bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil‐pile interaction in the pile vertical vibration considering true three‐dimensional wave effect of soil
Authors: Wu W.B. , Wang K.H. , Zhang Z.Q. , Leo Chin Jian 
Published: January 2013

SUMMARYThe dynamic response of an end bearing pile embedded in a linear visco‐elastic soil layer with hysteretic type damping is theoretically investigated when the pile is subjected to a time‐harmonic vertical loading at the pile top. The soil is modeled as a three‐dimensional axisymmetric continuum in which both its radial and vertical displacements are taken into account. The pile is assumed to be vertical, elastic and of uniform circular cross section. By using two potential functions to decompose the displacements of the soil layer and utilizing the separation of variables technique, the dynamic equilibrium equation is uncoupled and solved. At the interface of soil‐pile system, the boundary conditions of displacement continuity and force equilibrium are invoked to derive a closed‐form solution of the vertical dynamic response of the pile in frequency domain. The corresponding inverted solutions in time domain for the velocity response of a pile subjected to a semi‐sine excitation force applied at the pile top are obtained by means of inverse Fourier transform and the convolution theorem. A comparison with two other simplified solutions has been performed to verify the more rigorous solutions presented in this paper. Using the developed solutions, a parametric study has also been conducted to investigate the influence of the major parameters of the soil‐pile system on the vertical vibration characteristics of the pile. Copyright © 2013 John Wiley & Sons, Ltd.
Axial kinematic response of end‐bearing piles to P waves
Authors: Anoyatis George , Di Laora Raffaele , Mylonakis George 
Published: January 2013

SUMMARYKinematic pile–soil interaction under vertically impinging seismic P waves is revisited through a novel continuum elastodynamic solution of the Tajimi type. The proposed model simulates the steady‐state kinematic response of a cylindrical end‐bearing pile embedded in a homogeneous viscoelastic soil stratum over a rigid base, subjected to vertically propagating harmonic compressional waves. Closed‐form solutions are obtained for the following: (i) the displacement field in the soil and along the pile; (ii) the kinematic Winkler moduli (i.e., distributed springs and dashpots) along the pile; (iii) equivalent, depth‐independent, Winkler moduli to match the motion at the pile head. The solution for displacements is expressed in terms of dimensionless transfer functions relating the motion of the pile head to the free‐field surface motion and the rock motion. It is shown that (i) a pile foundation may significantly alter (possibly amplify) the vertical seismic excitation transmitted to the base of a structure and (ii) Winkler moduli pertaining to kinematic loading differ from those for inertial loading. Simple approximate expressions for kinematic Winkler moduli are derived for use in applications. Copyright © 2013 John Wiley & Sons, Ltd.
A polyhedral study of the capacity formulation of the multilayer network design problem
Authors: Mattia Sara 
Published: January 2013

AbstractA multilayer network is a hierarchical network where each layer is built using the components of the previous one. Optical networks are an example of two layered networks. The multilayer network design problem consists of installing minimum cost integer capacities on the edges of all the layers so that a set of demands can be routed on the network. In this article, two versions of the optical network design problem are studied, and polyhedral results for the corresponding capacity formulations are presented. We also show how to extend the results to a network with an arbitrary number of layers. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
Parametrized relocation of low‐mobility resources
Authors: Wildstrom D. Jacob 
Published: January 2013

AbstractRelocation of service‐providers in response to changing real‐time needs is suboptimal due to limited foreknowledge of client requests. Simple cost schedules for relocation and remote‐service provision have been investigated both for the possibility of complete optimizability and the degree of inefficiency introduced by imperfect future knowledge. This work further explores a parametrization developed for reflecting limitations in the mobility of some resources. The optimizability response to this parameter exhibits two significant thresholds. Below the first threshold, optimization is trivial, but many real‐world resource‐location problems correspond to parameter values past the second threshold. This work explores both the value of the second threshold and the behavior of optimal limited‐lookahead responses for resources whose immobility places them past this threshold. It is determined that, for resources of sufficiently high immobility α, it is possible with finite lookahead to achieve a relocation schedule which is within a ratio of (1+α) of the optimal omniscient schedule. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
In vitro sealing of iatrogenic fetal membrane defects by a collagen plug imbued with fibrinogen and plasma
Authors: Engels A. C. , Hoylaerts M. F. , Endo M. , Loyen S. , Verbist G. , Manodoro S. , DeKoninck P. , Richter J. , Deprest J. A. 
Published: January 2013

