bluuebunny/crossref_metadata_2025 huggingface dataset:
State, Power, Anarchism
Authors: Clunan Anne
Published: March 2011

The Art of Not Being Governed: An Anarchist History of Upland Southeast Asia.By James C. Scott. New Haven: Yale University Press, 2009. 464p. $35.00.

The book under discussion is James C. Scott's latest contribution to the study of agrarian politics, culture, and society, and to the ways that marginalized communities evade or resist projects of state authority. The book offers a synoptic history of Upland Southeast Asia, a 2.5 million–kilometer region of hill country spanning Vietnam, Cambodia, Laos, Thailand, Burma, and China. It offers a kind of “area study.” It also builds on Scott's earlier work on “hidden transcripts” of subaltern groups and on “seeing like a state.” The book raises many important theoretical questions about research methods and social inquiry, the relationship between political science and anthropology, the nature of states, and of modernity more generally. The book is also deeply relevant to problems of “state-building” and “failed states” in places like Afghanistan, Iraq, and Somalia. As Scott writes, “The huge literature on state-making, contemporary and historic, pays virtually no attention to its obverse: the history of deliberate and reactive statelessness. This is the history of those who got away, and state-making cannot be understood apart from it. This is also what makes it an anarchist history” (p. x).

In this symposium, I have invited a number of prominent political and social scientists to comment on the book, its historical narrative, and its broader theoretical implications for thinking about power, state failure, state-building, and foreign policy. How does the book shed light on the limits of states and the modes of resistance to state authority? Are there limits, theoretical and normative, to this “anarchist” understanding of governance and the “art of being governed”?

—Jeffrey C. Isaac, Editor
Response to Megan Mullin's review ofGlobal Governance of Hazardous Chemicals: Challenges of Multilevel Management
Authors: Selin Henrik
Published: March 2011

First, I want to thank Megan Mullin for her careful review of my book, which raises several important issues worthy of careful consideration. These will be helpful to me in my continued research and analysis of global environmental governance. A main criticism offered by Mullin's review is that my book includes a great deal of empirical detail but is less focused on testing propositions. This is largely by design, however, and her critique reflects our different views on research design and our varying ways of approaching empirical case studies and analysis.
Vibrant Matter: A Political Ecology of Things. By Jane Bennett. Durham, NC: Duke University Press, 2010. 176p. $74.95 cloth, $21.95 paper.
Authors: Princen Thomas
Published: March 2011

Hiking through the desert once I stopped to hug a large round boulder. I don't know what compelled me to do it. I had never done it before or since, but I can still feel it. It was as if the rock hugged back.
The Regime Complex for Climate Change
Authors: Keohane Robert O. , Victor David G.
Published: March 2011

There is no integrated regime governing efforts to limit the extent of climate change. Instead, there is a regime complex: a loosely-coupled set of specific regimes. We describe the regime complex for climate change and seek to explain it, using interest-based, functional, and organizational arguments. This institutional form is likely to persist; efforts to build a comprehensive regime are unlikely to succeed, but experiments abound with narrower institutions focused on particular aspects of the climate change problem. Building on this analysis, we argue that a climate change regime complex, if it meets specified criteria, has advantages over any politically feasible comprehensive regime. Adaptability and flexibility are particularly important in a setting—such as climate change policy—in which the most demanding international commitments are interdependent yet governments vary widely in their interest and ability to implement them. Yet in view of the serious political constraints, both domestic and international, there is little reason for optimism that the climate regime complex that is emerging will lead to reductions in emissions rapid enough to meet widely discussed goals, such as stopping global warming at two degrees above pre-industrial levels.
The Tea Party and the Remaking of Republican Conservatism
Authors: Williamson Vanessa , Skocpol Theda , Coggin John
Published: March 2011

In the aftermath of a potentially demoralizing 2008 electoral defeat, when the Republican Party seemed widely discredited, the emergence of the Tea Party provided conservative activists with a new identity funded by Republican business elites and reinforced by a network of conservative media sources. Untethered from recent GOP baggage and policy specifics, the Tea Party energized disgruntled white middle-class conservatives and garnered widespread attention, despite stagnant or declining favorability ratings among the general public. As participant observation and interviews with Massachusetts activists reveal, Tea Partiers are not monolithically hostile toward government; they distinguish between programs perceived as going to hard-working contributors to US society like themselves and “handouts” perceived as going to unworthy or freeloading people. During 2010, Tea Party activism reshaped many GOP primaries and enhanced voter turnout, but achieved a mixed record in the November general election. Activism may well continue to influence dynamics in Congress and GOP presidential primaries. Even if the Tea Party eventually subsides, it has undercut Obama's presidency, revitalized conservatism, and pulled the national Republican Party toward the far right.
Die Entwicklungen im DSM-5: Kritische Aspekte
Authors: Rumpf Hans-Jürgen , Kiefer Falk
Published: March 2011

Replik auf Kommentare zu Rumpf und Kiefer (2011). DSM-5: Die Aufhebung der Unterscheidung von Abhängigkeit und Missbrauch und die Öffnung für Verhaltenssüchte
Störungen von Selbsterleben und Beziehungsverhalten bei Menschen mit Internetabhängigkeit
Authors: Wildt Bert Theodor te , Putzig Inken , Vukicevic Andrija , Wedegärtner Felix
Published: March 2011

