bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Ru and RuO2 thin films prepared by pulsed metal organic chemical vapor deposition
Authors: Roeder G. , Manke C. , Baumann P. K. , Petersen S. , Yanev V. , Gschwandtner A. , Ruhl G. , Petrik P. , Schellenberger M. , Pfitzner L. , Ryssel H. 
Published: March 2008

AbstractUltra‐thin ruthenium (Ru) layers were fabricated by pulsed metal organic chemical vapor deposition in an Aixtron Tricent reactor using a metal‐organic Ru precursor. Layer deposition was performed on different metal barrier combinations and on Al2O3 dielectric layers used in the fabrication of advanced Metal‐Insulator‐Metal (MIM) capacitor structures and on thermal SiO2 as reference structure. Ru layers with a thickness of 10 nm were characterized by Spectroscopic Ellipsometry (SE) and additional reference methods such as Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), and X‐Ray Reflectometry (XRR). As deposited and in situ annealed Ru layers were characterized by SE applying Drude‐Lorentz‐ and Effective Medium Approximation (EMA) models. It was shown that the deposited layers consist of a Ru‐RuO2 bilayer structure. By in situ annealing, the RuO2 layer thickness is reduced and highly pure Ru films are obtained. On the metal barriers the formation of a metal oxide interface, which is related to the deposition process, was determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical modeling and XRR/AFM characterization of highly conductive thin Ag layers
Authors: Ulrich S. , Pflug A. , Schiffmann K. , Szyszka B. 
Published: March 2008

AbstractThin silver layers (≈ 12 nm) are widely used in low‐E architectural glass coatings. For these and other applications thin Ag films with high conductivity are desired. We prepared Glass/ZnO:Al/Ag layer stacks with Ag thicknesses in the range of 7 – 40 nm by means of magnetron sputtering. The ZnO:Al Layer was RF/DC sputtered from a ceramic target and serves as seed layer for growth of strongly (111) oriented silver with high conductivity (M. Arbab, Thin Solid Films 381, 15 (2001) [1]). Layer thicknesses, top surface and interface roughnesses were determined by XRR and compared with AFM rough ness for the top layer. We present a dielectric function model for thin silver films with which the optical measurements are excellently described. The hereby determined layer thicknesses correspond precisely to those determined by XRR. The best agreement was found when only reflectance and transmittance measurements were used. The model for the dielectric function assumes a constant charge density and uses the electron mobility as free parameter. For the Ag resistivity ρ we found a strong decrease with increasing Ag thickness. A value of ρ‐Ag = 3.83 µΩcm was interpolated for an Ag thickness of 12 nm for pure DC plasma excitation during ZnO:Al seed layer deposition. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐order phase transitions of spin‐crossover and charge transfer solids probed by spectroscopic ellipsometry
Authors: Boukheddaden K. , Loutete‐Dangui E.D. , Koubaa M. , Eypert C. 
Published: March 2008

AbstractWe present a quantitative and comparative ellipsometric study of two switchable solids, undergoing a first‐order transition around ambient temperature: the spin‐crossover (SC), [Fe(NH2‐trz)3]Br2 and the cooperative Jahn‐Teller (JT) switch, RbMn[Fe(CN)6]. Ellipsometric spectra have been recorded in the optical range 240‐1000nm and temperature interval 260‐380 K for both solids. We found that absorption spectra of the SC show temperature invariant isobestic point, while that of the JT clearly indicates a thermally induced energy shift, in relation with the structural transition of this material. Integrating the absorption spectra, we derived the thermal dependence of the fractions of the high‐temperature phases for both solids, and found them in excellent agreement with that of magnetic data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic ellipsometry and vector network analysis for determination of the electromagnetic response in two wavelength regions
Authors: Åkerlind C. , Jänis A. , Kariis H. , Arwin H. , Järrendahl K. 
Published: March 2008

AbstractIn this work, spectroscopic ellipsometry and vector network analysis are used to determine the electromagnetic response of three samples, an epoxy polymer, a sample with ferrit‐based nanoparticles in a polymer matrix and silicon, in the wavelength ranges 0.4‐30 μm and 0.75‐7.59 cm. Both methods measure amplitude and phase changes due to interaction with a sample and can be used to measure the full complex‐valued dielectric response to electromagnetic radiation. The data from the two methods show similar levels of the response at the two ends of the spectral gap between the ranges of the two methods. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric and magnetic birefringence in low‐chlorine‐doped n ‐type Zn1–xMnxSe
Authors: Saenger M. F. , Hetterich M. , Hofmann T. , Kirby R. D. , Sellmyer D. J. , Schubert M. 
Published: March 2008

