bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Pendry's superlens with computational image reconstruction
Authors: Neice Andrew 
Published: September 2009

AbstractA comparison of two methods of subwavelength imaging is undertaken. Pendry's superlens is compared with a computational image reconstruction technique. In both cases, limitations of materials impose limits on resolution. Both systems have similar limits, suggesting that resolution restrictions on Pendry's superlens apply generally to various forms of subwavelength imaging. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2913–2914, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24791
Design of a dual‐mode annular ring antenna with a coupling feed
Authors: Kim Jae Hee , Woo Dae Woong , Park Wee Sang 
Published: September 2009

AbstractA dual‐mode annular ring antenna for both global positioning system (GPS) and satellite digital multimedia broadcasting (S‐DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on an annular ring patch. A gap between the feed line and the annular ring patch is used for an input impedance matching; the slots are used for adjusting the resonant frequency of the TM21 mode at the DMB frequency. The antenna was fabricated and measured. The antenna resonates at the GPS and DMB frequencies with suitable bandwidths. It has a broadside radiation pattern in the GPS band and a conical beam radiation pattern in the DMB band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 3011–3013, 2009; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24796
Novel terahertz wave modulator based on modulated laser
Authors: Jiusheng Li 
Published: September 2009

AbstractA sample realizable method for terahertz wave modulation is demonstrated experimentally by using optical controllable ultra‐high resistivity silicon wafer. With modulated 100 mw of 808 nm CW light, a maximum of 21 dB terahertz attenuation was achieved with 0.2 kb/s of modulation speed. The experimental results show good agreement with the Drude‐Lorentz model. Further work is underway to improve the modulation speed above Mb/s. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2825–2826, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24798
A compact multiband antenna based on CRLH‐TL ZOR for wireless mobile system
Authors: Ji Jeong Keun , Kim Gi Ho , Seong Won Mo 
Published: September 2009

AbstractA compact multiband antenna using a composite right/left‐handed transmission line (CRLH‐TL) zeroth‐order resonator (ZOR) for global system for mobile communications (GSM900/1800/1900, 880‐960/1710‐1880/1850‐1990 MHz), wideband code division multiple access (WCDMA, 1920–2170 MHz), and wireless broadband (WiBro, 2.3–2.4 GHz) operations is presented. The proposed antenna having a total volume of 35 mm × 5 mm × 3 mm comprises a lower band ZOR antenna part and an upper band ZOR antenna part. The zeroth‐order resonant properties are described and analyzed using dispersion diagrams based on the CRLH‐TL ZOR theory and the full‐wave simulation. The radiation patterns are the same as the omnidirectional characteristics and the maximum gains are 1.64, 2.47, and 3.32 dBi at 0.92, 1.88, and 2.2 GHz, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2852–2855, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24799
The methods of RF phase locked loops for active mode‐locking picosecond laser with different repetition rates
Authors: Zhou Yan , Gu Claire 
Published: September 2009

AbstractThe novel methods of RF phase locked loops for picosecond laser system with four repetition rate 402.5 MHz, 1.792 GHz, 10 GHz, and 40 GHz have been presented in this article. Double loop integration parameter adjustment has been used to provide suitable feedback optical‐RF signal controlling. Four kinds of RF phase locked loops ways for different repetition rates' picosecond laser system have been introduced with complete configuration and analysis. To different microwave frequency range, different PLL method has been adopted to fit the demand of reducing phase noise and jitters while to get better pulse output feature. Data are obtained from experiments to make measurement of the pulse output performance and phase noise. Agreement of the theoretical and experimental results confirms the applicability of these phase locked loops design methods and theoretical analysis given in this article. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2886–2892, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24803
A new coplanar waveguide bandpass filter using interdigital DGS
Authors: Lee Jae‐Kwan , Kim Young‐Sik 
Published: September 2009

AbstractIn this letter, a new bandpass filter (BPF) with coplanar waveguide using interdigital capacitor and interdigital defected ground structure is proposed. The proposed BPF size is reduced about 33% compared to the BPF using a conventional DGS one. Both filters have lower and higher cutoff frequency at about 1.4 and 2.4 GHz. The measured results are well agreed with the simulation ones. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2915–2917, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24804
Miniaturized microstrip bandpass filter using coupled SCRLH zeroth‐order resonators
Authors: Gong Jian‐Qiang , Chu Qing‐Xin 
Published: September 2009

