bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanometric crystal defects in transmission electron microscopy
Authors: Schäublin Robin 
Published: April 2006

AbstractTransmission electron microscopy (TEM) is revisited in order to define methods for the identification of nanometric defects. Nanometric crystal defects play an important role as they influence, generally in a detrimental way, physical properties. For instance, radiation‐induced damage in metals strongly degrades mechanical properties, rendering the material stronger but brittle. The difficulty in using TEM to identify the nature and size of such defects resides in their small size. TEM image simulations are deployed to explore limits and possible ways to improve on spatial resolution and contrast. The contrast of dislocation loops, cavities, and a stacking fault tetrahedra (SFT) are simulated in weak beam, interfering reflections (HRTEM), and scanned condensed electron probe (STEM) mode. Results indicate that STEM is a possible way to image small defects. In addition, a new objective aperture is proposed to improve resolution in diffraction contrast. It is investigated by simulations of the weak beam imaging of SFT and successfully applied in experimental observations. Microsc. Res. Tech. 69:305–316, 2006. © 2006 Wiley‐Liss, Inc.
Atomic scale defect analysis in the scanning transmission electron microscope
Authors: Arslan Ilke , Browning Nigel D. 
Published: April 2006

AbstractZ‐contrast imaging and electron energy loss spectroscopy in the scanning transmission electron microscope provide the ability to investigate the structure–composition–property relationship at individual defects on the atomic scale. In this article, the main principles behind the techniques will be described. The application of these methods to the analysis of individual dislocations in GaN will also be discussed. In this case, the atomic scale methods indicate that many of the structural and electronic properties of dislocations are modified by the presence of impurities, such as oxygen. Microsc. Res. Tech 69:330–342, 2006. Published 2006 Wiley‐Liss, Inc.
Design and analysis of fMRI studies with neurologically impaired patients
Authors: Price Cathy J. , Crinion Jenny , Friston Karl J. 
Published: April 2006

AbstractFunctional neuroimaging can be used to characterize two types of abnormality in patients with neurological deficits: abnormal functional segregation and abnormal functional integration. In this paper we consider the factors that influence the experimental design, analysis, and interpretation of such studies. With respect to experimental design, we emphasize that: 1) task selection is constrained to tasks the patient is able to perform correctly, and 2) the most sensitive designs entail presenting stimuli of the same type close together. In terms of data preprocessing, prior to statistical analysis, we note that structural pathology may call for constraints on nonlinear transformations, used by spatial normalization, to prevent distortion of intact tissue. This means that one may have to increase spatial smoothing to reduce the impact of inaccurate normalization. Important issues in statistical modeling concern the first level of analysis (estimation of activation within subject), which has to distinguish correct from incorrect responses. At the second level (between subjects), inference should be based on between‐subjects variance. Provided that these and other constraints are met, deficits in functional segregation are indicated when activation in one or a set of regions is higher or lower in patients relative to control subjects. In contrast, deficits in functional integration are implied when the influence of one brain region on another is stronger or weaker in patients relative to control subjects. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
What is Conservation Science?
Authors: Townsend Joyce H. 
Published: April 2006

Abstract‘Conservation science’ or ‘cultural heritage research’ is defined through a discussion of research needs, training and employment patterns world‐wide, and trends in published work. Parallels with mainstream polymer science are drawn throughout. Some aspects are discussed in more detail: traditional paint composites; studies in modern, synthetic, paint composites; the relevance of accelerated ageing to a range of polymer types.
State of Art in the SIMS (Secondary Ion Mass Spectrometry) Application to Archaeometry Studies
Authors: Anderle Mariano , Bersani Massimo , Vanzetti Lia , Pederzoli Simone 
Published: April 2006

AbstractOne of the main problems of cultural heritages in all the different forms (buildings, monuments, painting) is their deterioration caused by natural and artificial decay processes. To address the conservation issue specific studies are required to determine, for example, origin, date, materials composition, technology processes involved, etc. The use of microanalysis techniques, in particular secondary ion mass spectrometry (SIMS), in the cultural heritage area has been demonstrated extremely useful to approach and provide this kind of information and support the experts involved in studies within this area (art historians, archaeologists, curators etc.). In this work, an up to date overview of possible SIMS applications to archaeological topics is given, pointing out the peculiarity and the main limitations and drawbacks of this analytical approach. One example of SIMS application to archaeological glasses is reported. Moreover the wide technique flexibility and its strength in combination with other complementary techniques are remarked.
Degradation of PEG in the Warship Vasa
Authors: Glastrup Jens , Shashoua Yvonne , Egsgaard Helge , Mortensen Martin Nordvig 
Published: April 2006