Fragestellung: Internetabhängigkeit geht bei den zumeist jungen Betroffenen in der Regel mit einem ausgeprägten sozialen Rückzug und Entwicklungsverzögerungen in verschiedenen Lebensbereichen einher. Die vorliegende Untersuchung geht darüber hinaus von der Hypothese aus, dass Internetabhängige vergleichsweise häufig unter Störungen in den Bereichen Identität und Interpersonalität leiden. Methode: 25 Internetabhängige wurden klinisch und mit dem Strukturierten Klinischen Interview nach DSM-IV (SKID-I) auf komorbide Störungen untersucht. Psychometrisch wurden die Betroffenen mit einer gesunden Vergleichsgruppe (n = 25) mit Hilfe der Internetsuchtskala (ISS), der Sense-of-Coherence-Scale (SOC), dem Fragebogen für Dissoziative Symptome (FDS) und dem Inventar für Interpersonale Probleme (IIP-D) verglichen. Ergebnisse: Im Vergleich zeigen die Internetabhängigen neben einer hohen Komorbidität, insbesondere für Depressionen und Angsterkrankungen, signifikant niedrigere Werte für Selbstkohärenz (SOC) und signifikant höhere Werte für Dissoziation (FDS) und interpersonale Probleme (IIP-D). Besonders hohe Werte erzielen die Probanden auf der IIP-D-Subskala Zu selbstunsicher/zu unterwürfig, dies auch in Korrelation mit der Ausprägung der Internetabhängigkeit (ISS). Schlussfolgerungen: Die Ergebnisse sprechen dafür, dass Selbstunsicherheit und soziale Schwierigkeiten bei Internetabhängigen von besonderer Bedeutung sind. Störungen von Identität und Interpersonalität dürften im Hinblick auf die Diagnostik und Therapie von Internetabhängigkeit eine höhere Beachtung finden.
Deep Seismic Investigation of the Ontong Java Plateau
Authors: Miura Seiichi , Noguchi Naoto , Kodaira Shuichi , Fukao Yoshio , Coffin Millard F. , Kawagle Simon A. , Verave Ronald T.
Published: March 2011

The Ontong Java Plateau (OJP; see Figure 1a), in the western equatorial Pacific Ocean, is one of the largest oceanic plateaus on Earth, covering 1.86 million square kilometers—equivalent to roughly one third of the contiguous United States [Coffin and Eldholm, 1994]. This voluminous plateau is thought to have formed about 120 million years ago and to have caused significant global environmental changes; however, a consensus has not been reached on how the OJP formed. Competing theories include formation through a mantle plume, a meteor impact, and fast spreading ridges. Detailed knowledge of the OJP's crustal and upper mantle structure is necessary to help distinguish among existing models and to develop new models of how the OJP formed. Previous seismic studies acquired data by exploding charges at the ocean's surface and, through seismic analyses of travel times, deducing horizons of reflections and refractions below the ocean floor. However, most of these studies used relatively low energy shots and sparse source and receiver intervals and thus were unable to unambiguously determine the depth of the crust‐mantle boundary.
Misapplication of a Statistical Test: Comment on “Lies, Damned Lies, and Statistics (in Geology)”
Authors: Weigel Robert S.
Published: March 2011

In his Forum, P. Vermeesch (Eos, 90(47), 443, doi:10.1029/2009EO470004, 2009) argues that “the strong dependence ofp values on sample size makes them uninterpretable” with an example where p values in a hypothesis test using Pearson's chi‐square statistic differed by a factor of 1016 when the sample size decreased tenfold. The data were a sequence of magnitude 4 or larger earthquake events (N = 118,415) spanning 3654 days [U.S. Geological Survey, 2010]. There are two problems with the analysis. First, Vermeesch applied the chi‐square test to data with statistical properties that are inconsistent with those assumed in the derivation of the chi‐square test. Second, he made an assumption that, using a straightforward calculation, can be shown to be inconsistent with the data. I address here only problems related to the application of statistics without reference to any additional physical processes that may also need to be addressed before statistical analysis is performed (e.g., the physics of how aftershocks are related to main earthquakes).
Statistical Significance Does Not Equal Geological Significance: Reply to Comments on “Lies, Damned Lies, and Statistics (in Geology)”
Authors: Vermeesch Pieter
Published: March 2011

In my Eos Forum of 24 November 2009 (90(47), 443), I used the chi‐square test to reject the null hypothesis that earthquakes occur independent of the weekday to make the point that statistical significance should not be confused with geological significance. Of the five comments on my article, only the one by Sornette and Pisarenko [2011] disputes this conclusion, while the remaining comments take issue with certain aspects of the geophysical case study. In this reply I will address all of these points, after providing some necessary further background about statistical tests. Two types of error can result from a hypothesis test. A Type I error occurs when a true null hypothesis is erroneously rejected by chance. A Type II error occurs when a false null hypothesis is erroneously accepted by chance. By definition, thep value is the probability, under the null hypothesis, of obtaining a test statistic at least as extreme as the one observed. In other words, the smaller thep value, the lower the probability that a Type I error has been made. In light of the exceedingly small p value of the earthquake data set,Tseng and Chen's [2011] assertion that a Type I error has been committed is clearly wrong. How about Type II errors?
Hydroecological Responses to Climate Change in Northern Catchments
Authors: Tetzlaff Doerthe , Soulsby Chris
Published: March 2011

