bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of transmission lines with through-silicon-vias and bump joints on high-resistivity Si interposers for RF three-dimensional modules
Authors: Choi Kwang-Seong , Eom Yong-Sung , Bae Hyun-Cheol , Moon Seok Hwan , Lee Jin Ho 
Published: May 2016

Abstract
Microstrip lines and coplanar waveguides (CPWs) for RF three-dimensional (3D) modules were characterized on high-resistivity Si interposers: 2,000 Ω·cm. The diameter and thickness of through-silicon-vias (TSVs) in Si interposers were 50 and 250 µm, respectively. A signal TSV around five ground TSVs, and a signal solder bump around five ground solder bumps were designed to obtain the vertical transitions with low electrical loss between the transmission lines. For the 3D interconnections between Si interposers, a fluxing underfill material was developed and used as a preapplied underfill during the thermocompression bonding. The S-parameters of transmission lines and stacked transmission lines were measured from 0.5 to 10 GHz using a vector network analyzer (VNA) and de-embedded so that their electrical losses were obtained and compared. By comparing with the electrical loss of the transmission line on low-temperature cofired ceramics (LTCC), we found that both transmission lines were sufficiently good for applications in RF 3D modules.
Foraging loads of red wood ants:Formica aquilonia(Hymenoptera: Formicidae) in relation to tree characteristics and stand age
Authors: Gibb Heloise , Andersson Jon , Johansson Therese 
Published: May 2016

Background.Foraging efficiency is critical in determining the success of organisms and may be affected by a range of factors, including resource distance and quality. For social insects such as ants, outcomes must be considered at the level of both the individual and the colony. It is important to understand whether anthropogenic disturbances, such as forestry, affect foraging loads, independent of effects on the quality and distribution of resources. We asked if ants harvest greater loads from more distant and higher quality resources, how individual efforts scale to the colony level, and whether worker loads are affected by stand age.Methods.First, we performed a fine-scale study examining the effect of distance and resource quality (tree diameter and species) on harvesting of honeydew by red wood ants,Formica aquilonia, in terms of crop load per worker ant and numbers of workers walking up and down each tree (ant activity) (study 1). Second, we modelled what the combination of load and worker number responses meant for colony-level foraging loads. Third, at a larger scale, we asked whether the relationship between worker load and resource quality and distance depended on stand age (study 2).Results.Study 1 revealed that seventy percent of ants descending trees carried honeydew, and the percentage of workers that were honeydew harvesters was not related to tree species or diameter, but increased weakly with distance. Distance positively affected load mass in both studies 1 and 2, while diameter had weak negative effects on load. Relationships between load and distance and diameter did not differ among stands of different ages. Our model showed that colony-level loads declined much more rapidly with distance for small diameter than large diameter trees.Discussion.We suggest that a negative relationship between diameter and honeydew load detected in study 1 might be a result of crowding on large diameter trees close to nests, while the increase in honeydew load with distance may result from resource depletion close to nests. At the colony level, our model suggests that very little honeydew was harvested from more distant trees if they were small, but that more distant larger trees continued to contribute substantially to colony harvest. Although forestry alters the activity and foraging success of red wood ants, study 2 showed that it does not alter the fundamental rules determining the allocation of foraging effort.
Full 3‐D TLM simulations of the Earth‐ionosphere cavity: Effect of conductivity on the Schumann resonances
Authors: Toledo‐Redondo S. , Salinas A. , Fornieles J. , Portí J. , Lichtenegger H. I. M. 
Published: May 2016

AbstractSchumann resonances can be found in planetary atmospheres, inside the cavity formed by the conducting surface of the planet and the lower ionosphere. They are a powerful tool to investigate both the electric processes that occur in the atmosphere and the characteristics of the surface and the lower ionosphere. Results from a full 3‐D model of the Earth‐ionosphere electromagnetic cavity based on the Transmission‐Line Modeling (TLM) method are presented. A Cartesian scheme with homogeneous cell size of 10 km is used to minimize numerical dispersion present in spherical schemes. Time and frequency domain results have been obtained to study the resonance phenomenon. The effect of conductivity on the Schumann resonances in the cavity is investigated by means of numerical simulations, studying the transition from resonant to nonresonant response and setting the conductivity limit for the resonances to develop inside the cavity. It is found that the transition from resonant to nonresonant behavior occurs for conductivity values above roughly 10−9 S/m. For large losses in the cavity, the resonances are damped, but, in addition, the peak frequencies change according to the local distance to the source and with the particular electromagnetic field component. These spatial variations present steep variations around each mode's nodal position, covering distances around 1/4 of the mode wavelength, the higher modes being more sensitive to this effect than the lower ones. The dependence of the measured frequency on the distance to the source and particular component of the electric field offers information on the source generating these resonances.
Spatial scales of optical variability in the coastal ocean: Implications for remote sensing and in situ sampling
Authors: Moses Wesley J. , Ackleson Steven G. , Hair Johnathan W. , Hostetler Chris A. , Miller W. David 
Published: May 2016

