bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tillage intensity and pasture in rotation effectively shape soil microbial communities at a landscape scale
Authors: Le Guillou Cédric , Chemidlin Prévost‐Bouré Nicolas , Karimi Battle , Akkal‐Corfini Nouraya , Dequiedt Samuel , Nowak Virginie , Terrat Sébastien , Menasseri‐Aubry Safya , Viaud Valérie , Maron Pierre‐Alain , Ranjard Lionel 
Published: June 2018

AbstractSoil microorganisms are essential to agroecosystem functioning and services. Yet, we still lack information on which farming practices can effectively shape the soil microbial communities. The aim of this study was to identify the farming practices, which are most effective at positively or negatively modifying bacterial and fungal diversity while considering the soil environmental variation at a landscape scale. A long‐term research study catchment (12 km2) representative of intensive mixed farming (livestock and crop) in Western Europe was investigated using a regular grid for soil sampling (n = 186). Farming systems on this landscape scale were described in terms of crop rotation, use of fertilizer, soil tillage, pesticides treatments, and liming. Molecular microbial biomass was estimated by soil DNA recovery. Bacterial and fungal communities were analyzed by 16S and 18S rRNA gene pyrosequencing. Microbial biomass was significantly stimulated by the presence of pasture during the crop rotation since temporary and permanent pastures, as compared to annual crops, increased the soil microbial biomass by +23% and +93% respectively. While soil properties (mainly pH) explained much of the variation in bacterial diversity, soil tillage seemed to be the most influential among the farming practices. A 2.4% increase in bacterial richness was observed along our gradient of soil tillage intensity. In contrast, farming practices were the predominant drivers of fungal diversity, which was mainly determined by the presence of pastures during the crop rotation. Compared to annual crops, temporary and permanent pastures increased soil fungal richness by +10% and +14.5%, respectively. Altogether, our landscape‐scale investigation allows the identification of farming practices that can effectively shape the soil microbial abundance and diversity, with the goal to improve agricultural soil management and soil ecological integrity.
Analyzing antenna effects on mobile chassis currents using theory of characteristic modes
Authors: Ghalib Asim , Sharawi Mohammad S. 
Published: June 2018

AbstractIn this article, the use of the mobile chassis for frequencies greater than 2 GHz is investigated. The analysis is conducted on 120 × 60 mm2 chassis size with 2 antenna types; monopole and planar inverted‐F antenna (PIFA). The use of the mobile chassis as the main radiating element for frequencies greater than 2 GHz is not practical or realistic. For such frequencies, the antenna is main radiating source that is why in an antenna and chassis scenario a 90% reduction in the ground plane for 2 different antenna types at 2.0 GHz did not affect the response (impedance bandwidth) of the system. At frequencies around 1 GHz, a 44% reduction in the ground plane did not affect the response either but one can observe that at lower frequencies the effect is more severe. The study shows that the antenna type and its localized currents are responsible for radiation. The effect of practical antenna elements on the chassis current modes is investigated. Different antenna types affect the chassis modes differently and the characteristic mode current maxima concentrate around the antenna element. Under such scenarios the excitation of a single mode is very difficult.
A wideband hybrid feeding circularly polarized magneto‐electric dipole antenna for 5G Wi‐Fi
Authors: Sun Kai , Yang Deqiang , Liu Sihao 
Published: June 2018

AbstractA hybrid‐fed circularly polarized magneto‐electric (ME) dipole antenna is presented for 5G Wi‐Fi application. A single series feeding cross‐aperture coupled structure is used to stimulate the ME dipole antenna. Measurement shows that the ME dipole antenna has an overlapped bandwidth of 23.5% from 4.98 to 6.31 GHz for the standards of both |S11| < −10 dB and axial ratio < 3 dB. A measured gain of approximately 7.5 dBi is obtained and the fluctuation of the realized gain is <1 dB from the whole operating frequency band. Moreover, because of the advantages of ME dipole, the proposed design realized a stable radiation patterns and roughly coincide radiation patterns at x‐o‐z and y‐o‐z plane in the operating frequency band.
3D‐printed index‐modulated substrate for beam in Fabry‐Perot cavity antennas
Authors: Ratni Badreddine , Kessi Sayad Ourdia , de Lustrac André , Piau Gérard‐Pascal , Burokur Shah Nawaz 
Published: June 2018