Northern Watershed Ecosystem Response to Climate Change (North‐Watch) Workshop III: Hydroecological Responses to Climate Change in Northern Catchments; Aviemore, United Kingdom, 29 August to 2 September 2010; North‐Watch is an interdisciplinary intersite comparison project funded by the Leverhulme Trust, United Kingdom, and run by the Northern Rivers Institute, University of Aberdeen, Aberdeen, United Kingdom. The overall aim of the North‐Watch project is to facilitate an intercatchment comparison study of high‐latitude catchments that will yield a comprehensive, interdisciplinary, and regional understanding of the recent effects of climatic change and provide a stronger scientific basis for predicting what further changes are likely. Examining a range of sites across a climatic transect in the northern zone will give a much stronger regional perspective on the responses to climatic change than individual studies alone. The project is analyzing long‐term data from experimental catchments including sensitive boreal, sub‐Arctic, and sub‐Alpine environments ranging from the Yukon and northern Sweden to the Scottish Cairngorms to assess the integrated physical, chemical, and biological response to climatic change.
Vulnerability and Feedbacks of Permafrost to Climate Change
Authors: Grosse Guido , Romanovsky Vladimir , Jorgenson Torre , Anthony Katey Walter , Brown Jerry , Overduin Pier Paul
Published: March 2011

The effects of permafrost degradation on terrestrial and offshore environments in polar regions and on the Earth's atmosphere are significant. Field‐based observations, remote sensing, and modeling document regional warming and thawing of permafrost. However, major research questions regarding vulnerability of permafrost to thawing, the projected decline in permafrost extent during coming decades, resulting ecosystem feedbacks, and the possibly global consequences to climate change due to remobilization of carbon pools from thawing permafrost still require answers.
NOAA Budget Request Looks Positive, Though Numbers Could Shift in Congress
Authors: Showstack Randy
Published: March 2011

The Obama administration's budget request for the National Oceanic and Atmospheric Administration (NOAA) for fiscal year (FY) 2012, which begins on 1 October, would increase the agency's funding level to $5.5 billion, up from $4.75 billion in the FY 2010 budget enacted by Congress. The budget request is $56.8 million less than the administration's FY 2011 request of $5.54 billion. However, as Eos went to press, Congress was considering a new budget continuing resolution (CR) that could fund the federal government through the end of FY 2011 at a significantly lower level than the president requested for the current year. The CR could dramatically affect NOAA's current budget, the upcoming debate over the FY 2012 budget, and high‐priority programs including the Joint Polar Satellite System (JPSS) to improve weather forecasting and climate monitoring.
In Brief: NOAA announces next step in Gulf of Mexico assessment
Authors: Tretkoff Ernie
Published: March 2011

The U.S. National Oceanic and Atmospheric Administration (NOAA) announced on 19 February that it will develop a Programmatic Environmental Impact Statement (PEIS) as the next step in its assessment of impacts from the Deepwater Horizon oil spill on the Gulf of Mexico. The PEIS is part of the Natural Resource Damage Assessment (NRDA), the legal process to determine the type and extent of environmental restoration needed to compensate the public for the harm caused to natural resources by the oil spill. The restoration would be paid for by BP and other parties deemed responsible for the oil spill. Public meetings will be held in the affected states to begin the PEIS process. NOAA administrator Jane Lubchenco stated at a press conference at the annual meeting of the American Association for the Advancement of Science (AAAS) that this “heralds the beginning of a formal public process.”
President's Budget Proposal Favors NSF, Though Congress Could Push for Reductions
Authors: Showstack Randy
Published: March 2011

The U.S. National Science Foundation (NSF) is one of the winners in the Obama administration's proposed budget for fiscal year (FY) 2012, which begins on 1 October, with a proposed funding level of $7.767 billion; this would be an increase of 13% above the congressionally enacted FY 2010 budget level. However, the administration's proposed budget is just a starting point for discussions. Congress has approved a 2‐week budget continuing resolution (CR) for the current fiscal year, 2011. A longer‐term CR passed by the House of Representatives (HR 1) could dramatically cut this year's funding for some federal agencies and also affect budget discussions for FY 2012.
John R. Filson Receives 2010 Edward A. Flinn III Award
Authors: Ellsworth William L. , Thatcher Wayne , Filson John
Published: March 2011

John R. Filson received the Edward A. Flinn III Award at the 2010 AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The award honors an “individual who personifies the Union's motto ‘unselfish cooperation in research’ through their facilitating, coordinating, and implementing activities.”
How easy are the syntheses of allenes?
Authors: Yu Shichao , Ma Shengming
Published: March 2011

This short review highlights some of the recent important developments on the synthesis of allenes and its applications on the synthesis of some allenic natural products and allenic-based optoelectronic materials.
Coping With Dysphonia–How Do They Do It?
Authors: Epstein Ruth , Hirani Shashivadan P.
Published: March 2011

Coping is a key concept in psychological medicine and refers to the way in which people deal with the stress of illness. Voice disorders may have pervasive effects upon the individual's life beyond the vocal impairment, yet there is little reference in the current literature as to how people cope with voice problems. The purpose of this article is to provide a brief review of coping and its evaluation and to explore cultural differences and coping styles in individuals with voice disorders. The implications for voice therapy also are discussed.
Electro-optic tunable optical isolator in periodically poled LiNbO3
Authors: Qian Xiao-shi , Wu Hao , Wang Qin , Yu Zi-Yan , Xu Fei , Lu Yan-Qing , Chen Yan-Feng
Published: March 2011

