of 0 (sham exposure), 2.3, 10.0, and 34.3 W/kg over 1.0 g rabbit ear tissue. The effects of RF exposures on skin temperature were measured under normal blood flow and without blood flow in the ear. The results showed: (1) physiological blood flow clearly modified RF induced thermal elevation in the pinna as blood flow significantly suppressed temperature increases even at 34.3 W/kg; (2) under normal blood flow conditions, exposures at 2.3 and 10.0 W/kg, approximating existing safety limits for the general public (2 W/kg) and occupational exposure (10 W/kg), did not induce significant temperature rises in the rabbit ear. However, 2.3 W/kg induced local skin temperature elevation under no blood flow conditions. Our results demonstrate that the physiological effects of blood flow should be considered when extrapolating modeling data to living animals, and particular caution is needed when interpreting the results of modeling studies that do not include blood flow. Bioelectromagnetics 28:163–172, 2007. © 2006 Wiley‐Liss, Inc.
Challenging computer‐based projects for a Mechatronics course: Teaching and learning through projects employing virtual instrumentation
Authors: See Alex 
Published: September 2006

AbstractFor the Mechatronics program in the School of Engineering, at Monash University, one of the approaches to Mechatronics education is mainly through a project‐based course. In this pedagogical approach, the synergistic combination of traditional lecture‐type of teaching and projects were presented to students. This approach is believed to be useful in the providing for hands‐on engineering experience for Mechatronics undergraduate students (MechUGs). This paper describes a second‐year Mechatronics undergraduate project‐based course. This paper deals with and reports on the successfully utilization of virtual instrumentation for Mechatronics projects and engaging the students to learn intuitively. This paper summarizes four different projects based on commercial National Instruments (NIs) LabVIEW software and various hardware, which were successfully implemented. Four groups of second‐year MechUGs were enrolled for a project‐based course for one semester period. The four projects involved the utilization of a variety of hardwares. A common software, LabVIEW was used for all the four projects. These projects involved data acquisition, signal processing, motion control, low‐cost machine vision, and digital I/O (Input/Output) control on NI‐ELVIS (Educational Laboratory Virtual Instrumentation Suite) workstation. This approach has prolifically enabled intuitive learning and hands‐on experience gained by these MechUGs. They were able to successfully complete their Mechatronics projects within a short span of 13 weeks. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 222–242, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20083
Academic pathways and increased opportunities for underserved students: Crosscutting themes and lessons learned
Authors: Barnett Elisabeth A. , Bragg Debra D. 
Published: September 2006

AbstractDrawing on previous chapters in the volume, this chapter identifies crosscutting themes and lessons for those engaged in the development and study of academic pathways. Particular attention is paid to the ways that pathways can increase opportunities for traditionally underserved students.
Enantioselective Palladium‐Catalyzed Total Synthesis of Vitamin E by Employing a Domino Wacker–Heck Reaction
Authors: Tietze Lutz F. , Stecker Florian , Zinngrebe Julia , Sommer Konrad M. 
Published: September 2006

AbstractAn enantioselective total synthesis of vitamin E in which a novel palladium‐catalyzed domino reaction was employed as the key step is described. This reaction allows the formation of the chiral chroman framework and the concurrent introduction of part of the side chain of vitamin E. The sequence comprises an enantioselective Wacker cyclization and a subsequent Heck reaction. Accordingly, reaction of alkenylphenol 12 with methyl vinyl ketone (13) in the presence of catalytic amounts of Pd(OTFA)2 (TFA = trifluoroacetate), the enantiopure ligand (S,S)‐Bn‐BOXAX (8 b; Bn = benzyl, BOXAX = 2,2′‐bis(oxazolyl)‐1,1′‐binaphthyl, and p‐benzoquinone (9) as an oxidant gives access to chiral chroman 10 with an enantioselectivity of 97 % ee in 84 % yield. Chroman 10 is then converted into 24 by an aldol condensation reaction with (3R)‐3,7‐dimethyloctanal (11). Subsequent 1,2‐addition of methyllithium, elimination of water, and hydrogenation yields vitamin E.
Changes in surgical management resulting from case review at a breast cancer multidisciplinary tumor board
Authors: Newman Erika A. , Guest Amy B. , Helvie Mark A. , Roubidoux Marilyn A , Chang Alfred E. , Kleer Celina G. , Diehl Kathleen M. , Cimmino Vincent M. , Pierce Lori , Hayes Daniel , Newman Lisa A. , Sabel Michael S. 
Published: September 2006

