bluuebunny/crossref_metadata_2025 huggingface dataset:
Erratum: Application of the Foldy‐Lax multiple scattering method to the analysis of vias in ball grid arrays and interior layers of printed circuit boards
Authors: Ong C.‐J. , Tsang L.
Published: November 2007

Originally published Microwave Opt Technol Lett 49 (2007), 225–231. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 263, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23005
Temperature and strain sensor based on weak LPG and fiber ring down
Authors: Bo Liu , Jianhua Luo , Guiyun Kai
Published: November 2007

A fiber ring down with a weak long period grating (WLPG) for temperature and strain sensing is proposed and demonstrated. The sensing devices consist of two matched fiber Bragg gratings, a section of single mode fiber, a WLPG, a pulsed laser source, and a photodiode. The LPG incorporated in fiber ring cavity is used as sensing element, the induced resonance wavelength shift of which will cause an additional loss in the cavity. As a result, the amplitude of applied temperature variation or strain can be obtained by simply measuring the fiber ring down time. The proposed sensing system has advantages of easy configuration and rapid response. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 111–114, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23006
Analysis of waveguide slot antennas using MLFMA
Authors: Liu Xu , Liang Changhong , Zhao Xunwang
Published: November 2007

Slotted waveguide array is analyzed using the multilevel fast multipole algorithm (MLFMA) combined with the near‐field preconditioner applied to the metallic surfaces of the waveguide structure. The approach differs from existing methods that utilize asymptotic method, method of moments (MoM) with the magnetic field integral equation (MFIE), or hybrid methods of MoM and boundary element method (BEM). Since no ideal assumptions are made, the analysis and computation are considered to be theoretically and numerically rigorous. In addition, the low complexity of the MLFMA is especially favorable for fast calculation of the large‐scale waveguide arrays. The experimental results validate the algorithm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 65–68, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23015
Improved formulas for the resonant frequencies of dual frequency arrow shaped compact microstrip antenna
Authors: Akdagli Ali , Ozdemir Caner , Yamacli Serhan , Arcasoy C. Cengiz
Published: November 2007

In this article, simple expressions for calculating the resonant frequencies at TM10 and TM01 modes of dual frequency arrow‐shaped compact microstrip antennas are presented. These empirical expressions are derived with the use of differential evolution algorithm by using the simulation data reported in the literature. The resonant frequency results achieved in this study are compared with the simulation results and theoretical results of the design formulas proposed elsewhere. It is shown that our formulas provide more accurate results with respect to the theoretical analyses previously published in the literature. The new formulas also give a simpler way to calculate the resonant frequencies of arrow‐shaped compact patch antenna with dual frequency. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 62–65, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23020
High‐sensitivity pressure sensor using a polymer‐embedded FBG
Authors: Ahmad H. , Harun S. W. , Chong W. Y. , Zulkifli M. Z. , Thant M. M. M. , Yusof Z. , Poopalan P.
Published: November 2007

A new pressure sensor based on fiber Bragg gratings (FBG), is described with high‐pressure sensitivity. The sensor is configured by embedding the FBG in a polymer‐field aluminum casing with an opening on one side, which is exposed to pressure measurand. The measured pressure response is 0.06 nm/psi that is ∼2700 times higher than the pressure response measured with a bare FBG. The linearity of the designed sensor is also shown to be good at pressures below 50 psi. This sensor has numerous potential applications in the area of low‐pressure measurements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 60–61, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23021
Boro arrays–broadside antenna arrays with passive elements
Authors: Reljić Boro M.
Published: November 2007

A new class of broadside antenna arrays with passive elements—Boro arrays is reviewed. The array is other boundary case of passive arrays, while the first is Yagi‐Uda array which is an endfire array. Main area of the array applications is high efficiency, high gain, and planar antenna systems. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 184–188, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23023
Experimental implementation of B92 quantum key distribution protocol
Authors: Mendonça F. A. , de Brito D. B. , Silva J. B. R. , Thé G. A. P. , Ramos R. V.
Published: November 2007

Quantum key distribution is a technique that permits the secure distribution of a bit string that is used as key in cryptographic protocols. The security is guaranteed by suitable coding of the information in a quantum property and from the fact that a quantum cannot be both split and cloned. In this article, we give details and show the results of an experimental realization of the B92 quantum key distribution protocol in 1550‐nm telecom window. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 236–241, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23025
Analysis of optical fiber waveguides using the body of revolution version of the finite difference time domain method
Authors: Farahat Nader , Mittra Raj , Carrión José
Published: November 2007

In this paper we use the body of revolution (BOR) version of the finite difference time domain method to analyze axially‐symmetric dielectric waveguides including optical fibers. Because the BOR technique is two‐dimensional in nature, it is an efficient tool for analyzing the modes in optical fibers. In addition, the method is capable of dealing with individual modes propagating in the guide and this, in turn, facilitates the derivation of the dispersion diagrams for these modes without postprocessing. Dispersion diagrams of several modes of a dielectric guide, obtained by using the proposed technique show good agreement with the analytical results. Of course, the numerical technique is capable of handling dielectric guides with arbitrary radial profiles that are not readily amenable to analytical treatment. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 213–216, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23026
Dual‐frequency circularly polarized antenna
Authors: Beddeleem G. , Ribero J. M. , Kossiavas G. , Staraj R. , Fond E.
Published: November 2007