We proposed a design of a tunable optical isolator. The electro-optic (EO) effects in periodically poled lithium niobate (PPLN) with a defect were studied. EO effects and second harmonic generation (SHG) allow three-wave coupling in this nonlinear optics process. A defect is inserted in an asymmetrical position in PPLN to break the reciprocity of the fundamental-wave transmission in two reversed propagating directions. We numerically demonstrated that the contrast of this optical isolator can be tuned from −1 to 1 by simply changing the external dc electric field. With EO effects, the position of the defect can be designed more flexibly maintaining a high contrast of the optical isolation.
Raman spectra of proton ordered phase XI of ICE I. Translational vibrations below 350 cm−1
Authors: Abe Kohji , Shigenari Takeshi
Published: March 2011

Polarized Raman spectra from single crystals of ice XI (proton ordered phase of ice Ih) were measured and assigned for the modes below 350 cm−1 in the translational vibration region. In contrast to the proton disordered ice Ih, the spectra in ice XI show clear polarization dependence and several new peaks are observed. Most of the vibrational modes were successfully assigned by the simplified point mass model with the symmetry \documentclass[12pt]{minimal}\begin{document}${\rm C}_{\text{2v}}^{12}$\end{document}C2v12(Cmc21) and by the depolarization effect. In particular, LO–TO splitting of the mode near 240 cm−1 was experimentally confirmed for the first time, which indicates that the long range force effect appears distinctly in ice XI.
Design and measurements of a broadband two-dimensional acoustic metamaterial with anisotropic effective mass density
Authors: Zigoneanu Lucian , Popa Bogdan-Ioan , Starr Anthony F. , Cummer Steven A.
Published: March 2011

We present the experimental realization and characterization of a broadband acoustic metamaterial with strongly anisotropic effective mass density. The metamaterial is composed of arrays of solid inclusions in an air background, and the anisotropy is controlled by the rotational asymmetry of these inclusions. Transmission and reflection measurements inside a one-dimensional waveguide are used to extract the relevant components of the effective density tensor together with the effective bulk modulus of the metamaterial. Its broadband anisotropy is demonstrated by measurements that span 500–3000 Hz. Excellent agreement between these measurements and numerical simulations confirms the accuracy of the design approach.
Acoustically perturbed turbulent premixed swirling flames
Authors: Palies P. , Schuller T. , Durox D. , Gicquel L. Y. M. , Candel S.
Published: March 2011

The dynamics of a turbulent premixed confined swirling flame is investigated using large eddy simulation. The flame response is determined by introducing an external acoustic forcing at two modulation frequencies corresponding to characteristic values of the flame transfer function obtained experimentally. These values were found to give different responses in terms of gain in a previous series of experiments. The underlying physical mechanisms identified experimentally are investigated numerically. Simulations confirm that swirl number fluctuations and vortex roll-up govern the flame response. It is also confirmed that the first mechanism is associated with a mode conversion process taking place when acoustic waves impinge on the swirler unit. The axial acoustic velocity disturbance on the upstream side of the swirler generates an axial acoustic wave and an azimuthal convective disturbance in the downstream flow. These combined disturbances are retrieved in the simulation and their effect on the swirl number is extracted. Calculations also indicate that vortex shedding synchronized by the acoustic forcing takes place at the injector lip outlet. Vortices originating from this region are convected in the jet shear layer, impinge on the flame, and roll-up the flame tip. This process interferes with oscillations in the flame angle induced by swirl number fluctuations. The phasing of the flame angle with respect to the instant of vortex shedding from the injector lips determines the lifetime of the vortex before interaction with the flame and controls the strength of this interaction. When this lifetime is reduced, the vortex cannot fully develop and the flame response remains weak. For larger lifetimes, the vortex can fully develop and produce larger heat release rate perturbations. This process depends on the forcing frequency, which determines the phasing between swirl number fluctuations and vortices generation.
Evaluation of domain wall motion during polymorphic phase transition in (K, Na)NbO3-based piezoelectric ceramics by nonlinear response measurements
Authors: Peng Bin , Yue Zhenxing , Li Longtu
Published: March 2011

Based on the investigation of the nonlinear dielectric response of 0.95(K0.5Na0.5)NbO3-0.05LiTaO3 (KNN-0.05LT) piezoelectric ceramics, the contribution of irreversible domain wall movement to the dielectric constant with increasing temperature were quantitatively evaluated. Rayleigh law reasonably interpreted these nonlinear dielectric behaviors and successfully separated the contribution of irreversible domain walls movement from the macroscopic dielectric properties. The extrinsic contribution from irreversible domain wall movement, denoted by the Rayleigh coefficient (α), undergoes an abrupt decline during the polymorphic phase transition due to the change of the crystal structure and the domain configuration. The dielectric nonlinearity is significantly reduced in the tetragonal phase zone after the polymorphic phase transition. Furthermore, the tetragonal phase is more stable than the orthorhombic phase.
Influence of the absorber doping for p-type polycrystalline silicon thin-film solar cells on glass prepared by electron beam evaporation and solid-phase crystallization
Authors: Ouyang Zi , Kunz Oliver , Sproul Alistair B. , Varlamov Sergey
Published: March 2011

