bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the concentration scaling law of the scattering coefficient of water solutions of Intralipid at 832 nm by comparison between collimated detection measurements and Monte Carlo simulations
Authors: Autiero Maddalena , Liuzzi Raffaele , Riccio Patrizia , Roberti Giuseppe 
Published: May 2005

AbstractBackground and ObjectivesIntralipid (IP) is a scatterer extensively used in the building of phantoms for Biomedical Optics measurements. Recently, deviations from the linearity have been shown for the concentration scaling law of the scattering coefficient of IP water solutions at visible wavelengths. In this work this scaling law was determined at 832 nm.Study Design/Materials and MethodsSpace resolved transmittance measurements of a laser beam at 832 nm through water solutions of IP and ink were performed and compared with the corresponding results of Monte Carlo simulations.ResultsThe comparison provides a quadratic dependence of μ on the volume‐to‐volume scatterer concentration, CIP, in the range of CIP values (0.0024<CIP<0.0075). These deviations from the linear behavior are related to the failure of the independent scatterer approximation.ConclusionThe quadratic dependence of on CIP is in agreement with recent results obtained by other groups with different experimental techniques and is validated by a recent theoretical work. © 2005 Wiley‐Liss, Inc.
Infusion of SiC Nanoparticles Into SC‐15 Epoxy: An Investigation of Thermal and Mechanical Response
Authors: Rodgers Reneé M. , Mahfuz Hassan , Rangari Vijaya K. , Chisholm Nathaniel , Jeelani Shaik 
Published: May 2005

AbstractSummary: In the present investigation we have developed a novel technique to synthesize nanocomposite materials consisting of SC‐15 epoxy resin and silicon carbide (β‐SiC) nanoparticles. A high intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and β‐SiC nanoparticles. In this study, we have prepared three different samples containing 0.5, 1, and 1.5% of β‐SiC nanoparticles by weight of the epoxy resin. In parallel, control samples were also made following identical procedures without the infusion of nanoparticles. Test samples were characterized by TGA, DSC and three‐point bend flexural tests to evaluate thermal and mechanical properties. The results indicate that 1 wt.‐% loading derives the maximum improvement in both thermal and mechanical properties when compared to the neat system. The dispersion of nanoparticles and morphological changes were studied by field emission scanning electron microscopy (FE‐SEM) and high resolution transmission electron microscopy (TEM). These results demonstrate that the nanoparticles are spherical in shape (≈30 nm sizes) and are uniformly dispersed over the entire volume of the resin.FE‐SEM micrograph of the plasma etched 1 wt.‐% SiC‐epoxy system.magnified imageFE‐SEM micrograph of the plasma etched 1 wt.‐% SiC‐epoxy system.
Extrusion Monitoring of Polymer Melts Using a High‐Temperature Surface‐NMR Probe
Authors: Gottwald Antje , Scheler Ulrich 
Published: May 2005

AbstractSummary: Extrusion is one of the major ways of polymer processing, and extrusion monitoring is important to control or improve the extrusion process and the product quality. Especially methods for in‐line monitoring are desired because those enable the fastest possible response and a localization of chemical reactions in reactive processing. Methods of optical and acoustic spectroscopy have successfully been implemented so far. NMR provides a wealth of information. Surface NMR mostly gives access to molecular mobility via relaxation times. These can be correlated to temperature, composition and homogeneity which are substantial indicators for the product quality. NMR is a non‐destructive method, which does not require direct contact with the sample and it is not restricted to optical transparent materials and is therefore suitable for extrusion monitoring. The problem for the adaptation is the hostile environment in and in front of an extruder for polymer melts. Here, a NMR surface probe is presented sustaining this environment in front of an extruder. First measurements with this device are shown.High‐temperature surface‐NMR probe.magnified imageHigh‐temperature surface‐NMR probe.
Preparation of Pyrolytic Carbon Black from Scrap Tire Rubber Crumb and Evaluation in New Rubber Compounds
Authors: Cataldo Franco 
Published: May 2005

