bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Lead Zirconate Titanate—Lanthanum Ruthenate Thin Film Structures Prepared by Chemical Solution Deposition
Authors: BenČan Andreja , MaliČ Barbara , DraŽiČ Goran , VukadinoviĆ MiŠo , Kosec Marija
Published: December 2007

In this work, the results of compositional and microstructural analysis of lead zirconate titanate—lanthanum ruthenate thin film structures prepared by chemical solution deposition are discussed. The cross‐section transmission electron microscope (TEM) micrographs of the La‐Ru‐O film deposited on a SiO2/Si substrate and annealed at 700 °C revealed RuO2 crystals embedded in a glassy silicate matrix. When the La‐Ru‐O film was deposited on a Pt/TiO2/SiO2/Si substrate, RuO2 and La4Ru6O19 crystallized after annealing at 700 °C. After firing at 550 °C randomly oriented lead zirconate titanate (PZT) thin films crystallized on the La‐Ru‐O/SiO2/Si substrate, while on La‐Ru‐O/Pt/TiO2/SiO2/Si substrates PZT thin films with (111) preferred orientation were obtained. No diffusion of the Ru atoms in the PZT film was found. Ferroelectric response of PZT thin films on these substrates is shown in comparison with the PZT film deposited directly on the Pt/TiO2/SiO2/Si substrate without a La‐Ru‐O layer. SCANNING 29: 287–293, 2007. © 2007 Wiley Periodicals, Inc.
Transfer of algebraic and graphical thinking between mathematics and chemistry
Authors: Potgieter Marietjie , Harding Ansie , Engelbrecht Johann
Published: December 2007

Students in undergraduate chemistry courses find, as a rule, topics with a strong mathematical basis difficult to master. In this study we investigate whether such mathematically related problems are due to deficiencies in their mathematics foundation or due to the complexity introduced by transfer of mathematics to a new scientific domain. In the investigation we exposed a group of students to a chemistry instrument based on the Nernst equation in electrochemistry, and an equivalent group of students to a similar mathematics instrument in which the questions were stripped of all chemistry context. Both tests contained items requiring algebraic as well as graphical skills. Students experienced few problems with the algebraic questions in both the chemistry and mathematics tests. Their graphical construction and interpretation skills, on the other hand, are inadequate, as can be seen from the poor performance in both the mathematics and the chemistry results of the graphical question. Our conclusion is that the problem seems to lie at the mathematics side and is not due to the transfer of mathematics to an application. © Wiley Periodicals, Inc. J Res Sci Teach 45: 197–218, 2008.
Students' use of the energy model to account for changes in physical systems
Authors: Papadouris Nicos , Constantinou Constantinos P. , Kyratsi Theodora
Published: December 2007

The aim of this study is to explore the ways in which students, aged 11–14 years, account for certain changes in physical systems and the extent to which they draw on an energy model as a common framework for explaining changes observed in diverse systems. Data were combined from two sources: interviews with 20 individuals and an open‐ended questionnaire that was administered to 240 students (121 upper elementary school students and 119 middle school students). We observed a wealth of approaches ranging from accounts of energy transfer and transformation to responses identifying specific objects or processes as the cause of changes. The findings also provide evidence that students do not seem to appreciate the transphenomenological and unifying nature of energy. Students' thinking was influenced by various conceptual difficulties that are compounded by traditional science teaching; for instance, students tended to confuse energy with force or electric current. In addition, the comparison between the responses from middle school students and those of elementary school students demonstrates that science teaching and maturation appeared to have a negligible influence on whether students had constructed a coherent energy model, which they could use consistently to account for changes in certain physical systems. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 444–469, 2008
The Sacred Character of Community Life
Authors: Pargament Kenneth I.
Published: December 2007

Theory and research suggest that there is a basic and irreducible human yearning for a relationship with something that transcends ourselves, something sacred. The sacred can be understood not only in individual terms, but also in terms of relationships, settings, and communities. Empirical studies indicate that the sacred has powerful implications for human behavior; it can be an organizing force and a resource to people in their most difficult times, yet it can also be a source of seemingly intractable problems. This paper reviews several of the promising steps psychologists have taken to learn about the sacred, learn from spiritual communities, and collaborate with these communities in efforts to better the world. Research and practice in this area is enriching our understanding of the meaning of community and the meaning of spirituality.
Synthesis and Characterization of Metal Nanoparticle Embedded Conducting Polymer–Polyoxometalate Composites
Authors: Kishore PilliSatyananda , Viswanathan Balasubramanian , Varadarajan ThirukkallamKanthadai
Published: December 2007

Phosphomolybdate has been employed simultaneously as the oxidizing agent for the monomer polymerization and the reduced polyoxometalate is used as reducing agent for the reduction of metal ions. The composites thus obtained have been characterized and may have many potential applications.
Emerging Technologies in the OR and Their Effect on Perioperative Professionals
Authors: Catalano Kathleen , Fickenscher Kevin
Published: December 2007

NEW AND EMERGING TECHNOLOGIES can help increase the quality of health care, but implementing these technologies in a perioperative setting can create many challenges. Practitioners need to be aware of premises underlying future trends in health care and the kinds of technological changes that they can expect.

