bluuebunny/crossref_metadata_2025 huggingface dataset:
What's for dinner? Types of food served at family dinner differ across parent and family characteristics
Authors: Neumark-Sztainer Dianne , MacLehose Rich , Loth Katie , Fulkerson Jayne A , Eisenberg Marla E , Berge Jerica
Published: October 2012

Objective

To examine the types of food served at family dinner in the homes of adolescents and correlations with parent and family sociodemographic characteristics, psychosocial factors and meal-specific variables.

Design

A cross-sectional population-based survey completed by mail or telephone by parents participating in Project F-EAT (Families and Eating and Activity in Teens) in 2009–2010.

Setting

Homes of families with adolescents in Minneapolis/St. Paul urban area, MN, USA.

Subjects

Participants included 1923 parents/guardians (90·8 % female; 68·5 % from ethnic/racial minorities) of adolescents who participated in EAT 2010.

Results

Less than a third (28 %) of parents reported serving a green salad at family dinner on a regular basis, but 70 % reported regularly serving vegetables (other than potatoes). About one-fifth (21 %) of families had fast food at family dinners two or more times per week. Variables from within the sociodemographic domain (low educational attainment) psychosocial domain (high work–life stress, depressive symptoms, low family functioning) and meal-specific domain (low value of family meals, low enjoyment of cooking, low meal planning, high food purchasing barriers and fewer hours in food preparation) were associated with lower healthfulness of foods served at family dinners, in analyses adjusted for sociodemographic characteristics.

Conclusions

There is a need for interventions to improve the healthfulness of food served at family meals. Interventions need to be suitable for parents with low levels of education; take parent and family psychosocial factors into account; promote more positive attitudes toward family meals; and provide skills to make it easier to plan and prepare healthful family meals.
Manilamen and seafaring: engaging the maritime world beyond the Spanish realm
Authors: Aguilar Filomeno V.
Published: October 2012

Although the Philippines is hardly known for sending out migrants prior to the twentieth century, and even among seafarers only the galleon age is remembered, this article provides evidence of transcontinental maritime movements from the late eighteenth century until the early twentieth century. These migrants were known in the English-speaking world as Manilamen. Most were seafarers, but some became involved in pearl-shell fishing, while others engaged in mercenary activities. They settled in key ports around the world, their numbers in any one location fluctuating in response to changing circumstances. Despite relocation to distant places, the difficulties of communication, and the impetus toward naturalization, Manilamen seem to have retained some form of identification with the Philippines as homeland, no matter how inchoately imagined.
The friendly planet: ‘Oddfellows’, networks, and the ‘British World’c.1840–1914
Authors: Downing Arthur
Published: October 2012

British clubs and societies spread around the English-speaking world in the long nineteenth century. This article focuses on one particularly large friendly society, the Manchester Unity Independent Order of Oddfellows (MU), which by 1913 had more than a thousand lodges around the world, especially concentrated in Australia and New Zealand. The MU spread so widely because of micro-social and macro-social forces, both of which this article investigates. It also examines the transfer of members, funds, and information between different districts of the society, and argues that such transfers may have smoothed internal and long-distance migration.
Between global aspirations and local realities: the global dimensions of interwar communism
Authors: Häberlen Joachim C.
Published: October 2012

This article explores the global dimension of communism during the interwar period. It criticizes a literature that either depicts communist parties as small ‘red armies’ obeying any order from Moscow, or focuses exclusively on the local level and ignores any international aspects. The article first discusses attempts of communist leaders to create a ‘world party’ based in Moscow. It next analyses the conflicts between a globally acting communist leadership and rank-and-file members concerned about their local circumstances. Finally, it highlights the role that internationalism played on the local level. Such an approach – which locates ‘the global’ on the local level, both in terms of how internationalist ideas informed people's behaviour in local contexts and in terms of how they resisted forms of globalism – might provide a means for bridging the gap between global and local histories.
‘Segregation has fallen on evil days’: Smuts' South Africa, global war, and transnational politics, 1939–46
Authors: Hyslop Jonathan
Published: October 2012

South African state policy in the 1940s moved in significantly new political directions that were not simply the prelude to apartheid. This shift, under the leadership of Jan Smuts, towards a welfarist management of black urbanization, can only be understood by focusing on transnational dimensions of the period that have been neglected by historians of South Africa. The reorganization of the state was made possible as a consequence of the business of fighting a global war. South African policy changes were intimately linked to the evolution of British colonial policy. And the South African interventions in world politics to support the creation of the United Nations and to reconfigure the southern African subcontinent were to have drastic and unforeseen consequences.
Re-reading W. E. B. Du Bois: the global dimensions of the US civil rights struggle
Authors: Darian-Smith Eve
Published: October 2012