Spatial communication systems need antennas circularly polarized. In this article, we propose a new compact dual‐frequency circularly polarized antenna. The two circular polarizations obtained in each frequency band are on opposite sense. This antenna is a patch of dimensions 36 × 36 mm2, printed on duroid substrate. Left hand circular polarization and right hand circular polarization maximum gains are 6.46 dB at the low frequency and 7.14 dB at the high frequency. Theoretical total efficiency is about 91% in the two bands. Parametric study shows that each frequency band can be controlled separately and that circular polarization can be maintained in each band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 177–180, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23028
Compact structure of UHF band RFID tag antenna mountable on metallic objects
Authors: Lee Byungje , Yu Byunggil
Published: November 2007

A new type of a compact tag antenna, which can be effectively mounted on metallic objects, is proposed for UHF band RFID systems. The proposed antenna consists of a simple microstrip path and feed line, and it is fabricated on a very thin (1.6 mm) subtrate compared with previous works. The impedance of the proposed antenna can be easily adjusted to match the various impedance values of tag chips by simply changing the length of the feed line only. The antenna is analyzed by simulations by Ansoft HFSS software, and the measured results based on backscattering method are provided. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 232–234, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23031
Domain decomposition technique based on equivalent currents for moments method
Authors: Laviada Jaime , Pino Marcos R. , Las‐Heras Fernando
Published: November 2007

This article presents a technique based on domain decomposition applied to method of moments. Geometry is split in overlapped sections. Radiation due to other sections is considered as excitation to solve every section. This radiation is modeled by equivalent currents situated on surfaces at the beginning and end of every section. The aim of this method is to reduce the computational complexity of method of moments. Several examples with 2D corridors are shown and also some examples of converge failures. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 172–176, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23034
OBI reduction method using optical carrier suppression
Authors: Al‐Qdah M. T. , Abdul‐Rashid H. A. , Tayahi M. B. , Chuah H. T. , Abdullah M. K.
Published: November 2007

Optical Beat Interference (OBI) can adversely affect passive optical networks that employs Multiple Optical Carrier Subcarrier Multiplexing (MOC‐SCM). The authors propose an OBI reduction method employing carrier suppressed MOC‐SCM system. A mathematical model is developed and an experiment is carried out to analyze the performance of the proposed system. The experimental results are in agreement with the mathematical model, which demonstrate an improvement of 27.8 dB in the carrier‐to‐interference ratio. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 256–259, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23037
Dual‐wavelength injection seeded Q‐switched fiber ring laser
Authors: Dragic Peter D.
Published: November 2007

We present a dual longitudinal mode narrow linewidth, injection‐seeded, Q‐switched fiber ring laser. Deeply modulated pulses near 1.55 μm with a modulation frequency that can be tuned continuously from DC to a demonstrated 25 GHz have been achieved. High peak powers are attained through the use of a reduced‐stimulated Brillouin scattering single‐clad erbium doped fiber. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 202–204, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23040
Reconfigurable microstrip rectangular loop antennas using RF MEMS switches
Authors: Zhou Lei , Sharma Satish K. , Kassegne Samuel K.
Published: November 2007

In this article, a low‐actuation voltage DC contact RF MEMS switch is developed for a reconfigurable microstrip rectangular loop antenna implementation providing frequency tunability. Electromechanical design optimization, microfabrication through the PolyMUMPS commercial process, and RF simulation is presented. The application of such RF MEMS switches to frequency‐tunable reconfigurable microstrip loop antennas is subsequently investigated by electromagnetic full wave analysis simulation tool. The physical perimeter of the loop antenna is electronically varied by controlling the ON/OFF states of the MEMS switches. The resonance frequency of the microstrip loop antenna is shown to be reconfigurable linearly by 56% with the linear change of the physical perimeter while the radiation pattern is almost invariant. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 252–256, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23042
Design of a novel compact antenna for a bluetooth LTCC module
Authors: Seo Donghyun , Jeon Seunggil , Kang Namkee , Ryu Join , Choi Jae‐Hoon
Published: November 2007

A novel design concept for implementing an antenna on a compact LTCC module is proposed for a Bluetooth application. The integrated antenna consists of an LTCC module and a two‐layered radiating element, which occupies a volume of 5 mm × 6.3 mm × 0.8 mm. The antenna has a 7.5 dB return loss bandwidth of 100 MHz, from 2.39 to 2.49 GHz and has nearly omni‐directional radiation patterns with good antenna gain in spite of its small size. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 180–183, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23051
A compact wideband planar diversity antenna for mobile handsets
Authors: Liu Qingyuan , Du Zhengwei , Gong Ke , Feng Zhenghe
Published: November 2007