ROBOTS, DIGITAL DISPLAYS, patient tracking systems, artificial organs, and magnetic sensors are some of the emerging technologies that are changing the perioperative landscape.

PRACTITIONERS MUST BE PREPARED to implement strategies that address the practical aspects of integrating these new technologies into the perioperative area. AORN J 86 (December 2007) 958–969. © AORN, Inc, 2007.
The revenue cycle: What it is, how it works, and how to enhance it
Authors: Niedzwiecki Marilyn Hart
Published: December 2007

UNDERSTANDING THE REVENUE CYCLE PROCESS helps perioperative personnel and managers improve health care charging practices and enables them to make informed policy decisions. INTEGRATING KNOWLEDGE of the revenue cycle processes throughout an organization can improve reimbursement, improve compliance with reporting requirements, reduce payer denials, and decrease rework by staff members. THIS ARTICLE provides information to develop a basic understanding of the revenue cycle and makes suggestions on how to improve this process in ealth care rganizations. AORN J 84 (October 2006) 578–6601. © AORN, Inc, 2006
Results of the 2007 AORN Salary Survey
Authors: Bacon Donald
Published: December 2007

AORN CONDUCTED ITS FIFTH ANNUAL compensation survey for perioperative nurses in August of 2007.

A MULTIPLE REGRESSION MODEL was used to examine how a variety of variables including job title, education level, certification, experience, and geographic region affect nursing compensation.

COMPARISONS BETWEEN 2007 and previous years' data also are presented.

THE EFFECTS OF OTHER FORMS of compensation, such as on‐call compensation, overtime, bonuses, and shift differentials on average base compensation rates are examined. AORN J 86 (December 2007) 944–957. © AORN, Inc, 2007.
Reviews
Authors: Zahidani Shuja Hussain , Hennessey Jeannemarie , Jackson Beverly
Published: December 2007

Nursing Care of the Pediatric Surgical Patient second edition Nancy Tkacz Browne, Laura M. Flanigan, Carmel A. McComiskey, and Pam Pieper 2007, 531 pages $99.95 hardcover

Perioperative Pharmacology Reference Book and Perioperative Pharmacology Pocket GuideCCI 2006, 63 pages and 71 pages, respectively $30 softcover and $20 spiralbound, respectively, or $45 for both

The Practice of Patient Education: A Case Study Approach 10th edition Barbara Klug Redman 2007, 176 pages $39.95 softcover
Bilingual children with language impairment: A comparison with monolinguals and second language learners
Authors: GUTIÉRREZ-CLELLEN VERA F. , SIMON-CEREIJIDO GABRIELA , WAGNER CHRISTINE
Published: December 2007

The purpose of this study is twofold: (a) to examine whether English finite morphology has the potential to differentiate children with and without language impairment (LI) from Spanish-speaking backgrounds and different levels of English proficiency in comparison to Hispanic English speakers and (b) to investigate the extent to which children who are bilingual exhibit differences in their grammatical performance because of cross-linguistic influence from their first language. Seventy-one children between the ages of 4 years, 5 months and 6 years, 5 months were distributed into the following five groups: English as a first language (EL1) speakers with typical language development (TLD), EL1 speakers with LI, Spanish–English bilinguals with TLD, Spanish–English bilinguals with LI, and English as a second language (EL2) learners with TLD were compared on regular verb finiteness and nominative subject use using spontaneous narrative samples. The EL1 children with LI had significantly lower verb accuracy rates than the EL1 controls with TLD. Verb finiteness marking was also a significant discriminator for the bilinguals with LI. There was no evidence of cross-linguistic influence, however. The analysis indicated no significant differences between EL1 and bilingual children on subject or verb use. The EL2 group only presented difficulties with finite verb use. The typological differences between English and Spanish for overt subject use did not seem to affect the performance of either typical or atypical bilingual learners. The findings underscore the need for addressing language dominance in future bilingual studies.
The use of psychological state words by late talkers at ages 3, 4, and 5 years
Authors: LEE ELIZA CARLSON , RESCORLA LESLIE
Published: December 2007

The use of four types of psychological state words (physiological, emotional, desire, and cognitive) during mother–child play sessions at ages 3, 4, and 5 years was examined in 30 children diagnosed with delayed expressive language at 24–31 months and 15 age-matched comparison children with typical development. The children's mean length of utterance, total words uttered, lexical diversity, and use of propositional complements were assessed. The late talkers used significantly more physiological state words at ages 3 and 4, but the two groups did not differ in their use of physiological state terms at age 5. The late talkers used significantly fewer cognitive words than the comparison children at each age. The mothers of the late talkers made significantly fewer references to cognitive states than the mothers of the comparison children at each age. The delay in the emergence of cognitive state words in the preschool years may affect other aspects of late talkers’ cognitive and social development.
Bilingual language representation and cognitive processes in translation
Authors: HATZIDAKI ANNA , POTHOS EMMANUEL M.
Published: December 2007