Drawing on the increasingly important insights of historians concerned with global and transnational perspectives, in this article I argue that Du Bois' international activism and writings on global oppression in the decades following the Second World War profoundly shaped the ways in which people in the United States engaged with race as a concept and social practice in the mid decades of the twentieth century. Du Bois' efforts to bring his insights on global racism home to the US domestic legal arena were to a large degree thwarted by a US foreign policy focused on Cold War politics and interested in pursuing racial equality not on the basis of universal human rights principles but as a Cold War political strategy. Nonetheless, I argue that Du Bois' writings, which were informed by a new rhetoric of global responsibility and universal citizenship, had unpredictable and significant consequences in shaping the direction of US racial politics in the civil rights era.
Resurrecting Che: radicalism, the transnational imagination, and the politics of heroes
Authors: Prestholdt Jeremy
Published: October 2012

This article explores the symbolic appeal of Che Guevara within radical Left circles of the 1960s and 1970s. Che's importance as a shared political reference offers a unique window on aspirational symbols and the desire for meaningful transnational solidarity. By tracing Che's resonance in Latin America, western Europe, the United States, and the Middle East, the article brings into conversation the study of post-war radicalism, political iconography, and the cognitive dimensions of interconnectivity. As a means of understanding Che's appeal to both protest movements and guerrilla organizations, the article develops the notion of a ‘transnational imagination’, or mode of perception that frames local circumstances in a world historical trajectory and thereby affects collective aspirations and actions.
Delivering better end-of-life care in England: barriers to access for patients with a non-cancer diagnosis
Authors: Addicott Rachael
Published: October 2012

The End of Life Care Strategy (Department of Health, 2008) radically raised the profile of end-of-life care in England, signalling the need for development in planning and delivery, to ensure that individuals are able to exercise genuine choice in how and where they are cared for and die. Research has indicated that there have been continuing difficulties in access to high-quality and appropriate support at the end of life, particularly for patients with a diagnosis other than cancer. This article uses research findings from three case studies of end-of-life care delivery in England to highlight some of the barriers that continue to exist, and understand these challenges in more depth. Access to high-quality and appropriate end-of-life care has been a challenge for all patients nearing the end of life. However, the findings from this research indicate that there are several interrelated reasons why access to end-of-life care services can be more difficult for patients with a non-cancer diagnosis. These issues relate to differences in disease trajectories and subsequent care planning, which are further entrenched by existing funding arrangements.
Dementia, death and advance directives
Authors: WOLFF JONATHAN
Published: October 2012

This article considers the ethics of advance directives, especially in relation to conditions such as dementia. For some choices, such as over whether one's life should end at home or in a hospice, advance directives can be very enlightened and helpful. For others, such as those to end the life of an autonomous subject, against their will, have no moral appeal and would rightly be ignored. In a wide range of intermediate cases, given our typical lack of insight into how changes in our health condition will affect us in other ways, we should be very cautious indeed in promoting the use of advance directives in end-of-life decisions, at least where a reasonable quality of life remains. There may be some reasons for giving priority to the earlier autonomous self over a later, contented but non-autonomous self, but these reasons seem far from compelling.
The Hungarian Twin Registry
Authors: Littvay Levente , Métneki Julia , Tárnoki Ádám D. , Tárnoki Dávid L.
Published: October 2012

The first Hungarian Twin Registry was established in Budapest in 1970 through the mandatory reporting of multiple-births. In the 1980s a second, volunteer adult registry was also founded. Unfortunately, both registries ceased to exist in the 1990s. Efforts started in 2006 to revive a Hungarian twin registry. The team spearheading this effort reports here on this progress. Currently, the voluntary Hungarian Twin Registry consists of 310 adult twin pairs and multiplets. Current research focuses on cardiovascular and respiratory health and yielded multiple awards and publications. Efforts are on the way to expand into social, psychological, and obesity studies.
The Danish Twin Registry: Linking Surveys, National Registers, and Biological Information
Authors: Skytthe Axel , Christiansen Lene , Kyvik Kirsten Ohm , Bødker Frans L. , Hvidberg Lars , Petersen Inge , Nielsen Morten M. F. , Bingley Paul , Hjelmborg Jacob , Tan Qihua , Holm Niels V. , Vaupel James W. , McGue Matt , Christensen Kaare
Published: October 2012

Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008–2011 and included both in-person assessments of 14,000+ twins born 1931–1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions.
Thermal growing season and timing of biospheric carbon uptake across the Northern Hemisphere
Authors: Barichivich J. , Briffa K. R. , Osborn T. J. , Melvin T. M. , Caesar J.
Published: October 2012