A systematic investigation of the influence of the absorber doping on the performance of planar, p-type, evaporated, solid-phase crystallized polycrystalline silicon thin-film solar cells on glass is presented. It is found that the optimum Suns-Voc parameters (open-circuit voltage and pseudo fill factor) are achieved at intermediate absorber doping of Nabs∼1–2 × 1017 cm−3, while high short-circuit currents are achieved at the lowest absorber doping of Nabs ≤ 6 × 1015 cm−3. Since the short-circuit current is the dominating factor to achieve high conversion efficiencies for evaporated polycrystalline silicon cells, the maximum pseudo efficiencies are achieved at very low absorber doping. The Suns-Voc characteristics of lightly doped cells can be adequately described by a modified two-diode model with n1=1 and n2≈1.5, which is in contrast to the value of 2 for n2 commonly quoted in the literature. PC1D modeling demonstrates that such a low ideality factor for space charge region recombination can be modeled by a single trap energy level located at ∼0.18 eV away from midgap. Although the achievable short-circuit current densities and the conversion efficiencies can be higher for textured cells, planar cells are chosen intentionally to allow accurate modeling and extraction of relevant material parameters, such as minority carrier diffusion length.
Thermoelectric instability induced by single pulses and alternating currents in second-generation superconducting tapes
Authors: Degtyarenko P. N. , Dul’kin I. N. , Fisher L. M. , Kalinov A. V. , Voloshin I. F. , Yampol’skii V. A.
Published: March 2011

We have studied current flow instabilities in a second-generation superconducting tapes and the transition of the tapes into the resistive state. Contrary to the usual quasisteady instability regimes, here we consider the adiabatic case in which the sample is heated rapidly. Two kinds of measurements of the current-voltage characteristics (CVC) have been made, specifically, with excitation of the tape by a single sinusoidal current pulse I (t)=I0sin(ωt) at different amplitudes I0 and by a continuous ac current. The main results were obtained for current amplitudes I0 exceeding the critical current Ic. We find that the dynamic CVC are essentially reversible for low amplitudes, whereas they become irreversible and acquire an N-shape for higher current amplitudes. The dynamic CVC change radically if the dissipated energy attains a threshold value Wth roughly equal to 5mJ∕cm for our tapes. When this energy is reached, the tape undergoes a transition to the resistive state owing to formation of normal domains. The development of the instability with steady ac currents was studied at relatively small amplitudes such that the energy dissipated per half cycle is much lower than Wth. Even in this case, a tape undergoes a transition to the resistive state because of energy accumulation (heat pumping). With this pumping, the transition takes place after a definite number of ac cycles, when the total accumulated energy reaches the same threshold value Wth. The specific features of the dynamic CVC are interpreted qualitatively, with the appearance of resistive domains taken into account. Estimates based on the CVC agree well with our experimental data. These results can be useful in the design of superconducting fault current limiters.
Two-dimensional growth, anisotropic polaron transport, and magnetic phase segregation in epitaxial Nd0.52Sr0.48MnO3 films
Authors: Prokhorov V. G. , Kaminsky G. G. , Kim J. M. , Eom T. W. , Park J. S. , Lee Y. P. , Svetchnikov V. L. , Levtchenko G. G. , Paschenko A. V. , Medvedev Yu. V. , Nikolaenko Yu. M. , Bukin G. V. , Khokhlov V. A.
Published: March 2011

Nd 0.52 Sr 0.48 Mn O 3 films have been fabricated by dc magnetron sputtering on single-crystal LaAlO3 (001) and SrTiO3 (011) substrates with additional annealing to relax the lattice strain. Although the Nd0.52Sr0.48MnO3 films were deposited simultaneously on different substrates at the same deposition rate, they differ in thickness by a factor of ≃2. The observed difference in thickness is explained by the two-dimensional (layer-by-layer) film growth, rather than by a difference in growth rate controlled by the crystalline orientation of the substrate. An analysis of optical and transport properties reveals that the observed anisotropy in the polaron motion is governed by a strong anisotropy in the trapping energy, rather than in polaron formation. It is shown that the deposited Nd0.52Sr0.48MnO3 films exhibit magnetic behavior typical of two-phase magnetic systems and should be regarded as an assembly of interacting magnetic clusters.
Structure of domain boundaries with spin-reorientation phase transitions in ferrite-garnet films with a weak uniaxial anisotropy
Authors: Mamalui Ju. A. , Siryuk Ju. A. , Bezus A. V.
Published: March 2011

The equilibrium domain structure in ferrite-garnet films with a weak uniaxial anisotropy is studied experimentally at temperatures of 90−450K. Two types of spin-reorientation phase transitions are found which occur on opposite sides of the magnetic compensation temperature. The change in the structure of the domain boundaries during phase transitions is studied. A model for the domain structure is proposed that is consistent with the experiment.
Chemical response of lithiated graphite with deuterium irradiation
Authors: Taylor C. N. , Heim B. , Allain J. P.
Published: March 2011