Atext-translation task and a recognition task investigated the hypothesis thatsemantic memoryprincipally mediates translation from a bilingual's native first language (L1) to her second language (L2), whereaslexical memorymediates translation from L2 to L1. This has been held for word translation by the revised hierarchical model (RHM) of Kroll and Stewart. The results from Greek, English, and French fluent bilinguals showed semantic errors in L1–L2 direction and lexical errors in L2–L1 direction in the translation task as RHM would predict, but not semantic effects in L1–L2 direction in the word recognition task. These findings suggest a flexible use of conceptual and lexical connections that fluent bilinguals engage, depending upon the cognitive processes required by the task at hand.
Mental imagery of concrete proverbs: A developmental study of children, adolescents, and adults
Authors: DUTHIE JILL K. , NIPPOLD MARILYN A. , BILLOW JESSE L. , MANSFIELD TRACY C.
Published: December 2007

The development of mental imagery in relation to the comprehension of concrete proverbs (e.g., one rotten apple spoils the barrel) was examined in children, adolescents, and adults who were ages 11 to 29 years old (n = 210). The findings indicated that age-related changes occurred in mental imagery and in proverb comprehension during the years between late childhood and early adulthood, and that the two domains were associated in children and adults but not in adolescents. Children and adults were more likely to describe relevant mental imagery (age 11: “A big barrel of apples and a woman picks up one that is rotten and there are worms in it and the worms go to all the other apples”) when they also comprehended the proverb on a multiple-choice task. It was also found that participants' mental images became more metaphorical in relation to increasing age (age 21: “One bad comment can spoil the entire conversation”). The findings are consistent with dual coding theory, the view that nonverbal information (relevant visual imagery) in addition to verbal information (related words and phrases) supports language comprehension in the case of concrete meanings. The results also support the view that mental imagery reflects figurative understanding and the individual's tacit awareness of underlying metaphorical concepts.
Optimal trajectory planning for a redundant mobile manipulator with non-holonomic constraints performing push–pull tasks
Authors: Puga José P. , Chiang Luciano E.
Published: December 2007

This work presents a method to generate optimal trajectories for redundant mobile manipulators based on a weighted function that considers simultaneously joint torques, manipulability and preferred joint angle references. This method is applicable to a group of tasks, commonly known as push–pull tasks, in which a redundant mobile manipulator subject to non-holonomic constraints moves slowly while exerting a set of forces against the environment. In practice, this occurs when the manipulator is pulling against an object such as when opening a door or unearthing a buried object. Torque is computed in a quasi-static manner, mainly taking into consideration the effect of multiple external forces while neglecting dynamic effects. The formulation incorporates a criterion for optimizing a starting configuration, and special considerations are made to account for non-holonomic constraints. The application to an existing mobile manipulator is described.
PRESERVATION OF RELIABILITY CLASSES UNDER MIXTURES OF RENEWAL PROCESSES
Authors: Badía F. G. , Sangüesa C.
Published: December 2007

In this work we provide sufficient conditions for the arrival times of a renewal process so that the number of its events occurring before a randomly distributed time, T, independent of the process preserves the aging properties of T.
Comparing mathematical and heuristic approaches for scientific data analysis
Authors: Varde Aparna S. , Ma Shuhui , Maniruzzaman Mohammed , Brown David C. , Rundensteiner Elke A. , SissonJR. Richard D.
Published: December 2007

Scientific data is often analyzed in the context of domain-specific problems, for example, failure diagnostics, predictive analysis, and computational estimation. These problems can be solved using approaches such as mathematical models or heuristic methods. In this paper we compare a heuristic approach based on mining stored data with a mathematical approach based on applying state-of-the-art formulae to solve an estimation problem. The goal is to estimate results of scientific experiments given their input conditions. We present a comparative study based on sample space, time complexity, and data storage with respect to a real application in materials science. Performance evaluation with real materials science data is also presented, taking into account accuracy and efficiency. We find that both approaches have their pros and cons in computational estimation. Similar arguments can be applied to other scientific problems such as failure diagnostics and predictive analysis. In the estimation problem in this paper, heuristic methods outperform mathematical models.
Searching for the Answer 2.0
Authors: Ayton Phil , Billingham Paul
Published: December 2007

This article by Paul Billingham of Concept Searching and Phil Ayton of UC Logic covers the history of computerised searching aids in the context of knowledge management projects and describes conceptSearching, which is a scientific approach to trying to solve natural language searching problems using a number of techniques, not just an algorithm. They also consider federated searching and describe the Sysero information portal and a taxonomy manager application.
Certified Registered Nurse Anesthetists in America
Authors: Moos Daniel D.
Published: December 2007

ABSTRACT

Nurse anesthetists are crucial healthcare providers throughout the world. The duties, regulations, and educational requirements for nurse anesthetists vary from country to country. The purpose of this article is to provide the reader with a brief historical perspective on the development of nurse anesthesia in the United States; describe current nurse anesthesia practice; and allow the reader to compare and contrast it with the practice of nurse anesthesia in their own country.
Impact of mesospheric intrusions on ozone‐tracer relations in the stratospheric polar vortex
Authors: Müller Rolf , Tilmes Simone , Grooß Jens‐Uwe , Engel Andreas , Oelhaf Hermann , Wetzel Gerald , Huret Nathalie , Pirre Michel , Catoire Valéry , Toon Geoff , Nakajima Hideaki
Published: December 2007

