bluuebunny/crossref_metadata_2025 huggingface dataset:
A Symposium on “The Troubled Future of Colleges and Universities”
Authors: King Gary , Sen Maya
Published: January 2013

The American system of higher education is under attack by political, economic, and educational forces that threaten to undermine its business model, governmental support, and operating mission. The potential changes are considerably more dramatic and disruptive than anything previously experienced. Traditional colleges and universities urgently need a coherent, thought-out response. Their central role in fostering the creation, preservation, and distribution of knowledge in the world may be at risk and, as a consequence, so too may be the spectacular progress across fields we have come to expect as a result.
RECAP: FORECASTING THE 2012 ELECTION
Authors: Campbell James E.
Published: January 2013

The October 2012 issue ofPSpublished a symposium of presidential and congressional forecasts made in the months leading up to the election. In the following articles, the forecasters assess the accuracy of their models.
Major Depressive Disorder, Cognitive Symptoms, and Neuropsychological Performance among Ethnically Diverse HIV+ Men and Women
Authors: Fellows Robert P. , Byrd Desiree A. , Morgello Susan
Published: January 2013

Major depressive disorder (MDD), cognitive symptoms, and mild cognitive deficits commonly occur in HIV-infected individuals, despite highly active antiretroviral therapies. In this study, we compared neuropsychological performance and cognitive symptoms of 191 HIV-infected participants. Results indicated that participants with a formal diagnosis of current MDD performed significantly worse than participants without MDD in all seven neuropsychological domains evaluated, with the largest effect sizes in information processing speed, learning, and memory. In addition, a brief assessment of cognitive symptoms, derived from a comprehensive neuromedical interview, correlated significantly with neurocognitive functioning. Participants with MDD reported more cognitive symptoms and showed greater neurocognitive deficits than participants without MDD. These findings indicate that HIV-infected adults with MDD have more cognitive symptoms and worse neuropsychological performance than HIV-infected individuals without MDD. The results of this study have important implications for the diagnosis of HIV-associated neurocognitive disorders (HAND). (JINS, 2013,19, 1–10)
A 79 GHz SiGe short-range radar sensor for automotive applications
Authors: Massen Joachim , Frei Michael , Menzel Wolfgang , Möller Ulrich
Published: January 2013

The field of short- and mid-range radar sensors for automotive comfort and safety systems is a fast-growing market. The frequency regulation provides a new 76–81 GHz frequency band, which will be mandatory in the EU for ultra-wideband sensors from 2018. In the “radar-on-chip for cars” (RoCC) project funded by the German Ministry of Research (BMBF), a new technology was developed based on SiGe components with the objective to make the sensors affordable for all car platforms. This paper reports on the contribution of Continental A.D.C. GmbH to the joint “RoCC” project. The aim of the project was to exploit the cost-reduction potential of the SiGe technology by a further integration of the individual components and to show that the reliability and the functionality of the new sensors can meet the current requirements of the market. For this purpose, we evaluated the new eWLB package technology of Infineon. The Institute of Microwave Techniques of the University of Ulm supported us in designing a substrate integrated slotted waveguide antenna array. Demonstration sensors for short- and mid-range applications were built up and tested in the laboratory. To show the ability of the sensors to deal with real scenarios on the road, they were integrated into an experimental vehicle.
Migratory Rituals or Classical Dance Forms?: “Trance” Dance and Bharatanatyam as Signifiers of Tamil Identity in Diasporic Hindu Communities in Britain
Authors: David Ann R.
Published: January 2013

This paper examines the performance of religion in British Sri Lankan Tamil Hindu communities using ethnographic research to investigate the use of classical dance and trance, or embodied dance, as performative practice. Contemporary U.K. evidence of Tamil Saivite worship shows an affiliation of dance and ritual being articulated and reinvented through the classical dance form of Bharatanatyam and through its transmission in the temple environment in an increasing display of embodied diasporic Hinduism.
Rina Nikova and the Yemenite Group: Between East and West, North and South
Authors: Elron Sari
Published: January 2013

