bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gigabit LED‐based visible light transparent transmission from free‐space to a 100‐m ultra‐large effective area pure silica fiber
Authors: Shi Jianyang , Zhou Yingjun , Chi Nan , Xiong Liangming , Luo Jie 
Published: December 2017

AbstractWe experimentally demonstrate the LED‐based visible light transmission (VLC) over a 100‐m special designed low‐loss ultra‐large effective area (diameter >1 mm) pure silica fiber (ULEAPS fiber). Three‐channel wavelength multiplexing is achieved by using a single chip RGB LED as the light source. The total insertion loss after 100‐meter transmission for the red light, green light and blue light are 1.015, 1.582, and 3.660 dB, respectively. A total data rate of 3.1 Gb s−1 is experimentally achieved over 5‐m ULEAPS fiber and a data rate of 2 Gb s−1 is achieved over 100‐m fiber with the bit error rate (BER) below 7% forward error correction (FEC) limit of 3.8 × 10−3. The results obtained here may also serve as a valuable information on how to realize LED based VLC transparent transmission from free‐space to a pure silica fiber utilizing a commercial illumination LED as the light source.
Semi‐transparent frequency reconfigurable antenna with DGS
Authors: Lim M.C. , Rahim S.K.A. , Hamid M.R. , Soh P.J. , Eteng Aa 
Published: December 2017

AbstractIn this letter, a semi‐transparent frequency reconfigurable antenna is proposed and investigated. This antenna is implemented on glass as a substrate, AgHT‐4 as a radiating element and copper as its ground plane to result in a semi‐transparent feature. A pair of PIN diodes is utilized as microwave switches along with a DC biasing circuit. This proposed antenna is fed by a CPW arrangement and introduces unequal E‐shaped Defected Ground Structure (DGS) on the ground plane for modification of the electrical length. The antenna exhibits a −10 dB impedance bandwidth from 3 to 6 GHz when PIN diodes are ON, and a resonance at 4.75 GHz when pin diodes are OFF. The proposed antenna is fabricated to validate its performance in terms of reflection coefficient and radiation pattern.
Compact planar 2 × 2 and 4 × 4 UWB mimo antenna arrays for portable wireless devices
Authors: Sipal Deepika , Abegaonkar Mahesh. P. , Koul Shiban K. 
Published: December 2017

AbstractA very compact 2 × 2 and 4 × 4 ultra wide band (UWB) multiple input multiple output (MIMO) antenna array with high isolation and polarization/pattern diversity are proposed in this letter. The compact size of antenna with orthogonally polarized elements help in achieving high isolation between elements of the arrays without using any decoupling circuit while maintaining its overall size very compact. The monopole UWB antenna prototype has compact size of 14 × 14 mm2 and enlarged to 2 × 2 array having size of 14 × 31 mm2 and 4 × 4 array having overall size of 31 × 31 mm2. The proposed designs have been fabricated and tested. Measured isolations |S21| are ≤ −25 dB and ≤ −20 dB for 2 × 2 and 4 × 4 arrays, respectively. However, impedance bandwidth |S11| is ≤ −10 dB for both arrays in the range from 3.6 to 10.6 GHz. The simulated, measured and calculated result shows good agreement for its impedance matching, isolation and dual polarization characteristics. Dual polarization improves its diversity performance and compact size improves its spatial multiplexing.
A compact 1:15 unequal Wilkinson power divider using A‐CRLH coupled lines
Authors: Torabi Yalda , Dadashzadeh Gholamreza 
Published: December 2017

AbstractA novel asymmetric composite right/left‐handed (A‐CRLH) coupled‐line circuit structure for a miniaturized unequal Wilkinson power divider (WPD) with arbitrary large power division ratio and reduced arm's length is proposed. Compared with the traditional unequal WPD, using the A‐CRLH coupled‐line section in the proposed power divider, due to its controllable phase response and characteristic impedances, not only leads to more compact layout but also results in a larger power‐dividing ratio with relaxed line width and separation. The simplified design procedure along with closed form equations based on c‐ and π‐mode analysis and transmission‐line‐based metamaterial theory is derived. For demonstration, a practical A‐CRLH WPD with a high power‐dividing ratio of 1:15 as a typical example, at 1.4 GHz is designed, simulated and fabricated. The occurred area of the implemented power divider is 58.7% smaller than that of the conventional one at the same frequency and its experimental results show good agreement with simulation data.
Time domain characterization of high power solid state amplifiers for the next generation linear accelerators
Authors: Hoang Duc Long , Bhattacharyya Anirban , Goryasko Vitaliy , Ruber Roger , Rydberg Anders , Olsson Jorgen , Dancila Dragos 
Published: December 2017