AbstractA novel miniaturized microstrip bandpass filter (BPF) has been proposed by using coupled simplified composite right/left‐handed (SCRLH) zeroth‐order resonators (ZORs). The SCRLH ZOR consists of microstrip high/low‐impedance short‐line elements, grounded stub, and transmission line sections. Being one of the artificial metamaterials, the SCRLH ZOR resonates when the phase constant equals to zero. Compared with the conventional half‐wavelength resonator, the superiority of the proposed ZOR mainly lies in its compact size. In addition, it is easy to tune the zeroth‐order resonant frequency, thanks to its simple structure and easy fabrication. In this article, the performance and design of the novel ZOR is first studied in detail. Then, the ZOR is exploited to devise a three‐order Chebyshev coupled microstrip BPF. Different coupling schemes are adopted, including interdigital capacitor coupling for the interstages and aperture‐backed dual‐finger parallel‐coupled line structures at the terminals, thus, the specified coupling strengths can be conveniently satisfied. Finally, a prototype device filter operative at S‐band is provided to illustrate the proposed techniques. Salient feature of the size reduction of the novel filter is achieved (more than 70%) when compared to a conventional structure. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2985–2989, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24808
A low‐power 2.4‐GHz receiver front‐end for wireless sensor networks
Authors: Lin Yu‐Tso , Lin Yo‐Sheng , Lu Shey‐Shi 
Published: September 2009

AbstractA low‐power 2.4‐GHz SiGe HBT receiver front‐end for wireless sensor networks utilizing current‐ reuse technique is reported for the first time. The proposed receiver comprises the low‐noise amplifier (LNA), the passive mixer, and the intermediate frequency (IF) amplifier. To reduce the power consumption, the dc bias current of the IF amplifier is reused by the LNA. The receiver front‐end dissipated 13.8 mW, and achieved input return loss (S11) of −22 dB, conversion voltage gain of 34 dB, noise figure of 6.3 dB, and input third‐order intermodulation point (IIP3) of −21 dBm at IF of 1 MHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 3021–3024, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24812
Relationship between structures of phosphorus compounds and flame retardancies of the mixtures with acrylonitrile–butadiene–styrene and ethylene–vinyl acetate copolymer
Authors: Nguyen Congtranh , Lee Minsoo , Kim Jinhwan 
Published: September 2009

AbstractVarious analogos of phosphonic acid, phosphinic acid, and CH3P(O) group containing organo‐phosphorus compounds were synthesized as model compounds to investigate the effects of P content and the structure of flame retardant (FR) on their fire retarding performances of acrylonitrile–butadiene–styrene (ABS) and ethylene–vinyl acetate (EVA) copolymer. The success of synthesis was confirmed by 1H‐ and 31P‐NMR. The flame retarding efficiencies were evaluated by a UL‐94 vertical test method. Thermogravimetric analysis results reveal that all the mixtures of FRs with ABS or EVA exhibit no or very little charred residues at 600°C under inert atmosphere condition, indicating that all FRs work in the gas phase rather than in the condensed phase for both ABS and EVA. The fire retarding efficiency of FR depends not only on the P content in FR but also on the nature of its structure. UL‐94 results show that P FRs with CH3 group attached to the P atom exhibits the best fire retarding performance on both ABS and EVA. It was found that at least 4 wt% P in the formulation is required to show self‐extinguishing ability for both ABS and EVA when P FRs having CH3 group are employed. The fire retarding efficiency of P FRs with different attached group is in order of: CH3 > C6H5 > OH > H. Copyright © 2009 John Wiley & Sons, Ltd.
A review on flame retardant technology in China. Part I: development of flame retardants
Authors: Chen Li , Wang Yu‐Zhong 
Published: September 2009

