bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the large‐gap‐ground rectangular patch antenna
Authors: Wang Yiying , Lu Yinghua 
Published: July 2017

AbstractThe wearable antenna is being investigated, however, it faces a challenge in the special situation where the threads will be broken abruptly because of the aging or be cut. In this article, this satiation is imitated by cutting off part of the ground of the rectangular conventional patch antenna, which is excited by the coaxial cable, because it can be a textile one easily if the material is replaced by the fabric. Here, the ground plane is entirely sliced for a fixed area along the E‐plane direction and the sliced structure is symmetrical on the width direction. And the conventional patch antenna is designed as a benchmark to be compared with the gap‐ground antennas. Their corresponding results show the cross‐polarizations of the E‐plane increase and the resonances shift to the lower frequency, but the back radiation is affected little because of the coupling opposite currents on the strips. Also, the antenna has dual‐band characteristic if the gap ratio of the gap to the original solid ground plane is <1:4, and the biggest sliced gap ratio up to 3:4 so that the antenna has a large‐gap ground. Besides, the pattern of E‐plane has a tilt while that of H‐plane hasn't.
CPW feed dual band and wideband antennas using crescent shape and T‐shape stub for Wi‐Fi and WiMAX application
Authors: Dwivedi Ravi Prakash , Kommuri Usha Kiran 
Published: July 2017

AbstractThis letter presents design of novel annular ring crescent shape dual band and wideband antennas using T‐shape stub for worldwide interoperability for microwave access (Wi‐MAX) and wireless local area network (WLAN). These antennas are designed based on annular ring antenna and CPW feed. Dual band ring antenna with truncated ground plane provides a resonance at 3.5 GHz and addition of crescent shape with tuning of T‐shape stub provides a second resonance at 5.8 GHz. Ground plane shape is extremely significant for impedance matching. Wide band ring antenna with crescent shape and modified T‐shape stub exhibits bandwidth of 6.35 GHz from 4.75 to 11.1 GHz, further study shows that compactness of the antenna makes it suitable for active integrated antenna (AIA) application. Both dual band and wideband compact antennas are fabricated on FR4 substrate with the compact size of
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A miniaturized triple band‐notched UWB antenna
Authors: Arshed Talha , Tahir Farooq A. 
Published: July 2017

AbstractIn this study, a compact microstrip‐fed ultra‐wideband (UWB) monopole antenna with triple band‐notched characteristics is presented. UWB bandwidth is achieved through tapering of both the radiating element and the transmission line. A single parasitic microstrip resonator on the backside of the radiator is introduced to realize filtering at WiMAX (3.5 GHz) and WLAN (5.25, 5.775) bands. The microstrip resonator having dimensions of 8.2 mm × 8 mm is made up of three L‐shaped strips inside a C‐shaped strip. The overall size of the antenna is very compact 12 × 18 mm2. The antenna provides sharp cut‐offs in the notched‐bands to conserve all the useful frequencies within the ultra‐wideband. Measured impedance‐bandwidth of the antenna is 3.1–11.5 GHz for voltage standing wave ratio (VSWR) <2 except for the notched‐bands 3.4–3.6 GHz, 5.15–5.39 GHz, and 5.75–5.96 GHz. The antenna is also analyzed for far‐field characteristics and a good agreement is found between simulated and measured results.
A novel FSS for gain enhancement of printed antennas in UWB frequency spectrum
Authors: Tahir Farooq A. , Arshad Talha , Ullah Sadiq , Flint James A. 
Published: July 2017

AbstractThis paper presents a novel compact unilayer frequency selective surface (FSS) for ultra‐wideband (UWB) applications particularly for gain enhancement of printed antennas. The proposed FSS unit cell consists of simple metallic patterns printed on both sides of 14 mm × 14 mm FR4 substrate. The proposed FSS has very low transmission co‐efficient and linearly decreasing reflection phase over the bandwidth of 9 GHz in 3–12 GHz range, which makes it suitable candidate to provide in‐phase reflection for UWB antennas. For the validation of gain‐enhancement capability, the FSS is paired with a general monopole UWB antenna demonstrating an average gain improvement of 4 dB. The antenna composite has a maximum gain of 8.9 dBi.
Design and characterization of a diamond‐shaped monopole antenna
Authors: Maricar Mohamed Ismaeel , Bahar Ahmad , Greedy Steve , Smartt Chris , Phang Sendy , Gradoni Gabriele , Cross Richard , Creagh Stephen C. , Tanner Gregor , Thomas David W. P. 
Published: July 2017