ABSTRACTObjectivesWe aimed to demonstrate local thrombin generation by fetal membranes, as well as its ability to generate fibrin from fibrinogen concentrate. Furthermore, we aimed to investigate the efficacy of collagen plugs, soaked with plasma and fibrinogen, to seal iatrogenic fetal membrane defects.MethodsThrombin generation by homogenized fetal membranes was measured by calibrated automated thrombography. To identify the coagulation caused by an iatrogenic membrane defect, we analyzed fibrin formation by optical densitometry, upon various concentrations of fibrinogen. The ability of a collagen plug soaked with fibrinogen and plasma was tested in an ex vivo model for its ability to seal an iatrogenic fetal membrane defect.ResultsFetal membrane homogenates potently induced thrombin generation in amniotic fluid and diluted plasma. Upon the addition of fibrinogen concentrate, potent fibrin formation was triggered. Measured by densiometry, fibrin formation was optimal at 1250 µg/mL fibrinogen in combination with 4% plasma. A collagen plug soaked with fibrinogen and plasma sealed an iatrogenic membrane defect about 35% better than collagen plugs without these additives (P = 0.037).ConclusionsThese in vitro experiments suggest that the addition of fibrinogen and plasma may enhance the sealing efficacy of collagen plugs in closing iatrogenic fetal membrane defects. © 2013 John Wiley & Sons, Ltd.
Low‐temperature cure high‐performance cyanate ester resins/microencapsulated catalyst systems
Authors: Chen Feng , Yuan Li , Gu Aijuan , Lin Chao , Liang Guozheng 
Published: January 2013

AbstractThe encapsulated catalyst can be released under stimulation conditions to control the polymerization reaction. In this study, poly(urea‐formaldehyde) (PUF) microcapsules (MCs) filled with dibutyltin dilaurate (DBTDL) catalyst (PUF/DBTDL MCs) were applied to bisphenol A dicyanate ester (BADCy) resins to develop a novel low temperature cure high performance BADCy/MCs systems. The effect of PUF/DBTDL MCs on the reactivity of BADCy was investigated. The mechanical property, the thermal property, the water uptake, and the dielectric property of cured BADCy/MCs resin systems were discussed in detail. Results indicate that roughly varying the content of the encapsulated DBTDL can easily and safely adjust the polymerization temperature. The BADCy systems with proper content of MCs cured at low temperature show excellent mechanical property, good thermal property, low water uptake, and low dielectric property. When the content of MCs is 0.125 wt%, the cured BADCy/MCs system has the optimal integrated properties owing to the formation of more uniform crosslinked structure and high conversion of cyanate ester (OCN) groups resulting from the slow release of DBTDL catalyst through the wall shell under heating condition. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers
Electrodeposited Cu2ZnSnSe4 thin film solar cell with 7% power conversion efficiency
Authors: Guo Lian , Zhu Yu , Gunawan Oki , Gokmen Tayfun , Deline Vaughn R. , Ahmed Shafaat , Romankiw Lubomyr T. , Deligianni Hariklia 
Published: January 2013

