bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classification of precipitation series using fuzzy cluster method
Authors: Dikbas Fatih , Firat Mahmut , Koc A. Cem , Gungor Mahmud 
Published: May 2011

AbstractThe identification of hydrologically homogeneous regions is one of the most important steps of regional frequency analysis. The hydrologically homogeneous regions should be determined using cluster analysis instead of the geographically close regions or stations. In this study, fuzzy cluster method (Fuzzy C‐Means: FCM) is applied to classify the precipitation series and identify the hydrologically homogeneous groups. The choice of appropriate cluster method and the variables that will be used according to the data of the basin is also very important. In the context of this study, total precipitation data of stations operated by National Meteorology Works (DMI) in Turkish basins for cluster analysis are used. The optimal number of groups is determined as six, based on different performance evaluation indexes. Regional homogeneity tests based on L‐moments method are applied to check homogeneity of these six regions identified by cluster analysis. Regional homogeneity test results show that regions defined by FCM method are sufficiently homogeneous for regional frequency analysis. According to the results, FCM method is recommended for classifying the precipitation series and for identifying the hydrologically homogenous regions. Copyright © 2011 Royal Meteorological Society
Relationship of summer soil moisture with early winter monsoon and air temperature over eastern China
Authors: Liu Ge , Chen Jun‐Ming , Ji Li‐Ren , Sun Shu‐Qing 
Published: May 2011

AbstractThe time‐lagged effect of summer soil moisture (SM) on ensuing winter climate in eastern China is examined. The East Asian winter monsoon (EAWM) in early winter (November) and associated air temperature over eastern China are shown to significantly correlate with the previous summer (June–August) SM in eastern China with a center located at the lower reaches of the Yellow River (LRYR). The positive anomalies of summer SM, persisting for a few months, may act as a buffer to defer the ground cooling of eastern China in early winter mainly through modulating thermal capacity. And the warmer ground of eastern China could lead to a warmer air temperature above the ground through direct land–air interactions and through indirectly adjusting the EAWM which is sensitive to the land–sea thermal contrast. These results provide an empirical predictor for the EAWM and for the variability of air temperature over eastern China in early winter. Copyright © 2011 Royal Meteorological Society
Characterising the long‐range transport mechanisms of different aerosol types over Athens, Greece during 2000–2005
Authors: Kaskaoutis D. G. , Nastos P. T. , Kosmopoulos P. G. , Kambezidis H. D. 
Published: May 2011

AbstractThis study analyses the weather conditions, the main pathways and transport mechanisms favouring the presence of specific aerosol types over Athens, Greece. On the basis of the aerosol optical depth at 550 nm (AOD550) and fine mode (FM) values from a Terra‐MODIS dataset in the period 2000–2005, three main aerosol types are identified (urban/industrial, UI; clean maritime, CM; and desert dust, DD), each one corresponding to different optical characteristics and source regions. The UI aerosols are associated with polluted air masses from Europe, the CM aerosols with clean Atlantic air masses and the DD aerosols with air masses from North African arid regions carrying significant amount of dust in certain cases. The comparison of the three aerosol types with the air masses from their favourable sector constitutes a first ‘quick‐validation’ of the identification scheme. Thus, the incidence of transport from Europe explain 81% of the variability in the observed UI type, while the 73% of the Atlantic air masses correspond to the CM type; the 50% of the African air masses can be considered as DD aerosols over Athens. The mean synoptic meteorological patterns, favouring the presence of each aerosol type, are also investigated. Further analysing the air‐mass trajectories at three altitudes, the transport mechanisms of the aerosol types are identified. The results clearly show that the UI aerosols are mainly transported within the boundary layer, while the CM conditions are associated with Atlantic air masses at higher altitudes. Moreover, the DD aerosols are transported either in the upper atmosphere or in the whole atmospheric column. This is among the first studies conducted over Athens aiming at investigating the weather conditions, pathways and transport mechanisms that favour the presence of aerosols of different characteristics. Copyright © 2011 Royal Meteorological Society
Characterization of typical coastal circulations with high‐resolution measurements in the Gulf of Valencia
Authors: Fock Björn Hendrik , Schlünzen K. Heinke 
Published: May 2011