Rina Nikova, a Jewish dancer, ballet master, and choreographer, was born in Russia around 1898 and died in Israel in 1974. Nikova established her Yemenite Singing Ballet in 1932. She trained her dancers—young Jewish emigrates from Yemen—with classical ballet technique augmented with various local and migrating influences. She gathered firsthand information on folk dances, music, and costumes by visiting Arab towns and villages and communities of Oriental Jews. Nikova combined those influences into an original creation that was to become a cornerstone of nation-building in Israel.
CEO Migrant: The Case of Hanya Holm
Authors: Gitelman Claudia
Published: January 2013

Peter Meilaender reminds us that a CEO relocating to a foreign country to head up an international branch is as much an immigrant as is an impoverished refuge. This paper situates Hanya Holm within structural and personal paradigms of migration theory to examine her first year in the United States, when she faced the prospect of financial ruin in the host country and a threat to loyalties and interdependencies in the sending country.
American Body Pedagogies: Somatics and the Cultural Construction of Bodies in the Institution of Higher Education
Authors: Green Jill
Published: January 2013

This paper explores body pedagogy, particularly related to how we teach dance technique in the United States. It addresses the paradigmatic positions underlying dance education and how somatics plays a role in how educators teach dance. Although somatics is viewed as a positive addition to a pedagogical repertoire, the author questions viewing it as a universal panacea for all the world's ills and points to larger sociopolitical factors concerning power dynamics and institutional power (that is, higher education dance).
Identity Peddlers and the Influence of Gertrud Kraus
Authors: Ingber Judith Brin
Published: January 2013

Gertrud Kraus, Jewish expressionist modern dancer, directed a company and school both in interwar Vienna and in Tel Aviv after she fled the Nazis in 1935. This paper examines her work as both a Diaspora and Israeli dance artist and her influence on the identities of different dancers who in turn affected American audiences, students, and dancers. Some of the Kraus dancers who emigrated to America from Vienna before and during World War II included Jan Veen, Fred Berk, Katya Delakova, and Claudia Vall; from Israel they included Ze'eva Cohen and Zvi Gotheiner, whose latest work, Gertrud premiered in 2007 in New York.
The Dynamic Realities of “Traditional” Dance: Les Ballets Africains
Authors: Moss Michèle
Published: January 2013

This paper presents the author's journey to West Africa, which grew out of a desire to trace the roots of “real” jazz dance. Seeking the “authentic,” the author (ironically) sought out the oldest national company of Guinée-Conakry, Les Ballets Africains, which has been performing and creating for fifty-three years years. Mandated to preserve the rich cultural traditions of Guinée, they are the “real thing,” revealed in what the author calls a “dynamic reality”: traditional dance that is at once authentic, significant, contemporary, and fluid.
Humphrey and Limón: Firsthand Observations
Authors: Vachon Ann
Published: January 2013

Limón became a student and devoted follower of Doris Humphrey in 1929 and continued working with her until her death thirty years later. In his memoir he wrote about the brilliance of her dancing and her choreography and even admits in one passage to “plagiarizing” her work. This presentation explores how their evolving relationship was viewed by various individuals who were present during their working process and whose memories of their interaction differ considerably.
Motion/Perception: William Forsythe's Spectatorial Shifts
Authors: Vass-Rhee Freya
Published: January 2013

What do we mean when we talk about perception in/of dance? The movement of viewers of William Forsythe's dance and performance installation works affords perceptual change in multiple senses—sensory, cognitive, philosophical, aesthetic. This paper explores issues of action, perspective, and convention in the performance of dance spectatorship through a consideration of Forsythe's mobilized audiences. Moving within and between diverse disciplines, this paper simultaneously examines disciplinary specificity, variance, and crossover of the term “perception.”
Women, Protest, and Dance: An Activist Art?
Authors: Faulkner Kristi
Published: January 2013