AbstractWe report a new planar antenna design in the shape of a diamond. The performance of the antenna design is initially obtained through simulation, then fabricated, and its performance evaluated through experiment. Experimental characterization of the diamond‐shaped monopole antenna shows good agreement with simulation. In comparison with a simple monopole antenna, our diamond‐shaped monopole antenna features smaller geometric footprint and displays a higher bandwidth at millimeteric wave frequencies.
Multiband plasmonic nanoantenna structure for infrared energy harvesting based on electron field emission rectification
Authors: Chekini A. , Sheikhaei S. , Neshat M. 
Published: July 2017

AbstractIn this article, a multiband, planar, direct energy rectification, and dual polarized infrared plasmonic nanoantenna is presented and numerically simulated using finite element method (FEM). Broadband characteristics are highly suitable for energy harvesting applications. The proposed nanoantenna structure comprises cross bowtie aluminum structures deposited on the silicon dioxide (SiO2) substrate. In the proposed device, incoming thermal electromagnetic energy is first enhanced by micro‐lenses through focusing the thermal energy onto the nanoantenna. Then, further enhancement is achieved using several nanoantennas, each with different resonance length, to achieve enough electrical field for electron field emission from sharp metallic tips in their gaps. Each nanoantenna resonates in the proper wavelength, electrical field is enhanced in the gap, and finally, a total current is generated from electron field emissions. The calculated current, based on Fowler‐Nordheim theory, matches well with the simulation results. The total current of the proposed nanostructure is superposition of the produced current of each nanoantenna. To our best knowledge, this is the first report on a multiband nanostructure for energy harvesting. As a typical implementation, a structure is designed for energy absorption in the mid infrared wavelengths, 1‐4 µm.
Experimental realization of micromachined terahertz multistepped quasi‐diagonal horn antenna
Authors: Zhao Pengfei , Liu Yong , lv Xin 
Published: July 2017

AbstractA design of a terahertz (THz) quasi‐diagonal horn antenna with multistepped isosceles trapezoid slots based on the micromachining technology is presented. The radiation patterns are designed to be with high Gaussian coupling efficiency. The radiation patterns, VSWR, gain are measured, and good agreements with the simulated results are found.
Diffuse bifurcations engraving diverse shear bands in granular materials
Authors: Yamakawa Yuki , Ikeda Kiyohiro , Saiki Isao , Desrues Jacques , Tanaka Reiko J. 
Published: July 2017

SummaryShear bands with characteristic spatial patterns observed in an experiment for a cubic or parallelepiped specimen of dry dense sand were simulated by numerical bifurcation analysis using the Cam‐clay plasticity model. By incorporating the subloading surface concept into the plasticity model, the model became capable of reproducing hardening/softening and contractive/dilative behavior observed in the experiment. The model was reformulated to be compatible with the multiplicative hyperelasto‐plasticity for finite strains. This enhanced constitutive model was implemented into a finite‐element code reinforced by a stress updating algorithm based on the return‐mapping scheme, and by an efficient numerical procedure to compute critical eigenvectors of elastoplastic tangent stiffness matrix at bifurcation points. The emergence of diamond‐ and column‐like diffuse bifurcation modes breaking uniformity of the materials, followed by the evolution of shear bands through strain localization, was observed in the analysis. In the bifurcation analysis of plane strain compression test, unexpected bifurcation modes, which broke out‐of‐plane uniformity and led to 3‐dimensional diamond‐like patterns, were detected. Diffuse bifurcations, which were difficult to observe by experiments, have thus been found as a catalyst creating diverse shear band patterns.
Synthesis of nitrogen doped activated carbon/polyaniline material for CO2 adsorption
Authors: Peyravi Majid 
Published: July 2017