AbstractMeasurements from 27 stations taken in the coastal area of the Gulf of Valencia are utilized to characterize the typical coastal circulation systems observed in this area. The wind measurements are available in a resolution of 15 s at daytime and 5 min at nighttime and cover the period of May 2006–April 2007. The analysis of median daily cycles shows that the meteorological situation in the Gulf of Valencia is dominated by a distinguished sea breeze. The observed development of local circulation systems varies within a distance of just a few kilometres, not only over land but also over water. These variations can be explained by the local influences of a pronounced coastal orography, land use and shape of the coastline. The measurements are classified in days with and days without pronounced sea breeze effects. This classification allows a refined discussion on spatial and temporal characteristics of the observed circulation systems. The classification shows an occurrence of sea breezes at 2 out of 3 days. Copyright © 2011 Royal Meteorological Society
Polymeric ionic liquid‐coated capillary for capillary electrophoresis
Authors: Li Jing , Han Haifeng , Wang Qing , Liu Xia , Jiang Shengxiang 
Published: May 2011

AbstractA new application of the polymeric ionic liquid (PIL) in capillary electrophoresis is reported. Poly(1‐vinyl‐3‐butylimidazolium bromide) was physically adsorbed on silica capillary as the simple and effective coating for capillary electrophoresis (CE) analysis, in which the PIL is not present in the background electrolyte. The electroosmotic flow (EOF) of the PIL‐coated capillary as compared with that of the bare fused‐silica capillary shows a different dependence on electrolyte pH values. The EOF is reversed over a wide pH range from 3.0 to 9.0 and shows good repeatability. It is also found that the coated capillary has a good tolerance to some organic solvents, 0.1 M NaOH and 0.1 M HCl. The PIL‐coated capillary has been employed in different areas. Both the basic proteins and anionic analytes can be well separated by PIL‐coated capillaries in a fast and easy way. The PIL‐coated capillary is also able to separate organic acid additives in a grape juice. The results showed that this type of coating provides an alternative to the CE separation of anions and basic proteins.
EXCLOSURE EFFECTS ON RECOVERY OF SELECTED SOIL PROPERTIES IN A MIXED BROADLEAF FOREST RECREATION SITE
Authors: Özcan M. , GÖkbulak F. , Hizal A. 
Published: May 2011

ABSTRACTHuman‐caused trampling that results from excessive recreational use has caused damage to soil and vegetation in forest ecosystems in the Belgrad Forest of Istanbul. The objectives of this study were to examine effects of exclosure on selected soil properties and to determine the recovery time required for soil characteristics in a broadleaf forest recreation site.Litter biomass and topsoil (0–15 cm) were sampled in the forest, exclosure and recreational sites, and soil samples were analysed for saturation capacity, permeability, bulk density, total porosity, organic matter, root biomass, electrical conductivity and soil pH.Results showed that saturation capacity, permeability, total porosity and organic matter increased whereas bulk density decreased significantly in the topsoil under the exclosure, and all these soil properties in the topsoil of the exclosure were greater than those of recreational site. When effects of main factors were compared, averaging over sampling year and soil sampling depth, soils from the exclosure had significantly greater saturation capacity, permeability, total porosity, organic matter and litter biomass and lower bulk density values than the soils from recreational site.Six years of exclosure was effective in improving most of the soil properties in the topsoil. When topsoil and subsoil are considered together, it is obvious that a longer time period is needed for soil recovery in the forest recreational sites. Copyright © 2011 John Wiley & Sons, Ltd.
Nitrogen‐Rich Plasma‐Polymerized Coatings on PET and PTFE Surfaces Improve Endothelial Cell Attachment and Resistance to Shear Flow
Authors: Gigout Anne , Ruiz Juan‐Carlos , Wertheimer Michael R. , Jolicoeur Mario , Lerouge Sophie 
Published: May 2011