ABSTRACTHigh performance Cu2ZnSnSe4 (CZTSe) photovoltaic materials were synthesized by electrodeposition of metal stack precursors followed by selenization. A champion solar cell with 7.0% efficiency is demonstrated. This is the highest efficiency among all of the CZTSe solar cells prepared from electrodeposited metallic precursors reported to‐date. Device parameters are discussed from the perspective of material microstructure and composition in order to improve performance. In addition, a high performance electrodeposited CZTS (S only) solar cell was demonstrated and its device characteristics were compared against the CZTSe (Se only) cell. Using secondary ion mass spectrometry for the analysis of the chemical composition of the absorber layer, a higher concentration of oxygen in the electrodeposited absorber is thought to be the root cause of the lower performance of the electrodeposited CZTS or CZTSe solar cells with respect to a solar cell fabricated by evaporation. The grain boundary areas of Sn‐rich composition are thought to be responsible for the lower shunt resistance commonly observed in CZTSe devices. We measured the longest minority carrier lifetime of 18 ns among all reported kesterite devices. This work builds a good baseline for obtaining higher efficiency earth‐abundant solar cells, while it highlights electrodepositon as a low cost and feasible method for earth‐abundant thin film solar cell fabrication. Copyright © 2013 John Wiley & Sons, Ltd.
A water soluble macromolecular nanobox having porphyrinic walls as a large host for giant guests
Authors: Mineo Placido , Spitaleri Fabiola , Scamporrino Emilio 
Published: January 2013

AbstractCyclic tetra{5,15‐di‐[p(ω‐methoxypolyethyleneoxy)phenyl]‐10,20‐[p‐oxyphenyl] methylen porphyrin}, cy‐[O‐(H2‐PTPEG2)‐O‐CH2‐]4, a water soluble macromolecule consisting of four porphyrin units [each with two long ω‐methoxypolyethyleneoxy (PEG) branches bound on its peripheral positions] linked by means of four methylenoxy bridges, was prepared by an interfacial etherification reaction. Structural and spectroscopic characterization of cy‐[O‐(H2‐PTPEG2)‐O‐CH2‐]4 and of its cobalt‐derivative {cy‐[O‐(Co‐PTPEG2)‐O‐CH2‐]4} was performed by means of MALDI‐TOF mass spectrometry, NMR, UV–vis, and circular dichroism spectroscopy. The data obtained from the cy‐[O‐(Co‐PTPEG2)‐O‐CH2‐]4/Gramicidin‐S mixture showed that some evident spectral changes were compatible with the formation of a supramolecular structure between the porphyrinic nanobox and the Gramicidin S (a polypeptide having a relevant pharmacological importance). These preliminary data highlight how cy‐[O‐(H2‐PTPEG2)‐O‐CH2‐]4 and/or its metalled derivatives, for their both chemical composition and structural arrangement, have promising properties for applications as a drug carrier in aqueous media. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
A renaissance of color: New structures and building blocks for organic electronics
Authors: Robb Maxwell J. , Ku Sung‐Yu , Brunetti Fulvio G. , Hawker Craig J. 
Published: January 2013

AbstractNatural dyes and pigments like indigo and its derivatives valued for their bright colors and photochemical stability has been used since antiquity. Recently, the need for better performing materials in the organic electronics field has inspired a resurgence of these historical molecules and their subsequent transformation into new families of π‐conjugated building blocks used to construct new (macro)molecular semiconductors. This Highlight will explore the renaissance of notable building blocks including diketopyrrolopyrrole, (iso)indigo, benzodipyrrolidone, and benzodifuranone, as well as nonfullerene acceptor structures 9,9′‐bifluorenylidene and quinacridone. In addition, as the organic electronics field continues to evolve, the design of molecules with precise structure and function embodies a new paradigm for the next generation of materials. Representative examples will be described that embrace this new model and point the direction for advanced technologies. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Novel pH‐responsive mixed‐charge copolymer brushes based on carboxylic acid and quaternary amine monomers
Authors: Demirci Serkan , Kinali‐Demirci Selin , Caykara Tuncer 
Published: January 2013