AbstractSummary: Pyrolytic carbon black (CBp) has been prepared by rubber crumb pyrolysis under nitrogen flow at 700 °C. The CBp obtained by this process had an average surface area of 81 m2 · g−1 and was obtained in 43% yield over the starting rubber crumb. Although the CBp surface area can be increased up to 109 m2 · g−1 by washing away the Zn‐ and Si‐based ashes with HF treatment, the CBp was tested in a standard NR/SBR‐based formulation without any purification and ash extraction. CBp was tested at increasing loading levels as partial or full replacement of a standard N339 furnace carbon black. CBp depresses the physical properties of the rubber compound in a way which is directly proportional to the amount added. The reason of this result and the limited reinforcing effect is discussed in terms of low surface area and low structure in comparison to N339 carbon black as well as in terms of low surface activity, the interference of the ashes and the poor dispersion. Ideas of further development works are outlined.
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External Stimuli‐Responsive Characteristics of Ionic Poly[(N,N‐diethylaminoethyl methacrylate)‐co‐(N‐vinyl‐2‐pyrrolidone)] Hydrogels
Authors: Çaykara Tuncer , Ayçiçek İbrahim 
Published: May 2005

AbstractSummary: Polyelectrolyte hydrogels containing diprotic acid moieties sensitive to ionic strength changes of the swelling medium were synthesized from N,N‐diethylaminoethyl methacrylate (DEAEMA), N‐vinyl‐2‐pyrrolidone (VP) and itaconic acid (IA) by using ammonium persulfate (APS) as a free radical initiator in the presence of the cross‐linker, methylenebisacrylamide (MBAAm). The swelling behavior of the ionic poly[(N,N‐diethylaminoethyl methacrylate)‐co‐(N‐vinyl‐2‐pyrrolidone)] [P(DEAEMA/VP)] hydrogels were investigated in pure water; in NaCI solutions with pH 4 and 9; and in water‐acetone mixtures depending on the IA content in the hydrogel. The average molecular mass between cross‐links ($\overline M _{\rm c}$) and polymer‐solvent interaction parameter (χ) of the hydrogels were determined from equilibrium swelling values. The pulsatile swelling behavior was also observed in response to solvent changes between the solution in water and in acetone. The equilibrium swelling ratio of these hydrogels was basically unaffected with change in temperature. The swelling variations were explained according to the swelling theory based on the hydrogel chemical structure.Pulsatile swelling behavior of ionic P(DEAEMA/VP) hydrogels in response to solvent changes between water and acetone at 25 °C.magnified imagePulsatile swelling behavior of ionic P(DEAEMA/VP) hydrogels in response to solvent changes between water and acetone at 25 °C.
The Influence of Cooling Rate on the Specific Volume of Isotactic Poly(propylene) at Elevated Pressures
Authors: Van der Beek Maurice H. E. , Peters Gerrit W. M. , Meijer Han E. H. 
Published: May 2005

AbstractSummary: We used a custom designed dilatometer to measure quantitatively the time evolution of the specific volume of (semi‐crystalline) polymers for an unusual combined wide range of cooling rates and elevated pressures, covering processing conditions. For an isotactic poly(propylene), applying the Schneider rate equations for quiescent crystallization, experimental results are compared to numerical predictions. Average cooling rates imposed during crystallization of the material vary from 0.1 to 35 °C · s−1 while pressures range from 20 to 60 MPa. The results show the well‐known profound influence of pressure and cooling rate on the specific volume. An increasing cooling rate shifts the crystallization temperature Tc towards lower temperatures, increases the final specific volume, and the transition due to crystallization is more gradual and widespread. For the highest cooling rate applied, the shift in Tc is as much as 30 °C, while the final specific volume increases up to 1.4%. Increasing pressure has an opposite effect on the shift in Tc, while the final specific volume, after pressure release, also increases. Finally, a comparison of numerical predictions with experimental data shows that the crystallization temperature Tc is consistently predicted too low, and that the predictions at high cooling rate are sensitive to (small) variations in model parameters.Influence of cooling rate on the specific volume of iPP.magnified imageInfluence of cooling rate on the specific volume of iPP.
Artificial Neural Networks Associated to Calorimetric Measurements Used as a Method to Predict Polymer Composition of High Solid Content Emulsion Copolymerizations
Authors: Giordani Domingos Sávio , Lona Liliane M. F. , McKenna Timothy F. , Krähenbühl Maria A. , dos Santos Amilton Martins 
Published: May 2005