Ozone‐tracer relations are used to quantify chemical ozone loss in the polar vortices. The underlying assumptions for the application of this technique were extensively discussed in recent years. However, the impact intrusions of mesospheric air into the polar stratosphere have on estimates of chemical ozone loss based on the ozone‐tracer technique has not hitherto been studied. Here, we revisit observations of an intrusion of mesospheric air down to altitudes of ∼25 km (∼600 K potential temperature) in the Arctic vortex in 2003. The mesospheric intrusion was identified in three balloon profiles in January and March 2003 as a strong enhancement in CO. In contrast, NOy was not enhanced in the mesospheric air relative to surrounding air masses as shown by the measurement in late March 2003. The measurements influenced by mesospheric air show ozone mixing ratios ranging between 3.6 and 5.6 ppm, which are clearly greater than those found in the “early vortex” reference relation employed to deduce chemical ozone loss. Thus the impact of intrusions of mesospheric air into the polar vortex on chemical ozone loss estimates based on ozone‐tracer relations are likely small; the correlations cannot be affected in a way that would lead to an overestimate of ozone depletion. Therefore ozone‐tracer relations may be used for deducing chemical ozone loss in Arctic winter 2002–2003. Here we use ILAS‐II satellite measurements to deduce an average chemical ozone loss in the vortex core for the partial column 380–550 K of 37 ± 11 Dobson units in March and of 50 ± 10 Dobson units in April 2003.
Improved accuracy of GRACE gravity solutions through empirical orthogonal function filtering of spherical harmonics
Authors: Wouters B. , Schrama E. J. O.
Published: December 2007

One of the major problems one has to deal with when working with Gravity Recovery and Climate Experiment (GRACE) data is the increasing error spectrum at higher degrees in the provided Stokes coefficients, appearing as unphysical North‐South striping patterns in the maps of equivalent water height (EWH). This phenomenon is commonly suppressed by application of a Gaussian smoothing filter, which unfortunately causes loss of signal and leakage between basins. In this paper we show how a significant amount of the striping can be removed by making use of the temporal characteristics of the error spectrum. The Stokes coefficients are decomposed using empirical orthogonal function analysis and the individual modes are tested for temporal noisiness. After filtering, maps of EWH are largely free of striping. Tests on simulated EWH estimates show that our filtering technique has a marginal effect on the predicted geophysical signal.
Limits on climate sensitivity derived from recent satellite and surface observations
Authors: Chylek Petr , Lohmann Ulrike , Dubey Manvendra , Mishchenko Michael , Kahn Ralph , Ohmura Atsumu
Published: December 2007

An analysis of satellite and surface measurements of aerosol optical depth suggests that global average of aerosol optical depth has been recently decreasing at the rate of around 0.0014/a. This decrease is nonuniform with the fastest decrease observed over the United States and Europe. The observed rate of decreasing aerosol optical depth produces the top of the atmosphere radiative forcing that is comparable to forcing due to the current rate of increasing atmospheric concentration of carbon dioxide and other greenhouse gases. Consequently, both increasing atmospheric concentration of greenhouse gases and decreasing loading of atmospheric aerosols are major contributors to the top‐of‐atmosphere radiative forcing. We find that the climate sensitivity is reduced by at least a factor of 2 when direct and indirect effects of decreasing aerosols are included, compared to the case where the radiative forcing is ascribed only to increases in atmospheric concentrations of carbon dioxide. We find the empirical climate sensitivity to be between 0.29 and 0.48 K/Wm−2 when aerosol direct and indirect radiative forcing is included.
Recent advances in regularization techniques for scattering and diffraction
Authors: Smith P. D.
Published: December 2007

Numerical techniques for Maxwell's equations or the Helmholtz equation often encounter difficulties of accuracy and convergence with scattering structures that feature cavities and sharp edges and are of moderate or large size (in wavelengths). Conversion to an equivalent integral equation formulation usually does not ameliorate the difficulty. This paper surveys some recent progress in techniques that address these difficulties for a variety of canonical and noncanonical structures. While some canonical cavity problems admit a purely analytical approach, another promising approach employs processes of analytical regularization that transform the basic integral equations to a second kind Fredholm matrix equation. The main tool is the Abel integral transform applied to trigonometric and other appropriate functions of hypergeometric type. The transformed equations are well conditioned (in contrast to the original formulation derived from Maxwell's equations); standard numerical techniques for their solution are easily applicable; near‐ and far‐field scattered field results may be computed reliably and accurately. The process in spherical and spheroidal geometry is illustrated for the simplest canonical problem of a cavity excited by an axially located electric dipole. Extension of the technique to arbitrarily shaped (nonsymmetric) cavities has great practical implications, and progress on two‐dimensional structures is described. Finally, recent developments from another class of noncanonical scatterers, arbitrarily shaped bodies of revolution, are reviewed.
Generation of fast propagating combustion and shock waves with copper oxide/aluminum nanothermite composites
Authors: Apperson S. , Shende R. V. , Subramanian S. , Tappmeyer D. , Gangopadhyay S. , Chen Z. , Gangopadhyay K. , Redner P. , Nicholich S. , Kapoor D.
Published: December 2007

Nanothermite composites containing metallic fuel and inorganic oxidizer are gaining importance due to their outstanding combustion characteristics. In this paper, the combustion behaviors of copper oxide/aluminum nanothermites are discussed. CuO nanorods were synthesized using the surfactant-templating method, then mixed or self-assembled with Al nanoparticles. This nanoscale mixing resulted in a large interfacial contact area between fuel and oxidizer. As a result, the reaction of the low density nanothermite composite leads to a fast propagating combustion, generating shock waves with Mach numbers up to 3.
Multiscale modeling of materials based on force and charge density fidelity
Authors: Mallik Aditi , Runge Keith , Dufty James W. , Cheng Hai-Ping
Published: December 2007