AbstractIn this study, we report on the fabrication of tunable mixed‐charged copolymer brushes consisting of negatively charged carboxylic acid monomer (4‐vinylbenzoic acid, VBA) and positively charged quaternary amine monomer ((ar‐vinylbenzyl)trimethylammonium chloride) via reversible addition–fragmentation chain transfer‐mediated polymerization. The copolymer brushes have negative charge under neutral and basic conditions, and are positively charged under acidic conditions owing to the protonation of the carboxylate groups. The copolymer brushes revealed a unique reversible wetting behavior with pH. The reversible properties of the copolymer brushes can be employed to regulate the adsorption of charged biomacromolecules such as DNA and proteins. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Dual behavior of excess electrons in rutile TiO2
Authors: Janotti A. , Franchini C. , Varley J. B. , Kresse G. , Van de Walle C. G. 
Published: January 2013

AbstractThe behavior of electrons in the conduction band of TiO2 and other transition‐metal oxides is key to the many applications of these materials. Experiments seem to produce conflicting results: optical and spin‐resonance techniques reveal strongly localized small polarons, while electrical measurements show high mobilities that can only be explained by delocalized free electrons. By means of hybrid functional calculations we resolve this apparent contradiction and show that small polarons can actually coexist with delocalized electrons in the conduction band of TiO2, the former being energetically only slightly more favorable. We also find that small polarons can form complexes with oxygen vacancies and ionized shallow‐donor impurities, explaining the rich spectrum of Ti3+ species observed in electron spin resonance experiments. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wind‐gust parametrizations at heights relevant for wind energy: a study based on mast observations
Authors: Suomi I. , Vihma T. , Gryning S.‐E. , Fortelius C. 
Published: January 2013

AbstractWind gusts are traditionally observed and reported at the reference height of 10 m and most gust parametrization methods have been developed only for this height. In many practical applications, e.g. in wind energy, the relevant heights are, however, up to a few hundred metres. In this study, mean gustiness conditions were studied using observations from two coastal/archipelago weather masts in the Gulf of Finland (northern Europe) with observation heights between 30 and 143 m. Only moderate and strong wind cases were addressed. Both masts were located over relatively flat terrain but the local environment, and hence the surface roughness length, differed between the mast locations. The observations showed that above all the gust factor depended on the surface roughness. Stability had a more pronounced effect over the rough forested surface than over the smooth sea surface. At both locations the stability had a larger effect on gusts than the observation height. Two existing parametrization methods, developed for a 10 m reference height, were validated against the observations and a new parametrization was proposed. In the new method, the gust factor depends on the standard deviation of the wind speed, which is parametrized on the basis of the surface friction velocity, the Obukhov length and height and the boundary‐layer height. The new gust parametrization method outperformed the two older methods: the effects of surface roughness, stability and the height above the surface were well represented by the new method.
On‐line calibration of the vertical distribution of ensemble spread
Authors: Flowerdew Jonathan , Bowler Neill E. 
Published: January 2013

AbstractThe Met Office Global and Regional Ensemble Prediction System (MOGREPS) uses an on‐line inflation factor calculation to calibrate the spread of the ensemble in space and time and counteract the tendency of the Ensemble Transform Kalman Filter (ETKF) to underestimate analysis uncertainty. Sonde measurements are augmented with ATOVS brightness temperature observations to provide sufficient coverage across the globe. This paper describes how the scheme has been extended to improve the vertical distribution of spread. Separate inflation factors are derived for each of three ‘bands’ of model levels, loosely representing the boundary layer, troposphere and stratosphere. A continuous profile is ensured by linearly interpolating between the band centres. The error/spread relationship observed in each ATOVS channel is mapped onto the three bands using a set of weights obtained by integrating the appropriate Jacobians over the range of pressures covered by each band. These weights are found to be approximately constant, thanks to the small number of bands and the fact that near‐surface channels are not used over land. The revised initial perturbations lead to increased near‐surface spread which persists throughout the 72 h forecast and carries through to improved probabilistic scores. However, the near‐surface spread remains too small due to insufficient growth of spread by the forecast model. This suggests perturbation of sea‐surface temperatures, soil initial conditions, soil properties and boundary‐layer physics as priorities for future work.
The formation of ice in a long‐lived supercooled layer cloud
Authors: Westbrook C. D. , Illingworth A. J. 
Published: January 2013