A novel compact wideband printed diversity antenna for mobile handsets is presented. The antenna comprises two back‐to‐back G‐shaped monopoles placed symmetrically with respect to a T‐shaped and dual inverted‐L‐shaped ground plane. The measured results show that the proposed diversity antenna operates in a very wide bandwidth of 420 MHz starting from 1890 to 2310 MHz covering the UMTS band (1920–2170 MHz) with acceptable isolation. The antenna can provide pattern diversity to combat multipath fading. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 87–91, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23052
Analysis of the failure mechanism for a stable organic photovoltaic during 10 000 h of testing
Authors: Krebs Frederik C. , Norrman Kion
Published: November 2007

The degradation and failure mechanisms of a stable photovoltaic device comprising a bilayer heterojunction formed between poly(3‐carboxythiophene‐2,5‐diyl‐co‐thiophene‐2,5‐diyl) (P3CT) and Buckminsterfullerene (C60) sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes were elucidated by the time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analysis in conjunction with isotopic labelling using 18O2 after a total testing time of 13 000 h. This experiment allowed us to understand the chemistry that takes place in three dimensions during degradation and failure of the device under accelerated testing conditions. The cell was subjected to continuous illumination with an incident light intensity of 1000 W m−2 (AM1·5) at 72 ± 2°C under a vacuum of <10−6 mBar. During the illumination period, IV‐curves were recorded at regular intervals and the short circuit current of the device was monitored every 10 s for 10 760 h. The total illumination time was 12 200 h. During this period of time, the device performance degraded and the device was finally left in the dark at 25°C in an atmosphere where the oxygen had been replaced with the isotope 18O2. After 800 h in this atmosphere in the dark, the final IV‐curves in the dark and under illumination were recorded. The main purpose of this work was the analysis using TOF‐SIMS imaging and depth profiling of the degraded cell. The combined analyses correspond to the three‐dimensional chemical imaging of the device showing specifically where the oxygen had reacted during exposure. Several general findings were made that are applicable to similar devices. It was found that the oxygen diffuses into the device through the Al electrode in between the Al grains and through microscopic holes in the Al electrode. Once inside the device the oxygen diffuses in the lateral and vertical plane until the counter electrode is reached. C60 was found to be susceptible to the incorporation of 18O but P3CT was not under the conditions in question. The other prominent degradation pathway was found to be the diffusion of electrode materials into the device. Both electrode materials diffuse through the entire device to the counter electrode. Copyright © 2007 John Wiley & Sons, Ltd.
Efficiency potential of organic bulk heterojunction solar cells
Authors: Minnaert Ben , Burgelman Marc
Published: November 2007

In order for organic bulk heterojunction solar cells to compete with the traditional inorganic cells, power conversion efficiencies of more than 10% are desirable. Nowadays, efficiencies up to 5% are reached and the question about the limits for the attainable efficiency of organic cells arises. In this paper, we study the efficiency potential of organic bulk heterojunction solar cells. We make realistic assumptions to predict efficiencies obtainable in the near future, and calculate the upper‐limit. We study the influence of the difference between the lowest unoccupied molecular orbital (LUMO)‐energy levels of donor and acceptor, and the absorption window on the efficiency. Ideal material characteristics are obtained from these calculations, giving an idea how the ideal organic solar cell should look like. The calculations show that nowadays an efficiency of 5·8% for the single junction bulk heterojunction solar cell should be possible. Considering parameters which are credible to be achieved in the future, an organic solar cell of 15·2% is in reach, with an optimal bandgap of 1·5 eV for the absorber. We also consider the situation where both the n‐ and p‐type materials are absorbers. All calculations are not only done for a single junction cell, but also for tandem solar cells. For a tandem structure of organic cells, we find in a realistic scenario a maximum attainable efficiency of 10·1% and an efficiency of 23·2% in an optimistic scenario with optimal bandgaps Eg1 = 1·7 eV and Eg2 = 1·1 eV. Copyright © 2007 John Wiley & Sons, Ltd.
Fill factor as a probe of current‐matching for GaInP2/GaAs tandem cells in a concentrator system during outdoor operation
Authors: McMahon W. E. , Emery K. E. , Friedman D. J. , Ottoson L. , Young M. S. , Ward J. S. , Kramer C. M. , Duda A. , Kurtz Sarah
Published: November 2007

Designing a tandem solar cell for use in a concentrator system is challenging because: (a) the conditions are variable, so solar cells rarely operate under optimal conditions, and (b) the conditions are not controlled, so any design problems are difficult to characterize. Here, we show how the fill factor can be used as a diagnostic tool to either verify correct system design and operation or to help identify a problem. We give particular attention to the detection of spectral skewing by the concentrator optics, as this can reduce the performance of GaInP2/GaAs tandem cells and is difficult to characterize. The conclusions are equally valid for GaInP2/GaAs/Ge triple‐junction cells. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of tandem solar cell efficiencies under AM1.5G spectrum using a rapid flux calculation method
Authors: Bremner S. P. , Levy M. Y. , Honsberg C. B.
Published: November 2007