AbstractThis paper presents the time‐domain characterization of high power pulsed solid state amplifiers to be used for linear accelerator applications. The study comprises nonlinear circuit envelope simulations and time domain envelope measurements. Measurements and simulations are performed under the pulsed conditions (3.5 ms pulse width, 5% duty cycle) specific to the European Spallation Source (ESS) high intensity proton accelerator. We measure the characteristics of pulsed LDMOS based power amplifiers such as: pulse droop along the pulse, efficiency, average envelope pulse amplitude and phase, pulse drain current waveform, pulse drain voltage waveform, etc. A comparison between the measured results and the simulated results is also presented. In addition to the pulse profile characterization, the pulse to pulse (P2P) stability of the presented solid state power amplifier (SSPA) is investigated as variations of amplitude and phase. The P2P stability simulations are introduced as a combination of the Monte‐Carlo simulations and the nonlinear circuit envelope simulations. The simulated results are used for fitting the P2P measurements to give an early insight of causes of instabilities of the nonlinear LDMOS models.
Compact wide triband multicavity‐coupled slot antenna
Authors: Li Wei‐Wen , Su Jin‐Sheng , Zhou Jian‐Hua , Shi Zhi‐Yuan 
Published: December 2017

AbstractIn this letter, we propose a triband slot antenna with additional slots directly connected to an original slot radiator. The proposed antenna has been halved to reduce the antenna size. The experimental results show that this antenna can operate in three bands of 2.38–2.58 GHz, 3.34–3.85 GHz, and 5.07–5.60 GHz, respectively. Meanwhile, the parameter analysis has indicated that each band works according to the cavity‐coupled mode, which can enlarge the bandwidth and enhance the stability of radiating patterns in the corresponding bands.
Modalmetric interferometer under Fingerprint disturbances: The effect of lateral offset between the single‐mode and multimode fiber splice
Authors: Ribeiro Ricardo M. , Balod Yanes C. 
Published: December 2017

AbstractWe report on the wavelength and time‐domain responses of a lumped or distributed fiber‐optic modalmetric interferometer under a very smooth pressure (fingerprint) disturbances in the 1530–1610 nm wavelength range. A simple method to quantify such disturbances is proposed. It is shown that the lateral offset shift of 5.9 mm between the single‐mode and the multimode fiber splice makes the device even more sensitive. It was measured an electrical signal power enhancements of 3.5 and 7.5 dB for 1 m and 1.65 km multimode fiber link, respectively.
A novel miniaturized UWB monopole with five‐section stepped‐impedance feed line
Authors: Ul Haq Muhammad Aziz , Koziel Slawomir 
Published: December 2017

AbstractA structure and design procedure of a compact ultra‐wideband (UWB) monopole antenna is proposed. In order to achieve additional size reduction, a modified‐shape feed line and a five‐section rectangular slit below the feed line is incorporated into a reference antenna featuring a two‐section rectangular slit below the feed line and two radiator slots. The minimum‐size is obtained by adjustment of all geometry parameters of the structure using rigorous numerical optimization. An explicit constraint on antenna reflection characteristic is imposed in order to ensure sufficient matching in the entire UWB frequency range. The footprint area of the final design is only 167 mm2 with antenna dimensions of 22.46 mm × 7.45 mm. Experimental validation confirms good electrical and field properties. Thorough benchmarking indicates that the proposed antenna is competitive to recently reported designs.
A high FoM monopole antenna with asymmetrical L‐slots for WiMAX and WLAN applications
Authors: Gangwar A. , Alam M. S. 
Published: December 2017