AbstractThe design of a beam steerable Fabry‐Perot cavity antenna based on the use of a phase modulated partially reflective surface is reported. The latter partially reflective surface makes use of a 3D‐printed index‐modulated dielectric substrate so as to incorporate the phase modulation. The engineered substrate is combined with uniform inductive and capacitive grids in order to design the phase‐modulated metal‐dielectric‐metal metasurface acting as a partially reflecting surface in the cavity antenna. Thanks to the phase modulation, the radiated beam of the antenna is steered to an off‐normal direction.
Compact and high sensitivity low‐temperature sensor based on coreless silica fiber Mach‐Zehnder interferometer
Authors: Baharin N. F. , Musa S. M. A. , Azmi A. I. , Razak M. A. A. , Abdullah A. S. , Salim M. R. , Mohd Noor M. Y. 
Published: June 2018

AbstractAn all‐fiber Mach‐Zehnder interferometer based on symmetrical offset coreless silica fiber (CSF) is proposed and demonstrated for temperature sensing. The sensor is constructed by a symmetrical offset splicing of a short CSF section between two CSF sections. Thus, two distinct optical paths are created inside and outside of the offset section resembling a Mach‐Zehnder interferometer. For temperature sensing, the offset gap is filled with refractive index liquid with high thermo‐optic coefficient of 3.34 × 10−4. Measurement is established by monitoring wavelength shift resulting from interference of modes between the two distinct optical paths. A very high temperature sensitivity of 3220 pm/°C has been achieved with a short sensor length of 1.5 mm. Due to its compact size and high sensitivity, the proposed structure would be an attractive option for low temperature measurement such as for human body temperature monitoring.
A double‐gap klystron type resonator with inductive quasi‐fractal elements
Authors: Miroshnichenko A.Y. , Tsarev V.A. , Akafyeva N.A. 
Published: June 2018

AbstractElectrodynamic characteristics and parameters of the double‐gap klystron resonator with the inductive microstrip elements on the suspended ceramic substrate has been investigated. The inductive part of a resonator made on the basis of a quasi‐fractal Sierpinski's triangle, and a capacitor part, made between end faces of the multi‐channel drift tubes and forming a double gridless gap. The developed resonator can find application in micro vacuum klystron devices working in the systems of telecommunication and navigation in 1‐ and multi‐frequency mode of operation.
A wideband printed slot antenna with harmonic suppression
Authors: Li Wei‐Wen , Qin Zhao‐Zhao , Chen Si‐Jie , Zhang Liang , Liu Qing‐Huo 
Published: June 2018

AbstractA wideband slot antenna with harmonic suppression is proposed to utilize the environment microwave energy. The antenna element is a printed narrow slot with an offset microstrip‐feed line to widen the operating band by generating the double resonance of similar frequencies. By adding a rectangular notch in the middle of slot element and grounding the microstrip terminal, its second‐order and third‐order harmonics are effectively suppressed. The experimental results of the prototype antenna show that the fractional bandwidth of its fundamental mode can reach 37.4%, while the antenna efficiencies of the second and third harmonics both are less than 23%. In the operating band the prototype antenna has the approximately omnidirectional radiation characteristic. This antenna structure also provides relaxed fabrication tolerances.
A low‐profile dual‐polarized multilayer parasitic patch array antenna with narrow air gap
Authors: Guo Li , Tang Ming‐Chun , Li Daotong 
Published: June 2018