AbstractGeneralized spectroscopic ellipsometry over the spectral range from 1.24 to 3.34 eV is used to investigate a set of molecular beam epitaxy grown lowchlorine‐doped n ‐type Zn1–x Mnx Se films on (001)‐oriented GaAs for x = 0.0, 0.02, 0.14 and 0.28. We present evidence for intrinsic optical anisotropy in dependence of the Mn concentration caused by wurtzitestructure domain formation. We employ a previously established dielectric function model that accounts for band‐gap transition energy splitting in cubic semiconductors [Phys. Rev. B 60, 16618 (1999)]. Room temperature magneto‐optic generalized ellipsometry in the Kerrconfiguration reveals the sp‐d exchange energy splitting parameters upon expanding our anisotropy model by inclusion of chiral spin‐polarized band‐to‐band transition contributions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrooptic ellipsometry study of piezoelectric BaTiO3‐ZnO heterostructures
Authors: Voora V. M. , Hofmann T. , Brandt M. , Lorenz M. , Grundmann M. , Schubert M. 
Published: March 2008

AbstractWe report on electrooptic reflection‐type spectroscopic ellipsometry investigations of a wurtzite structure (ZnO) and perovskite structure (BaTiO3) thin film heterostructure between Pt contacts. The ZnO spontaneous polarization biases the ferroelectric polarization domain switching in BaTiO3, and causes a strong asymmetric electrooptic hysteresis behavior, reflected by an overall change of sample effective thickness and effective index of refraction. This hysteresis behavior is concordant with our previously observed electric hysteresis behavior of the same sample structure.We explain the hysteresis behavior by piezoelectric strain within the ferroelectric layer, by interface lattice charge coupling between the BaTiO3 and ZnO layer, and the previously identified depletion layer formation within the n ‐type doped ZnO layer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positionality of African Americans and a theoretical accommodation of it: Rethinking science education research
Authors: Parsons Eileen R. Carlton 
Published: March 2008

AbstractThis essay addresses a call for research involving African Americans to interpret data from the historical, contemporary, and cultural experiences of African Americans. The essay argues for a science education research approach that explicitly considers the positionality of African Americans in the United States. This positionality involves the negotiation of three distinct and conflicting realms of experience that pertain to oppression, African‐rooted Black culture, and the dominant culture in the United States. The theoretical tool proposed in this essay accommodates the positionality of African Americans by superimposing it upon a model that synthesizes the ideas of Michael Cole (cultural‐historical activity theory) and Urie Bronfenbrenner (ecology of human development). © 2008 Wiley Periodicals, Inc.Sci Ed92:1127–1144, 2008
Neurobiological perspectives of free will and freedom of choice
Authors: Drubach Daniel A. 
Published: March 2008

AbstractThe issue of free will and freedom of choice has been debated by countless theologians and philosophers throughout the history of mankind, but only recently have neuroscientists begun to address the subject from a neurobiological perspective. In this paper we explore the potential contributions of neurosciences towards answering the question of whether free will exists in humans and its potential neurobiological correlate. To accomplish this, we discuss the neural mechanisms of free will from two perspectives: that of voluntary movement and the stimulus response paradigm. We also address the role of awareness in free will and propose the existence of an underlying ‘volitional system’ contained within the central nervous system. Copyright © 2008 John Wiley & Sons, Ltd.
Healing as a creative art: opportunities to provide for the spiritual health of families when children need critical care
Authors: Macnab Andrew 
Published: March 2008

AbstractIn an Intensive Care Unit (ICU) of a Children's Hospital science, wisdom and compassion must be interwoven into the fabric of everyday in order for the children and their families to heal and the staff caring for them to remain healthy. The challenge is to practise both the art and science of medicine and to respond to the different cultural and spiritual beliefs of those brought together by a child's illness.This paper summarizes the special needs of parents and children in the ICU, the obstacles and opportunities encountered by staff, and research from Vancouver which helps those who provide holistic and spiritually oriented care. Copyright © 2008 John Wiley & Sons, Ltd.
Adsorption and diffusion property of a hydrogen atom on a Pd3Ag(111) surface
Authors: Ozawa N. , Arboleda N. B. , Nakanishi H. , Shimoji N. , Kasai H. 
Published: March 2008