AbstractUse of ocean color remote sensing to understand the effects of environmental changes and anthropogenic activities on estuarine and coastal waters requires the capability to measure and track optically detectable complex biogeochemical processes. An important remote sensor design consideration is the minimum spatial resolution required to resolve key ocean features of physical and biological significance. The spatial scale of variability in optical properties of coastal waters has been investigated using continuous, along‐track measurements collected using instruments deployed from ships, aircraft, and satellites. We defined the average coefficient of variance,
, within an image pixel as the primary statistical measure of subpixel variability and investigated how
changes as a function of the Ground Sampling Distance (GSD). In general, d
/dGSD is positive, indicating that the subpixel variability increases with GSD. The relationship between
and GSD is generally nonlinear and the greatest rate of change occurs at small spatial scales. Points of distinct transition in the relationship between
and GSD are evident between 75 and 600 m, varying depending on the location and the optical parameter, and representing the GSD above which most of the spatial variability due to small‐scale features is subsumed within a pixel. At GSDs greater than the transition point, most of the small‐scale variability occurs at subpixel scales and, therefore, cannot be resolved. On average, the transition GSD is around 200 m. The results have application in both sensor design and in situ sampling strategy in support of coastal remote sensing operations.
Compensation of the impact of low‐cost manufacturing techniques in the design of E‐plane multiport waveguide junctions
Authors: San‐Blas A. A. , Roca J. M. , Cogollos S. , Morro J. V. , Boria V. E. , Gimeno B. 
Published: May 2016

AbstractIn this work, a full‐wave tool for the accurate analysis and design of compensated E‐plane multiport junctions is proposed. The implemented tool is capable of evaluating the undesired effects related to the use of low‐cost manufacturing techniques, which are mostly due to the introduction of rounded corners in the cross section of the rectangular waveguides of the device. The obtained results show that, although stringent mechanical effects are imposed, it is possible to compensate for the impact of the cited low‐cost manufacturing techniques by redesigning the matching elements considered in the original device. Several new designs concerning a great variety of E‐plane components (such as right‐angled bends, T‐junctions and magic‐Ts) are presented, and useful design guidelines are provided. The implemented tool, which is mainly based on the boundary integral‐resonant mode expansion technique, has been successfully validated by comparing the obtained results to simulated data provided by a commercial software based on the finite element method.
Ugi‐type Multicomponent Reaction of Nitrile Imines, Isocyanides, and Isocyanates: Effective Synthesis of 1,2,4‐Triazinedione Derivatives
Authors: Soeta Takahiro , Takashita Suguru , Sakata Yoko , Ukaji Yutaka 
Published: May 2016

AbstractWe have developed a Ugi‐type multicomponent reaction, in which a nitrile imine, an isocyanide, and an isocyanate reacted to give the corresponding 1,2,4‐triazinedione derivatives in good‐to‐high yields. This reaction is one of the few examples of isocyanide‐based multicomponent reactions using an isocyanate in place of a carboxylic acid. A wide range of nitrile imines, isocyanides, and isocyanates were found to be applicable to the reaction.
Effects of oxidant and dopants on the properties of cellulose/PPy conductive composite hydrogels
Authors: Fang Liangjing , Zhao Lihong , Liang Xiangtao , Xiao Huining , Qian Liying 
Published: May 2016