AbstractThis article proposes a low‐profile dual‐linear polarized multilayer parasitic patch array antenna, which is composed of 3‐layer printed substrates and 1 air gap layer inserted between the lower and middle substrate. There is 1 slotted square patch printed on the lower substrate with 2 excited probes acting as feeding element, and 1 and 4 slotted square patches are on the middle and upper substrate respectively as parasitic elements. The stacked patches introduce additional dual‐polarized resonances for bandwidth enhancement. Specifically, the T‐ and rectangular slots and T‐stubs are employed near/on the orthogonal axis of the patches in order to achieve impedance matching and to improve 2 orthogonal polarizations. Furthermore, 6 stacked complementary split‐ring resonators (CSRRs) are loaded in the middle and upper substrate mainly for both impedance matching and port isolation adjustment. Simulated and measured results comply with each other, which shows that the fabricated antenna has an operational fractional bandwidth of 6.6% (2.34–2.5 GHz), a maximum gain of 7.9 and 6.9 dB at port 1 and 2 (while 10.2 and 9.3 dBi for the simulated ones), respectively, and port isolation better than 19 dB. In addition, the air‐gap thickness can be maintained at an extremely narrow level of 0.02λ0 (λ0 is the free‐space wavelength at the central frequency).
Fabrication of three‐dimensional printed rectangular waveguide T‐junction with in‐phase and equal power division
Authors: Genc A. , Goksu T. , Helhel S. 
Published: June 2018

AbstractThree‐dimensional (3D) printed rectangular waveguide T‐junction is presented with in‐phase and equal power division by means of iris and septum at 10–15 GHz frequency range to use the waveguide feed network for array antenna. The proposed T‐junction structure is designed and fabricated with 3D printing, as novelty, that is a good alternative to traditional methods in terms of reduced‐weight, cost, flexible applicability, and being monolithic for complex geometry. After making the skeleton of T‐junction from acrylonitrile butadiene styrene, metal plating process is applied over the all surfaces with copper. Transmission and reflection characteristics and electric‐field distribution of the structure are obtained with CST Microwave Studio software. Qualitative agreement is obtained between measurement and simulation with ∼7 dB shift and that shift is because of high precision and low surface roughness on 3D printed junctions. Unlike studies in the literature, the proposed study provides two points, as a novelty: First is that the fabrication of rectangular waveguide T‐junction with 3D printing is made. Second is that the return loss of T‐junction is improved by changing the geometry of iris and septum.
Miniaturized dual‐band filter using triple‐folded substrate‐integrated waveguide resonators
Authors: Li Mingkang , Jiang Shan , Chen Chang , Chen Weidong , Zhang Hualiang 
Published: June 2018

AbstractA miniaturized dual‐band filter using novel triple‐folded substrate‐integrated waveguide (TFSIW) resonators is proposed in this paper. The proposed TFSIW is enabled by specially designed folding structures, which leads to significant size reduction. The 2 lowest resonant modes, namely folded TE102 mode and folded TE101 mode in the TFSIW cavity, are utilized to achieve a dual resonance response with a small frequency ratio. To validate the design concept, a dual‐band filter operating at 1.91 and 2.32 GHz is designed, fabricated and characterized. Good agreement has been achieved between the simulation and measurement results. Moreover, the size of the proposed TFSIW resonator has been reduced for 86% compared with the conventional SIW resonator (assuming the same frequency ratio).
Linking interprofessional work to outcomes for employees: A meta‐analysis
Authors: Kaiser Sabine , Patras Joshua , Martinussen Monica 
Published: June 2018

ABSTRACTThe aim of this meta‐analysis of studies of workers in the health and social care sector was to examine the relationship between interprofessional work and employee outcomes of job stress, autonomy, burnout, engagement, job satisfaction, turnover intention, and perceived service quality, and to examine the influence of different moderators on those relationships. A systematic literature search of the PsycInfo, Embase, Medline, and the Cumulative Index to Nursing and Allied Health Literature databases was conducted to identify relevant articles. A total of 45 articles with results for 53 independent samples was included in the meta‐analysis. A random effects model was used to estimate the mean effect sizes (correlations). Most employees were nurses working in hospitals. Interprofessional work was weakly negatively associated with job stress, burnout, and turnover intention (range mean r = −.13 to −.22); and was moderately positively associated with autonomy, engagement, job satisfaction, and perceived service quality (range mean r =.33 to .46). When feasible, interprofessional work was categorized as teamwork (most intensive), collaboration, or cooperation. Teamwork, the most intense of three forms of interprofessional work, promoted lower burnout and turnover intention. The results of this meta‐analysis suggest that interprofessional work is linked to better well‐being for employees in health and social care.
Insights into unusual stability of 5‐membered‐ring endocyclic benzyl carbocations in aqueous solution
Authors: Sung Robert , Sung Kuangsen 
Published: June 2018