Gridded daily temperature from 1950 to 2011 and atmospheric CO2concentration data from high‐latitude observing stations and the CarbonTracker assimilation system are used to examine recent spatiotemporal variability of the thermal growing season and its relationship with seasonal biospheric carbon uptake and release in the Northern Hemisphere. The thermal growing season has lengthened substantially since 1950 but most of the lengthening has occurred during the last three decades (2.9 days decade−1, p < 0.01 for 1980–2011), with stronger rates of extension in Eurasia (4.0 days decade−1, p < 0.01) than in North America (1.2 days decade−1, p > 0.05). Unlike most previous studies, which had more limited data coverage over the past decade, we find that strong autumn warming of about 1°C during the second half of the 2000s has led to a significant shift toward later termination of the thermal growing season, resulting in the longest potential growing seasons since 1950. On average, the thermal growing season has extended symmetrically by about a week during this period, starting some 4.0 days earlier and ending about 4.3 days later. The earlier start of the thermal growing season is associated with earlier onset of the biospheric carbon uptake period at high northern latitudes. In contrast, later termination of the growing season is associated with earlier termination of biospheric carbon uptake, but this relationship appears to have decoupled since the beginning of the period of strong autumn warming during the second half of the 2000s. Therefore, owing to these contrasting biospheric responses at the margins of the growing season, the current extension in the thermal growing season length has not led to a concomitant extension of the period of biospheric carbon uptake.
Oxygen and hydrogen ion abundance in the near‐Earth magnetosphere: Statistical results on the response to the geomagnetic and solar wind activity conditions
Authors: Kronberg E. A. , Haaland S. E. , Daly P. W. , Grigorenko E. E. , Kistler L. M. , Fränz M. , Dandouras I.
Published: October 2012

The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial magnetosphere. We investigate the oxygen‐to‐hydrogen ratio in the near‐Earth magnetosphere from −10 RE < XGSE < 10 RE. The results are based on seven years of ion flux measurements in the energy range ∼10 keV to ∼955 keV from the RAPID and CIS instruments on board the Cluster satellites. We find that (1) hydrogen ions at ∼10 keV show only a slight correlation with the geomagnetic conditions and interplanetary magnetic field changes. They are best correlated with the solar wind dynamic pressure and density, which is an expected effect of the magnetospheric compression; (2) ∼10 keV O+ ion intensities are more strongly affected during disturbed phase of a geomagnetic storm or substorm than >274 keV O+ ion intensities, relative to the corresponding hydrogen intensities; (3) In contrast to ∼10 keV ions, the >274 keV O+ions show the strongest acceleration during growth phase and not during the expansion phase itself. This suggests a connection between the energy input to the magnetosphere and the effective energization of energetic ions during growth phase; (4) The ratio between quiet and disturbed times for the intensities of ion ionospheric outflow is similar to those observed in the near‐Earth magnetosphere at >274 keV. Therefore, the increase of the energetic ion intensity during disturbed time is likely due to the intensification and the effective acceleration of the ionospheric source. In conclusion, the energization process in the near‐Earth magnetosphere is mass dependent and it is more effective for the heavier ions.
A 20 year independent record of sea surface temperature for climate from Along‐Track Scanning Radiometers
Authors: Merchant Christopher J. , Embury Owen , Rayner Nick A. , Berry David I. , Corlett Gary K. , Lean Katie , Veal Karen L. , Kent Elizabeth C. , Llewellyn‐Jones David T. , Remedios John J. , Saunders Roger
Published: October 2012

A new record of sea surface temperature (SST) for climate applications is described. This record provides independent corroboration of global variations estimated from SST measurements made in situ. Infrared imagery from Along‐Track Scanning Radiometers (ATSRs) is used to create a 20 year time series of SST at 0.1° latitude‐longitude resolution, in the ATSR Reprocessing for Climate (ARC) project. A very high degree of independence of in situ measurements is achieved via physics‐based techniques. Skin SST and SST estimated for 20 cm depth are provided, with grid cell uncertainty estimates. Comparison with in situ data sets establishes that ARC SSTs generally have bias of order 0.1 K or smaller. The precision of the ARC SSTs is 0.14 K during 2003 to 2009, from three‐way error analysis. Over the period 1994 to 2010, ARC SSTs are stable, with better than 95% confidence, to within 0.005 K yr−1(demonstrated for tropical regions). The data set appears useful for cleanly quantifying interannual variability in SST and major SST anomalies. The ARC SST global anomaly time series is compared to the in situ‐based Hadley Centre SST data set version 3 (HadSST3). Within known uncertainties in bias adjustments applied to in situ measurements, the independent ARC record and HadSST3 present the same variations in global marine temperature since 1996. Since the in situ observing system evolved significantly in its mix of measurement platforms and techniques over this period, ARC SSTs provide an important corroboration that HadSST3 accurately represents recent variability and change in this essential climate variable.
Toward reliable ensemble Kalman filter estimates of CO2 fluxes
Authors: Chatterjee Abhishek , Michalak Anna M. , Anderson Jeffrey L. , Mueller Kim L. , Yadav Vineet
Published: October 2012