AbstractThe distribution and ageing of polyethylene glycol (PEG) in the Vasa warship has been examined and compared with other archaeological shipwrecks which have also been impregnated with PEG. The distribution of the PEG has been characterised using a variety of mass spectrometric and FT‐IR techniques. Our results show that the PEG after 30 years is still in a reasonably good condition, with a molecular weight distribution that resembles fresh PEG. Only minor levels of degradation products were found. It seems that the PEG preserved wood contains an increased amount of formic acid and the results suggest that it originates from the PEG. Acetic acid is also present; this probably originates from the wood.
Nanotechnology for Vasa Wood De‐Acidification
Authors: Chelazzi David , Giorgi Rodorico , Baglioni Piero 
Published: April 2006

AbstractThe conservation of the seventeenth‐century Swedish warship Vasa is a challenge due the unique history of its recovery and the delicate interventions made for its preservation. In the past years the strong acidity of wood came out as a threat for its conservation. The large amount of sulfur, produced by metabolic action of bacteria in the seabed, partly converted to sulfuric acid, catalyzes the chemical degradation of the wood through the acid hydrolysis of cellulose. This contribution reviews recent studies on the degradation of Vasa wood. We show how wood acidity can be neutralized by the application of calcium or magnesium hydroxide nanoparticles, forming an alkaline reservoir inside the wood that protect it from further acid attack. This has been evidenced by the thermal analysis carried out on fresh wood, Vasa wood, artificially degraded wood, and paper samples studied as reference cellulose‐made materials. Pyrolysis temperature of cellulose was studied, as an important parameter of degradation, also related to the acidity of wood. Decreases in the pyrolysis temperature of degraded cellulose were correlated to decreases of its polymerization degree. Thermal analysis has been also used to investigate the wood de‐acidification efficacy after the treatment with alkaline nanoparticles. Hydro‐thermally aging, carried out on de‐acidified Vasa wood samples demonstrated that de‐acidification with nanoparticles facilitates protection of wood toward further acid degradation.
Innovative Plasma Processes for Consolidation of Biodeteriorated Ancient Papers
Authors: Vassallo E. , Laguardia L. , Ricci D. , Bonizzoni G. 
Published: April 2006

AbstractDeterioration of paper materials is mainly due to the degradation of cellulose caused by a lot of factors such as chemical attack due to acidic hydrolysis, oxidative agent, light, air pollution and biological attack due to presence of microorganisms like bacteria and fungi. Various technologies exist to limit the degradation of the paper materials but in a few cases are unsuited or produce no good results. Plasma technology is an innovative process which can be an alternative to the conventional methods. The plasma treatment produces a synergetic result of sterilization and coating of the paper. This technology is environmentally friendly and can be used for industrial applications. The aim of this project is the increasing of the paper tensile strength and paper conservation by means of several different plasma treatments.
Wave scattering with the UV multilevel partitioning method: Three‐dimensional problem of dielectric rough‐surface scattering
Authors: Li Zhong‐Xin 
Published: April 2006

AbstractA scalar wave 3D dielectric rough‐surface scattering problem solved by a UV method with multilevel partitioning (UV‐MLP) is developed in this paper. For a 3D dielectric rough‐surface scattering problem, the scattering structure is partitioned into a multilevel block. By looking up the rank in the static problem, the impedance matrix for a given transmitting and receiving block is expressed into a product of U and V matrices. The UV method is illustrated by applying a 3D scattering problem to a random dielectric rough surface in this paper. The coupled scalar integral equations for dielectric rough‐surface boundary conditions are treated. Numerical simulation results are illustrated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1313–1317, 2006;Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.21613
Design of the band‐rejected UWB antenna with the ring‐shaped parasitic patch
Authors: Kim Ki‐Hak , Park Seong‐Ook 
Published: April 2006

AbstractA novel UWB antenna with band‐elimination characteristic is presented. The proposed antenna is fed by microstrip line and consists of an inversed bell‐shape radiation patch, rounded ground, and a ring‐shaped parasitic patch. The proposed antenna utilizes a ring‐shape parasitic patch to reject the frequency band (5.15–5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2. In addition, the rejected frequency band can be varied by adjusting the length and location of the ring‐shape parasitic patch. By means of a normalized antenna transfer function, both the frequency‐domain and time‐domain characteristics of the antenna are carefully investigated. The fabricated antenna can achieve broad bandwidth covering 2.2 to 11.8 GHz with VSWR below 2. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:1310–1313, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21614
Spiral inductors fabricated on multi‐layered Bragg reflector for Si‐based RF IC applications
Authors: Mai Linh , Song Hae‐il , Minh Tuan Le , Van Su Pham , Yoon Giwan 
Published: April 2006