AbstractThe acyclic o‐oxygen benzyl carbocation 1, the 6‐membered‐ring endocyclic o‐oxygen benzyl carbocation 2, and the 5‐membered‐ring endocyclic o‐oxygen benzyl carbocation 3 were used as model compounds to get insights into the general phenomenon for the unusual stability of the 5‐membered‐ring endocyclic benzyl carbocations in aqueous solution. The hydride‐ion affinities of 1, 2, and 3 in gas phase, acetonitrile, and DMSO were calculated and compared by the density functional theory method, and 3 isodesmic reactions were designed to confirm their thermodynamic stability. What we found is that the 5‐membered‐ring endocyclic o‐oxygen stabilizes the benzyl carbocation 3 less than the acyclic o‐oxygen stabilizes the benzyl carbocation 1 in gas phase because of ring strain and through‐bond induction. However, the high solvation energies of the 5‐membered‐ring endocyclic o‐oxygen benzyl carbocation 3 not only offset the destabilizing effects of ring strain and through‐bond induction but also make it even more stable than the acyclic o‐oxygen benzyl carbocation 1 in polar solvents like acetonitrile, DMSO, and water.
An investigation of the relationship between social support and coping with stress in women with breast cancer
Authors: Ozdemir Deniz , Tas Arslan Fatma 
Published: June 2018

AbstractObjectivesSocial support may play a role in effective stress management and make a positive contribution to the health of women with breast cancer. The aim of this study was to determine the ways of coping with stress and levels of perceived social support of women with breast cancer, as well as the associated factors.MethodsThe descriptive and cross‐sectional study was conducted with 100 women with breast cancer at a training and research hospital in Turkey. Data were collected using an information form including sociodemographic and disease characteristics, the Scale of Ways of Coping with Stress, and the Multidimensional Scale of Perceived Social Support.ResultsEffective ways of coping with stress were found to be significantly lower in women who were primary school graduates and who did not undergo surgery (P < .05). The women's levels of effective coping with stress decreased with increasing age, and as the score of perceived social support from family and total score of perceived social support increased, so did the levels of effective coping with stress (P < .05). It was determined that social support and age significantly predicted effective stress management (P < .05).ConclusionsSocial support given to women with breast cancer is a key reference point in effective stress management, and increased age also has an important effect on women's ability to cope with stress.
Cosmopolitanism and ethical consumption: An extended theory of planned behavior and modeling for fair trade coffee consumers in South Korea
Authors: Lee Hyemi , Jin Yanhong , Shin Hyun 
Published: June 2018

AbstractTo better understand consumers' fair trade purchasing intentions, this study proposed an extended model of the Theory of Planned Behavior (TPB) in which a new determinant, cosmopolitanism, was added to reflect consumers' global orientation and perception of fair trade coffee in the context of globalization. In addition, this study employed the construct of “purchase implementation intention” to address the gap between stated intention and actual behavior. To test the study's hypotheses, a random survey was administered to 400 participants in Seoul, South Korea, a key emerging market for fair trade coffee consumption. The data were analyzed using a hierarchical regression method. Our findings suggest that (i) attitudes toward purchasing fair trade coffee, subjective norms, and cosmopolitanism were significant factors in predicting purchase implementation intentions with regard to fair trade coffee; (ii) perceived behavioral control was not statistically significant; and (iii) cosmopolitanism had a partial moderating effect on purchase implementation intentions. To confirm the utility of purchase implementation intention, a choice experiment involving 145 undergraduate and graduate students was administered. The data were analyzed using logistic regression. Purchase implementation intention was shown to reflect consumers' actual choice of fair trade coffee. Theoretical and managerial implications are discussed.
Effective‐Medium Models of Inner‐Core Anisotropy
Authors: Song Xin , Jordan Thomas H. 
Published: June 2018