ABSTRACTCellulose/Polypyrrole (PPy) composite hydrogels were prepared by in situ chemically oxidative polymerization of pyrrole in the cellulose matrix. Ferric chloride (FeCl3) was used as an oxidant and four sulfonic compounds were used as dopants in order to investigate the effects on the properties of cellulose/PPy conductive composite hydrogels. The extent of polymerization of PPy was determined by the amount of the oxidant and the composite hydrogels with oxidant at 0.3M−0.5M exhibited the higher conductivities for the intrachain and interchain conductivities of conductive polymers; the fracture stress of the composite hydrogels could be up to 26.25 MPa with a strain of 86.8% when the oxidant was at 0.5M. Doping is an efficient way to improve the conductivity of the composite hydrogels and four kinds of dopant were compared in this work. Long alkane chain and side group in dopants can increase the steric hindrance of PPy polymerization which resulted in the lower conductivity of the composite hydrogels compared to dopants with smaller steric hindrance. The conductivity of the composite hydrogel firstly increased and then decreased with the concentration of dopants from 0.1M to 1.0M in this work. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43759.
Synthesis and studies on core–shell type anion exchange resins based on a hybrid polymeric support
Authors: Cyganowski Piotr , Jermakowicz‐Bartkowiak Dorota 
Published: May 2016

ABSTRACTIn pursuit for new materials for recovery of noble metals, novel anion exchangers, based on new type of core–shell polymeric supports have been synthesized. The designed matrices, with reactive chloromethyl groups concentrated on a surface of the polymeric base, the Amberlite XAD‐4 adsorbent, have been modified using ethylenediamine and polyethyleneimine. The obtained ion exchangers were employed in processes of sorption of gold, platinum, and palladium chlorocomplexes, then, they were compared to similar resins based on volumetric polymeric supports. The studies covered porosity measurements, determination of sorption behavior in the presence of counter ions as well as kinetic and column studies. Ultimately, an attempt to access a core–shell character of the resins has been made using digital‐optical microscopy. The proceeded analyses allowed to determine the localization of the resins’ functionalities and their advantages over traditional ion exchange resins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43841.
SiAlON–epoxy nanocomposite coatings: Corrosion and wear behavior
Authors: Moradi M. H. , Aliofkhazraei M. , Toorani M. , Golgoon A. , Rouhaghdam A. Sabour 
Published: May 2016

ABSTRACTIn this study, epoxy powder as a matrix was combined with different contents of silicon–aluminum–oxygen–nitrogen (SiAlON) nanoparticles using a planetary ball mill. Pure epoxy and nanocomposite powders were applied on the surface of plain carbon steel components by the electrostatic spraying method. Curing of the coatings was done in an oven or microwave for the appropriate time. The coating structure and morphology of the SiAlON nanoparticles were studied by scanning electron microscopy and transmission electron microscopy, respectively. The corrosion properties of the coatings were assessed by immersion, Tafel polarization, and electrochemical impedance spectroscopy tests in 3.5% NaCl solution. The results show that addition of 10 wt % SiAlON nanoparticles markedly increases the corrosion resistance of epoxy coatings. Thus, it can be inferred that the corrosion rate of these coatings is 15 to 18 times lower than that of pure epoxy samples and 8 to 11 times lower than coatings with 20 wt % SiAlON. The higher corrosion resistance of nanocomposite coatings can be attributed to the barrier properties of SiAlON nanoparticles. The tribological performance of the coatings was studied with the pin‐on‐disk test. The results of wear testing show that the samples containing 10 wt % SiAlON provide about five times more wear resistance than pure ones and about two times more than coatings with 20 wt % SiAlON. However, the coefficient of friction for nanocomposite coatings is reduced about 50% compared to the pure sample. Also, the curing process in either regime (oven or microwave) has the same effect on the corrosion and wear properties, and the coatings are completely crosslinked. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43855.
Research on Payne effect of natural rubber reinforced by graft‐modified silica
Authors: Fu Wen , Wang Li 
Published: May 2016

ABSTRACTSilica (SiO2) modified by in situ solid‐phase grafting was used for natural rubber (NR) reinforcement. The physical mechanical properties and Payne effect of natural rubber reinforced by SiO2 and graft‐modified silica (G‐SiO2) were analyzed systematically. The results showed the comprehensive performance of NR/G‐SiO2 was better than that of NR/SiO2. There was a proportional relationship between the filler loading and Payne effect. NR/G‐SiO2 presented weaker Payne effect in comparison with NR/SiO2. A qualitative analysis on the correlation of filler 3D network structure and filler loading was carried out according to the relationship between the bound rubber content and the shear modulus. The Payne effect mechanisms of rubber compounds differed according to the different filler loading. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43891.
Stabilization of Discrete‐time Switched Systems with State Constraints Based on Mode‐Dependent Average Dwell Time
Authors: Su Qingyu , Wang Peipei , Li Jian , Liu Honghai 
Published: May 2016