The use of ensemble filters for estimating sources and sinks of carbon dioxide (CO2) is becoming increasingly common, because they provide a relatively computationally efficient framework for assimilating high‐density observations of CO2. Their applicability for estimating fluxes at high‐resolutions and the equivalence of their estimates to those from more traditional “batch” inversion methods have not been demonstrated, however. In this study, we introduce a Geostatistical Ensemble Square Root Filter (GEnSRF) as a prototypical filter and examine its performance using a synthetic data study over North America at a high spatial (1° × 1°) and temporal (3‐hourly) resolution. The ensemble performance, both in terms of estimates and associated uncertainties, is benchmarked against a batch inverse modeling setup in order to isolate and quantify the degradation in the estimates due to the numerical approximations and parameter choices in the ensemble filter. The examined case studies demonstrate that adopting state‐of‐the‐art covariance inflation and localization schemes is a necessary but not sufficient condition for ensuring good filter performance, as defined by its ability to yield reliable flux estimates and uncertainties across a range of resolutions. Observational density is found to be another critical factor for stabilizing the ensemble performance, which is attributed to the lack of a dynamical model for evolving the ensemble between assimilation times. This and other results point to key differences between the applicability of ensemble approaches to carbon cycle science relative to its use in meteorological applications where these tools were originally developed.
The severity of mammary gland developmental defects is linked to the overall functional status of Cx43 as revealed by genetically modified mice
Authors: Stewart Michael K. G. , Gong Xiang-Qun , Barr Kevin J. , Bai Donglin , Fishman Glenn I. , Laird Dale W.
Published: October 2012

Genetically modified mice mimicking ODDD (oculodentodigital dysplasia), a disease characterized by reduced Cx43 (connexin 43)-mediated gap junctional intercellular communication, represent an in vivo model to assess the role of Cx43 in mammary gland development and function. We previously reported that severely compromised Cx43 function delayed mammary gland development and impaired milk ejection in mice that harboured a G60S Cx43 mutant, yet there are no reports of lactation defects in ODDD patients. To address this further, we obtained a second mouse model of ODDD expressing an I130T Cx43 mutant to assess whether a mutant with partial gap junction channel activity would be sufficient to retain mammary gland development and function. The results of the present study show that virgin Cx43I130T/+ mice exhibited a temporary delay in ductal elongation at 4 weeks. In addition, Cx43I130T/+ mice develop smaller mammary glands at parturition due to reduced cell proliferation despite similar overall gland architecture. Distinct from Cx43G60S/+ mice, Cx43I130T/+ mice adequately produce and deliver milk to pups, suggesting that milk ejection is unaffected. Thus the present study suggests that a loss-of-function mutant of Cx43 with partial gap junction channel coupling conductance results in a less severe mammary gland phenotype, which may partially explain the lack of reported lactation defects associated with ODDD patients.
Supplying enriched uranium
Authors: Abajian Vincent V. , Fishman Alan M.
Published: October 2012

Among the problems that must be solved before nuclear power can finally become a mature industry providing a major fraction of the nation's electric power, perhaps the least publicized is the problem of making sure there will be enough enriched uranium to fuel the rapidly growing numbers of nuclear power plants. Currently there are 29 nuclear plants generating 15 000 megawatts, or less than 5% of the nation's total capacity; by 1990, the AEC predicts that the nuclear plant capacity will have grown by more than a factor of 40 and will be roughly half of the total national capacity. Unfortunately, no plans have been made for a parallel expansion in the country's uranium-enrichment facilities that must supply the fuel for all these new plants.
Laser-induced thermonuclear fusion
Authors: Nuckolls John , Emmett John , Wood Lowell
Published: October 2012

Laser-induced fusion has recently joined magnetic-confinement fusion as a prime prospect for generating controlled thermonuclear power. During the past three years, the Atomic Energy Commission has accelerated the national laser-fusion program more than tenfold, to about $30 million annually, and the Soviet Union has a program of comparable size.
Quantum degenerate systems
Authors: de Micheli Fiorenza , Zanelli Jorge
Published: October 2012

A degenerate dynamical system is characterized by a symplectic structure whose rank is not constant throughout phase space. Its phase space is divided into causally disconnected, nonoverlapping regions in each of which the rank of the symplectic matrix is constant, and there are no classical orbits connecting two different regions. Here the question of whether this classical disconnectedness survives quantization is addressed. Our conclusion is that in irreducible degenerate systems—in which the degeneracy cannot be eliminated by redefining variables in the action—the disconnectedness is maintained in the quantum theory: there is no quantum tunnelling across degeneracy surfaces. This shows that the degeneracy surfaces are boundaries separating distinct physical systems, not only classically, but in the quantum realm as well. The relevance of this feature for gravitation and Chern-Simons theories in higher dimensions cannot be overstated.
Calculation and analysis of the harmonic vibrational frequencies in molecules at extreme pressure: Methodology and diborane as a test case
Authors: Cammi R. , Cappelli C. , Mennucci B. , Tomasi J.
Published: October 2012

We present a new quantum chemical method for the calculation of the equilibrium geometry and the harmonic vibrational frequencies of molecular systems in dense medium at high pressures (of the order of GPa). The new computational method, named PCM-XP, is based on the polarizable continuum model (PCM), amply used for the study of the solvent effects at standard condition of pressure, and it is accompanied by a new method of analysis for the interpretation of the mechanisms underpinning the effects of pressure on the molecular geometries and the harmonic vibrational frequencies. The PCM-XP has been applied at the density functional theory level to diborane as a molecular system under high pressure. The computed harmonic vibrational frequencies as a function of the pressure have shown a satisfactory agreement with the corresponding experimental results, and the parallel application of the method of analysis has reveled that the effects of the pressure on the equilibrium geometry can be interpreted in terms of direct effects on the electronic charge distribution of the molecular solutes, and that the effects on the harmonic vibrational frequencies can be described in terms of two physically distinct effects of the pressure (curvature and relaxation) on the potential energy for the motion of the nuclei.
Role of electronic localization in the phosphorescence of iridium sensitizing dyes
Authors: Himmetoglu Burak , Marchenko Alex , Dabo Ismaïla , Cococcioni Matteo
Published: October 2012