AbstractBody‐wave and normal‐mode observations of Earth's inner core show cylindrical anisotropy consistent with an alignment of hexagonal close‐packed iron (hcp‐Fe) crystals along the rotation axis. We quantify the degree of alignment by comparing seismic observations longitudinally averaged over the outer 600 km of the inner core with stochastic rotation models based on ab initio calculations of hcp‐Fe stiffness tensors. Likelihood functions are constructed for the Woodhouse anisotropy ratios from an ensemble of normal‐mode models and for the Backus ray‐angle parameters from the Irving‐Deuss traveltime data set. The tensor at each inner‐core location is modeled as a random rotation of the hcp‐Fe stiffness tensor, and the rotations are assumed to have transversely isotropic statistics with correlation lengths that are small compared to the seismic wavelengths. Two stochastic rotation models are used, one based on Fisher statistics (F model) with concentration parameter κ and one by Jordan (J model) with orientation ratio ξ. The first‐order estimates, obtained by Voigt averaging, imply that hcp‐Fe tensors by Martorell and others considering premelting softening can account for the seismic data if the hcp‐Fe axes are moderately aligned with Earth's rotation axis (
,
). The J model is extended to include second‐order Born scattering, which in the low‐frequency limit depends on the aspect ratio η of the transversely isotropic correlation tensor. Although η is not usefully constrained by the existing data, we show that second‐order scattering acts to increase the required bipolar concentration of hcp‐Fe axes. Integrating over η yields the marginal estimate
, corresponding to a 50% dispersion angle of
.
Multiple Phase Changes in the Mantle Transition Zone Beneath Northeast Asia: Constraints From Teleseismic Reflected and Converted Body Waves
Authors: Tauzin Benoit , Kim Seongryong , Afonso Juan Carlos 
Published: June 2018

AbstractWe reassess the mantle transition zone structure below the northeast Asia margin in the context of subduction of the Pacific plate below the Eurasian continent. We use two independent approaches of teleseismic imaging, namely, compressional‐to‐shear converted waves (receiver functions) and shear wave underside reflections (SS precursors), and compare them within their statistical uncertainties. We find localized complexity in the interfaces marking solid phase changes in mantle minerals, in terms of both apparent topography and reflectivity. The 660‐km discontinuity is doubled, with ∼80‐km maximum vertical distance between the interfaces, over an 890 × 350 km2 region between 36–44°N and 130–133°E at the tip of the subducted Pacific plate. A similar complexity exists on the 410‐km discontinuity, coinciding with the presence of a deep cluster of seismicity below the Japan Sea. Both methods suggest the presence of low‐velocity zones atop the 410, within the mantle transition zone, and below the 660. This complex seismic signature is related to the Pacific plate and interpreted in light of the subduction thermal regime and phase equilibria for a pyrolitic mantle composition. Phase changes manifest themselves as broad zones of velocity gradients with localized doubled or multiple first‐order discontinuities, associated with transitions in the olivine, pyroxene, and garnet systems. An average pyrolitic composition and local temperatures of 1000–1300 K can explain the observed velocity gradients and multiple discontinuities. We show that the dissolution of stishovite, a high‐pressure polymorph of SiO2, into the higher‐pressure perovskite mineral, is a possible explanation for the low‐velocity zones at the top of the lower mantle.
On the Importance of Advective Versus Diffusive Transport in Controlling the Distribution of Methane Hydrate in Heterogeneous Marine Sediments
Authors: VanderBeek Brandon P. , Rempel Alan W. 
Published: June 2018

AbstractThe occurrence of methane hydrate in marine reservoirs often correlates with the physical properties of the host sediments. High hydrate saturations (>60% of the pore volume) found in association with coarser‐grained strata have been attributed to both enhanced advective transport through more permeable sediment layers and to perturbations in phase equilibrium related to pore space geometry that results in increased diffusive transport. To assess the relative importance of these mechanism in controlling hydrate occurrence, we develop a 1‐D model for hydrate growth along dipping, coarse‐grained layers embedded in a fine‐grained sediment package. We explicitly account for pore size effects on methane solubility and permeability‐driven variations in fluid flux. We show how the vertical distribution of hydrate varies in response to changes in grain size and rates of fluid advection, sedimentation, and in situ methane production. We then use our model to simulate centimeter‐scale variations in hydrate saturation observed at Walker Ridge Block 313, Hole H in the Gulf of Mexico. We find that the largest concentrations of hydrate are controlled by diffusion, while increased advective methane supply favors more distributed growth throughout high‐permeability regions. Our results hold promise for using well log‐derived estimates of hydrate saturation to infer sediment properties and the sources and rates of methane supply during reservoir emplacement.