AbstractThis paper considers the stabilization problem for a class of switched systems with state constraints based on mode‐dependent average dwell time (MDADT) in discrete‐time context. An improved average dwell time method is proposed, which is less conservative than the common average dwell time method. The sufficient conditions and stabilizing state feedback controllers for stabilization of discrete‐time switched systems with state constraints under MDADT switching are derived. Finally, the simulation results show that the approach designed by this paper is effective.
Synthetic MUC1 Antitumor Vaccine Candidates with Varied Glycosylation Pattern Bearing R/S‐configured Pam3CysSerLys4
Authors: Shi Lei , Cai Hui , Huang Zhi‐Hua , Sun Zhan‐Yi , Chen Yong‐Xiang , Zhao Yu‐Fen , Kunz Horst , Li Yan‐Mei 
Published: May 2016

AbstractThe Toll‐like receptor 2 ligand Pam3CysSer is of particular interest for the construction synthetic vaccines because of its ability to stimulate of the innate immune system. Such vaccines usually comprise Pam3CysSer with the natural R‐configuration at the glycerol 2‐position. Pam3CysSer peptide vaccines with natural configuration have been shown to be more efficient than the corresponding R/S diastereomers. In order to clarify whether the effect of the configuration of Pam3Cys on the immune response also applies to glycopeptide vaccines, MUC1 glycopeptide–lipopeptide vaccines bearing either R‐ or R/S‐configured Pam3CysSerLys4 were compared for their immunological effects. In order to find out whether glycosylated MUC1 tandem repeat domains comprise not only B‐cell epitopes but also T‐cell epitopes, two‐component vaccines containing the Pam3CysSerLys4 lipopeptide and MUC1 glycopeptides with various glycosylation patterns were synthesized, and their immune reactions in mice were studied.
The influence of deficient retro‐aortic rim on technical success and early adverse events following device closure of secundum atrial septal defects
Authors: O'Byrne Michael L. , Gillespie Matthew J. , Kennedy Kevin F. , Dori Yoav , Rome Jonathan J. , Glatz Andrew C. 
Published: May 2016

BackgroundConcern regarding aortic erosion has focused attention on the retro‐aortic rim in patients undergoing device closure of atrial septal defects (ASD), but its effect on early outcomes is not well studied.MethodsA multicenter retrospective cohort study of patients undergoing device occlusion of ASD between 1/2011‐10/2014 was performed, using data from the IMproving Pediatric and Adult Congenital Treatment Registry. Subjects were divided between those with retro‐aortic rim <5 and ≥5 mm. Primary outcomes were technical failure and major early adverse events. Case times were measured as surrogates of technical complexity. The effect of deficient retro‐aortic rim on primary outcomes was assessed using hierarchical logistic regression, adjusting for other suspected covariates and assessing whether they represent independent risk factorsResults1,564 subjects (from 77 centers) were included, with deficient retro‐aortic rim present in 40%. Technical failure occurred in 91 subjects (5.8%) and a major early adverse event in 64 subjects (4.1%). Adjusting for known covariates, the presence of a deficient retro‐aortic rim was not significantly associated with technical failure (OR: 1.3, 95% CI: 0.9–2.1) or major early adverse event (OR: 0.7, 95% CI: 0.4–1. 2). Total case (P = 0.01) and fluoroscopy time (P = 0.02) were greater in subjects with deficient rim, but sheath time was not significantly different (P = 0.07). Additional covariates independently associated with these outcomes were identified.ConclusionDeficient retro‐aortic rim was highly prevalent but not associated with increased risk of technical failure or early adverse events. Studies with longer follow‐up are necessary to assess other outcomes, including device erosion. © 2016 Wiley Periodicals, Inc.
Experimental Methodologies to Understand Degradation of Nanostructured Electrocatalysts for PEM Fuel Cells: Advances and Opportunities
Authors: Mezzavilla Stefano , Cherevko Serhiy , Baldizzone Claudio , Pizzutilo Enrico , Polymeros George , Mayrhofer Karl J. J. 
Published: May 2016

AbstractThe development and application of advanced experimental tools is a major driving force in modern electrocatalysis. This is particularly true for stability studies with nanostructured oxygen reduction reaction electrocatalysts for PEM fuel cells. Indeed, our understanding of the catalyst degradation mechanisms could not have been achieved without the arsenal of analytical tools developed over the last decades. This contribution aims at highlighting the value of such a multi‐faceted analytical toolbox. Several classes are examined: from techniques applied for dissolution studies with bulk electrodes, to ex situ and in situ investigations with model high‐surface‐area catalysts. Finally, electrochemical and imaging methods employed to characterize catalyst layers are presented. The respective features, advantages, problems and possible future developments are discussed.
Rapid Dihydrogen Cleavage by Persistent Nitroxide Radicals under Frustrated Lewis Pair Conditions
Authors: Tao Xin , Kehr Gerald , Wang Xiaowu , Daniliuc Constantin G. , Grimme Stefan , Erker Gerhard 
Published: May 2016