The approximate representation of a quantum solid as an equivalent composite semiclassical solid is considered for insulating materials. The composite is comprised of point ions moving on a potential energy surface. In the classical bulk domain this potential energy is represented by potentials constructed to give the same structure and elastic properties as the underlying quantum solid. In a small local quantum domain the potential is determined from a detailed quantum calculation of the electronic structure. The new features of this well-studied problem are (1) a clearly stated theoretical context in which approximations leading to the model are introduced, (2) the representation of the classical domain by potentials focused on reproducing the specific quantum response being studied, (3) development of “pseudoatoms” for a realistic treatment of charge densities where bonds have been broken to define the environment of the quantum domain, and (4) inclusion of polarization effects on the quantum domain due to its distant bulk environment. This formal structure is illustrated in detail for a SiO2 nanorod. More importantly, each component of the proposed modeling is tested quantitatively for this case, verifying its accuracy as a faithful multiscale model of the original quantum solid. To do so, the charge density of the entire nanorod is calculated quantum mechanically to provide the reference by which to judge the accuracy of the modeling. The construction of the classical potentials, the rod, the pseudoatoms, and the multipoles is discussed and tested in detail. It is then shown that the quantum rod, the rod constructed from the classical potentials, and the composite classical/quantum rod all have the same equilibrium structure and response to elastic strain. In more detail, the charge density and forces in the quantum subdomain are accurately reproduced by the proposed modeling of the environmental effects even for strains beyond the linear domain. The accuracy of the modeling is shown to apply for two quite different choices for the underlying quantum chemical method: transfer Hamiltonian and density functional methods.
High-resolution laser spectroscopy on the S1←S transition of jet-cooled anthracene: Rotational structure and Stark effect
Authors: Bendkowsky Vera , Heinecke Elke , Hese Achim
Published: December 2007

We present rotationally resolved spectra of the S1←S0 transition of anthracene at 27687.153(4)cm−1 as well as Stark effect measurements of the free anthracene molecule in electric fields of up to 85kV∕cm. The molecule is rotationally cooled in a supersonic jet expansion to a temperature of 4K. The rotational constants of the electronic states S0 and S1 are determined by a simplex fit comparing the experimental spectra with simulations for an asymmetric rigid rotor. The measured and simulated energies are in very good agreement and the estimated accuracy of the rotational constants is 1‰. Furthermore, the polarizabilities of the electronic states S0 and S1 are investigated. At an electric field of 85kV∕cm, line shifts of up to 150MHz caused by a change in the polarizability of Δα¯=123(7)a.u. and broadenings due to the anisotropy are observed. The components of the tensor polarizabilities of the electronic states S0 and S1 are determined by simulating the complete spectra using second-order perturbation theory.
Large deviations and Chernoff bound for certain correlated states on a spin chain
Authors: Hiai Fumio , Mosonyi Milán , Ogawa Tomohiro
Published: December 2007

In this paper we extend the results of Lenci and Rey-Bellet [J. Stat. Phys. 119, 715 (2005)] on the large deviation upper bound of the distribution measures of local Hamiltonians with respect to a Gibbs state in the setting of translation-invariant finite-range interactions. We show that a certain factorization property of the reference state is sufficient for a large deviation upper bound to hold and that this factorization property is satisfied by Gibbs states of the above kind as well as finitely correlated states. As an application of the methods, the Chernoff bound for correlated states with factorization property is studied. In the specific case of the distributions of the ergodic averages of a one-site observable with respect to an ergodic finitely correlated state, the spectral theory of positive maps is applied to prove the full large deviation principle.
Influences of nonlinearities of loudspeakers on performances of thermoacoustic refrigerators
Authors: Fan Li , Zhang Shu-yi , Zheng Kai , Zhang Hui
Published: December 2007

A nonlinear model of an electrodynamic loudspeaker is used to study the influences of the loudspeaker’s nonlinearities on the performances of thermoacoustic refrigerators. The results demonstrate that the nonlinearities of the magnetic field and vibration component of a loudspeaker change the acoustic output power and electroacoustic transfer efficiency. Additionally, the nonlinearity of the vibration component shifts the resonance frequency of the thermoacoustic refrigerator, which induces deviation of the load resistance of the loudspeaker at the resonance frequency. Therefore, the loudspeaker’s nonlinearities influence the acoustic coupling between the loudspeaker and resonance pipe, and also the performances of thermoacoustic refrigerators.
Rapid liquid phase sintered Mn doped BiFeO3 ceramics with enhanced polarization and weak magnetization
Authors: Kumar Manoj , Yadav K. L.
Published: December 2007