The equilibrium adsorption isotherms of carbon dioxide and nitrogen on the nitrogen doped activated carbon (NAC) prepared by the chemical activation of a pine cone‐based char/polyaniline composite were measured using a volumetric technique. CO2 and N2 adsorption experiments were done at three different temperatures (298, 308, and 318 K) and pressures up to 16 bar, and correlated with the Langmuir, Freundlich, and Sips models. The Sips isotherm model presented the best fit to the experimental data. The N‐doped adsorbent showed CO2 and N2 adsorption capacity of 3.96 mmol·g−1 and 0.86 mmol·g−1, respectively, at 298 K and 1 bar. The selectivity predicted by ideal adsorbed solution theory (IAST) model was achieved 47.17 for NAC at 1 bar and yN2 = 0.85 which is a composition similar to flue gas. The results showed that NAC adsorbent has a high CO2‐over‐N2 selectivity in a binary mixture. The relatively fast sorption rate of CO2 on NAC compared to N2 indicates the stronger affinity between CO2 and amine groups. The isosteric heat of adsorption of CO2 by the NAC demonstrated the physico‐chemical adsorption of CO2 on the adsorbent surface. These data showed that prepared NAC could be successfully applied in separation of CO2 from N2.
Connector type‐controlled mesophase structures in poly(propyl ether imine) dendritic liquid crystals of identical dendrimer generations
Authors: Kumar Prabhat , Shankar Rao D. S. , Krishna Prasad S. , Jayaraman Narayanaswamy 
Published: July 2017

ABSTRACTPoly(propyl ether imine) (PETIM) dendrimers of one to three generations are used as dendritic cores to identify the influence of varying connector types that connect the dendritic core with peripheral mesogens on the emerging liquid crystalline (LC) properties. The LC properties vary in these dendritic liquid crystals, even when the dendrimer generations and thus the number of peripheral mesogenic moieties remain identical. PETIM dendrimer generations one to three, ester and amide connectors varying with succinates, phthalates, and succinamides, are studied herein. Cholesteryl moieties are installed at the peripheries through the above connectors to induce mesogenic properties. These modified dendritic liquid crystals reveal a layered mesophase structure in most ester and amide connector‐derivatives, whereas a third‐generation phthalate ester dendrimer favors a rectangular columnar mesophase structure. A transition from layered to a rectangular columnar structure results by a mere change in the connector varying between a succinate or succinamide or phthalate, within one particular dendrimer generation and without altering the underlying dendrimer core or the number of mesogenic moieties. The study demonstrates that in dendritic liquid crystals with essentially identical chemical constitutions, a change in the connector type connecting the mesogen with the dendrimer core is sufficient to change the mesophase structures. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3665–3678
Poly(N‐vinylpyrrolidone)–polydimethylsiloxane amphiphilic ABA triblock copolymers
Authors: Pavlović Dražen , Lou Qin , Linhardt Jeffrey G. , Künzler Jay F. , Shipp Devon A. 
Published: July 2017

ABSTRACTTriblock copolymers of N‐vinylpyrrolidone (NVP) and polydimethylsiloxane (PDMS) were synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization using two different types of difunctional telechelic PDMS‐based dixanthate macroinitiators. The incorporation of PDMS into the triblock copolymers was evidenced by 1H NMR spectroscopy and varied between 4 mol % and as high as 20 mol %, dependent on reaction time and monomer conversion. The copolymer homogeneity was characterized in terms of molecular weight distribution determined by GPC to estimate the level of control over the chain length. Monomodal molecular weight distributions were observed, and 1H NMR spectroscopy indicated the copolymers had number average molecular weights (Mn) ranging between 28,000 and 160,000 g/mol. In addition, thin film phase separation and critical micelle concentrations for these copolymers were analyzed via transmission electron microscopy and surface tension measurements, respectively. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3387–3394
One pot synthesis of bimodal UHMWPE/HDPE in‐reactor blends with Cr/V bimetallic catalysts
Authors: Jin Yulong , Zhao Ning , Cheng Ruihua , He Xuelian , Liu Zhen , Dong Dalin , Bin Yuezhen , Chen Xiaowei , Li Liangbin , Liu Boping 
Published: July 2017