We report the use of a rapid flux calculation method using incomplete Riemann zeta functions as a replacement for the Bose–Einstein integral in detailed balance calculations to study the efficiency of tandem solar cell stacks under the terrestrial AM1.5G spectrum and under maximum concentration. The maximum limiting efficiency for unconstrained and constrained tandem stacks of up to eight solar cells, under the AM1.5G spectrum and maximum concentration, are presented. The results found agree well with previously published results with one exception highlighting the precautions necessary when calculating for devices under the AM1.5G spectrum. The band gap sensitivities of two tandem solar cell stack arrangements of current interest were also assessed. In the case of a three solar cell tandem stack the results show a large design space and illustrate that the constrained case is more sensitive to band gap variations. Finally, the effect of a non‐optimum uppermost band gap in a series constrained five solar cell tandem stack was investigated. The results indicate that a significant re‐design is only required when the uppermost band gap is greater than the optimum value with a relatively small effect on the limiting efficiency. It is concluded that this rapid flux calculation method is a powerful tool for the analysis of tandem solar cells and is particularly useful for the design of devices where optimum band gaps may not be available. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental energy yield in 1·5 × and 2 × PV concentrators with conventional modules
Authors: García Miguel , Marroyo Luis , Lorenzo Eduardo , Pérez Miguel
Published: November 2007

Low concentration devices along with standard (one sun) modules represent an attractive option to reduce the cost per kilowatt‐hour in photovoltaic installations. This paper deals with the energy gains obtained over a year by two of such devices: a 2 × V‐trough concentrator and a 1·5 × single flat mirror structure. The experiment was mounted on a two‐axis tracking system located in Arguedas (northern Spain). Due to various optical and electrical phenomena, the energy gain is notably lower than the geometrical concentration. We have conducted a theoretical analysis of these phenomena and quantified the energy loss associated with each. Daily and monthly energy gains show an influence of daylight clearness index on energy output. In view of this effect, and taking into account a possible increase in degradation of the photovoltaic modules due to high working temperatures and hot‐spots, the viability of these concentration devices is far from being clear. Copyright © 2007 John Wiley & Sons, Ltd.
Vitellogenin cleavage products as indicators for toxic stress in zebra fish embryos: A proteomic approach
Authors: Gündel Ulrike , Benndorf Dirk , von Bergen Martin , Altenburger Rolf , Küster Eberhard
Published: November 2007

Vitellogenins (Vtgs) are the major yolk proteins in all oviparous animals. Systematic and regulated processing of these during embryogenesis is crucial for embryonic development. In the present study, toxicant‐induced disturbance of Vtg degradation processes during Danio rerio (DR) embryogenesis was analysed to establish a sensitive tool for monitoring toxic stress at the molecular level. A 2‐DE‐based proteomic approach for whole DR embryos was established to study Vtg cleavage products (lipovitellin (Lv) derivatives). Ethanol was chosen as a positive control for a toxicity related change in the proteome of whole zebra fish embryos. Protein extracts from embryos treated with two ethanol concentrations, 0.5 and 2% v/v, showing either no or very strong visible effects, like absent heartbeat and blood circulation, were examined. Significant changes in the Lv pattern were detected for both conditions. The results are interpreted as scope for the use of the high abundant Lv derivatives as sensitive stress indicators in zebra fish embryos reflecting the overall fitness of the intact organisms.
Spatio‐temporal changes in germination and radical elongation of barley seeds tracked by proteome analysis of dissected embryo, aleurone layer, and endosperm tissues
Authors: Bønsager Birgit C. , Finnie Christine , Roepstorff Peter , Svensson Birte
Published: November 2007

Germination of barley is accompanied by changes in water‐soluble seed proteins. 2‐DE was used to describe spatio‐temporal proteome differences in dissected seed tissues associated with germination and the subsequent radicle elongation. Protein identification by MS enabled assignment of proteins and functions to the seed embryo, aleurone, and endosperm. Abundance in 2‐DE patterns was monitored for 48 different proteins appearing in 79 gel spots at 8 time‐points up to 72 h post imbibition (PI). In embryo, a β‐type proteasome subunit and a heat shock protein 70 fragment were among the earliest proteins to appear (at 4 h PI). Other early changes were observed that affected spots containing desiccation stress‐associated late embryogenesis abundant and abscisic acid (ABA)‐induced proteins. From 12 h PI proteins characteristic for desiccation stress disappeared rapidly, as did a putative embryonic protein and an ABA‐induced protein, suggesting that these proteins are also involved in desiccation stress. Several redox‐related proteins differed in spatio‐temporal patterns at the end of germination and onset of radicle elongation. Notably, ascorbate peroxidase that was observed only in the embryo, increased in abundance at 36 h PI. The surprisingly early changes seen in the protein profiles already 4 h after imbibition indicate that germination is programmed during seed maturation.
Simulation of experimentally observed dilation phenomena during integral gas sorption in glassy polymers
Authors: Hölck Ole , Heuchel Matthias , Böhning Martin , Hofmann Dieter
Published: November 2007