AbstractSummary: Inspired by biological systems, artificial neural networks (ANN) have demonstrated to be powerful tools to model non‐linear systems, such as high solid content latexes produced by emulsion polymerization which have a great importance in the polymeric industry, essentially for environmental reasons, since they usually have water as a continuous phase. The quality of the produced polymer is closely related to the structure of the polymeric chain. In order to propose technical and economically feasible alternatives to control a polymeric structure, this work is aimed to develop a new methodology based on ANN associated with calorimetry to predict the polymeric structure. The designed ANN presented excellent results when tested with process condition variations (such as temperature and reaction time) as well as when they were submitted to test concerning the variation on the proportion of monomers in the latex formulation. Hence, it was possible to conclude that ANN, associated to calorimetry, lead to an efficient method to predict the polymer composition in emulsion copolymerizations.
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A dual‐port dual‐frequency coaxial dual‐helical antenna with high decoupling
Authors: Zürcher J.‐F. 
Published: May 2005

AbstractIn order to obtain a circularly polarized and compact directive antenna for harmonic direction finding (HDF) of small animals using radio‐frequency identification (RFID), a dual‐port, dual‐frequency coaxial dual‐helical antenna is developed. The two frequencies are harmonics (2.45 and 4.9 GHz in our case). The antenna is realized using two coaxial, contradirective helices. Two different principles of realization are tested. The measured decoupling between ports is between 22 and 28 dB for the best antenna. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 1–4, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20883
A novel compact and wideband shorted patch antenna
Authors: Lee Chi‐Hun , Choi Dong‐Hyuk , Park Seong‐Ook 
Published: May 2005

AbstractA novel compact shorted patch antenna with the bowtie‐type patch and the dual triangle portion to obtain a large bandwidth (790–970 MHz) is presented in this paper. Using shorted patches with via holes, a size reduction of 95.7% is achieved, as compared to that of the conventional half‐wave patch antenna. Moreover, it has 10‐dB return‐loss bandwidth of 20.4% for the GSM and CDMA bands. This proposed antenna exhibits not only a compact and a thin profile, but also wideband characteristics. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 4–6, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20884
A new approach for the linearization of a distributed amplifier
Authors: Paul D. K. , Parkinson G. 
Published: May 2005

AbstractThis paper describes the application of the feedforward linearization technique to a distributed amplifier. The circuit architecture of the distributed amplifier is used in a new way to simplify the feedforward system's configuration. A distributed amplifier using a pseudomorphic HEMT with feedforward linearization based on the new concept is simulated to evaluate the performance and demonstrate the feasibility of achieving broadband linearity. The experimental results for an MIC implementation are also presented as proof of the concept. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 15–17, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20887
A novel low‐pass filter using defected ground structures
Authors: Guan Xue‐Hui , Li Guo‐Hui , Ma Zhewang 
Published: May 2005

AbstractIn this paper, an equivalent‐circuit model of a defected ground structure (DGS) is applied to explain the characteristics of the DGS. The parameters of the circuit model are extracted from the EM‐simulation results. A novel three‐pole lowpass filter is proposed and optimized by using the defected ground structures. It is demonstrated that the filter can provide a sharp rate of attenuation in the stop‐band, as predicted. To further verify this method, the filter with DGS is fabricated on a 30 × 30 mm2 substrate. A comparison between the simulation and the measurement confirms the effectiveness of the proposed schemes. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 17–20, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20888
Assessment of an alternative six‐port circuit for broadband complex voltage‐ratio measurements
Authors: Casares‐Miranda F. P. , Otero Pablo , Márquez‐Segura E. , Camacho‐Peñalosa C. 
Published: May 2005