In this work we present a systematic study of three representative iridium dyes, namely, Ir(ppy)3, FIrpic, and PQIr, which are commonly used as sensitizers in organic optoelectronic devices. We show that electronic correlations play a crucial role in determining the excited-state energies in these systems, due to localization of electrons on Ir d orbitals. Electronic localization is captured by employing hybrid functionals within time-dependent density-functional theory and with Hubbard-model corrections within the Δ-SCF approach. The performance of both methods are studied comparatively and shown to be in good agreement with experiment. The Hubbard-corrected functionals provide further insight into the localization of electrons and on the charge-transfer character of excited-states. The gained insight allows us to comment on envisioned functionalization strategies to improve the performance of these systems. Complementary discussions on the Δ-SCF method are also presented in order to fill some of the gaps in the literature.
Nonadiabatic effects in substitutional isomers of Jahn-Teller molecules: The strange case of hydroxymethoxy
Authors: Dillon Joseph , Yarkony David R.
Published: October 2012

The effects of nonadiabatic interactions attributable to a seam of conical intersections on the electronic structure of the 1,22A states of hydroxymethoxy (HO)CH2O is explored. Illuminating comparisons are made between hydroxymethoxy and ethoxy and isopropoxy, all of which can be thought of as substitutional isomers of the methoxy radical. Surprisingly, the potential energy surfaces and conical topographies for hydroxymethoxy are shown to be dramatically different from those evidenced in ethoxy or isopropoxy radicals, dissimilarities traced to the hydroxyl group. Also considered in this study was the feasibility of representing the coupled 1,22A adiabatic electronic states of hydroxymethoxy within the vibronic coupling approximation using a quasi-diabatic Hamiltonian and subsequently using that representation to simulate the photoelectron spectrum of the hydroxymethoxide anion. Complications attributable to the torsional motion of the hydroxyl hydrogen are analyzed.
Ion energy analyzer for measurement of ion turbulent transport
Authors: Sokolov V. , Sen A. K.
Published: October 2012

For local measurement of radial ion thermal transport, we developed a novel time-resolved gridded ion energy analyzer. The turbulent thermal flux is obtained by correlating fluctuations of ion temperature, plasma density and plasma velocity. The simultaneous measurement of the ion current fluctuations from an ion energy analyzer $\tilde I_{IEA} (t)$ĨIEA(t) and the fluctuation of ion saturation current from a conventional Langmuir probe $\tilde I_{LP} (t)$ĨLP(t) allow us to determine local fluctuations of ion temperature $\tilde T_i (t)$T̃i(t). To reduce the effect of plasma potential fluctuations in the energy analyzer measurements, we use special a compensative circuit loop.
Stability of developing film flow down an inclined surface
Authors: Ramadurgam Sarath , Chakravarthy R. V. K. , Tomar Gaurav , Govindarajan Rama
Published: October 2012

Film flows on inclined surfaces are often assumed to be of constant thickness, which ensures that the velocity profile is half-Poiseuille. It is shown here that by shallow water theory, only flows in a portion of Reynolds number-Froude number (Re–Fr) plane can asymptotically attain constant film thickness. In another portion on the plane, the constant thickness solution appears as an unstable fixed point, while in other regions the film thickness seems to asymptote to a positive slope. Our simulations of the Navier-Stokes equations confirm the predictions of shallow water theory at higher Froude numbers, but disagree with them at lower Froude numbers. We show that different regimes of film flow show completely different stability behaviour from that predicted earlier. Supercritical decelerating flows are shown to be always unstable, whereas accelerating flows become unstable below a certain Reynolds number for a given Froude number. Subcritical flows on the other hand are shown to be unstable above a certain Reynolds number. In some range of parameters, two solutions for the base flow exist, and the attached profile is found to be more stable. All flows except those with separation become more stable as they proceed downstream.
Magnetization dynamics of a MgO-based spin-torque oscillator with a perpendicular polarizer layer and a planar free layer
Authors: Suto Hirofumi , Yang Tao , Nagasawa Tazumi , Kudo Kiwamu , Mizushima Koichi , Sato Rie
Published: October 2012