AbstractThis paper provides an insight into some developments in flame retardants for different polymeric materials in China, primarily based on the publications that have appeared in the last 15 years. It focuses on the following aspects: halogen‐containing flame retardants, inorganic flame retardants (e.g. metal oxides and hydroxides, silicon‐containing materials, ammonium polyphosphate, red phosphorus, and expandable graphite), and organic flame retardants (e.g. aliphatic and aromatic phosphonates, nitrogen‐containing organics, and multi‐element organics). The inherently flame‐retardant polymer systems are also reviewed. The exploration of the novel flame retardants and flame‐retardant systems provides a powerful basis for the construction of flame‐retardant technologies and industrial applications in China. Copyright © 2009 John Wiley & Sons, Ltd.
Maternal serum placental protein 13 at 11–13 weeks of gestation in preeclampsia
Authors: Akolekar Ranjit , Syngelaki Argyro , Beta Jarek , Kocylowski Rafal , Nicolaides Kypros H. 
Published: September 2009

AbstractObjectiveTo examine the potential value of maternal serum concentration of placental protein 13 (PP13) at 11–13 weeks' gestation in screening for preeclampsia (PE).MethodsSerum PP13, PAPP‐A and uterine artery pulsatility index (PI) were determined in a case–control study of 208 cases that developed PE including 48 that required delivery before 34 weeks (early‐PE) and 416 unaffected controls.ResultsSerum PP13 levels, expressed as multiples of the median (MoM) in the unaffected group, were significantly reduced in early‐PE (0.83 MoM) but not in late‐PE (0.96 MoM). In both early‐ and late‐PE serum PAPP‐A (0.55 and 0.84 MoM) was reduced and uterine artery PI (1.61 and 1.25 MoM) was increased. In PE pregnancies there was a significant association between serum PP13 and both uterine artery PI and serum PAPP‐A (p < 0.0001 for both). Logistic regression analysis demonstrated that serum PP13 did not improve significantly the prediction of early‐PE provided by a combination of maternal factors, uterine artery PI and PAPP‐A.ConclusionPP13 is implicated in the pathogenesis of impaired placentation and subsequent development of early‐PE but measurement of this placental product is unlikely to be useful in screening for the disease at 11–13 weeks. Copyright © 2009 John Wiley & Sons, Ltd.
Redox initiated cationic polymerization: Reduction of diaryliodonium salts by 9‐BBN
Authors: Crivello James V. 
Published: September 2009

AbstractDiaryliodonium salts undergo facile reduction by the dialkylborane, 9‐BBN. The combination of these two reagents constitutes a redox couple that can be employed as a convenient and versatile initiator system for the cationic polymerizations of styrenic monomers, vinyl ethers and the ring‐opening polymerizations of cyclic ethers and acetals including; epoxides, oxetanes, tetrahydrofuran, and 1,3,5‐trioxane. The polymerizations of these monomers can be carried out in either neat monomer or under solution conditions. Typically, the redox cationic polymerizations of the above monomers are rapid and exothermic. Optical pyrometry (infrared thermography) was employed as a convenient method with which to monitor and optimize the aforementioned redox initiated cationic polymerizations. Studies of the effects of variations in the structure and concentrations of the diaryliodonium salt and 9‐BBN on the polymerizations of various monomers were carried out. A mechanism for the redox cationic initiation of the polymerizations was proposed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5639–5651, 2009
The disproportionation of Cu(I)X mediated by ligand and solvent into Cu(0) and Cu(II)X2 and its implications for SET‐LRP
Authors: Rosen Brad M. , Jiang Xuan , Wilson Christopher J. , Nguyen Nga H. , Monteiro Michael J. , Percec Virgil 
Published: September 2009

AbstractDisproportionation of Cu(I)X is the major step in Single‐Electron Transfer Living Radical Polymerization (SET‐LRP). The disproportionation of Cu(I)X mediated by Me6‐TREN in various solvents was studied through UV–vis spectroscopy and Dynamic Light Scattering (DLS). UV–vis experiments reveal that disproportionation is dependent on both solvent composition and concentration of Me6‐TREN, consistent with a revised equilibrium expression and corroborated by mathematical models. Electrochemistry data do not accurately predict the extent of disproportionation in the presence of Me6‐TREN. Exemplified by DMSO, a favored solvent for SET‐LRP, UV–vis spectroscopy shows that under certain conditions disproportionation is four‐orders of magnitude greater than the value reported from electrochemistry experiments. Through UV–vis and DLS analysis, it was demonstrated that DMSO, DMF, DMAC, and NMP, stabilize colloidal Cu(0), while acetone, EtOH, EC, MeOH, PC, and H2O facilitate agglomeration of Cu(0) particles. Additionally, for colloidal Cu(0) stabilizing solvents, the amount of ligand and solvent composition decide the particle size distribution. Therefore, the kinetics of SET‐LRP are cooperatively and synergistically determined by the complex interplay of solvent polarity, the extent of disproportionation in the solvent/ligand mixture, and the ability of that mixture to stabilize colloidal Cu(0) or control particle size distribution. The implications of these results for SET‐LRP are discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5606–5628, 2009
Modeling the time and temperature dependence of the oPs formation probability in polystyrene and its derivatives
Authors: Laforest Nicolas , Bas Corine , De Baerdemaeker Jérémie , Dauwe Charles 
Published: September 2009