AbstractBACKGROUNDThe treatment of breast cancer requires a multidisciplinary approach, and patients are often referred to a multidisciplinary cancer clinic. The purpose of the current study was to evaluate the impact of this approach on the surgical management of breast cancer.METHODSThe medical records of 149 consecutive patients referred to a multidisciplinary breast cancer clinic over a 1‐year period with a diagnosis of breast cancer were reviewed retrospectively for alterations in radiologic, pathologic, surgical, and medical interpretations and the effect that these alterations had on recommendations for surgical management.RESULTSA review of the imaging studies resulted in changes in interpretations in 67 of the 149 patients studied (45%). This resulted in a change in surgical management in 11% of patients. Review of the pathology resulted in changes in the interpretation for 43 of the 149 patients (29%). Thirteen patients (9%) had surgical management changes made solely as a result of pathologic reinterpretation. In 51 patients (34%), a change in surgical management was recommended after discussion with the surgeons, medical oncologists, and radiation oncologists that was not based on reinterpretation of the radiologic or pathologic findings. Overall, a second evaluation of patients referred to a multidisciplinary tumor board led to changes in the recommendations for surgical management in 77 of 149 of those patients studied (52%).CONCLUSIONSThe changes in management stemmed from differences in mammographic interpretation, pathologic interpretation, and evaluation by medical and radiation oncologists and surgical breast specialists. Multidisciplinary review can provide patients with useful additional information when making difficult treatment decisions. Cancer 2006. © 2006 American Cancer Society.
A Novel Copper(I) Halide Framework Templated by Organic–Inorganic Hybrid Polyoxometalate Chains Formed In Situ: A New Route for the Design and Synthesis of Porous Frameworks
Authors: Jin Hua , Qi Yanfei , Wang Enbo , Li Yangguang , Qin Chao , Wang Xinlong , Chang Song 
Published: September 2006

AbstractA 1D organic–inorganic hybrid polyoxometalate chain has been used as a non‐coordinating anionic template for the construction of a novel 3D copper halide 4,4′‐bipy framework, namely [Cu3ICl(4,4′‐bipy)4][CuII(1,10‐phen)2Mo8O26]. X‐ray diffraction experiments revealed that the title compound consists of chloride‐bridged trinuclear CuI units linked by neutral organic 4,4′‐bipy groups into a 3D framework with hexagon‐like channels in which 1D organic–inorganic hybrid polyoxometalate chains reside. This is the first example of a 1D organic–inorganic hybrid polyoxometalate chain functioning as a novel anionic template for the construction of a 3D framework. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
The influence of articulation, self‐monitoring ability, and sensitivity to others on creativity
Authors: De Vet Arne J. , De Dreu Carsten K. W. 
Published: September 2006

AbstractAlthough it is often recommended to think aloud to solve problems and to become more creative, cognitive and social psychological research suggests thinking aloud may actually produce less creative ideas than thinking in silence. The results of two experiments indeed showed that thinking aloud hinders creativity—although people produced the same amount of new uses for an object, these were judged to be less original in the thinking aloud condition. Experiment 2 further showed that this effect was particularly pronounced for individuals with high sensitivity to what other's think of them and low ability to adapt to these expectations. From this, we conclude that the felt presence of an actual or implied audience when thinking aloud, reduces creative idea generation especially among those having difficulty adapting to others. Implications for creativity research, and for promoting creativity in applied settings such as organizational teams are discussed. Copyright © 2006 John Wiley & Sons, Ltd.