AbstractThe assessment of an alternative six‐port circuit in terms of frequency behavior when used to measure complex voltage ratio is presented. A numerical comparison to commonly used and well‐known six‐port circuits is carried out. The presented results can help us to choose between different six‐port configurations depending on the application, and show that the proposed circuit is the most suitable in general. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 24–27, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20890
An RHCP/LHCP switchable slotline‐fed slot‐ring antenna
Authors: Ho Min‐Hua , Wu Ming‐Ting , Hsu Chung‐I G. , Sze Jia‐Yi 
Published: May 2005

AbstractIn this paper, two irises are orthogonally connected to a slot‐ring antenna via short‐length slits with each of the slits loaded by a pin diode. This antenna can be switched back and forth between right‐hand and left‐hand circular polarization by turning on/off the pin diodes. The slot ring is excited by a slotline. The conformability of the slotline with an SMA is accomplished by inserting a CPW‐to‐slotline transition between them. An experimental antenna is built on a low‐cost FR4 substrate in order to validate the design. The antenna's uniplanar architecture and its polarization‐diversity property will be very useful in wireless‐communication systems. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 30–33, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20892
Compact coplanar waveguide band‐pass filter at the S‐band
Authors: Bonache J. , Martín F. , Falcone F. , García‐García J. , Gil I. , Lopetegi T. , Laso M. A. G. , Marqués R. , Medina F. , Sorolla M. 
Published: May 2005

AbstractIn this paper, it is demonstrated that split‐ring resonators (SRRs) magnetically coupled to a coplanar waveguide (CPW) structure can be applied to the design of miniaturized band‐pass filters. To this end, a two‐stage prototype device consisting of a CPW with two signal‐to‐ground shorts and a series gap, combined with SRRs, is designed and fabricated. By virtue of the subwavelength operation of SRRs at their quasi‐static resonance, the filter dimensions can be made to be very small in comparison to conventional distributed implementations. Other relevant features of the proposed structures are: (i) low insertion losses (<3.5 dB) in the allowed band, (ii) out‐of‐band rejection levels above 30 dB, and (iii) very sharp transition slopes. It is believed that these SRR‐based structures can be of interest for the design of planar filters with potential application in future communication transceivers. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 33–35, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20893
Wideband 2D array of microstrip fed rectangular‐slot antennas for radar applications
Authors: Eldek Abdelnasser A. , Elsherbeni Atef Z. , Smith Charles E. 
Published: May 2005

AbstractThis paper presents the design of a wideband 16 × 4 element array of a microstrip‐proximity‐fed rectangular‐slot antenna for marine radar systems operating in the X‐band. A wideband corporate‐feed network is designed to feed the proposed array. The new design has a small size, a wide bandwidth of 52%, and good radiation characteristics in the entire operating band. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 36–40, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20894
Optically tunable multiturn spiral inductor for RF applications
Authors: Bheema Rao N. , Chandorkar A. N. 
Published: May 2005

AbstractThe tunability of an inductor using an additional conductor segments with optical switching is presented. When the additional conductor is in the horizontal plane of the spiral inductor, a two‐turn spiral‐inductor tunability of 30% can be obtained. The tunability is reduced when the number of turns of the spiral is increased. The tunability can be further improved over the horizontal position by choosing an additional conductor segment structure above the spiral inductor (that is, in the vertical plane). The tunability of the inductor can be improved by 54% as compared to the horizontal tuning for a high number of turns of the spiral inductor (N = 6). This analysis was carried out using the TSMC 0.18‐μm 1P6M process. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 40–43, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20895
Microstrip bandpass filter using series‐connected triangular patches
Authors: Chen Jian‐Xin , Xue Quan 
Published: May 2005

AbstractA novel microstrip bandpass filter using series‐connected triangular patches is proposed. Centered at 1.34 GHz, the insertion loss of the second resonant mode is about 18‐dB below that of the first mode. A demonstration filter is designed, fabricated, and tested. The theoretical and experimental results are presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 46–48, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20897
Frequency‐dependent guided‐wave characteristics of periodically series‐capacitive loaded coplanar waveguides
Authors: Zhu Lei , Shi Huamin 
Published: May 2005