Lithium wall conditioning has been found to enhance plasma performance for graphite walled fusion devices such as TFTR, CDX-U, T-11M, TJ-II and NSTX. Among observed plasma enhancements is a reduction in edge density and reduced deuterium recycling. The mechanism by which lithiated graphite retains deuterium is largely unknown. Under controlled laboratory conditions, X-ray photoelectron spectroscopy (XPS) is used to observe the chemical changes that occur on ATJ graphite after lithium deposition. The chemical state of lithiated graphite is found to change upon deuterium irradiation indicating the formation Li-O-D, manifest at 532.9 ± 0.6 eV. Lithium-deuterium interactions are also manifest in the C 1s photoelectron energy range and show Li-C-D interactions at 291.2 ± 0.6 eV. Post-mortem NSTX tiles that have been exposed to air upon extraction are cleaned and examined, revealing the chemical archaeology that formed during NSTX operations. XPS spectra show strong correlation (± 0.3 eV) in Li-O-D and Li-O peaks from post-mortem and control experiments, thus validating offline experiments. We report findings that show that deuterium is found to interact with lithium after lithium has already reacted with carbon and oxygen.
Domain switching energies: Mechanical versus electrical loading in La-doped bismuth ferrite–lead titanate
Authors: Leist T. , Webber K. G. , Jo W. , Granzow T. , Aulbach E. , Suffner J. , Rödel J.
Published: March 2011

The mechanical stress-induced domain switching and energy dissipation in morphotropic phase boundary (1−x)(Bi1 − yLay)FeO3–xPbTiO3 during uniaxial compressive loading have been investigated at three different temperatures. The strain obtained was found to decrease with increasing lanthanum content, although a sharp increase in strain was observed for compositions doped with 7.5 and 10 at. % La. Increased domain switching was found in compositions with decreased tetragonality. This is discussed in terms of the competing influences of the amount of domain switching and the spontaneous strain on the macroscopic behavior under external fields. Comparison of the mechanically and electrically dissipated energy showed significant differences, discussed in terms of the different microscopic interactions of electric field and stress.
Large-eddy simulation of the flow and acoustic fields of a Reynolds number 105 subsonic jet with tripped exit boundary layers
Authors: Bogey Christophe , Marsden Olivier , Bailly Christophe
Published: March 2011

Large-eddy simulations (LESs) of isothermal round jets at a Mach number of 0.9 and a diameter-based Reynolds number ReD of 105 originating from a pipe are performed using low-dissipation schemes in combination with relaxation filtering. The aim is to carefully examine the capability of LES to compute the flow and acoustic fields of initially nominally turbulent jets. As in experiments on laboratory-scale jets, the boundary layers inside the pipe are tripped in order to obtain laminar mean exit velocity profiles with high perturbation levels. At the pipe outlet, their momentum thickness is δθ(0)=0.018 times the jet radius, yielding a Reynolds number Reθ=900, and peak turbulence intensities are around 9% of the jet velocity. Two methods of boundary-layer tripping and five grids are considered. The results are found to vary negligibly with the tripping procedure but appreciably with the grid resolution. Based on analyses of the LES quality and on comparisons with measurements at high Reynolds numbers, fine discretizations appear necessary in the three coordinate directions over the entire jet flow. The final LES carried out using 252×106 points with minimum radial, azimuthal, and axial mesh spacings, respectively, of 0.20, 0.34, and 0.40×δθ(0) is also shown to provide shear-layer solutions that are practically grid converged and, more generally, results that can be regarded as numerically accurate as well as physically relevant. They suggest that the mixing-layer development in the present tripped jet, while exhibiting a wide range of turbulent scales, is characterized by persistent coherent vortex pairings.
Some features of the phase diagram of the ferroelectromagnet TbMnO3
Authors: Chupis I. E.
Published: March 2011

The magnetic phase diagram of terbium manganite in a magnetic field Hz directed along the polarization is described phenomenologically. This description is in good agreement with experiment for certain relationships among the system parameters. It is shown that terbium ion spins contribute to the observed linear dependence of the polarization on the magnetic fields Hx and Hy at low temperatures.
Effect of pressure on the magnetic properties of YNi5, LaNi5, and CeNi5
Authors: Grechnev G. E. , Logosha A. V. , Panfilov A. S. , Kuchin A. G. , Vasijev A. N.
Published: March 2011

The effect of pressure on the electronic structure and magnetic properties of the compounds YNi5, LaNi5, and CeNi5 is studied. Large magnetovolume effects of magnitude dlnχ∕dlnV≃4–7 are found for the magnetic susceptibility χ of these systems at low temperatures. Experimental data and “first principles” calculations of the electronic structure and paramagnetic contributions to the susceptibility indicate that YNi5, LaNi5, and CeNi5 are close to a quantum critical point. It is found that the van Vleck orbital contribution to the magnetic susceptibility is 15–20% in these exchange-enhanced paramagnetic materials and should be taken into account in analyzing experimental data on χ and dlnχ∕dlnV. Calculations of the magnetic-field induced moments for atoms in the unit cell of YNi5 reveal an inhomogeneous distribution of the magnetization density and a nontrivial competition between the spin and orbital moments.
Electrostatic solitary waves in a quantum plasma with relativistically degenerate electrons
Authors: Masood W. , Eliasson B.
Published: March 2011

A model for nonlinear ion waves in an unmagnetized plasma with relativistically degenerate electrons and cold fluid ions is presented here. The inertia is given here by the ion mass while the restoring force is provided by the relativistic electron degeneracy pressure, and the dispersion is due to the deviation from charge neutrality. A nonlinear Korteweg–de Vries equation is derived for small but finite amplitude waves and is used to study the properties of localized ion acoustic solitons for parameters relevant for dense astrophysical objects such as white dwarf stars. Different degrees of relativistic electron degeneracy are discussed and compared.
Role of the magnetic ordering on the dielectric response of M2V2O7 (M = Co and Cu) divanadates
Authors: Sánchez-Andújar M. , Yáñez-Vilar S. , Mira J. , Biskup N. , Rivas J. , Castro-García S. , Señarís-Rodríguez M. A.
Published: March 2011