AbstractA triband monopole patch antenna with high figure‐of‐merit (FoM) for WiMAX and WLAN applications has been proposed. It consists of a rectangular patch with two asymmetrical L‐shaped slots, where L‐slots generate two lower resonance frequencies and patch the higher. A parametric study to optimize the slot length is carried out to achieve the desired frequency bands. An equivalent circuit model of the antenna is developed and analyzed for loss due to input impedance mismatch at each resonance frequency. The simulated results of return loss of antenna and radiation patterns are validated with experimental results.
Demonstration of negative refractive index with low‐cost inkjet‐printed microwave metamaterials
Authors: İbili Hande , Karaosmanoğlu Barışcan , Ergül Özgür 
Published: December 2017

AbstractWe present low‐cost fabrications of inkjet‐printed metamaterials that are resonating at microwave frequencies. A very low‐cost setup involving commercial desktop printers loaded with silver‐based inks is constructed and used to fabricate the metamaterials. We show that, despite the challenges in the low‐cost fabrication processes, successful prints, and metamaterial samples can be obtained. A composite metamaterial design, which possesses a bandlimited transparency due to the induced negative refractive index, is fabricated and tested to demonstrate the feasibility of low‐cost metamaterials with relatively complex geometries involving three‐dimensional arrangements.
Antipodal Vivaldi antennas with foldable hinged plates for adaptive polarization and gain adjustments
Authors: Byun G. , Lim T. H. , Kang M. C. , Choo H. 
Published: December 2017

AbstractThis letter proposes a novel approach to adaptive polarization and gain adjustments for antipodal Vivaldi antennas using foldable hinged plates. The proposed antenna consists of upper and lower flared wings, and the wings are electrically extended using two rectangular plates. Metal hinges are then adopted to fold and unfold the plates, which allows the antenna to adjust the polarization in the entire range of the axial ratio and to further enhance the gain in the end‐fire direction. Measured antenna characteristics demonstrate that the polarization and the gains are adaptively adjusted by varying the tilt angles of the hinged plates without a distortion of the broadband properties.
A broadband U‐shaped patch antenna on PTFE/Cu substrate for 60 GHz wireless communications
Authors: Adane Amar , Person Christian , Gallee François 
Published: December 2017

AbstractA U‐shaped antenna is printed on polytetrafluoroethylene film, deposited on a copper base having air cavity inside, using thin film micro‐strip technology. This antenna is as compact as the rectangular patch and covers the 51.5–62 GHz band. Unlike the silicon substrate, its metallic support yields better radiation patterns.
Diminished cerebral oxygen extraction and metabolic rate in sickle cell disease using T2 relaxation under spin tagging MRI
Authors: Bush Adam M. , Coates Thomas D. , Wood John C. 
Published: December 2017

PurposeT2 MRI oximetry can noninvasively determine oxygen saturation (Y) but requires empirical MR calibration models to convert the measured blood transverse relaxation (T2b) into Y. The accuracy of existing T2b models in the presence of blood disorders such as sickle cell disease (SCD) remains unknown.MethodsA Carr Purcell Meiboom Gill T2 preparation sequence was used to make 83 whole blood measurements from 11 subjects with SCD to derive an ex vivo sickle hemoglobin (HbS) T2b model. Forearm venous blood gas, sagittal sinus T2 (T2 Relaxation Under Spin Tagging) and total brain blood flow (phase contrast MRI) were measured in 37 healthy controls and 33 SCD subjects (age 24.6 ± 10.2 years). Cerebral oxygen saturation, extraction fraction, and metabolic rate estimates were calculated using three separate T2b models. Cerebral and forearm oxygen extraction fraction were compared.ResultsEx vivo, SCD blood had greater saturation dependent relaxivity than control blood, with a weak dependence on HbS and no dependence on hematocrit. In vivo, the HbS T2b model predicted Yv values with lowest coefficient of variation (compared with existing T2b models) and the strongest correlation with peripheral venous oximetry (r2 = .29). The HbS T2b model predicted systematically higher Yv measurements in SCD patients (73 ± 5 and 61 ± 6; P < 0.0001) which was mirrored by peripheral venous measurements (75 ± 20 and 45 ± 20; P < 0.0001).ConclusionCerebral and peripheral oxygen extraction are decreased in SCD patients, suggesting either blood flow is increased beyond metabolic demands or the presence of physiological arterial‐venous shunting. Magn Reson Med 80:294–303, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Der Gestank aus Plastikspielzeug
Authors: Wiedmer Christoph , Büttner Andrea 
Published: December 2017