As members of society, artists have historically served a dualistic purpose—to reflect the ideologies of the world in which they live, and to challenge those ideologies. By challenging ideologies, artists may enter into a world of social and political activism. However, can art be an effective form of protest? In this paper I explore the characteristics that allow dance to function as a form of social and political activism. Furthermore, I explore the potential implications of the female dancing body as it pertains to dance as an activist art form.
WomenWork It On Out: An Intergenerational Encounter through Dance
Authors: King Jayne
Published: January 2013

In “Dance Narratives and Fantasies” Angela Mc Robbie writes that for generations of women dance has represented “an arena for self expression … away from the difficulties of everyday life. … a symbolic escape route from the more normative expectations of young women.” “I dance because it … makes me feel free,” writes Ms Mae, one of twenty seniors who participated in Work It On Out, a community dance project that brought elders together with dance majors at Northwest Vista College. Sharing dances and stories about dance, we would form a unique intergenerational community to celebrate a woman's ongoing love affair with dance. Though dance is not something that old and young typically share, the exuberance in the simple acts of moving together created instant rapport. With Aretha crooning “freedom …” in the background, looking good and shaking our shoulders and hips was a “fem-positive” message of grace, dignity, and strength over circumstance, signified by the freedom of the body.
3″ Golden Lotus: The Tradition of Bound Feet as Depicted in Contemporary Choreography
Authors: Knox Kelly
Published: January 2013

The Chinese tradition of female foot binding dates back thousands of years and has had a profound impact on the status and expectations of Chinese women well into the twentieth century. This paper explores the cross-cultural collaboration between a male Chinese choreographer and a female American dancer and the intersection of metaphoric movement with female identity in Er-Dong Hu's choreographic work,3” Golden Lotus(2007). Addressing a personal and cultural history, Hu offers a gallery of kinesthetic images that portray the imposed practice of foot binding. What is revealed is one dancer's psychological journey as she follows in the tiny and excruciating footsteps of her female ancestors,3” Golden Lotusserves as a choreographic springboard for investigating not only the Chinese tradition of bound feet but also its counterparts in other times and cultures, all of which represent a global subjugation of the woman's body.
You Tube, Beyonceworld, and Second Life: Do Girls Still “Go to Ballet”?
Authors: Taylor Virginia
Published: January 2013

This paper presents updates from my ongoing ethnographic study into the lived experience and worldviews of eight- to eleven-year-old girls in the United Kindom and responds to my 1999 Selma Jeanne Cohen award-winning paper, “Respect, Antipathy, and Tenderness: Why Do Girls ‘Go to Ballet’?” History has moved very fast: technologies have transformed the daily lived experience of children, now supersaturated with images and with access to communities far beyond their physical and cultural environment. The paper reports on the girls' assessment of their experience and considers whether the girls' bodies are being re-choreographed by an unprecedented excess of images of bodies and ways of moving, very different from and potentially more powerful than those they encounter in their own cultural setting.
Developing Taiwanese Kindergarten Teachers' Pedagogy in Creative Dance
Authors: Liu Shu-Ying
Published: January 2013

This paper considers how Taiwanese kindergarten teachers' skills and abilities in teaching creative dance are being developed through a government-funded project in which researchers are collaborating with volunteer kindergartens to research, develop, and assess strategies for teacher training and development. In doing so, they are addressing the significant gap between government policy, teacher skills and knowledge, and classroom practice. The paper reflects on specific cases and the success with which teachers have been empowered and motivated by their direct involvement in the development of strategies, and their dance teaching abilities developed by fully involving them in the research process.
The Pedagogic Significance of Modern Dance Training on the Twenty-First-Century Dancing Body, with Reference to Doris Humphrey's Dance Technique and Movement Philosophy
Authors: Main Lesley
Published: January 2013

A primary issue for dance education and training is ensuring that the “trained body” is equipped for the range of activity today's dance practitioner will encounter. Modern dance techniques offer a breadth of knowledge on numerous and inter-related levels, encompassing the physical, physiological, artistic, historical, musical, and analytical. This paper will consider the relevance and benefits that “traditional” modern dance training can have on today's dancer. Issues addressed will include what our students are using technique for; what a codified dance technique can offer; and the progression to a “trained body” and how this can be achieved.
Historiography of Ballet Studies at the Undergraduate Level in the United Kingdom
Authors: Farrugia Kathrina
Published: January 2013