AbstractThis article focuses on the characteristics of persistent thin single‐layer mixed‐phase clouds. We seek to answer two important questions: (i) how does ice continually nucleate and precipitate from these clouds, without the available ice nuclei becoming depleted? (ii) how do the supercooled liquid droplets persist in spite of the net flux of water vapour to the growing ice crystals? These questions are answered quantitatively using in situ and radar observations of a long‐lived mixed‐phase cloud layer over the Chilbolton Observatory.Doppler radar measurements show that the top 500 m of cloud (the top 250 m of which is mixed‐phase, with ice virga beneath) is turbulent and well‐mixed, and the liquid water content is adiabatic. This well‐mixed layer is bounded above and below by stable layers. This inhibits entrainment of fresh ice nuclei into the cloud layer, yet our in situ and radar observations show that a steady flux of ≈︁100 m−2s−1 ice crystals fell from the cloud over the course of ∼1 day. Comparing this flux to the concentration of conventional ice nuclei expected to be present within the well‐mixed layer, we find that these nuclei would be depleted within less than 1 h. We therefore argue that nucleation in these persistent supercooled clouds is strongly time‐dependent in nature, with droplets freezing slowly over many hours, significantly longer than the few seconds residence time of an ice nucleus counter.Once nucleated, the ice crystals are observed to grow primarily by vapour deposition, because of the low liquid water path (21 g m−2) yet vapour‐rich environment. Evidence for this comes from high differential reflectivity in the radar observations, and in situ imaging of the crystals. The flux of vapour from liquid to ice is quantified from in situ measurements, and we show that this modest flux (3.3 g m−2h−1) can be readily offset by slow radiative cooling of the layer to space.
Impact of a virtual resistor on the input admittance of a grid‐connected inverter
Authors: Rizqiawan Arwindra , Fujita Goro , Funabashi Toshihisa , Nomura Masakatsu 
Published: January 2013

AbstractA grid‐connected inverter offers good operation and controllability; however, there is a risk of local instabilities due to particular control schemes. As long as the input admittance is positive at a particular resonance frequency, the risk of local instability can be suppressed. In this paper, an attempt to improve the input admittance of the grid‐connected inverter (GCI)[vnsn1] using a virtual resistor is proposed. The impact of the virtual resistor on the inverter's passivity is analyzed by observing the input admittance of the inverter. Numerical analysis shows that the employment of the virtual resistor gives better input admittance to the GCI, particularly in the low‐frequency regions. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Role of physical activity in tumor patients and possible underlying mechanisms
Authors: Bloch Wilhelm , Zopf Eva , Zimmer Philipp , Baumann Freerk T. 
Published: January 2013

Abstract
A growing knowledge regarding the influence of exercise on adverse physiologic outcomes associated with cancer and its treatment exists. Aside from its effects on psychological behavior, quality of life, and cancer-related fatigue, physical exercise can target physical and cardio-respiratory fitness, insulin regulation and metabolic syndrome, body weight and composition, and immune function in tumor patients. The increasing number of study results for different cancer types, which prove the positive influences of physical activity in cancer patients, changed the contradictory opinions which existed until the end of the last century. Although an increasing number of studies showing the positive effects of physical activity and more specifically of endurance and resistance training in cancer patients have been published, the underlying mechanisms are mostly unknown. Thus, we summarized the current knowledge of the effects of physical activity and specific training in different tumor entities with specific respect to the possible underlying mechanisms. Especially, the association between physical activity and (1) the improvement of fatigue and the role of free radicals in this process, (2) the counterbalance of tumor-induced cachexia, (3) the improvement of the immune system for supportive tumor treatment, and (4) the possible role of epigenetic modulation against tumor and tumor treatment-dependent adverse physiologic outcomes is focused.