AbstractImmer wieder fallen Kunststoffprodukte für Kinder wie Schwimmringe, Gummitiere oder Faschingsartikel durch ihren intensiven Geruch auf. Die Substanzen, die solche Fehlgerüche verursachen, sind nicht in jedem Fall bekannt und lassen sich deshalb bei Routineanalysen nicht umfassend bestimmen. Mit Nachweisverfahren, die instrumentelle Analytik mit der menschlichen Nase kombinieren, ist es nun möglich, die Strukturen verschiedener Geruchsstoffe aufzuklären.
Zersetzung bringt Neues: Korrosionsprodukte im Museum
Authors: Bette Sebastian , Dinnebier Robert E. , Eggert Gerhard 
Published: December 2017

AbstractUm Sammlungsgüter wie Geschirr, Krüge und Bilder in Museen und Sammlungen sachgemäß zu konservieren, müssen die Korrosionsprodukte im Detail bekannt sein. Methoden der Röntgenpulverdiffraktometrie helfen, die Carbonat‐, Acetat‐ und Formiatphasen zu charakterisieren, Einkristalle sind nicht nötig.
Mehr Zitationen erhalten
Authors: Böhme Uwe , Tesch Silke 
Published: December 2017

AbstractWissenschaftler möchten, dass die wissenschaftliche Community ihre Arbeiten beachtet und möglichst häufig zitiert. Wie oft ein Artikel zitiert wird, lässt sich beeinflussen, auch ohne die gute wissenschaftliche Praxis zu verletzen.
Wie Licht Klebrigkeit steuert
Authors: Kizilkan Emre , Staubitz Anne , Gorb Stanislav N. 
Published: December 2017

AbstractEin bioinspirierter Haftvermittler mit Mikrostrukturen haftet leimfrei und trocken. Kombiniert mit flüssigkristallinen Elastomeren, die auf UV‐Licht reagieren, lässt sich die Haftung ein‐ und ausschalten, sodass sich Gegenstände transportieren lassen.
Für das Heute lernen
Authors: Panne Ulrich 
Published: December 2017

AbstractIm Jahr 1867 gründete sich die Deutsche Chemische Gesellschaft, die ältere der beiden Vorgängerorganisationen der GDCh. In Zeiten des technologischen und wissenschaftlichen Wandels wird die Innovationskraft der Chemie gerne auch mal bezweifelt.
Analytical approach for time‐dependent groundwater inflow into shield tunnel face in confined aquifer
Authors: Liu Xiao‐Xue , Shen Shui‐Long , Xu Ye‐Shuang , Yin Zhen‐Yu 
Published: December 2017

SummaryPrediction of time‐dependent groundwater inflow into a shield tunnel is a significant task facing engineers. Published literature shows that there is no available method with which to predict time‐dependent groundwater inflow into a tunnel. This paper presents a prediction approach for time‐dependent groundwater inflow into a tunnel in both anisotropic and isotropic confined aquifers. The proposed solution can predict groundwater inrush from the tunnel cutting face. To obtain the time‐dependent groundwater flow quantity, the concept of a horizontal‐well pumping test based on the theory of a point source is adopted. Multiple factors, eg, drawdown, thickness of aquifer, conductivities, and specific storage, are taken into account. Both groundwater inflow to the cross section of a tunnel face in the y‐z plane and total tunnel inflow are obtained. Based on the proposed approach, the time‐dependent groundwater inflow to a tunnel can be classified as either a uniform or non‐uniform flow. The proposed approach is applied to analyse groundwater inflow of 2 field cases: (1) Metro line No. 7, Guangzhou City and (2) an underground tunnel in Huizhou, Guangdong Province. Results show that the proposed method can predict the measured values, and drawdown‐related curves are also derived. In addition, the calculated results also reveal that the effect of hydraulic conductivity kz on the total groundwater inflow differs from that of hydraulic conductivities kx and ky and the thickness of the aquifer.
Together Eating & Activity Matters (TEAM): results of a pilot randomized‐clinical trial of a spousal support weight loss intervention for Black men
Authors: Alick C. L. , Samuel‐Hodge C. , Ward D. , Ammerman A. , Rini C. , Tate D. F. 
Published: December 2017