AbstractPositron annihilation lifetime spectroscopy measurements of polystyrene and its derivatives have been performed in the temperature range 20–300 K. The ortho‐positronium lifetime calculated from the lifetime spectrum analysis is related to the mean free‐volume hole size. However, the ortho‐positronium yield in the medium is dependent on the polymer chemistry and also on the irradiation effect induced by the positron source. We proposed a model based on two simple processes that cause, respectively, enhancement and inhibition of positronium formation to fit the experimental data over a broad temperature range. Using this model, intrinsic parameters for the polymers under study, such as the shallowly trapped electron recombination energy and the free‐radical recombination energy, were calculated and discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2063–2073, 2009
Using vibrational mode analysis for predicting the coefficient of thermal expansion of amorphous polymers
Authors: Shenogin Sergei , Raravikar Nachiket , Ozisik Rahmi , Keblinski Pawel 
Published: September 2009

AbstractMolecular dynamics simulations and vibrational analysis on model amorphous polyethylene structures demonstrate that the main contribution to the coefficient of thermal expansion (CTE) is due to structural relaxations even at temperatures below the glass transition. The contribution due to vibrational relaxation, calculated within the Grüneissen theory of solids, accounts only for a small fraction of the CTE. Based on our findings we argue that tailoring of polymers with low CTE should focus on reduction of the relaxation processes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2114–2121, 2009
Counterion mixing effects on the conformational transitions of polyelectrolytes. I. Volume phase transition and coil‐globule transition of alkali metal poly(acrylate)s
Authors: Hayashi Mariko , Wakagawa Masaki , Minato Takafumi , Nishiyama Yuji , Kuroki Shigeki , Satoh Mitsuru 
Published: September 2009

AbstractCounterion mixing effects on the volume phase transition and the coil‐globule transition of alkali metal poly(acrylate)s (PAAM) in aqueous organic solvents were investigated by observing the swelling behavior of PAAM gel and by measuring the solution viscosity and the conductivity as a function of the counterion mixing ratio. Marked transitions to the collapsed states were induced only for Li+/Cs+ system in most solvent systems; namely, PAA gel significantly collapsed in the presence of Li+ and Cs+ counterions irrespective of the solvent species employed, while only a slight deswelling was observed for Li+/K+ system in some aqueous organic solvents. Corresponding specific decrements in the solution viscosity and conductivity were also confirmed for the combination of Li+ and Cs+ in aqueous dimethyl sulfoxide (DMSO) system. A simple analysis of the conductivity decrement observed for Li+/Cs+ system in 60 vol % DMSO suggested that only Cs+ is tightly bound upon addition of Li+ while no restriction is induced for Li+ upon mixing with Cs+. A working hypothesis is proposed for the apparently intriguing behaviors of the counterions in the mixed system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2122–2131, 2009
Solubility of polystyrene in selectively deuterated methyl acetate
Authors: Siporska Agnieszka , Szydłowski Jerzy 
Published: September 2009

AbstractCloud point measurements were made for binary systems of polystyrene (PS) + methyl acetate (MA) and polystyrene (PS) + selectively deuterated MA: CD3COOCH3 and CH3COOCD3 with three PS samples of Mw = 4.0 × 105, 2.0 × 106, and 13.2 × 106. All systems are characterized by the phase diagrams with upper and lower critical temperature. H/D isotope effects on miscibility for both selectively deuterated acetates are very large and appeared to be independent of the site of deuterium substitution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47:2140–2143, 2009
Hypergolic Reactions of TNT
Authors: Oxley Jimmie C. , Smith James L. , Yue Junqi , Moran Jesse 
Published: September 2009