This paper explores the histories, practices, and legacies of ballet studies in academic education in the United Kingdom. Charting the coexistence of vocational training in mainstream professional colleges and the emergence of ballet studies in select higher education institutions provides a reading into the marginalisation of ballet studies within the spectrum of dance degrees in the twenty-first century. The paper presents selected readings of sociocultural, artistic, and pedagogical trends concerned with the proliferation of dance and ballet degrees (1980S–1990S); and the effect of issues in training and academic studies on the nature of past and current programmes in the field of ballet studies.
Digital Literacy and the Dance Student: Digital Dance Objects and the Implications for Teaching, Learning, and Assessment
Authors: Whatley Sarah , Bennett David
Published: January 2013

This paper provides an overview of a project led by Sarah Whatley and David Bennett at Coventry University as part of the JISC-funded project CURVE (Coventry University Repository for a Virtual Environment). The project was one of a number of work packages developed throughout 2007–2008, in this case a dance learning objects package, to assist student engagement with the university's virtual learning environment (VLE). The dance learning objects package was developed, trialled, and is now in place. In developing these materials, the interest was in how the digital dance objects that we were creating for a parallel project—the AHRC funded Siobhan Davies Archive, which is an online digital archive—could be developed into learning objects and how this might lead to the development of new ways of teaching and learning, new assessment methods, and the development of further dance learning objects.
Navigating Liminal Space in the Feminist Ballet Class
Authors: Wootten Claire F.
Published: January 2013

The historically autocratic teaching model of Western concert dance provides both student and teacher with the comfort of expected ritual and outcomes. That comfort is greatly disrupted, however, in employing a pedagogy that has student empowerment at its center—feminist pedagogy. This paper will focus on the conditions of the liminal space created in shifting to a process-based educational approach from a traditionally product-driven training model.
Critical Issues in Pedagogy and Research: Perspectives on Dance Education Theory and Practice
Authors: Anttila Eeva
Published: January 2013

From a Scandinavian perspective, the current scenario for dance education practice and research appears quite challenging. One great challenge seems to be preserving the basic values of democracy, equity, and access of the Nordic educational system that is being contested by neoliberal policies, much like elsewhere in the Western world. I am echoing Sue Stinson about the concerns that accountability and standardization have generated in preparing future dance teachers. The restraints seem to creep in from all directions. From the European Union and the Bologna process, higher education is affected by directives that compel us to reformulate the program goals in terms derived from Bloom's taxonomy (Bloom 1956). On the national level, increasing governmental regulations regarding higher education have altered the criteria for allocating funds, and beginning in January 2010 the whole system will drastically change toward privatization. Another significant national development is more difficult to discern but is even more disturbing.
Workshop: Ready, Set, Unset
Authors: Koch Jürg
Published: January 2013

“Diversity” is a buzzword in higher education. Over the past twenty-five years dance companies integrating disabled and nondisabled performers have developed methodologies effective in workshop and company training. Transferring these methods into mainstream teaching, providing a comprehensive training and education, proves both difficult and problematic. This workshop provides an insight into the research and practice based on the presenter's experience in integrated dance. Central to the research is to move integrated dance beyond adaptation, developing a skill-specific curriculum and applying methodologies, class structure, and material relevant to all participants consistent with main principles of universal design of instruction.
Studying Dance at German Universities: Research vs. Practice
Authors: Kretschmann Rolf
Published: January 2013

Being interested in studying dance in Germany at a university inevitably leads to a department of sport science. Thus, dance (often coupled with rhythmic gymnastics to fuse into one subject) is obligatory within the studies of sport science. Taking a closer look at the practical dance seminars, one can easily identify inconsistencies in the conceptually intended interlinking of theory, research, and practice. However, the subject of dance at German universities is factually constrained with the enforced aim of exercising students in dance techniques and skills, and therefore it disregards the scientific claims of a predominant amount of theoretical and scientific theory and reflection.
Organophosphorus Veterinary Medicines
Authors: Marrs Timothy C.
Published: January 2013