Single-phase BiFe1−xMnxO3 multiferroic ceramics have been synthesized by rapid liquid phase sintering method to study the influence of Mn substitution on their crystal structure, dielectric, magnetic, and ferroelectric behaviors. From XRD analysis it is seen that Mn substitution does not affect the crystal structure of the BiFe1−xMnxO3 system. An enhancement in magnetization was observed for BiFe1−xMnxO3 ceramics. However, the ferooelectric hysteresis loops were not really saturated, we observed a spontaneous polarization of 10.23μC∕cm2 under the applied field of 42kV∕cm and remanent polarization of 3.99μC∕cm2 for x=0.3 ceramic.
Specific resistance and scattering asymmetry of Py/Pd, Fe/V, Fe/Nb, and Co/Pt interfaces
Authors: Sharma A. , Romero J. A. , Theodoropoulou N. , Loloee R. , Pratt W. P. , Bass J.
Published: December 2007

The properties of interfaces between normal (N) and ferromagnetic (F) metals, described by enhanced specific resistance, ARF/N∗ (A=area, R=resistance), and scattering asymmetry, γF/N, are of interest to optimize current-perpendicular-to-plane (CPP) magnetoresistance (MR) and current-induced magnetization-switching (CIMS) in nanopillars. Sputtered standard Py/Cu, Co/Cu, and Fe/Cr interfaces have 2ARF/N∗∼1 fΩ m2 and γF/N∼0.7 at 4.2 K. Recently, sputtered F/Al interfaces with F=Py, Co, Fe, and Co91Fe9 were found to have very large 2ARF/Al∗∼9 fΩ m2, but small γF/Al≤0.1. In hopes of finding interfaces with both large 2ARF/N∗ and larger γF/N than for F/Al, the authors examined four new sputtered F/N pairs, Py/Pd, Fe/V, Fe/Nb, and Co/Pt, where the N metals all have fairly long spin-diffusion lengths, and the crystal structures of the F and N metals are matched. With the exception of Py/Pd, where 2ARPy/Pd∗ is smaller, all the other values of both 2ARF/N∗ and the magnitudes of γF/N for these new pairs lie between those for Co/Cu and F/Al. Unfortunately, these combinations of 2ARF/N∗ and γF/N mean that none of these pairs is superior to standard pairs for devices.
Formation of Si nanocrystallites observed by in situ transmission electron microscopy and their effect on the enhancement of Er photoluminescence in Er-doped SiO2
Authors: Fukata N. , Morihiro H. , Shirakawa R. , Murakami K. , Mitome M. , Bando Y.
Published: December 2007

The formation of Si nanocrystallites (nc-Si) in erbium (Er)-dispersed SiOx (x⩽2) films was investigated by in situ annealing while performing transmission electron microscopy measurements. The correlation between the formation of nc-Si and Er ion emissions was also comprehensively investigated by photoluminescence and electron spin resonance measurements. The results showed that the formation of nano-Si region with the suitable size is important for enhancement of Er ion emission.
Dynamics of the chain of forced oscillators with long-range interaction: From synchronization to chaos
Authors: Zaslavsky G. M. , Edelman M. , Tarasov V. E.
Published: December 2007

We consider a chain of nonlinear oscillators with long-range interaction of the type 1∕l1+α, where l is a distance between oscillators and 0<α<2. In the continuous limit, the system’s dynamics is described by a fractional generalization of the Ginzburg-Landau equation with complex coefficients. Such a system has a new parameter α that is responsible for the complexity of the medium and that strongly influences possible regimes of the dynamics, especially near α=2 and α=1. We study different spatiotemporal patterns of the dynamics depending on α and show transitions from synchronization of the motion to broad-spectrum oscillations and to chaos.
Dielectric-constant measurement of thin insulating films at low frequency by nanoscale capacitance microscopy
Authors: Fumagalli Laura , Ferrari Giorgio , Sampietro Marco , Gomila Gabriel
Published: December 2007

We demonstrate a method for quantitatively probing the local low-frequency dielectric constant of thin insulating films by nanoscale capacitance microscopy. The calibrated capacitance-distance curves are measured on the dielectric film and analyzed by using a tip-sample capacitance model here proposed. Applied to SiO2 films as small as 1×1μm2 area and 20–30nm thickness, the method gives a dielectric constant on the submicron scale in agreement with the value determined on the large scale. The observed precision is set by the capacitance noise level of the instrument and the tip radius.
Formation of a five-seven pair couple defect in double-walled carbon nanotubes under bending deformation
Authors: Wako Kei , Okada Isamu , Tachibana Masaru , Kojima Kenichi , Oda Tatsuki
Published: December 2007

Simulations of double-walled carbon nanotubes under bending deformation using the tight-binding molecular dynamics method were carried out. Five- and seven-membered ring pair defects were formed after emission of several atoms from the tube structure. These defect pair couples have different structures corresponding to the number of emitted atoms and stabilize the resulting nanotubes. Our results imply that the defect pair couples represent one of the potential origins of the experimentally observed plastic deformations that have been shown to occur in double-walled carbon nanotubes. The various defects obtained by the simulations are discussed in relation to other defect types.
Deformation quantization of almost Kähler models and Lagrange-Finsler spaces
Authors: Vacaru Sergiu I.
Published: December 2007

Finsler and Lagrange spaces can be equivalently represented as almost Kähler manifolds endowed with a metric compatible canonical distinguished connection structure generalizing the Levi-Civita connection. The goal of this paper is to perform a natural Fedosov-type deformation quantization of such geometries. All constructions are canonically derived for regular Lagrangians and/or fundamental Finsler functions on tangent bundles.
Defect-related local magnetism at dilute Fe atoms in ion-implanted ZnO
Authors: Weyer G. , Gunnlaugsson H. P. , Mantovan R. , Fanciulli M. , Naidoo D. , Bharuth-Ram K. , Agne T.
Published: December 2007