AbstractOne way being considered to destroy trinitrotoluene (TNT) land or surf mines is to exploit its reactivity using darts containing chemicals, which, upon contact with TNT, cause instantaneous decomposition, but not detonation. To determine the best candidates to fill the darts, liquids, specifically amines, which react in a hypergolic fashion with TNT were examined for both the rate of reaction and amount of energy released. Micro‐calorimetry was used to measure heat release while spectroscopy and conventional peak intensity monitoring by chromatography were used to examine the rate of reaction. Calorimetry measurements showed little variation between different amines reacting with TNT (about 110–130 kJ mol−1 TNT). TNT reaction with hydride actually produced more heat than with amines. Further, dinitrotoluene (DNT), which generates substantial heat, did not undergo a hypergolic reaction with amines suggesting that heat release is not the controlling factor for the hypergolic reactions. Rate constants, determined for the loss of TNT in dilute acetonitrile solution, clearly showed distinctions among the amines. The more primary amine functionalities in the amine compound, the faster it destroyed TNT. Hydrides or amine mixtures spiked with hydride decomposed substantially faster than the amines alone. However, a direct correlation between reaction rate and time‐to‐ignition was not observed.
Stimulatory effect of undecylenic acid on mouse osteoblast differentiation
Authors: Kim Myung Hee , Shim Ki Shuk , Lee Su‐Ui , Kim Young Sup , Min Yong Ki , Kim Seong Hwan 
Published: September 2009

AbstractNatural compounds with bone‐forming (or anabolic) activity have been recently focused on in bone research. The present study investigated the effect of undecylenic acid (UA) on osteoblast differentiation in mouse osteoblastic MC3T3‐E1 subclone 4 cells and primary mouse calvarial cells. Low concentrations of UA (up to 5 μM) exhibited no cytotoxicity and significantly increased the expression and activity of alkaline phosphatase (early differentiation marker of osteoblast) and calcium deposition with the induction of expression of the osteocalcin gene in both cells. Interestingly, at low concentration of UA, the induction of NF‐κB p65 translocation into nucleus and the up‐regulation of AP‐1 and NFATc1 transcript levels were also observed, suggesting that the stimulatory effect of UA on osteoblast differentiation could be mediated through the activation of transcription factors. Additionally, although the patterns of UA‐induced activation of MAP kinases (JNK and p38) were not completely consistent with the increase of both ALP activity and calcium deposition by UA, MAP kinases might be partially involved in the biological function of UA during the early and late stages of osteoblast differentiation. Copyright © 2009 John Wiley & Sons, Ltd.
Diuretic and antioxidant effects of Cacti‐Nea®, a dehydrated water extract from prickly pear fruit, in rats
Authors: Bisson Jean‐François , Daubié Stéphanie , Hidalgo Sophie , Guillemet Damien , Linarés Elodie 
Published: September 2009

AbstractDehydrated extract of the prickly pear fruit Opuntia ficus indica, Cacti‐Nea®, was evaluated for its chronic diuretic and antioxidant effects in Wistar rats. Cacti‐Nea® was orally administered daily for seven days at the dose of 240 mg/kg/day. A positive group was orally treated with hydrochlorothiazide at the dose of 10 mg/kg/day and a control group with vehicle. Daily measurements of body weight, urine volume, and concentration of sodium, potassium and uric acid in urine were performed for each rat. At the end of the study, the blood globular level of glutathione peroxidase was determined. Cacti‐Nea® significantly increased the urine volumes excreted by rats in comparison with the control group and it showed a trend to reduce significantly the body weight gain of rats. No significant differences were observed in the urine concentration of sodium, potassium and uric acid in comparison with the control group. The chronic diuretic effects of Cacti‐Nea® were comparable with that of the standard drug hydrochlorothiazide. Chronic oral administration of Cacti‐Nea® significantly increased the blood globular levels of glutathione peroxidase in comparison with control and hydrochlorothiazide groups. The prickly pear fruit extract Cacti‐Nea® demonstrated chronic diuretic and antioxidant effects in Wistar rats with respect to the excretion of the metabolites. Copyright © 2009 John Wiley & Sons, Ltd.