AbstractThe behavior of a hydrogen atom on a Pd3Ag(111) surface is investigated by calculating the quantum states of the hydrogen atom via the first principles calculation methods. The calculation results show that the ground state wave function for the motion of hydrogen atom is localized on the fcc hollow site surrounded by three Pd atoms. Moreover, activation energies for the diffusion of the hydrogen atom on the whole Pd3Ag(111) surface are estimated as 394 and 520 meV via quantum and classical methods, respectively. Compared with our previous study on the behavior of hydrogen atom on the Pd(111) surface, the adsorption energy of hydrogen atom becomes smaller, while the activation energy becomes larger as a result of Ag alloying. Copyright © 2008 John Wiley & Sons, Ltd.
Uniformalization of AT cut quartz crystal wafer thickness using open‐air type plasma CVM process
Authors: Yamamura Kazuya , Morikawa Tetsuya , Shibahara Masafumi , Zettsu Nobuyuki , Mori Yuzo 
Published: March 2008

AbstractImprovement of thickness variation of the AT cut quartz crystal wafer is very important to advance the performance of the quartz resonator and to improve the productivity. However, conventional machining cannot exceed its technical limit any more, because quartz crystal is brittle and the wafer having thickness less than several tens of micrometers is required. We have newly developed the chemical finishing process to correct the thickness variation of the quartz crystal wafer, which utilizes localized atmospheric pressure plasma without gas replacing process. In the case of the atmospheric pressure plasma, high‐density plasma region is localized in the vicinity of the electrode because of its small mean free path. Removal volume is proportional to the dwelling time of the plasma on the workpiece surface. Therefore, free figuring without mask pattern is realized by numerically controlled scanning of the localized reactive area. By applying our proposed correcting process, thickness variation of the commercially available AT cut quartz crystal wafer was improved from 270 to 40 nm. Copyright © 2008 John Wiley & Sons, Ltd.
Towards interoperability: a wrapper model for integrating remote laboratories in a collaborative discovery learning environment
Authors: Martínez‐Carreras M. Antonia , Gómez‐Skarmeta Antonio F. 
Published: March 2008

AbstractCollaborative theories in learning are playing a vital role in the way learners interact with each other. More concretely, in collaborative learning the communication between learners is considered the most important element in their knowledge building. Regarding experimental subjects, the discovery learning discipline has emerged, in which students construct their knowledge through experimentation. In this sense, platforms such as Pedagogica, Web‐based inquiry science environment, SimQuest, Interactive Physics, Working Models and Co‐Lab provide support of this kind of learning. Regarding experimentation, one of the resources that may enrich the learning of students is the use of remote laboratories. However, the majority of these learning systems lack interfaces and models to provide interoperability with remote laboratories. Regarding interoperability issues, service‐oriented architecture (SOA) is the most well‐known paradigm for this issue. In this paper, we describe a wrapper model based on SOA for interoperability between Co‐Lab and existing remote laboratories. Moreover, we explain how we have integrated the existing remote laboratories in Co‐Lab using this model and we show the general pattern for including external experiments. Copyright © 2008 John Wiley & Sons, Ltd.
Mobility handling in MAC for wireless ad hoc networks
Authors: Raja Anjali , Su Xiao 
Published: March 2008

AbstractWireless Sensor Networks (WSNs) are becoming popular in a wide variety of applications. In a WSN, sensor nodes can be static or mobile, depending on applications. Handling mobility in a sensor network can pose interesting challenges in sensor protocol design, and special algorithms are needed to adapt to mobility in the network. In this paper, we survey the current state of art in handling mobility in sensor networks. We first study how mobility affects the design of different layers in the sensor network architecture, and then take a closer look at mobility handling in the MAC layer. We also describe the results of simulations that we conducted to compare and analyze existing mobility‐aware MAC protocols. Finally, we discuss open issues in dealing with mobility in sensor networks. Copyright © 2008 John Wiley & Sons, Ltd.
Image-guided focused ultrasound ablation of breast cancer: current status, challenges, and future directions
Authors: Schmitz A. C. , Gianfelice D. , Daniel B. L. , Mali W. P. Th. M. , van den Bosch M. A. A. J. 
Published: March 2008