Current-induced magnetization excitations are studied for a spin-torque oscillator (STO) composed of a nanopillar with a perpendicular polarizer layer (PL), a MgO barrier layer, and a planar free layer (FL). By applying direct current and perpendicular-to-plane magnetic field, we measure resistance and radio-frequency electrical signal of the STO, which reflect magnetization motions of both PL and FL. Examination of the experimental results reveals that large-cone-angle magnetization oscillation occurs in the FL regardless of the current direction, whereas the PL magnetization shows principally either synchronized excitation with the FL oscillation or thermal-induced ferromagnetic resonance (FMR), depending on the current direction. Utilizing macrospin simulations, we show that hybridization of the excitation modes of the PL and FL through mutual dipolar field explains the magnetization dynamics. When the current flows from the PL to the FL, large-cone-angle oscillation of the FL magnetization occurs with the same rotation direction as that of FMR of the PL magnetization, leading to emergence of the synchronized excitation modes. On the other hand, when the current flows from the FL to the PL, the magnetization motions of the two layers have opposite rotation directions, and consequently, the PL and FL show their respective intrinsic excitation modes.
Density functional theory study of rutile VO2 surfaces
Authors: Mellan Thomas A. , Grau-Crespo Ricardo
Published: October 2012

We present the results of a density functional theory investigation of the surfaces of rutile-like vanadium dioxide, VO2(R). We calculate the surface energies of low Miller index planes and find that the most stable surface orientation is the (110). The equilibrium morphology of a VO2(R) particle has an acicular shape, laterally confined by (110) planes and topped by (011) planes. The redox properties of the (110) surface are investigated by calculating the relative surface free energies of the non-stoichiometric compositions as a function of oxygen chemical potential. It is found that the VO2(110) surface is oxidized with respect to the stoichiometric composition, not only at ambient conditions but also at the more reducing conditions under which bulk VO2 is stable in comparison with bulk V2O5. The adsorbed oxygen forms surface vanadyl species much more favorably than surface peroxo species.
Enhanced microwave absorption in columnar structured magnetic materials
Authors: Wei Wenwen , Jiang Changjun , Wang Fenglong , Wang Gaoxue , Xue Desheng
Published: October 2012

CoZr columnar structured magnetic films were fabricated by oblique sputtering onto porous aluminum oxide substrates with different oblique angles. The scanning electron microscope images showed the formation of columnar structure and nanoporous structure was disappeared with increasing oblique angle. The static magnetic properties showed larger coercivity and lower magnetization squareness due to columnar structure resulted from nanopores. Dynamic magnetic properties were determined by effect of holes and oblique sputtering. Enhanced microwave absorption was obtained by complex permeability measurement, which line width of columnar film increased 1.4 GHz comparing with 0.5 GHz of continuous film. Therefore, it is an effective way to get the adjustable anisotropy field and line width, which is desirable for obtaining the high resonance and high permeability ferromagnetic film materials for high frequency application.
Improved spatial direct method with gradient-based diffusion to retain full diffusive fluctuations
Authors: Koh Wonryull , Blackwell Kim T.
Published: October 2012

The spatial direct method with gradient-based diffusion is an accelerated stochastic reaction-diffusion simulation algorithm that treats diffusive transfers between neighboring subvolumes based on concentration gradients. This recent method achieved a marked improvement in simulation speed and reduction in the number of time-steps required to complete a simulation run, compared with the exact algorithm, by sampling only the net diffusion events, instead of sampling all diffusion events. Although the spatial direct method with gradient-based diffusion gives accurate means of simulation ensembles, its gradient-based diffusion strategy results in reduced fluctuations in populations of diffusive species. In this paper, we present a new improved algorithm that is able to anticipate all possible microscopic fluctuations due to diffusive transfers in the system and incorporate this information to retain the same degree of fluctuations in populations of diffusing species as the exact algorithm. The new algorithm also provides a capability to set the desired level of fluctuation per diffusing species, which facilitates adjusting the balance between the degree of exactness in simulation results and the simulation speed. We present numerical results that illustrate the recovery of fluctuations together with the accuracy and efficiency of the new algorithm.
Growth and separation of a start-up vortex from a two-dimensional shear layer
Authors: Sattari Pooria , Rival David E. , Martinuzzi Robert J. , Tropea Cameron
Published: October 2012

The evolution of an isolated line vortex generated by a starting two-dimensional jet is studied experimentally using time-resolved particle image velocimetry. The vortex growth in this current configuration is not linked to any externally imposed length scales or interactions with other vortical structures or walls that could potentially influence vortex growth. A model for the early-stage vortex growth, based on the transport of circulation from the shear layer into the vortex, is proposed and found to agree well with experimental data. The model provides a scaling scheme for vortex growth using shear-layer characteristic velocity and shear-layer thickness. The vortex growth is limited through a gradual separation of the vortex from the feeding shear layer, arising from decreased shear-layer curvature. This phenomenon is linked to a competition between the shear-layer tendency to remain in the streamwise direction and the induced velocity from the vortex on the shear layer. Finally, a dimensionless number representing this competition is introduced, which in turn is able to describe the gradual separation of the vortex from the shear layer.
Vapor-deposited α,α,β-tris-naphthylbenzene glasses with low heat capacity and high kinetic stability
Authors: Whitaker Katherine R. , Ahrenberg Mathias , Schick Christoph , Ediger M. D.
Published: October 2012