Semiconductors, which are ferromagnetic at room temperature (RTFM), are strived after as potential multifunctional materials. For ZnO, RTFM has been achieved by heavy doping with 3d transition metals. However, neither the conditions for nor the origin of the magnetism is as yet understood. Here, by implanting ZnO at temperatures of 300–800K with dilute, radioactive Mn+57 ions, decaying to the Fe57m Mössbauer state, we show that, most likely, Fe atoms, located on Zn sites in a high-spin Fe3+ state at ⩽600K with large magnetic moments, are in a magnetically ordered atomic surrounding with ordering temperatures ⪢600K. The formation/annealing of the ordering is proposed to occur/disappear on an atomic scale upon the association/dissociation of complexes of Mn∕Fe probe atoms with the (mobile) Zn vacancies that are created in the implantation process. These results challenge present concepts to model (ferro)magnetic ordering in 3d-metal doped oxides and suggest this role of vacancies in the magnetism to be a rather general phenomenon.
The effect of Eu substitution on thermoelectric properties of SrTi0.8Nb0.2O3
Authors: Kato Keisuke , Yamamoto Masahiro , Ohta Shingo , Muta Hiroaki , Kurosaki Ken , Yamanaka Shinsuke , Iwasaki Hideo , Ohta Hiromichi , Koumoto Kunihito
Published: December 2007

Herein we demonstrate that Eu2+ substitution of SrTi0.8Nb0.2O3 is effective in reducing the thermal conductivity, with no reduction in the thermoelectric power factor (S2σ; S, Seebeck coefficient; σ, electrical conductivity). We prepared cubic (Sr,Eu)Ti0.8Nb0.2O3 crystals having the same lattice parameter (a=0.395 nm) over the whole composition range. Although no dependence upon the Eu content was observed for the electron transport properties, including the density of states effective mass and carrier relaxation time for (Sr,Eu)Ti0.8Nb0.2O3, the mean free path of the phonon was reduced ∼12% at room temperature when half of the Sr2+ was substituted by Eu2+.
Horizontally directed growth of carbon nanotubes utilizing self-generated electric field from plasma induced surface charging
Authors: Law J. B. K. , Koo C. K. , Thong J. T. L.
Published: December 2007

Plasma induced surface charging during carbon nanotube (CNT) growth via radio frequency plasma-enhanced chemical vapor deposition is exploited to direct the growth in a horizontal direction on a device substrate without the need for external biasing arrangements. Using a silicon-on-insulator substrate, a pair of electrodes is fabricated in which one electrode is shorted to the handle layer and the other is left floating. A potential difference results from the plasma, and creates a lateral electric field between the electrodes that is used to direct the growth of CNTs. The approach allows for wafer-scale growth of laterally aligned CNTs.
Consistent experimental determination of the charge neutrality level and the pillow effect at metal/organic interfaces
Authors: Molodtsova O. V. , Grobosch M. , Knupfer M. , Aristov V. Yu.
Published: December 2007

Experimental results for the interface dipoles at metal/organic and organis/organic interfaces have been analyzed on the basis of the induced density of interfaces states model. We demonstrate that a consistent analysis of a selected set of interfaces is possible, which allows the determination of all microscopic parameters of the model, and moreover enables the prediction of the electronic properties of further, yet unknown interfaces.
Community structure of temperate reef fishes in kelp-dominated subtidal habitats of northern Chile
Authors: Pérez-Matus Alejandro , Ferry-Graham Lara A. , Cea Alfredo , Vásquez Julio A.
Published: December 2007

An important aim of fish ecology is to understand and predict patterns of distribution and abundance in marine communities. Such patterns were examined at four kelp-dominated sites along the northern coast of Chile (19° through 30° S) over 1 year. Fish species richness, diversity and abundance estimates obtained via observational and destructive sampling methods were compared among sites as were habitat and environmental variables that characterised the sites; including sea water temperature below the surface, nutrients, productivity, visibility, density of macroalgae stands, and percentage cover of observed microhabitats (including understorey algae and faunal assemblages). In total, 19 fish species belonging to 14 families were observed from all sites. Species richness and diversity were highest in sites where kelp canopy was composed of two species and where kelp was densest, although only species diversity was significantly different among sites. The sites with high kelp density, in turn, sustained abundant habitat-forming species in the kelp understorey. Principal coordinate analysis indicated that the composition and structure of the fish assemblages varied significantly with depth at all study sites. The depth distribution of fishes was correlated with the arrangement of site-specific biological microhabitats, defined by the algae or invertebrate species that form the microhabitat. Temperature, productivity, and nutrients did not vary consistently across study sites, but did vary within individual sites. We suggest that kelp cover and composition strongly affects the diversity and distribution of fishes at shallow coastal habitats in northern Chile through the availability of microhabitats.
Prospects for immunocontraception in the European red fox (Vulpes vulpes)
Authors: Strive T. , Hardy C. M. , Reubel G. H.
Published: December 2007