We have synthesized two divanadates M2V2O7 (M2+ = Co2+ and Cu2+), that are known to show different and complex magnetic arrangements at low temperatures and have studied their dielectric behavior. We have observed a change in the slope of the dielectric constant at the magnetic transition temperature, result which confirms the existence of magnetodielectric coupling in these two divanadates. The origin of the magnetodielectric coupling seems to be different in the Cu- and Co-compounds, although in both cases it is related to their frustrated magnetic arrangement. In Cu2V2O7, the dielectric anomaly arises from a spin canting due to the antisymmetric exchange which is allowed by structural symmetry. In the Co-divanadate, the structural symmetry does not allow antisymmetric exchange but the compound shows correlation between the behavior of the dielectric constant and inverse magnetization, which points to a dependence of its electrical polarization with the pair correlation function of neighboring magnetic spins.
Electrically detected magnetic resonance in a W-band microwave cavity
Authors: Lang V. , Lo C. C. , George R. E. , Lyon S. A. , Bokor J. , Schenkel T. , Ardavan A. , Morton J. J. L.
Published: March 2011

We describe a low-temperature sample probe for the electrical detection of magnetic resonance in a resonant W-band (94 GHz) microwave cavity. The advantages of this approach are demonstrated by experiments on silicon field-effect transistors. A comparison with conventional low-frequency measurements at X-band (9.7 GHz) on the same devices reveals an up to 100-fold enhancement of the signal intensity. In addition, resonance lines that are unresolved at X-band are clearly separated in the W-band measurements. Electrically detected magnetic resonance at high magnetic fields and high microwave frequencies is therefore a very sensitive technique for studying electron spins with an enhanced spectral resolution and sensitivity.
Nanosecond photofragment imaging of adiabatic molecular alignment
Authors: Trippel S. , Stei M. , Eichhorn C. , Otto R. , Hlavenka P. , Weidemüller M. , Wester R.
Published: March 2011

Adiabatic alignment of CH3I, induced by the anisotropic interaction of this symmetric top molecule with the intense field of a nonresonant infrared laser pulse, has been studied using velocity map imaging. We are using photodissociation imaging with pulsed nanosecond lasers to probe the distribution of the molecular axis in the laboratory space. In contrast to the commonly used probing with femtosecond laser pulses, this technique directly yields the degree of alignment over an extended space–time volume. This will be relevant for future reactive scattering experiments with laser-aligned molecules. The obtained degree of alignment, 〈cos 2θ〉, measured as a function of the infrared laser intensity, agrees well with a quantum calculation for rotationally cold methyl iodide. The strong infrared laser is also found to modify the photofragmentation dynamics and open up pathways to CH3I+ formation and subsequent fragmentation.
A new method to measure torsion moments on small-scaled specimens
Authors: Walter M. , Kraft O.
Published: March 2011

As a result of a continuous evolution in the field of small-scaled components, an increasing need exists for mechanical characterization of single structures and materials in micrometer dimensions. Moreover, for a detailed analysis of the deformation and failure behavior, it is often necessary to perform investigations under multiaxial loading in addition to uniaxial loading. A simple possibility to create defined multiaxial stress–strain fields is offered by a torsion experiment. In the frame of this work, a new method is presented, which allows determining torsion moments applied to wires as thin as 10 μm in monotonic as well as cyclic manner. Besides a detailed description of the measuring principle, the experimental setup and the first results will be presented. In particular, investigations on gold wires with diameters ranging from 10 to 60 μm, applying torsion moments in the nNm regime, are shown.
A technique for combined dynamic compression-shear test
Authors: Zhao P. D. , Lu F. Y. , Chen R. , Lin Y. L. , Li J. L. , Lu L. , Sun G. L.
Published: March 2011

It is critically important to study the dynamic response of materials under a combined compression-shear loading for developing constitutive laws more accurately and fully. We present a novel technique to achieve the combined compression and shear loadings at high strain rates. The main apparatus consists of a strike bar, an incident bar, and two transmission bars. The close-to-specimen end of the incident bar is wedge-shaped with 90°. In each experiment, there are two identical specimens, respectively, agglutinated between one side of the wedge and one of transmission bars. When a loading impulse travels to specimens along the incident bar, because of the special geometrical shape, the specimen-incident bar interface gets an axial and a transverse velocity. Specimens endure a combined compression-shear loading at high strain rates. The compression stress and strain of the specimens are deduced from signals recorded by strain gages mounted on the bars. The shear stress is measured by two piezoelectric transducers of quartz (Y-cut with rotation angle 17.7°) embedded at the close-to-specimen end of transmission bars; the shear strain is measured with a novel optical technique, which is based on the luminous flux method. An analytic model was proposed and validated by the numerical simulations. The simulation results yield good agreement with the analytic results. The proposed technique was then validated through experiments carried out on lead specimens, by comparing experimental results with that of the split Hopkinson pressure bar experiments.
Room temperature ferromagnetism in metallic and insulating (In1−xFex)2O3 thin films
Authors: Jiang Feng-Xian , Xu Xiao-Hong , Zhang Jun , Fan Xiao-Chen , Wu Hai-Shun , Alshammari Marzook , Feng Qi , Blythe Harry J. , Score David S. , Addison Kiri , Al-Qahtani Mohammed , Gehring Gillian A.
Published: March 2011