ABSTRACTBimodal ultra‐high‐molecular‐weight polyethylene (UHMWPE)/high‐density polyethylene (HDPE) in‐reactor blends (IRBs) are produced by the bimetallic catalysts, which are synthesized through co‐supporting silylchromate and vanadium‐oxide‐based catalysts on silica or alumina, zirconia and titania‐modified silica. After support modification, the activities of the catalysts for ethylene polymerization are substantially enhanced. The IRBs produced by the modified catalysts also contain more UHMWPE and low‐molecular‐weight polyethylene (LMWPE) fractions, and have much broader molecular weight distribution (MWD). The homogeneous nature of the IRBs is preliminarily confirmed by the differential scanning calorimetry melting curves, showing unique melting peak in both nascent and recrystallized states. The rheological results reflect that the viscosity of the IRBs is reduced more or less when compared with UHMWPE. The distinct elastic dominance of the IRBs is also observed, implying the UHMWPE characteristics in the IRBs. In addition, the intimate mixing of the IRBs is further verified by the similar slopes of Han curves for the polyethylene (PE) samples. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3404–3412
Polyimides from an asymmetric hydroxyl‐containing aliphatic‐aromatic diamine synthesized via henry reaction
Authors: Wang Zhiang , Guo Liying , Han Songyu , Qi Haixia , Cheng Yusheng , Liu Feng 
Published: July 2017

ABSTRACTAn aliphatic amino and an aliphatic hydroxyl group have been incorporated via Henry reaction highly efficiently toward the synthesis of a novel asymmetric aliphatic–aromatic diamine 2‐amino‐1‐[4‐(5‐aminopyridyloxy)phenyl]‐1‐ethanol (AAPyPhE) in three steps. AAPyPhE shows good copolymerization reactivity with 4,4′‐oxydianiline (ODA) toward different aromatic dianhydrides, especially 4,4′‐oxydiphthalic anhydride (ODPA). TGA measurement and mechanical test results show that all polymers maintain the inherent thermal performance and tensile properties, while the glass transition temperatures (Tg's) by DMA show moderate decrease ranging from 185.5 to 253.3 °C due to the presence of aliphatic segments. The introduction of AAPyPhE is found to improve the solubility of the polymers, and the polymer films' optical transparency with decreased cutoff wavelength (λ0) ranging from 328 to 370 nm. Comparative studies reveal that the pendent aliphatic hydroxyls in the polymer chains would lead to interchain cross‐linking via condensation and secondary weak cross‐linking by hydrogen bond depending on different loading of AAPyPhE, which result in a fluctuation of hydrophilic–hydrophobic properties, DMA tanδand dielectric constant of the copolymer films. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2017,55, 3413–3423
Role of polythiophenes as electroactive materials
Authors: Pathiranage Taniya M. S. K. , Dissanayake Dushanthi S. , Niermann Crystal N. , Ren Yixin , Biewer Michael C. , Stefan Mihaela C. 
Published: July 2017

ABSTRACTSemiconducting polythiophenes display electroactive properties which make them excellent candidates for applications as electroactive materials. Ability to undergo doping and to switch between different oxidation states allow tuning the chemical and physical properties of polythiophenes. Furthermore, the ability to integrate polythiophenes into copolymers, hybrid composites with metals and inorganic materials make them useful in electronic and biomedical applications. The capability to vary the properties of the final material with low production cost and high processability into thin films makes polythiophenes desirable materials for many applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3327–3346
Synthesis and characterization of brush diblock and triblock copolymers bearing polynorbornene backbone and poly(l‐lactide) and/or poly(hexyl isocyanate) side chains by a combination of coordination and ring opening metathesis polymerization
Authors: Choinopoulos Ioannis , Patias George , Koinis Spyros , Pitsikalis Marinos 
Published: July 2017

ABSTRACTWe report the synthesis of poly(l‐lactide) and poly(hexyl isocyanate) macromonomers using bischloro‐η5‐cyclopentadienyl(bicyclo[2.2.1]‐hept‐5‐en‐2‐oxy) Titanium (IV), [CpTiCl2(O‐NBE)]. These macromonomers bearing a norbornene end group were polymerized towards brush copolymers employing Grubbs' first generation catalyst. Brush copolymers consisting of blocks with different side chains were synthesized. The polymers were characterized by Size Exclusion Chromatography, Nuclear Magnetic Resonance, and their thermal properties were investigated by Thermogravimetric Analysis, and Differential Scanning Calorimetry analysis. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3455–3465
Experimental Study on Dynamic Combustion Characteristics of Aluminum Particles
Authors: Zhou Yunan , Liu Jianzhong , Wang Jianru , Xv Tuanwei , Wang Jiahao , Zhou Junhu , Cen Kefa 
Published: July 2017