AbstractLow seeding efficiency and poor cell retention under flow‐induced shear stress limit the effectiveness of in vitro endothelialization strategies for small‐diameter vascular grafts. Primary‐amine‐rich plasma‐polymerized coatings (PPE:N) deposited using low‐ and atmospheric‐pressure plasma discharges on PET and PTFE are evaluated for their ability to improve endothelial cells' kinetics and strength of attachment. PPE:N coatings increase cell adhesion and adhesion rate, spreading, focal adhesion, and resistance to flow‐induced shear compared with bare and gelatin‐coated PET and PTFE. In particular, about 90% of the cells remain on coated surfaces after 1 h exposure to shear. These coatings, therefore, appear as a promising versatile approach to improve cell seeding strategies for vascular grafts. magnified image
Hybrid Coatings Containing Silver Nanoparticles Generated In situ in a Thiol‐Ene Photocurable System
Authors: Colucci Giovanna , Celasco Edvige , Mollea Chiara , Bosco Francesca , Conzatti Lucia , Sangermano Marco 
Published: May 2011

AbstractNovel silver/polymer composites based on thiol‐ene chemistry are prepared by an in situ bottom‐up approach. The in situ synthesis of silver particles inside the polymer matrix is achieved in one pot by photoreduction reaction in presence of a silver precursor and the concurrent crosslinking reaction. XPS analysis confirms the formation of silver particles; TEM morphological investigation shows a very good dispersion and distribution of the nanometric silver particles within the thiol‐ene network. Antimicrobial properties of the photocured hybrids are also evaluated. magnified image
Morphology and Properties of Polymer Composites Based on Biodegradable Polylactide/Poly[(butylene succinate)‐co‐adipate] Blend and Nanoclay
Authors: Ojijo Vincent , Cele Hastings , Sinha Ray Suprakas 
Published: May 2011

AbstractPolymer composites based on biodegradable polylactide/poly[(butylene succinate)‐co‐adipate] (PLA/PBSA) blend and pristine and organically modified clays have been prepared via melt‐mixing in a batch‐mixer. Four different surfactants have been used to modify the pristine montmorillonite (MMT) clay. The weight ratio of the PLA and PBSA is 70:30, while the weight of the MMT is fixed at 6%. The surface morphologies of the unmodified and organoclay‐modified blends have been studied by field‐emission scanning electron microscopy. Results show that the domain size of the dispersed PBSA‐phase is reduced with the addition of organoclay and the extent of this reduction in the size of PBSA domain is dependent on not only the interlayer spacing of the clay but also enthalpic interaction between the clay surface and the polymer blend. The degree of dispersion of silicate layers in the blend matrix has been characterised by X‐ray diffraction. The improved adhesion between the phases and the fine morphology of the dispersed phase contributes to the improvement in the mechanical and thermal properties of the final polymer blend–organoclay composites over PLA/PBSA blend. On the basis of these results, we propose a general understanding on how the morphology of the blends is related to the final properties. magnified image
Mimicking Lotus Leaf: Development of Micro‐Nanostructured Biomimetic Superhydrophobic Polymeric Surfaces by Ultrafine Powder Coating Technology
Authors: Mozumder Mohammad Sayem , Zhang Hui , Zhu Jesse 
Published: May 2011

AbstractThis study demonstrates the development of polymeric superhydrophobic surfaces by a solvent‐free ultrafine powder coating (UPC) technique for the first time. The developed surfaces exhibit lotus effect with water contact angles (CAs) of over 160° and sliding angle (SA) of less than 5°. It is evident that the higher CA and lower SA of the low‐energy surfaces are attributed to the appropriate surface textures of micro‐ and/or nano‐scales. AFM and SEM images revealed the unique double‐scale hierarchical (micro‐ and nano) structures on the developed superhydrophobic surfaces. As an additional advantage, these superhydrophobic UPC technology eliminates the use of toxic solvents that are responsible for the hazardous emissions of VOCs. Therefore, fabrication of polymeric superhydrophobic surfaces by solvent‐free PC technique has enormous opportunities for a revolutionary expansion in coating industry to save the surfaces from the intervention of moisture. magnified image
Ultra‐wideband monopole antenna with modified triangular patch
Authors: Sadeghzadeh R. A. , Zehforoosh Y. , Mirmotahhary N. 
Published: May 2011