Fe-doped In2O3 thin films are deposited on sapphire substrates using pulsed laser ablation. The effects of Fe concentration and oxygen partial pressure on the structure, magnetism and transport properties of (In1−xFex)2O3 films are studied systematically. A detailed analysis of the structural properties suggests the substitution of Fe dopant ions with mixture valences and rules out the presence of clusters and secondary phases as the source of ferromagnetism. Systematic investigations of transport properties for (In1−xFex)2O3 films with a wide range of carrier densities reveal that they occur in both metallic and insulating regimes. The insulating films exhibit variable range hopping at low temperatures and show temperature dependent ferromagnetism, which can be explained by bound magnetic polarons mechanism. For the metallic films, the carrier densities play a crucial role in their robust ferromagnetism and the resistivity and magnetization are independent of temperature; the carrier-mediated exchange mechanism has been suggested as responsible for magnetic ordering in these metallic films. Optical absorption and magneto-optic studies of (In1−xFex)2O3 films indicate further differences between metallic and semiconducting films and show significant magnetic circular dichroism below the In2O3 bandedge at room temperature, which also implies intrinsic ferromagnetism.
Individual GaAs quantum emitters grown on Ge substrates
Authors: Cavigli L. , Abbarchi M. , Bietti S. , Somaschini C. , Sanguinetti S. , Koguchi N. , Vinattieri A. , Gurioli M.
Published: March 2011

We report on the nucleation of low density and defect-free GaAs quantum dots (QDs) on Ge substrates. The growth of III-V nanostructures was realized via droplet epitaxy technique. A detailed micro- and macro-photoluminescence analysis shows that the optical quality of the GaAs QDs is almost comparable with state-of-the-art QDs directly grown on GaAs substrates. Bright and sharp exciton and biexciton lines of individual QDs have been observed. This achievement opens the route to the realization of quantum optoelectronic devices on IV semiconductor substrates.
Role of nitrogen substitution in phenyl ring on excited state intramolecular proton transfer and rotamerism of 2-(2′-hydroxyphenyl)benzimidazole: A theoretical study
Authors: Chipem Francis A. S. , Dash Nihar , Krishnamoorthy G.
Published: March 2011

A comparative study of 2-(2′-hydroxy-3′-pyridyl)benzimidazole (2′,3′-HPyBI), 2-(3′-hydroxy-4′-pyridyl)benzimidazole (3′,4′-HPyBI), 2-(4′-hydroxy-3′-pyridyl)benzimidazole (4′,3′-HPyBI), 2-(3′-hydroxy-2′-pyridyl)benzimidazole (3′,2′-HPyBI), and 2-(5′-hydroxy-4′-pyrimidinyl)benzimidazole (5′,4′-HPymBI) with 2-(2′-hydroxyphenyl)benzimidazole (HPBI) was performed theoretically to evaluate the effect of nitrogen substitution in the phenolic ring on the photophysics and rotamerism of HPBI. Density functional theory (DFT) and configuration interaction singles (CIS) combined with time-dependent DFT were employed for ground and excited state studies, respectively. Different possible molecular forms were considered for each molecule viz., cis-enol, trans-enol, open-enol, and keto forms. The computational results revealed that cis-enol is the most stable form in the ground state for all the molecules except in 2′,3′-HPyBI. In 2′,3′-HPyBI, K-2 keto is the most stable form. Water molecule assisted interconversions between different forms of 2′,3′-HPyBI were examined theoretically. Excitation and emission energies for all the forms have been calculated theoretically and the values are in good agreement with the available experimental data. The calculations show that intramolecular proton transfer (ESIPT) is endothermic in the ground state while it is exothermic in the first excited singlet state (except 5′,4′-HPymBI). The barrier for the excited state ESIPT reaction increases with nitrogen substitution. Torsional rotation between the benzimidazole and the pyridinyl/pyrimidinyl rings in the S1 state depicts that twisted-keto structures involve charge transfer from the hydroxypyridinyl/hydoxypyrimidinyl to the benzimidazole ring. However, the formation of twisted-keto is not energetically favored in these systems.
Nonequilibrium solvation for vertical photoemission and photoabsorption processes using the symmetry-adapted cluster–configuration interaction method in the polarizable continuum model
Authors: Fukuda Ryoichi , Ehara Masahiro , Nakatsuji Hiroshi , Cammi Roberto
Published: March 2011

In this paper, we present the theory and implementation of a nonequilibrium solvation model for the symmetry-adapted cluster (SAC) and symmetry-adapted cluster–configuration interaction (SAC–CI) method in the polarizable continuum model. For nonequilibrium solvation, we adopted the Pekar partition scheme in which solvent charges are divided into dynamical and inertial components. With this nonequilibrium solvation scheme, a vertical transition from an initial state to a final state may be described as follows: the initial state is described by equilibrium solvation, while in the final state, the inertial component remains in the solvation for the initial state; the dynamical component will be calculated self-consistently for the final state. The present method was applied to the vertical photoemission and absorption of s-trans acrolein and methylenecyclopropene. The effect of nonequilibrium solvation was significant for a polar solvent.