AbstractStudying the combustion characteristics and properties of the condensed phase products of aluminum particles is significant for the application of aluminum‐based propellants. The microstructure, particle size distribution, specific surface area and metallic Al contents of three different samples were analyzed by scanning electron microscopy, laser particle size analyzer, nitrogen adsorption and inductively coupled plasma atomic emission spectroscopy. The thermal oxidation characteristics of the samples were also studied by a thermal analyzer. A dynamic combustion test system was used to study the combustion process in motion and the properties of the products. The results show that as the activation energy of the sample decreases, the initial reaction temperature decreases during the thermal analysis. Moreover, the thermal oxidation degree increases with the decrease in particle size. In the dynamic combustion process, the combustion efficiency of the sample was calculated by using the temperature distribution in the combustion process, and the calculated results were in good agreement with the results of ICP measurements. With the increase in the particle size of the samples, the heat release was reduced, and the agglomerationand oxidation degree of the condensed phase products were also decreased. By increasing the feeding amount, the combustion temperature and the combustion efficiency would increase. The reaction mechanism in the dynamic furnace involves not only the diffusion reaction, but also the melt‐dispersion reaction. The initial reaction temperature of sample A was between 500∼600 °C, the combustion temperature was between 900∼1000 °C, the ignition delay time was around 270 ms, and the reaction time was about 0.6s.
The Synthesis of Energetic Compound on 4,4′‐((2,4,6‐trinitro‐1,3‐phenylene)bis(oxy)) bis(1,3‐dinitrobenzene)(ZXC‐5): Thermally Stable Explosive with Outstanding Properties
Authors: Zhang XingCheng , Xiong HuaLin , Yang HongWei , Cheng GuangBin 
Published: July 2017

AbstractThe novel, thermally stable explosive 4,4′‐((2,4,6‐trinitro‐1,3‐phenylene)bis(oxy))bis(1,3‐dinitrobenzene) (Be referred to as ZXC‐5 in our laboratory) has been reported. ZXC‐5 can be synthesized by a simple synthetic method (The total synthesis of ZXC‐5 requires only two steps and the total yield of ZXC‐5 is more than 89 %) and shows the superior detonation performances (detonation pressure, detonation velocity, sensitivity toward mechanical stimuli, and temperature of decomposition). The structure of ZXC‐5 was characterized by multinuclear (1H, 13C) NMR and mass spectrometry. The structure in the crystalline state was confirmed by low‐temperature single‐crystal X‐ray diffraction. From the calculated standard molar enthalpy of formation and the measured densities, the detonation properties were predicted by using the EXPLO5 V6.01 thermochemical computer code. The sensitivity of ZXC‐5 towards impact, electrostatic discharge, and friction were also measured.
Task‐Oriented Learning With Multiple Documents: Effects of Topic Familiarity, Author Expertise, and Content Relevance on Document Selection, Processing, and Use
Authors: Bråten Ivar , McCrudden Matthew T. , Stang Lund Elisabeth , Brante Eva W. , Strømsø Helge I. 
Published: July 2017

AbstractThis study investigated the effects of author expertise and content relevance on Norwegian secondary school students’ (n = 190) selection, processing, and use of multiple documents. Participants were presented with documents that pertained to more or less familiar topics, and received brief instructions that highlighted the importance of source credibility or content relevance, whereas those in a control group just received a general task instruction (to write a letter to the editor about their assigned topic). Results showed that content relevance had strong and nearly identical effects on students’ selection, processing, and use of documents independently of whether the topic was more or less familiar, whereas they valued author expertise to a greater extent when the topic was less familiar. Moreover, content relevance had a strong effect on students’ selection, processing, and use of documents independently of instructional condition, whereas brief instructions to focus on source credibility increased the value placed on author expertise when students selected, processed, and used documents for the less familiar topic. Theoretical and practical implications of the results are discussed.