AbstractPersistent radicals undergo hydrogen atom abstraction reactions with a great variety of substrates, but not with dihydrogen. It has now been found that the TEMPO radical splits dihydrogen under mild conditions in the presence of the strong bulky B(C6F5)3 boron Lewis acid. The reaction is thought to proceed by a typical frustrated Lewis pair mechanism with the TEMPO radical acting as the active Lewis base. The reaction was analyzed by DFT, which indicates that no significant spin density on the hydrogen atoms is accumulated along the H2 splitting reaction path.
ChemInform Abstract: Molecular Dynamics and X‐Ray Diffraction Study of Aqueous Beryllium(II) Chloride Solutions.
Authors: YAMAGUCHI T. , OHTAKI H. , SPOHR E. , PALINKAS G. , HEINZINGER K. , PROBST M. M. 
Published: May 2016

AbstractThe hydration shell of BeCl2 in aqueous solution has been investigated by a MD simulation and by X‐ray diffraction studies of 1.1 and 5.3 molal BeCl2 solutions at pH 1. The structure function obtained by MD simulation is in satisfactory agreement with that from X‐ray diffraction.
ChemInform Abstract: Crystal Structure of CuWO3F2.
Authors: MOUTOU J. M. , FRANCISCO R. H. P. , CHAMINADE J. P. , POUCHARD M. , HAGENMULLER P. 
Published: May 2016

AbstractThe title compound (prepared from WO3 and CuF2, Pt tube, Ar atmosphere, 580 °C, 48 h) crystallizes in the monoclinic system, space group P21/m with Z=2.
ChemInform Abstract: First Observation of 5‐Coordinate Aluminum by MAS 27Al NMR in Well‐Characterized Solids.
Authors: ALEMANY L. B. , KIRKER G. W. 
Published: May 2016

AbstractThe MAS 27Al NMR spectra of barium aluminum glycolate, BaAlO8C6.75H14.75, and the mineral andalusite, Al2SiO5, are reported.
ChemInform Abstract: 1H and 13C NMR Spectra of a Series of Methyl‐Substituted Imidazole Complexes of Pentaamminecobalt(III) and Crystal Structure of the Remote Isomer of ((4‐Methylimidazole)pentaamminecobalt(III)) Trichloride Dihydrate.
Authors: HENDERSON W. W. , SHEPHERD R. E. , ABOLA J. 
Published: May 2016

AbstractNMR data for the free ligands 1‐, 2‐, 4‐, 5‐methylimidazole, 1,2‐, 1,4‐, 1,5‐ and 2,5‐dimethylimidazole as well as for their Co(NH3)53+ complexes are reported and discussed.
ChemInform Abstract: Characterization of (Fe2(CO)6B3H6)‐: A Comment on the Dynamic Structure of Fe2(CO)6B3H7.
Authors: HOUSECROFT C. E. 
Published: May 2016

AbstractThe previously characterized compound (I) and its conjugate base (II)are investigated by 11B and 1H FT NMR spectroscopy and MO calculations.
ChemInform Abstract: Hydrophobic and Steric Effects on the Ion‐Pair Formation of Tris(1,10‐phenanthroline)iron(II) and Arenesulfonate Ions. Kinetic Determination of the Formation Constants of the Ion Pairs and a 1H NMR Study of Their Structures.
Authors: TACHIYASHIKI S. , YAMATERA H. 
Published: May 2016

AbstractIon‐pair formation constants for (I) and the ions (II) and (III) are obtained from kinetic studies of the aquation of the complex ion in aqueous sodium arenesulfonate solutions.
ChemInform Abstract: Simple Synthesis of 1‐Amino‐1‐cyclopropanecarboxylic Acids from t‐Butyl Isocyanacetate and Epoxides, Synthesis of Alkyl 5,6‐Dihydro‐4H‐1,3‐oxazine‐4‐carboxylates.
Authors: SCHOELLKOPF U. + , HUPFELD B. , GULL R. 
Published: May 2016

AbstractThe title acids (VIII) and (IX) are biologically interesting substances.