SummaryObjectivesThe objective of this study is to evaluate the feasibility, participation, preliminary efficacy and retention in a couples‐based weight loss intervention among Black men.Design, setting, participantsTwo‐arm pilot randomized clinical trial in an academic clinical setting. Forty self‐identified Black men and their female cohabitating partners (n = 80) aged 18 to 65 years with body mass index from 25 to 45 kg/m2 were randomized using computer generated tables to allocate treatments.InterventionParticipants were randomized to a standard behavioural weight loss (Standard) programme or the Standard programme plus partner involvement (Enhanced). Both interventions focused on calorie reduction, physical activity and self‐monitoring to facilitate weight loss. Enhanced included couples skills training and couple's communication components.Main outcome and measuresChanges in weight from baseline to 3 months among men. Partner weight loss (secondary).ResultsForty Black couples (men mean [SD] age, 47.4[11] years; body mass index, 35.0[6.1]), were recruited. Retention was 100% of the men and 98% of female partners. Attendance at group sessions was 63–73%. Between groups, mean (SD) weight changes among men were −3.4[.04] and −4.7[5.9] kg (p = 0.57) and among women −0.23[4.46] and −2.47[3.62] kg (p = 0.09), in the standard and enhanced groups.ConclusionsWeight losses from an intervention enhanced by partner involvement and an intervention with no partner involvement were not different. Treatment choice can be based on preference rather than outcome as both treatments are effective in producing clinically significant percent weight loss.Trial registration Clinical Trials NCT02458053.
Light and temperature effects on miR156 transgenic switchgrass flowering: A simulated latitudinal study
Authors: Johnson Chelsea R. , Millwood Reginald J. , Wang Zeng‐Yu , Stewart Charles N. 
Published: December 2017

AbstractThe control of flowering in perennial grasses is an important trait, especially among biofuel feedstocks. Lignocellulosic biomass may be increased commensurate with decreased or delayed flowering as the plant allocates energy for stems and leaves harvested for bioenergy at the end of the growing season. For transgenic feedstocks, such as switchgrass (Panicum virgatum L.) grown in its geographic center of distribution, it is foreseeable that regulators may require greatly decreased gene flow frequencies to enable commercialization. Transgenic switchgrass with various overexpression levels of a rice microRNA gene, miR156, when grown in field conditions, holds promise for decreased flowering, yielding high biomass, and altered cell wall traits, which renders it as a potential crossing partner for further breeding with switchgrass lines for decreased recalcitrance. In the current research, we simulated a latitudinal cline in controlled growth chamber experiments for various individual sites from the tropics to cool‐temperate conditions which included weekly average high and low temperatures and day lengths over the switchgrass growing season for each simulated site: Guayaquil, Ecuador; Laredo, Texas, USA; and Brattleboro, Vermont, USA. Flowering and reproduction among transgenic lines with low (T‐14 and T‐35)‐to‐moderate (T‐27 and T‐37) overexpression of miR156 were assessed. Lower simulated latitudes (higher temperatures with low‐variant day length) and long growing seasons promoted flowering of the miR156 transgenic switchgrass lines. Tropical conditions rescued the flowering phenotype in all transgenic lines except T‐27. Higher numbers of plants in lines T‐35 and T‐37 and the controls produced panicles, which also occurred earlier in the study as temperatures increased and day length decreased. Line T‐14 was the exception as more clonal replicates flowered in the cool‐temperate (Vermont) conditions. Increased biomass was found in transgenic lines T‐35 and T‐37 in tropical conditions. No difference in biomass was found in subtropical (Texas) chambers, and two lines (T‐14 and T‐35) produced less biomass than the control in cool‐temperate conditions. Our findings suggest that switchgrass plants engineered to overexpress miR156 for delayed flowering to promote bioconfinement and biomass production may be used for plant breeding at tropical sites.