A molecular modeling investigation of dilation effects induced by sorbed gas molecules in two glassy polymers is presented. As experimental reference, integral sorption of CO2 and CH4 was measured for polysulfone (PSU) and a polyimide (6FDA‐TrMPD, PI4) at 308 K and a pressure of 10 bar. Simultaneously, the gas induced swelling effect was measured with a dilatometer based on a capacitive distance sensor recorded. The experimental evidence of the (on the observed time scale and concentration levels) elastic nature of the gas induced dilation is supported by the dilation and contraction behavior observed in molecular dynamics (MD) simulations of respective detailed atomistic packing models. These models were constructed in accordance with gas concentration levels obtained from the experimental sorption results. Quantitative deviations between simulated and measured dilations are discussed as a consequence of an anelastic response of the polymer matrix which is too fast to be resolved in the experiments whose kinetics is dominated by diffusional processes. In the simulation, the initial insertion of penetrant molecules into equilibrated packing models “circumvents” the slow diffusional process of the experiment and allows a reasonable representation of the dilation process as well as a closer investigation. Our simulation approach reveals a different behavior for PSU and PI4 on the corresponding time scale. Most likely, the different chain mobility of the two polymers is responsible for the respective response to the inserted amount of gas molecules which is discussed in terms of the different chain mobilities of the two polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 59–71, 2008
Effect of diphenylsiloxane unit content on aggregation structure of poly(dimethylsiloxane‐co‐diphenylsiloxane)
Authors: Qu Liangliang , Huang Guangsu , Wang Qiang , Xie Zhijian
Published: November 2007

A series of poly(dimethylsiloxane‐co‐diphenylsiloxane)s with different molar content of diphenylsiloxane unit (from 0.91 to 9.07 mol %) were synthesized and characterized by use of 1H NMR, gel permeation chromatography (GPC), the differential scanning calorimetry (DSC) and wide angle X‐ray diffraction (WAXD). The presence of diphenylsiloxane unit results in a decrease in the “orderness” of the crystal phase and aggrandizement in degree of lattice distortion. By calculating the sequence length of dimethylsiloxane unit of the random copolymer, it can be concluded that the maximum average sequence length of dimethylsiloxane units required for the copolymer to be amorphous is 11, and increasing the dimethylsiloxane sequence length will favour crystallization. The reduction in sequence length of dimethylsiloxane unit leads to that the three‐dimensional crystal shape is destroyed and crystal shape transforms into two‐dimensional or one‐dimensional, and finally disappeared. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 72–79, 2008
The effects of Masai Barefoot Technology footwear on posture: an experimental designed study
Authors: New Paul , Pearce Julian
Published: November 2007

Introduction. This study was approved by the University of Southampton Ethics Committee. The aim of the study was to assess the anatomical changes to upright posture that occur in the sagittal plane as a result of wearing Masai Barefoot Technology (MBT) footwear during standing and walking. MBT claims that its innovative unstable shoes promote a more upright posture in which musculature is strengthened and joint wear reduced (Amann and Amann, 2004). This could be helpful in the management and prevention of conditions such as osteoarthritis and back pain. Method. Twelve students (six male and six female), aged between 18 and 40 years, at the University of Southampton participated in the study. Participants attended one session at a biomechanics laboratory. The kinematics of posture while wearing MBT shoes during standing and gait were examined, using a two‐dimensional motion analysis system, and compared to a control shoe. Statistical significance was tested by use of a paired t‐test and a Wilcoxon signed‐ranks test. Results. Students standing in MBT footwear demonstrated a statistically significant increase in plantar flexion at the ankle joint (p = 0.025; mean flexion 3.02°; 95% confidence interval [95% CI] −5.6 to −0.4). Walking in MBT shoes showed a decrease in trunk flexion (p = 0.007; mean flexion 1.44°; 95% CI −2.4 to −0.4) and a reduction in anterior tilt of the pelvis (p = 0.003; mean tilt 3.20°; 95% CI −5.06 to −1.35) at heel strike. At toe‐off a significant reduction in anterior pelvic tilt (p = 0.035; mean tilt 2.35°; 95% CI) was found in the MBT shoes. There was no significant difference found between the two shoe conditions at mid‐stance, pelvic tilt (p = 0.53; mean tilt 1.83 degrees) trunk flexion (p = 0.05; mean flexion 0.95 deg). Conclusion. MBT footwear changes certain characteristics of posture in quiet standing and walking. These findings could have positive implications for the management of conditions such as osteoarthritis and back pain; however, further research is needed. Copyright © 2007 John Wiley & Sons, Ltd.
Scapular taping in the therapeutic management of sub‐acromial impingement symptoms — exploration of a clinical theory
Authors: Sparkes Valerie , Smith Michael , Busse Monica
Published: November 2007