The European red fox is an introduced pest species in Australia for which improved means of control are urgently needed. Research efforts have focussed recently on the development of novel biological control methods to reduce the serious impact this species continues to have on both native fauna and the sheep industry. The ultimate goal has been to generate an antifertility vaccine for use on foxes that relies on a process termed ‘immunocontraception’. A variety of proteins derived from sperm and oocytes, together with different delivery vectors, have been experimentally assessed for their ability to induce immunocontraceptive responses in foxes. Vaccine vectors screened have included Salmonella typhimurium, vaccinia virus and canine herpesvirus but suppression of fertility has yet to be achieved with any combination of antigen and delivery vector. Downregulation of fox mucosal antibodies during oestrus, lack of vector replication and low antibody responses to the target antigens have been the main constraints in successful fertility control. The fox is not well known as an experimental animal and the logistics of dealing with this difficult-to-handle species proved to be a major challenge when compared with other species, such as rabbits and mice. Despite these difficulties, research on fox immunocontraception has generated important insights into the reproductive biology, husbandry, biology and basic immunology of viral vectors in European red foxes. This information represents a valuable knowledge base should antifertility vaccination for foxes be revisited in the future.
Prospects for virally vectored immunocontraception in the control of wild house mice (Mus domesticus)
Authors: Redwood Alec J. , Smith Lee M. , Lloyd Megan L. , Hinds Lyn A. , Hardy Christopher M. , Shellam Geoffrey R.
Published: December 2007

The wild house mouse (Mus domesticus) is not native to Australia and was introduced from Europe with early settlement. It undergoes periodic population explosions or plagues, which place significant economic and social burdens on agricultural communities. Present control mechanisms rely on improvements to farm hygiene and the use of rodenticides. This review covers over a decade of work on the use of virally vectored immunocontraception (VVIC) as an adjunct method of controlling mouse populations. Two viral vectors, ectromelia virus (ECTV) and murine cytomegalovirus (MCMV) have been tested as potential VVIC vectors: MCMV has been the most widely studied vector because it is endemic to Australia; ECTV less so because its use would have required the introduction of a new pathogen into the Australian environment. Issues such as efficacy, antigen choice, resistance, transmission, species specificity and safety of VVIC are discussed. In broad terms, both vectors when expressing murine zona pellucida 3 (mZP3) induced long-term infertility in most directly inoculated female mice. Whereas innate and acquired resistance to MCMV may be a barrier to VVIC, the most significant barrier appears to be the attenuation seen in MCMV-based vectors. This attenuation is likely to prevent sufficient transmission for broad-scale use. Should this issue be overcome, VVIC has the potential to contribute to the control of house mouse populations in Australia.
Gap junction remodeling and cardiac arrhythmogenesis in a murine model of oculodentodigital dysplasia
Authors: Kalcheva Nellie , Qu Jiaxiang , Sandeep Nefthi , Garcia Luis , Zhang Jie , Wang Zhiyong , Lampe Paul D. , Suadicani Sylvia O. , Spray David C. , Fishman Glenn I.
Published: December 2007

Gap junction channels are required for normal cardiac impulse propagation, and gap junction remodeling is associated with enhanced arrhythmic risk. Oculodentodigital dysplasia (ODDD) is a multisystem syndrome due to mutations in the
connexin43
(
Cx43
) gap junction channel gene. To determine the effects of a human connexin channelopathy on cardiac electrophysiology and arrhythmogenesis, we generated a murine model of ODDD by introducing the disease-causing I130T mutant allele into the mouse genome. Cx43 abundance was markedly reduced in mutant hearts with preferential loss of phosphorylated forms that interfered with trafficking and assembly of gap junctions in the junctional membrane. Dual whole-cell patch–clamp studies showed significantly lower junctional conductance between neonatal cell pairs from mutant hearts, and optical mapping of isolated-perfused hearts with voltage-sensitive dyes demonstrated significant slowing of conduction velocity. Programmed electrical stimulation revealed a markedly increased susceptibility to spontaneous and inducible ventricular tachyarrhythmias. In summary, our data demonstrate that the I130T mutation interferes with Cx43 posttranslational processing, resulting in diminished cell–cell coupling, slowing of impulse propagation, and a proarrhythmic substrate.
Evasion of myofibroblasts from immune surveillance: A mechanism for tissue fibrosis
Authors: Wallach-Dayan Shulamit B. , Golan-Gerstl Regina , Breuer Raphael
Published: December 2007

Tissue fibrosis evolving from impaired tissue remodeling after injury is characterized by myofibroblast accumulation. We propose that during the development of fibrosis myofibroblasts acquire an immune-privileged cell phenotype, allowing their uninterrupted accumulation. Using the murine model of bleomycin-induced lung fibrosis in mice, we show that myofibroblasts that accumulate in lungs with fibrosis, but not in normal lungs, kill Fas+lymphocytes, resist Fas-induced apoptosis, and survive longer when grafted into allogeneic mice. In contrast, bleomycin-treated FasLigand (FasL)-deficient (gld) chimeric mice did not accumulate myofibroblasts or collagen in their lungs, and their FasL−myofibroblasts did not survive after alloengraftment. This finding indicates that myofibroblasts possess Fas/FasL-pathway-dependent characteristics that allow them to escape from immune surveillance and resulting organ fibrosis.