AbstractThis article presents the results of a novel triangular monopole antenna that exhibits multioctave performance.This modification significantly improves the antenna's impedance bandwidth by 158% over an ultra‐wideband frequency. The antenna's simulated return loss and radiation patterns show very good correlation with the fabricated antenna's measured results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26093
Terahertz wave bandpass filter based on metamaterials
Authors: Jin Ning , Li Jiu‐Sheng 
Published: May 2011

AbstractWe designed and demonstrated experimentally a narrow terahertz wave bandpass filter based on metamaterials. By using terahertz time‐domain spectroscopy system, we examined the transmittance spectra for the proposed terahertz wave filter. The experimental results show that terahertz wave bandpass filter with a narrow transmission bandwidth (1.5%) centered at 2.0 THz, transmittance peak of 0.56419 (i.e., insertion loss of 2.48 dB) and very sharp edges can be achieved. The measurement results closely correspond to the simulated predictions are observed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26097
A planar triangular monopole antenna with modified ground for UWB application
Authors: Mu Xin , Gong Shu‐Xi , Hong Tao 
Published: May 2011

AbstractA new design about planar triangular monopole antenna using a modified ground plane for bandwidth enhancement is proposed. By symmetrically etching a pair of modified L‐shaped slots in the ground plane, the impendence bandwidth is increased to 2.5–10.8 GHz under the condition of VSWR<2. Comparing with the original antenna (not slotted), the operating band of the proposed antenna is largely expended, whereas good radiation characteristics hold. The measured and simulated results show that the operating band of the proposed antenna completely covers the frequency range of ultra‐wide band (UWB). © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26100
Dual band frequency selective surface based on circular aperture‐coupled patches
Authors: Zhou Hang , Qu Shao‐Bo , Lin Bao‐Qin , Zhang Jie‐Qiu , Gu Chao , Ma Hua , Xu Zhuo , Bai Peng , Peng Wei‐Dong 
Published: May 2011

AbstractA dual band frequency selective surface (FSS) based on circular aperture‐coupled patches is presented. The technique is based on using two same structures with different sizes. A special topology is proposed to arrange the two different sizes structures. Each structure is composed of two circular patches and a circular coupling aperture. The dual band FSS has a second‐order band pass responses at each band of operation and owes its advantages to high selectivity and stable performance for both various incident angles and different polarizations. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26102
Tunable microwave photonic frequencies generation based on stimulated Brillouin scattering operating in the L‐band region
Authors: Ahmad Harith , Norizan Siti Fatimah , Awang Noor Azura , Zulkifli M.Z. , Ghani Z. A. , Harun Sulaiman Wadi 
Published: May 2011

AbstractA tunable up frequencies of microwave photonics based on stimulated Brillouin scattering (SBS) for application in radio over fiber is demonstrated. The experimental setup consists of 7.7 km dispersion compensated fiber, which acts as the nonlinear medium for generating the SBS and is pumped by a narrow linewidth (0.015 nm) tunable laser operating in L‐band region. The input‐modulated RF at 2 GHz is upshifted to new frequencies of 7.71, 7.68, 7.65, 7.62, 7.58, and 7.56 GHz at Brillouin pump wavelengths of 1580, 1585, 1590, 1595, 1600, and 1605 nm, respectively. This system allows certain tunability in the upshifted frequencies by using a tunable laser source. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26106
Compact and high selectivity broadband bandpass filter with dual‐mode folded‐T‐type resonator
Authors: Deng Hong‐Wei , Zhao Yong‐Jiu , Zhang Xue‐Shun , Chen Wen , Qiang Li 
Published: May 2011