AbstractImage-guided focussed ultrasound (FUS) ablation is a non-invasive procedure that has been used for treatment of benign or malignant breast tumours. Image-guidance during ablation is achieved either by using real-time ultrasound (US) or magnetic resonance imaging (MRI). The past decade phase I studies have proven MRI-guided and US-guided FUS ablation of breast cancer to be technically feasible and safe. We provide an overview of studies assessing the efficacy of FUS for breast tumour ablation as measured by percentages of complete tumour necrosis. Successful ablation ranged from 20% to 100%, depending on FUS system type, imaging technique, ablation protocol, and patient selection. Specific issues related to FUS ablation of breast cancer, such as increased treatment time for larger tumours, size of ablation margins, methods used for margin assessment and residual tumour detection after FUS ablation, and impact of FUS ablation on sentinel node procedure are presented. Finally, potential future applications of FUS for breast cancer treatment such as FUS-induced anti-tumour immune response, FUS-mediated gene transfer, and enhanced drug delivery are discussed. Currently, breast-conserving surgery remains the gold standard for breast cancer treatment.
Biomarkers of endothelial dysfunction are elevated and related to prognosis in chronic heart failure patients with diabetes but not in those without diabetes
Authors: Kistorp Caroline , Chong Aun Y. , Gustafsson Finn , Galatius Søren , Raymond Ilan , Faber Jens , Lip Gregory Y.H. , Hildebrandt Per 
Published: March 2008

AbstractBackground:Biomarkers of endothelial dysfunction, such as soluble E‐selectin, and von Willebrand factor (vWf) are elevated in patients with chronic heart failure (CHF). The impact of diabetes mellitus (DM) on these biomarkers, and their relation to prognosis remains unknown.Aims:to investigate the impact of DM on plasma levels and the prognostic value of E‐selectin and vWf in patients with CHF.Methods and results:Plasma levels of E‐selectin and vWf were measured in 195 CHF patients with (n = 48, 24.5%), and without DM, and in 116 age‐matched healthy controls. Compared with controls, median plasma E‐selectin levels were higher in CHF patients with DM (P = 0.012), but not in CHF patients without DM (P = 0.45); vWf levels were also higher in CHF patients with DM (P < 0.001), but not without DM (P = 0.108). E‐selectin was associated with risk of recurrent ischaemic cardiovascular events among CHF patients with DM (HR 2.60; P = 0.009), but not among patients without DM (HR 1.09; P = 0.60) per 1 SD increment in log transformed variable. vWf was not related with outcome in CHF patients with or without DM.Conclusions:Plasma levels of E‐selectin and vWf are elevated in CHF patients with DM but not in those without DM. High E‐selectin levels may be associated with ischaemic events in patients with DM.
Synchronous early‐stage endometrial and ovarian cancer
Authors: Signorelli Mauro , Fruscio Robert , Lissoni Andrea Alberto , Pirovano Cecilia , Perego Patrizia , Mangioni Costantino 
Published: March 2008

AbstractObjectiveTo explore the clinicopathologic findings and oncological outcome of early‐stage synchronous endometrial and ovarian malignancies.MethodsA retrospective study of 93 women with synchronous stage I ovarian and stage I–II endometrial cancer treated between December 1981 and August 2005 in the gynecologic oncology department of San Gerardo Hospital, Italy.ResultsFifty‐one percent of the ovarian tumors were stage Ia and 71% of the endometrial cancers had minimal myometrial invasion. Endometrioid histology and grade 2 disease were prevalent in both sites. Hyperplasia and endometriosis coexisted in 71% and 22% of endometrial and ovarian cancers, respectively. The actuarial 5‐year disease‐free and overall survival rates were 83% and 96%, respectively.ConclusionThe incidence of synchronous endometrial and ovarian cancer is not negligible, especially among young women. Synchronous cancers show very favorable pathologic features and have an excellent oncologic outcome. Adjuvant therapy should be tailored according to surgical staging and histology.
Inviscid coupling between point symmetric bodies and singular distributions of vorticity
Authors: EAMES I. , LANDERYOU M. , FLÓR J. B. 
Published: March 2008