Introduction. Altered scapular rotator muscle activity has been implicated in symptomatic shoulder dysfunction of a sub‐acromial impingement (SI) nature (Michener et al., 2003). Scapular taping is a clinical intervention frequently applied in an attempt to change activity of the upper fibres of trapezius (UFT) and lower fibres of trapezius (LFT). The aim of the present study was to investigate the clinical theory that with scapular taping in situ, UFT activity would be inhibited, LFT facilitated, and accompanying symptomatic relief would occur. Ethical approval was granted by the School of Healthcare Studies Ethics Committee, Cardiff University and by the South East Wales Research Ethics Committee. Method. Twenty subjects who demonstrated SI symptoms on clinical testing were recruited. Surface electromyography (EMG) was used to measure change in the muscle activity of UFT and LFT under ‘no tape’ and ‘with tape’ conditions. The test movement used was repeated humeral elevation in the scapular plane and the intervention was a commonly used scapular taping technique (McConnell, 1999). Within‐muscle differences between conditions were analysed using the related t‐test. Subjective data were collected regarding symptom response to taping. Results. There was a highly statistically significant (p < 0.001) reduction in the EMG activity of the UFT but no statistically significant change in LFT activity (p = 0.132) with taping in situ. Forty‐five per cent of subjects reported an improvement in their symptoms and/or a feeling of beneficial support for their shoulder when the tape was in place. However, 40% reported there being no effect experienced and 15% stated that the tape felt restrictive. Conclusions. This study provides support for the clinical theory that, in subjects with SI symptoms, UFT activity is inhibited in the presence of scapular taping. However, the study findings do not provide evidence of LFT facilitation. Limited support is provided for the theory that symptomatic relief accompanies changes in scapular rotator activity. Copyright © 2007 John Wiley & Sons, Ltd.
Mitigating Hurricane storm surge perils at the DeLisle Plant
Authors: Harris Steven P. , Wilson Duane O.
Published: November 2007

Hurricane Katrina in 2005 caused significant damage to many refineries, chemical plants, and other industrial and harbor facilities along the Gulf Coast causing catastrophic levels of damage. DuPont's DeLisle Plant in Pass Christian, MS, was one of many facilities impacted by this event. DuPont has in place significant operational measures to respond to hurricane events, and post‐Katrina has taken measures to mitigate the effects of possible future recurrences through the construction of a higher storm levee. DuPont DeLisle Plant's fast track project to provide a significantly greater level of storm surge protection as well as analyses undertaken to define the extent of the storm surge hazard and design the physical levee improvements are described. © 2007 American Institute of Chemical Engineers Process Saf Prog 2008
Comparison of deep level spectra in p‐type and n‐type GaN grown by molecular beam epitaxy [phys. stat. sol. (b) 244, No. 6, 1867–1871 (2007)]
Authors: Armstrong A. , Corrion A. , Poblenz C. , Mishra U. K. , Speck J. S. , Ringel S. A.
Published: November 2007

The following author has to be added to the list of authors in phys. stat. sol. (b) 244, 1867 (2007): A. Corrion, Department of Materials and Electrical and Computer Engineering, University of California, Santa Barbara, USA. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles study of phase transition of tin and lead under high pressure
Authors: Cui Shouxin , Cai Lingcang , Feng Wenxia , Hu Haiquan , Wang Changzheng , Wang Yuanxu
Published: November 2007

The phase transitions of Sn and Pb under high pressure are investigated theoretically using the first‐principles pseudopotential method. The calculated results show that for Sn the sequence of phase transitions is α‐Sn → β‐Sn → bct → bcc under high pressure while hcp‐Sn is not observed up to 200 GPa, which is in good agreement with experiments. In addition, for Pb the calculated results indicate that Pb can un‐ dergo two phase transitions under high pressure: one is the phase transition from fcc to the hcp structure at a pressure of 16 GPa and the other is the phase transition from hcp to the bcc structure at a pressure of 109 GPa. Furthermore, all the transition pressure and volume changes during the phase transformation are consistent with the experimental values. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles study of electronic structures of CdMoO4 crystal containing F‐type color centers
Authors: Wang Xi'en , Liu Tingyu , Zhang Qiren , Zhang Haiyan , Yin Jigang , Song Min , Guo Xiaofeng
Published: November 2007

The electronic structures of the CdMoO4 crystal containing F‐type color centers are studied within the framework of the fully relativistic self‐consistent Dirac–Slater theory, using a numerically discrete variation (DV‐Xα) method. It is concluded from the calculated results that the F and F+ color centers have donor energy levels in the band gap and the optical transition energies are 1.761 eV and 1.941 eV, which correspond to the 706 nm and 640 nm red absorption bands, respectively. So the CdMoO4 crystal should exhibit a blue‐green color. It is predicted that the 650–750 nm absorption bands and the bluish green color originate from the F and F+ color centers in the CdMoO4 crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurement and analysis of vibration levels for truck transport in Spain as a function of payload, suspension and speed
Authors: Garcia‐Romeu‐Martinez Manuel‐Alfredo , Singh S. Paul , Cloquell‐Ballester Vicente‐Agustin
Published: November 2007