The reversing heat capacity of vapor-deposited glasses of α,α,β-tris-naphthylbenzene (ααβ-TNB) was measured using alternating current (AC) nanocalorimetry. Glasses deposited at 0.85 Tg, where Tg is the glass transition temperature, have a 4 ± 1% lower heat capacity than the ordinary glass prepared by cooling from the liquid. This is a result of efficient packing and is consistent with the higher density of the vapor-deposited glass. Isothermal experiments show that vapor-deposited ααβ-TNB glasses also have enhanced kinetic stability with respect to transformation into the supercooled liquid, as expected from previous work, with transformation times approaching 105 times the structural relaxation time of the liquid. Films thinner than 1 μm exhibit a thickness dependence to their transformation times that is consistent with transformation to the supercooled liquid via a surface-initiated growth front.
Torsion fracture of carbon nanocoils
Authors: Yonemura Taiichiro , Suda Yoshiyuki , Tanoue Hideto , Takikawa Hirofumi , Ue Hitoshi , Shimizu Kazuki , Umeda Yoshito
Published: October 2012

We fix a carbon nanocoil (CNC) on a substrate in a focused ion beam instrument and then fracture the CNC with a tensile load. Using the CNC spring index, we estimate the maximum to average stress ratio on the fractured surface to range from 1.3 to 1.7, indicating stress concentration on the coil wire inner edge. Scanning electron microscopy confirms a hollow region on the inner edge of all fractured surfaces.
Time-resolved multiple probe spectroscopy
Authors: Greetham G. M. , Sole D. , Clark I. P. , Parker A. W. , Pollard M. R. , Towrie M.
Published: October 2012

Time-resolved multiple probe spectroscopy combines optical, electronic, and data acquisition capabilities to enable measurement of picosecond to millisecond time-resolved spectra within a single experiment, using a single activation pulse. This technology enables a wide range of dynamic processes to be studied on a single laser and sample system. The technique includes a 1 kHz pump, 10 kHz probe flash photolysis-like mode of acquisition (pump–probe–probe–probe, etc.), increasing the amount of information from each experiment. We demonstrate the capability of the instrument by measuring the photolysis of tungsten hexacarbonyl (W(CO)6) monitored by IR absorption spectroscopy, following picosecond vibrational cooling of product formation through to slower bimolecular diffusion reactions on the microsecond time scale.
Charging effect simulation model used in simulations of plasma etching of silicon
Authors: Ishchuk Valentyn , Volland Burkhard E. , Hauguth Maik , Cooke Mike , Rangelow Ivo W.
Published: October 2012

Understanding the consequences of local surface charging on the evolving etching profile is a critical challenge in high density plasma etching. Deflection of the positively charged ions in locally varying electric fields can cause profile defects such as notching, bowing, and microtrenching. We have developed a numerical simulation model capturing the influence of the charging effect over the entire course of the etching process. The model is fully integrated into ViPER (Virtual Plasma Etch Reactor)—a full featured plasma processing simulation software developed at Ilmenau University of Technology. As a consequence, we show that local surface charge concurrently evolves with the feature profile to affect the final shape of the etched feature. Using gas chopping (sometimes called time-multiplexed) etch process for experimental validation of the simulation, we show that the model provides excellent fits to the experimental data and both, bowing and notching effects are captured—as long as the evolving profile and surface charge are simultaneously simulated. In addition, this new model explains that surface scallops, characteristic of gas chopping technique, are eroded and often absent in the final feature profile due to surface charging. The model is general and can be applied across many etching chemistries.
Noncontact technique for measuring the electrical resistivity and magnetic susceptibility of electrostatically levitated materials
Authors: Rustan G. E. , Spyrison N. S. , Kreyssig A. , Prozorov R. , Goldman A. I.
Published: October 2012

We describe the development of a new method for measuring the electrical resistivity and magnetic susceptibility of high temperature liquids and solids. The technique combines a tunnel diode oscillator with an electrostatic levitation furnace to perform noncontact measurements on spherical samples 2-3 mm in diameter. The tank circuit of the oscillator is inductively coupled to the sample, and measurements of the oscillator frequency as a function of sample temperature can be translated into changes in the sample's electrical resistivity and magnetic susceptibility. Particular emphasis is given on the need to improve the positional stability of the levitated samples, as well as the need to stabilize the temperature of the measurement coil. To demonstrate the validity of the technique, measurements have been performed on solid spheres of pure zirconium and low-carbon steel. In the case of zirconium, while absolute values of the resistivity were not determined, the temperature dependence of the resistivity was measured over the range of 640–1770 K and found to be in good agreement with literature data. In the case of low-carbon steel, the ferromagnetic-paramagnetic transition was clearly observable and, when combined with thermal data, appears to occur simultaneously with the solid-solid structural transition.
Variable viscosity effects on the dissipation instability in a porous layer with horizontal throughflow
Authors: Barletta A. , Nield D. A.
Published: October 2012