We study the inviscid coupled motion of a rigid body (of density ρb, in a fluid of density ρ) and singular distributions of vorticity in the absence of gravity, using for illustration a cylinder moving near a point vortex or dipolar vortex, and the axisymmetric interaction between a vortex ring and sphere.The coupled motion of a cylinder (radius a) and a point vortex, initially separated by a distance R and with zero total momentum, is governed by the parameter R4/(ρb/ρ+1)a4. When R4/(ρb/ρ+1)a4,≤,1, a (positive) point vortex moves anticlockwise around the cylinder which executes an oscillatory clockwise motion, with a mixture of two frequencies, centred around its initial position. When R4/(ρb/ρ+1)a4≫1, the initial velocity of the cylinder is sufficiently large that the dynamics become uncoupled, with the cylinder moving off to infinity. The final velocity of the cylinder is related to the permanent displacement of the point vortex.The interaction between a cylinder (initially at rest) and a dipolar vortex starting at infinity depends on the distance of the vortex from the centreline (h), the initial separation of the vortical elements (2d), and ρb/ρ. For a symmetric encounter (h=0) with a dense cylinder, the vortical elements pass around the cylinder and move off to infinity, with the cylinder being displaced a finite distance forward. However, when ρb/ρ<1, the cylinder is accelerated forward to such an extent that the vortex cannot overtake. Instead, the cylinder ‘extracts’ a proportion of the impulse from the dipolar vortex. An asymmetric interaction (h>0) leads to the cylinder moving off in the opposite direction to the dipolar vortex.To illustrate the difference between two- and three-dimensional flows, we consider the axisymmetric interaction between a vortex ring and a rigid sphere. The velocity perturbation decays so rapidly with distance that the interaction between the sphere and vortex ring is localized, but the underlying processes are similar to two-dimensional flows.We briefly discuss the general implications of these results for turbulent multiphase flows.
Denjoy systems and dimension groups
Authors: MASUI KENICHI , SUGISAKI FUMIAKI , YOSHIDA MASAMICHI 
Published: March 2008

AbstractWe construct an adic model for the Denjoy system (X,T) of finite double orbit number. It is based on the dual Ostrowski numeration system. By using this construction, we can determine the K-theory of $C(X)\rtimes _T \mathbb {Z}$ associated with (X,T) in an effective way.
Square summability of variations and convergence of the transfer operator
Authors: JOHANSSON ANDERS , ÖBERG ANDERS 
Published: March 2008

AbstractIn this paper we study the one-sided shift operator on a state space defined by a finite alphabet. Using a scheme developed by Walters [P. Walters. Trans. Amer. Math. Soc.353(1) (2001), 327–347], we prove that the sequence of iterates of the transfer operator converges under square summability of variations of the g-function, a condition which gave uniqueness of a g-measure in our earlier work [A. Johansson and A. Öberg. Math. Res. Lett.10(5–6) (2003), 587–601]. We also prove uniqueness of the so-called G-measures, introduced by Brown and Dooley [G. Brown and A. H. Dooley. Ergod. Th. & Dynam. Sys.11 (1991), 279–307], under square summability of variations.
Autonomous vehicle based in cooperative GPS and inertial systems
Authors: Milanés Vicente , Naranjo José E. , González Carlos , Alonso Javier , de Pedro Teresa 
Published: March 2008

SUMMARYA system including Global Positioning Systems (GPS) and digital cartography is a good solution to carry out vehicle's guidance. However, it has inconveniences like high sensibility to multipath and interference when the GPS signal is blocked by external agents. Another system is mandatory to avoid this error. This paper presents a cooperative system based on GPS and Inertial Navigation Systems (INS) for automated vehicle position. The control system includes a decision unit to choose which value is the correct. In case GPS is working at top precision, it takes the control. On the other part, GPS signal can be lost and inertial control system guides the car in this occasion. A third possibility is contemplated: we receive the signal from GPS but the accuracy is over one meter. Now, position value is obtained by means of both systems. Experimental results analyze two situations: guidance in an urban area where GPS signal can be occluded by buildings or trees during short time intervals and the possibility of loss of the signal in long time to simulate the circulation in tunnels. Good results have been observed in tests and it demonstrates how a cooperative system improves the automated vehicle guidance.