AbstractA broadband bandpass filter (BPF) with compact size and high selectivity performances is proposed using the dual‐mode folded‐T‐type resonator and the identical short stub loaded parallel‐coupling feed structure.The resonator can generate one even‐mode and one odd‐mode in the desired band. Two resonant frequencies can be adjusted easily to satisfy the bandwidth of the BPF. The feed structure can generate four transmission zeros near the cutoff frequencies and in the stopband, leading to sharp skirt and deep stopband. One filter prototype with the fractional bandwidth of 58.89% is fabricated for experimental verification of the predicted results. The size for the resonator is only 0.156λg × 0.303λg in which λg is the guided wavelength of 50 Ω microstrip line at the center frequency. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26108
Indirect evaluation of radiated emissions from a bent signal line on a printed circuit board with two attached cables
Authors: Kim Dong‐Yeon , Lee Jae W. , Cho Choon Sik , Lee Haeng S. , Chung Yeon‐Choon 
Published: May 2011

AbstractIn this article, the radiated emissions mechanism and the variation of radiated emissions level have been analyzed and investigated, respectively, according to the ratio of the horizontal to vertical traces in a bent signal line when a bent signal line on a printed circuit board (PCB) with two attached cables is used.Though many papers concerning two cables attached to a PCB have appeared, it is seen that the two cables can be modeled as a dipole antenna. In addition, it is conjectured from two‐ port S‐parameters that the ratio between the horizontal and vertical traces in a bent signal line leads to the variation in magnitude of common‐mode voltage induced as a noise source of the dipole antenna. As the signal line in parallel with the attached cable becomes longer, the radiated emissions level due to the current‐driven mechanism becomes more dominant while the contribution from the voltage‐driven mechanism remains unchanged regardless of the ratio between two signal lines. Based on the analysis of measured and simulated S‐parameters, we propose an alternate and relatively simple estimation method replacing the 3‐m measuring method to measure the radiated emissions level and investigate the accuracy of our analysis using commercially available software CST MWS 2006B. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26114
An active tri‐band (AMPS/PCS/GPS) antenna with enhanced cellular‐to‐GPS isolation for automotive applications
Authors: Aloi Daniel N. , Sharawi Mohammad S. 
Published: May 2011

AbstractThe design and performance of an active tri‐band antenna for automotive applications that includes the global positioning system (GPS), analog mobile phone service (AMPS), and personal communication service (PCS) is presented. For automotive emergency applications, the close proximity of the GPS and cellular antenna elements demands stringent isolation requirements on the GPS low noise amplifier (LNA) design to prevent interference to GPS during cellular transmissions. The GPS low‐noise amplifier designed in this letter exhibited a power gain of 26.4 dB, an out of band rejection in excess of 31 dB at +/‐50 MHz around the center frequency, a noise figure of 1.5 dB, a 1dB power compression of 9.7 dBm, isolation over the AMPS band in excess of 62 dB, isolation over the PCS band in excess of 48 dB, an input 3rd order intercept of −6.5 dBm and an output 3rd order intercept of 20.6 dBm while operating at 5 volts with a current draw of 20mA. In addition, the antenna patterns measured on a ground plane are presented for the active GPS antenna, AMPS passive antenna and the PCS passive antenna. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26117
Optical generation of microwave/millimeter‐wave based on Brillouin‐Erbium fiber laser
Authors: Liu Lan , Shen Yichun , Zheng Shilie , Jin Xiaofeng , Chi Hao , Zhang Xianmin 
Published: May 2011

AbstractA novel system configuration for optical generation of microwave/millimeter‐wave (mm‐wave), which is realized through Brillouin‐Erbium fiber laser (BEFL), is investigated.The microwave/mm‐wave is generated by the mixing of the nth‐order Stokes wave and the pump wave on the high‐speed photodetector. The nth‐order Stokes wave is generated in the BEFL and filtered out by fiber Bragg grating. The experiments are carried out based on such configuration, and experimental results verify the validity of it. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26118
Design of a Bethe‐hole directional coupler using substrate integrated waveguide technique
Authors: Amine Ali , Talbi Larbi , Sellal Kheireddine 
Published: May 2011

AbstractThis article proposes the design of a Bethe‐hole (BH) directional coupler using substrate integrated waveguide (SIW) technique. The design can readily be coupled with, for instance, an antenna and is therefore suitable for millimeter‐wave communication systems. Good agreements have been achieved between simulated and experimental results for a 25‐dB BH SIW coupler operating in the X‐band. Directivity greater than 20‐dB and a coupling of 24.7 dB were obtained. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26119