The vibration levels that occur during transportation in vehicles are complex and play a significant role in the level of damage experienced by products when shipped. In the past decade, technology has allowed packaging engineers to measure and analyse the vibration levels in commercial shipments. Recent studies have measured vibration in shipping environments on a global basis to allow packaging designers to develop packaging to meet worldwide distribution challenges. The purpose of this study was to measure and develop simulation methods for truck transport in Spain. The study quantifies vibration characteristics in trucks as a function of speed, payload and suspension type. The shipments were instrumented with vibration data recorders to measure the vibration levels and a global position system to measure the truck speed. The recorders were mounted at the rear and front location of the trailer. Two different trucks, one with leaf spring suspension and the other with air ride suspension were studied using two different load conditions. The road surface was asphalt. The data is presented in the form of power spectral density that can be used to program electrohydraulic vibration tables using ASTM, ISTA and ISO vibration test methods. Results showed that the air ride vibration levels were lower than that of leaf spring suspension trailers. Overall, the vibration intensity was lower for both types of truck as compared with the levels measured in North America, China, India and Southeast Asia. Copyright © 2007 John Wiley & Sons, Ltd.
Identification of diisobutyl phthalate (DIBP) suspected as possible contaminant in recycled cellulose for take‐away pizza boxes
Authors: Bononi Monica , Tateo Fernando
Published: November 2007

Italian law specifically requires the use of regenerated, rather than recycled, cellulose in the production of pizza boxes. We investigated the frequent failure to comply with this law: the identification and determination of phthalates, which have widespread use, contribute to the quality control of various food packaging materials.

Diisobutyl phthalate (DIBP) has similar structural and application properties to di‐n‐butyl‐phthlate (DBP), and it is used as a substitute for DBP.

We standardized an analytical method that allows the calculation of an ‘exposure index’ (EI) for DIBP in take‐away pizza boxes. The technique, which relies on Solid‐Phase Micro Extraction/Gas Chromatography/Mass Spectrometry (SPME/GC/MS), allows the definition of a large range of DIBP content in the headspace within various take‐away pizza boxes.

Data concerning pizza boxes purchased in 16 restaurants in 2006 were reported, and the ‘EIs’ were estimated to range between 6 and 72 µg. Copyright © 2007 John Wiley & Sons, Ltd.
High‐temperature ultra‐performance liquid chromatography coupled to hybrid quadrupole time‐of‐flight mass spectrometry applied to ibuprofen metabolites in human urine
Authors: Plumb Robert S. , Rainville Paul D. , Potts Warren B. , Castro‐Perez Jose M. , Johnson Kelly A. , Wilson Ian D.
Published: November 2007

The application of sub‐2 µm porous particle liquid chromatography (LC) operated at elevated temperatures, coupled with time‐of‐flight mass spectrometry (MS), to the separation and identification of metabolites of ibuprofen present in human urine following oral administrations is illustrated. The LC/MS system generated a high‐resolution analytical separation that, with an analysis time of 20 min, provided a peak capacity in the order of ca. 350. Using this system a total of nine glucuronides of the drug and its metabolites were detected, including a number of isomeric acyl glucuronides of ibuprofen itself, a side‐chain‐oxidized carboxylic acid acyl glucuronide and a number of acyl glucuronides of various hydroxylated metabolites. The identities of the metabolites were confirmed by their accurate mass values and the presence of the common fragment ions from ibuprofen. Copyright © 2007 John Wiley & Sons, Ltd.
Serum protein profiling in patients with inflammatory bowel diseases using selective solid‐phase bulk extraction, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry and chemometric data analysis
Authors: Nanni Paolo , Parisi Daniela , Roda Giulia , Casale Monica , Belluzzi Andrea , Roda Enrico , Mayer Lloyd , Roda Aldo
Published: November 2007

The identification of new biomarkers or a disease‐related protein fingerprint for inflammatory bowel diseases (IBDs) represents a major task in the diagnosis, prognosis and pharmacological therapy. To address these issues, a simple and rapid analytical proteomic method for serum protein profiling based on selective beads‐based solid‐phase bulk extraction, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) and chemometric data analysis was developed. Serum proteins from healthy subjects (22) and patients with Crohn's disease (15) and ulcerative colitis (26) were selectively extracted according to reversed‐phase (C18), strong anion‐exchange (SAX) and metal ion affinity (IDA‐Cu(II)) principles. This approach allowed enrichment of serum proteins/peptides due to the high interaction surface between analytes and the solid phase and high recovery due to the elution step performed directly on the MALDI‐target plate. The MALDI‐TOF MS serum protein profiles were acquired and, after a data pre‐processing step, analyzed by linear discriminant analysis (LDA), a chemometric classification technique, in order to classify serum samples among healthy subjects and patients with inflammatory bowel diseases (IBDs). Since the high number of variables in the MALDI spectra (more than 16000 m/z values) prevents the use of LDA, the variables were reduced to 10–20 by features selection, thus allowing the evaluation of a pattern of m/z values with high discriminant power. Serum protein profiles obtained by reversed‐phase extraction and the selection of 20 m/z values gave the best overall prediction ability (96.9%). The recognition of these m/z values may allow the identification of protein biomarkers involved in IBDs. Copyright © 2007 John Wiley & Sons, Ltd.
The structural performance of monolithic intersecting walls in a tall reinforced concrete building
Authors: Moghaddam H. , Samadi M.
Published: November 2007