AbstractPeriodically series‐capacitive loaded transmission line on coplanar waveguide (CPW) is studied in this work as a planar 1D guided‐wave medium. The two effective per‐unit‐length transmission parameters, that is, propagation constant and characteristic impedance, are numerically extracted to demonstrate the guided‐wave characteristics in a frequency range covering the first stopband, first passband, and second stopband. To further provide a proof, the six‐cell periodic CPW with impedance transformers at two sides are designed and fabricated. The predicted S‐parameters are well confirmed by the measured ones. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 54–58, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20899
T‐shaped monopole antenna with shorted L‐shaped strip‐sleeves for WLAN 2.4/5.8‐GHz operation
Authors: Wu Jeun‐Wen , Wang Yau‐Der , Hsiao Hai‐Ming , Lu Jui‐Han 
Published: May 2005

AbstractA novel dual‐broadband T‐shaped monopole antenna with dual shorted L‐shaped strip‐sleeves for 2.4/5.8‐GHz wireless local area networks (WLANs) is proposed. Dual L‐shaped strip‐sleeves to be shorted with the ground plane are introduced in order to excite the upper resonant mode for operation at the 5.8‐GHz band. The obtained impedance bandwidths reach about 35% for the 2.4‐GHz band and 10.0% for the 5.8‐GHz band, which meets the required bandwidth specifications of the IEEE 802.11a/b/g standards. The measured peak antenna gains for the operating frequencies across dual WLAN bands are measured to be 3.4 and 1.0 dBi, respectively, with gain variations within 0.8 dBi. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 65–69, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20903
A miniaturized high‐Q duplexer with attenuation poles using novel microstrip stacked open‐loop resonators
Authors: Jang Suk‐Hyung , Lee Jong‐Chul 
Published: May 2005

AbstractIn this paper, novel microstrip open‐loop resonator (OLR) bandpass filters are presented. By introducing additional spiral inductors as well as gap‐coupled capacitors, the bandpass filters (BPFs) exhibit another attenuation pole at the upper stopband. Also, a novel miniaturized high‐Q duplexer for Universal Mobile Telecommunications System (UMTS) bands using these BPFs is discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 69–72, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20904
A new free‐space method for measurement of electromagnetic parameters of biaxial materials at microwave frequencies
Authors: Yin Hong‐Cheng , Chao Zeng‐Ming , Xu Yan‐Ping 
Published: May 2005

AbstractA free‐space method for the measurement of biaxial material is proposed in this paper. Four complex transverse constitutive parameters are directly computed from the reflection and transmission coefficients of a planar sample in free space for the normally incident plane wave with two polarizations. However, because of the extreme insensibility of the reflection and transmission coefficients versus the longitudinal constitutive parameters for thin planar biaxial materials, the correct reconstruction of longitudinal parameters cannot be accomplished by the free‐space method. Considering that the principal coordinate system (PCS) to characterize biaxial material possibly does not coincide with the measurement coordinate system (MCS), an approach to determine PCS is also presented to ensure practicability of this method. A measurement system has been set up to perform measurements of transverse parameters of biaxial material and the validity of this method is experimentally verified. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 72–78, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20905
Complementary split‐ring resonator for compact waveguide filter design
Authors: Ortiz N. , Baena J. D. , Beruete M. , Falcone F. , Laso M. A. G. , Lopetegi T. , Marqués R. , Martín F. , García‐García J. , Sorolla M. 
Published: May 2005

AbstractIn this paper, the potential use of complementary split‐ring resonators (CSRRs) to design very compact waveguide filters, by etching a CSRR in the center of a metallic sheet, is demonstrated. This original layout reduces the dimensions of the well‐known resonant‐cavity waveguide filters coupled by irises. This has been made feasible due to the self‐resonance property of the CSRR. Thus, it is possible to design waveguide filters with lengths equal to the thickness of a metallic sheet. Consequently, this technique paves the way for the design of miniaturized waveguide filters, in contrast to conventional waveguide filters, based on bulk resonators. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 88–92, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20909