AbstractIn this paper, for the first time, a novel physical structure of planar spiral inductors fabricated on a multilayered Bragg reflector is proposed. The multilayered Bragg reflector (BR) was fabricated on Si substrate. The effects of the multilayered Bragg reflector and inductor patterns on the characteristics of inductors are studied. The results show that the inductors fabricated on the Bragg reflector result in a significant improvement in terms of the S11‐parameter. This approach seems highly feasible and promising for future Si‐based RF IC applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1296–1298, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21621
A Mach–Zehnder nonzero order joint transform correlator for aircraft pattern recognition
Authors: Lee Chungcheng , Chen Chulung 
Published: April 2006

AbstractA Mach–Zehnder device is utilized in a nonzero‐order joint‐transform correlator system for aircraft pattern recognition. The Stokes relations, which involve the amplitudes of reflected and transmitted parts of a plane wave incident on a plane‐refracting surface, are cleverly utilized. The proposed method can directly remove the large zero‐order term in one step. The correlator also shows the advantage of the ability to detect distortion invariance. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1290–1293, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21623
Electromagnetic scattering by arbitrary shaped inhomogeneous impedance cylinder using physical optics method
Authors: Tezel Necmi Serkan , Paker Selçuk 
Published: April 2006

AbstractThe electromagnetic scattering problem related to an arbitrarily shaped inhomogeneous impedance cylinder is investigated using the physical optics (PO) method. In the solution, induced electric and magnetic currents on the illuminated region of the impedance surface are expressed by means of the incident field and the inhomogeneous impedance boundary condition (IBC), then the scattered field is calculated using the Huygens‐type Green's formula. Obtained scattering width (SW) results are compared with those obtained by other analytical and numeric methods and good agreements are observed, especially for the monostatic case. Because of the fact that the PO method does not need matrix inversion, which requires high CPU time, the PO method also significantly reduces the computer calculation time according the other methods. In this study, the TM case is considered, but a similar procedure can be easily applied to TE case and also 3D inhomogeneous impedance objects. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1282–1286, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21625
A new optical gigabit Ethernet network element
Authors: Silva H. J. P. P. , Mosso M. M. , Lima R. A. A. , Guedes B. C. L. , Podcameni A. 
Published: April 2006

AbstractThe main purpose of this work is the generation of new intelligent functionalities at the optical network physical layer in Gigabit Ethernet interfaces and nodes. These new tools are achieved by the use of a field programmable gated array (FPGA) integrated circuit associated with microwave RF subcarriers. With such intelligence, a new IP/Ethernet network element is introduced and described, and special attention is dedicated to its structure, to its implementation and to the aspects of its use in networks. An experimental setup using the developed element is shown as a proof‐of‐concept, demonstrating the characteristics of the system and the transparency of the optical intelligence with respect to the Ethernet standard. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1330–1334, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21626
Studies on the dielectric behaviour of polypyrrole and its composites with poly (vinyl chloride)
Authors: John Honey , Thomas Rinku M. , Jacob Joe , Joseph Rani , Mathew K. T. 
Published: April 2006

AbstractPolypyrrole/poly (vinyl chloride) semi‐interpenetrating networks of different compositions are prepared using ammonium per sulfate initiator at room temperature in pellet form and film form and their dielectric properties are studied at different microwave frequencies. An HP 8510 Vector network analyzer interfaced with a computer is used. The cavity‐perturbation technique is employed for the study. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1324–1326, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21628
Optimum use of high‐impedance surface in PCB to mitigate the simultaneous switching noise and radiated emission
Authors: Peña‐Rivero R. , Jardón Aguilar H. , Linares y Miranda R. 
Published: April 2006

AbstractOptimum use of high‐impedance surfaces (HIS) in high‐speed printed circuit boards (PCBs) of two layers to mitigate the simultaneous switching noise (SSN) and radiated emission is presented. The optimum condition is obtained with two rows of square pads between which is the power supply bus, creating a rejection over the bandwidth frequency of interest. The effective method in two‐layer PCBs with two rows (3‐mm each) of square pads is implemented with a 0.5‐mm separation between the power‐supply bus, in the 8–12‐GHz frequency range, obtaining 20‐dB rejection and 15‐dB less radiated emission. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1446–1449, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21632
A two‐pole 900/1800‐MHz microstrip filter for dual‐band applications
Authors: Guan Xuehui , Ma Zhewang , Cai Peng , Anada Tetsuo , Hagiwara Gen 
Published: April 2006

AbstractA two‐pole 900/1800‐MHz dual‐band bandpass filter using microstrip open‐loop resonators is proposed. Dual‐band characteristics are obtained by using the fundamental and first spurious resonance of the resonators. Both the internal and external couplings of the filter are appropriately designed to simultaneously satisfy the dual‐band requirements. The measured filtering characteristics of the designed filter agree well with the simulated responses. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1388–1391, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21639
Analysis and selection of optimum driving current combinations for tunable wavelength laser
Authors: Lee Yang‐Han , Yang Chun‐Liang , Chuang Ming‐Hsueh , Tseng Hsien‐Wei , Chou Yung‐Shan , Tsao Hen‐Wai , Lee San‐Liang 
Published: April 2006