The role of viscous heating in the onset of the instability in a liquid-saturated porous medium is studied. The change of the liquid viscosity with the temperature is taken into account by using a linear fluidity model. The system examined is a horizontal porous layer with an adiabatic lower boundary and an isothermal upper boundary. The combined effects of the viscous heating and of the variable viscosity yield a basic stationary and parallel throughflow in a horizontal direction. This basic solution may display singularities when the product between the Péclet number and the viscosity-temperature slope parameter exceeds the threshold value π/2. The linear stability of the basic solution is studied with respect to normal modes disturbances arbitrarily oriented to the basic flow direction. In all the physically realistic cases, the most unstable disturbances are proved to be the longitudinal rolls (the wave vector is perpendicular to the basic velocity). The instability to the longitudinal rolls occurs when the product between the Péclet number and the viscosity-temperature slope parameter exceeds its critical value. This critical value is smaller than π/2, for every nonzero value of the buoyancy parameter, viz., the Gebhart number. As a consequence, the parametric domain where the singularities of the basic solution arise is in fact included in the instability domain.
Interatomic relaxation effects in double core ionization of chain molecules
Authors: Kryzhevoi Nikolai V. , Tashiro Motomichi , Ehara Masahiro , Cederbaum Lorenz S.
Published: October 2012

Core vacancies created on opposite sides of a molecule operate against each other in polarizing the environment between them. Consequently, the relaxation energy associated with the simultaneous creation of these two core holes turns out to be smaller than the sum of the relaxation energies associated with each individual single core vacancy created independently. The corresponding residual, termed interatomic relaxation energy, is sensitive to the environment. In the present paper we explore how the interatomic relaxation energy depends on the length and type of carbon chains bridging two core ionized nitrile groups (–C≡N). We have uncovered several trends and discuss them with the help of simple electrostatic and quantum mechanical models. Namely, the absolute value of the interatomic relaxation energy depends strongly on the orbital hybridization in carbons being noticeably larger in conjugated chains (sp and sp2 hybridizations) possessing highly mobile electrons in delocalized π-type orbitals than in saturated chains (sp3 hybridization) where only σ bonds are available. The interatomic relaxation energy decreases monotonically with increasing chain length. The corresponding descent is determined by the energetics of the molecular bridge, in particular, by the HOMO-LUMO gap. The smallest HOMO-LUMO gap is found in molecules with the sp2-hybridized backbone. Here, the interatomic relaxation energy decreases slowest with the chain length.
Spin-polarized state transport from ferromagnetic to conductive material: Signal amplification by ferromagnetic layer
Authors: Makarov Vladimir I. , Khmelinskii Igor , Kochubei Sergey A.
Published: October 2012

We continue the work on the quantum filter of spin polarized states induced by magnetic field in an iron nanolayer. Properties of a three-layer ferromagnetic (Fe)–dielectric (SiO2)–conductor (Au) device performing selective transport of spin polarized states were investigated. Reduced diameter of the input magnetic core and thinner conductive layer improved the filter resolution. Output signal amplitude decayed exponentially with the thickness of the dielectric layer. The filter properties were analyzed and explained using the previously developed theoretical approach, based on exchange interaction of the electronic energy levels located in the ferromagnetic and conductive layers. We also studied a five-layer Fe–SiO2–Au–SiO2–Fe sandwich system. Here the transmitted signal structure was more complex than that in a three-layer device. Theoretical model for the five-layer spin state filter device was proposed, based on an extension of that for the three-level device.
Preserving stable 100% spin polarization at (111) heterostructures of half-metallic Heusler alloy Co2VGa with semiconductor PbS
Authors: Han Hongpei , Hu Wanqiang , Gao G. Y. , Yao K. L.
Published: October 2012

Based on the half-metallicity confirmed experimentally in bulk Heusler alloy Co2VGa, we use the first-principles calculations to extend our previous studies on the Co2VGa (111) surfacial properties to the interfaces of Co2VGa/PbS (111) heterostructures in which four possible interfacial structures are considered between the V- and Ga-terminated (111) surfaces of Co2VGa and S- and Pb-terminated (111) surfaces of PbS. From the atomic density of states, it is shown that the half-metallicity of the bulk system is destroyed at Ga-S and Ga-Pb configurations while V-S and V-Pb configurations exhibit 100% spin polarization and nearly 100% spin polarization, respectively. Furthermore, the structure relaxation and the calculated interfacial adhesion energies indicate that V-S configuration is the most stable structure among them. In addition, we also discuss the changes of the atom magnetic moments at interface and subinterface layers with respect to the corresponding bulk values.
Room temperature microwave-assisted recording on 500-Gbpsi-class perpendicular medium
Authors: Nozaki Y. , Ishida N. , Soeno Y. , Sekiguchi K.
Published: October 2012

Microwave-assisted recording on a 500-Gbpsi-class perpendicular medium was experimentally demonstrated at room temperature. Magnetization reversal under a radio-frequency magnetic field was measured by an electrically shorted coplanar waveguide, which enabled us to evaluate the change in the medium's ferromagnetic resonance spectrum. A frequency-dependent reduction in the switching field was clearly observed in response to a microwave impulse 50 ns in duration. A significant reduction of up to 30% in the coercive field was achieved by applying a microwave impulse with an amplitude of 25 dBm and a frequency of 15 GHz.