Results of the seismic performance assessment of a new structural system that has been used in a 54‐story reinforced concrete building are presented. The structure, which is still under construction, and has a ‘Y‐shape’ form, utilizes a special structural system that does not include any beams or columns. Instead, walls and slabs are used for carrying both gravitational and lateral loads. The general distinctions of the system are discussed. The structural efficiency of the system is compared with other conventional systems in some existing tall buildings. The seismic responses and dynamic behavior of the structure that were achieved by conducting various analyses are presented. The effects of analysis method, as well as some other parameters such as modeling assumptions and bidirectional earthquake excitation on the linear responses, are studied. The influence of the number of modes and design spectrum on the spectral analysis results is discussed. Using dynamic analysis, the real heightwise distribution of lateral loads occurring during an earthquake is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Designing the ecoskyscraper: premises for tall building design
Authors: Yeang Ken , Powell Robert
Published: November 2007

Designing the ecoskyscraper involves configuring its built form and operational systems so that they integrate with nature in a benign and seamless way over its life cycle, by imitating the structure, processes and properties of ecosystems, an approach referred to here as ecomimesis. By biologically integrating compatibly all aspects and processes of our built environment with the natural environment, we enhance our human‐made ecosystems' abilities to sustain life in the biosphere. Part 1 discusses the theory and premises for the ecoskyscraper. Part 2 discusses exemplary projects from Ken Yeang's offices. Copyright © 2007 John Wiley & Sons, Ltd.
Frequency sharing hotspot communication under uplink multi‐carrier CDMA cellular system
Authors: Khoa Nguyen Tran , Fujii Takeo , Umebayashi Kenta , Kamiya Yukihiro , Suzuki Yasuo
Published: November 2007

In multi‐carrier CDMA cellular systems, hotspot communication can be established to support the high‐traffic areas by using the same frequency band of the original cellular systems. However, interference from the hotspots deteriorates the communication performance of the original cellular system. In this paper, in order to decrease the interference, we set up the access point (AP) of hotspots with the adaptive array antenna and code assignment method between the cellular and the hotspot communication is considered. In the proposed system, OFDM hotspot communication is overlapped to the uplink of MC/DS‐CDMA cellular system in the same frequency band and the beam‐forming method is applied to eliminate inter‐system interference. Moreover, by allocating orthogonal variable spreading factors (OVSF) code to the both hotspot users and cellular users in the hotspot uplink period, the orthogonality of each user is kept. As a result, we can embed many hotspots into the cellular system with very small interference toward the uplink communication of the cellular system and we can improve the throughput of total system. The performance of the proposed system is evaluated by computer simulation under additive white Gaussian noise (AWGN) and Rayleigh fading environment. Copyright © 2007 John Wiley & Sons, Ltd.
Intraductal Papillary Mucinous Neoplasms of the Pancreas: Clinicopathologic Characteristics and Long‐Term Follow‐Up After Resection
Authors: Nagai Kazuyuki , Doi Ryuichiro , Kida Atsushi , Kami Kazuhiro , Kawaguchi Yoshiya , Ito Tatsuo , Sakurai Takaki , Uemoto Shinji
Published: November 2007

Background

Resection is recommended for main duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas because of the high risk of malignancy, but the indications for resection of branch duct and mixed‐type IPMNs remain controversial. Our objective was to determine the appropriate management of IPMNs based on clinicopathologic characteristics and survival data obtained after resection.

Methods

A total of 72 consecutive IPMN patients who underwent resection between January 1984 and June 2006 were reviewed. The lesions were classified as main duct, branch duct, or mixed‐type IPMNs and histologically graded as noninvasive (adenoma, borderline neoplasm, carcinoma in situ) or invasive.

Results

Main duct IPMNs (n = 15) were associated with a significantly worse prognosis than other subtypes. For branch duct (n = 49) and mixed‐type IPMNs (n = 8), the diameter of the cystic lesions was an independent predictor of malignancy by multivariate analysis. However, four patients with cysts <30 mm in diameter and no mural nodules had a malignancy. No patient with noninvasive IPMN died of this disease, showing excellent survival, whereas the 5‐year survival rate of patients with invasive IPMNs was only 57.6% and was significantly worse than that of patients with noninvasive IPMNs (p = 0.0002).

Conclusions

Resection of all main duct IPMNs seems to be reasonable. Invasive IPMNs were associated with significantly worse survival than noninvasive IPMNs. Although the diameter of cystic lesions was a predictor of malignancy for branch duct and mixed‐type IPMNs, precise preoperative identification of malignancy was difficult. Therefore, these lesions should be managed by aggressive resection before invasion occurs to improve survival.