AbstractIn a distributed Bragg reflector (DBR) laser, driving currents in the tri‐electrode are adjusted to generate various channels in the ITU‐Band. Many driving‐current combinations can generate the same ITU channel. But when we take system performance into consideration, such as the chirping and the switching time when we switch DBR lasers between ITU channels, certain current combinations will generate better system performance than the others. In this paper, we develop the principle of how to select current combinations in order to obtain better system performance and also discuss the method of how to evaluate the system performance when different current combinations are selected. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1417–1423, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21643
A method to simultaneously extract the small‐signal equivalent circuit and noise parameters of heterojunction bipolar transistors
Authors: Maya Ma. Carmen , Lázaro Antonio , Pradell Lluís 
Published: April 2006

AbstractA method to extract the elements of the small‐signal equivalent circuit and the noise parameters (NPs) of heterojunction bipolar transistors (HBTs) is presented. The extraction is done by simultaneous fitting of the measured S‐parameters, noise figure (for a well‐matched impedance), and NPs (estimated using the so‐called F50 method). An additional error term, given by the root square sum of the differences between the NPs estimated from the F50 method and the NPs directly computed using the Hawkins model, is considered in order to avoid nonphysical results in the extraction of the intrinsic noise sources. To obtain the initial values of the equivalent‐circuit elements, analytical expressions are applied under a number of bias conditions, namely, reverse bias, forward bias, and active bias. Experimental verification of the extraction of the equivalent‐circuit elements and NPs of an HBT, up to 8 GHz, are presented, and the NPs are compared to those measured with an independent (tuner‐based) method. The behavior of Fmin, extracted using the proposed method, as a function of the HBT collector current, is also presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1372–1379, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21649
Wideband antenna for mobile terminals based on the handset PCB resonance
Authors: Antonino‐Daviu E. , Suarez‐Fajardo C. A. , Cabedo‐Fabrés M. , Ferrando‐Bataller M. 
Published: April 2006

AbstractThe resonant behavior of a handset printed circuit board (PCB) is analyzed by means of the Theory of Characteristic Modes (TCM). The information obtained is utilized to design a wideband antenna suitable for mobile terminals. To feed this resonant structure, a planar square plate is used. This antenna exhibits an excellent wideband performance and omnidirectional radiation patterns. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1408–1411, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21654
Line‐of‐Sight MIMO indoor measurements at 2.4 GHz
Authors: Ibernón‐Fernández Rubén , Molina‐García‐Pardo José‐María , Juan‐Llácer Leandro 
Published: April 2006

AbstractThe short‐range line‐of‐sight (LoS) multiple‐input multiple‐output (MIMO) channel transfer function is measured for a 4 × 4 system between 2.35 and 2.55 GHz for different antenna spacing and orientations in an indoor scenario. Capacity and correlation are investigated, and a mean capacity loss of 4 b/s/Hz is measured when the receiver is rotated 90°. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1403–1405, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21656
Electromagnetically‐coupled patch antenna for phased array applications for mobile satellite communications
Authors: Wang Qingyuan 
Published: April 2006

AbstractAn economical electronically‐scanned patch antenna array with quasi‐hemispheric coverage is under design in our laboratory for Inmarsat satellite communications. This paper reports the CAD simulation and test results of a simple‐structured, electromagnetically‐coupled patch antenna with circular polarization, for such array applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1279–1282, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21676
A triangular plate element for thermo‐elastic analysis of sandwich panels with a functionally graded core
Authors: Das M. , Barut A. , Madenci E. , Ambur D. R. 
Published: April 2006

AbstractA sandwich construction is commonly composed of a single soft isotropic core with relatively stiff orthotropic face sheets. The stiffness of the core may be functionally graded through the thickness in order to reduce the interfacial shear stresses. In analysing sandwich panels with a functionally gradient core, the three‐dimensional conventional finite elements or elements based on the layerwise (zig‐zag) theory can be used. Although these elements accurately model a sandwich panel, they are computationally costly when the core is modelled as composed of several layers due to its grading material properties. An alternative to these elements is an element based on a single‐layer plate theory in which the weighted‐average field variablescapture the panel deformation in the thickness direction. This study presents a new triangular finite element based on {3,2}‐order single‐layer theory for modelling thick sandwich panels with or without a functionally graded core subjected to thermo‐mechanical loading. A hybrid energy functional is employed in the derivation of the element because of a C1 interelement continuity requirement. The variations of temperature and distributed loading acting on the top and bottom surfaces are non‐uniform. The temperature also varies arbitrarily through the thickness. Copyright © 2006 John Wiley & Sons, Ltd.