Some products used in veterinary medicines contain organophosphorus (OP) compounds as their active ingredients. The major examples include the use of these compounds in the treatment of ectoparasites on sheep (usually diazinon although propetamphos and chlorfenvinphos have previously been used) and in the control of sea lice on farmed salmon. They have also been used in the treatment of other parasitic diseases in other animals. The OPs are esterase inhibitors, and notably inhibitors of cholinesterases, and exposure may result in acute cholinergic effects. However, other effects may also arise including the intermediate syndrome and a delayed polyneuropathy. In the United Kingdom, the use of sheep dips containing OPs has been associated with a particular syndrome characterised by acute and long-term effects. The effects of OPs on human health are reviewed in this chapter and the specific effects on those involved in dipping sheep are discussed.
Antifungal Drugs
Authors: Woodward K. N.
Published: January 2013

There are a number of antifungal drugs authorised for use in animals, the majority being members of the polyene or azole classes. Of these, only two are permitted for use in food animals, at least in the European Union, natamycin and enilconazole. Griseofulvin is a cyclohexenone derivative which has been used in companion and food animal medicine. However, it has been shown to be teratogenic and its use is now restricted to companion animals because of consumer safety concerns when used in food animals. Amphotericin B is a polyene antifungal agent whose use in human medicine is associated with nephrotoxicity which in some circumstances may be severe and may lead to renal failure. In contrast, another member of the group, natamycin, has low toxicity in humans and in animals. The azoles include the imidazoles and the traizoles. These drugs produce their desired pharmacodynamic effects through the inhibition of fungal steroidogenesis. However, they may also produce similar inhibitory effects on mammalian steroidogenesis. This inhibition may have beneficial effects, for example in the therapeutic treatment of steroid dependent cancers such as prostate. However, there may also be adverse effects including those on the reproductive system and on the outcome of gestation. Several members of the group including itraconazole, fluconazole and ketoconazole are also hepatotoxic. Many of the effects seen with these compounds only occur at high therapeutic doses in humans or at high doses in animal studies and so they are unlikely to occur as a result of infrequent occupational exposure to relatively low doses. Their restricted use in food animals reduces concerns over possible adverse effects in consumers who might otherwise be exposed to residues in food of animal origin.
Veterinary Medicines and the Environment
Authors: Woodward K. N.
Published: January 2013

Veterinary medicines are often used in circumstances where they may enter the natural environment in significant quantities, for example through the use of ectoparasiticides in animals or by direct discharge of spent sheep dip into rivers. However, the mass medication of farm animals with other drugs including antimicrobials and endectocides may also result in environmental contamination, largely through elimination in urine and faeces. These drugs may add to the burden of contamination caused by human medicines, which usually arise in the environment from elimination in urine and faeces followed by entry into the sewerage systems. These sources of pollution present a dilemma as the only certain way to prevent environmental contamination is to prevent the use of medicines, something which is not considered to be acceptable in human or veterinary medicine. To make matters worse, the adverse effects of environmental contamination with medicinal products are not at all clear. However, some agents may be toxic to animals and plants, while others may act as endocrine disrupting chemicals.
Potential Adverse Microbiological Effects of Antimicrobials
Authors: Silley P.
Published: January 2013

The potential adverse effects of antimicrobial drugs are not confined to their toxicological properties. These agents may induce adverse effects associated with their pharmacodynamic properties, including the induction of antimicrobial resistance. This is of particular significance when it occurs in organisms responsible for human disease such as Campylobacter. Studies using antimicrobial drugs and suitable bacterial populations may also be used to define microbiological acceptable daily intake (ADI) values in a manner analogous to the methods used for the calculation of toxicological ADI values. These values are important in elaborating maximum residue limits and similar indices for antimicrobial drugs. These issues, along with the experimental approaches used, are discussed in depth in this chapter.
Evolution of the dynamic susceptibility in molecular glass formers: Results from light scattering, dielectric spectroscopy, and NMR
Authors: Petzold N. , Schmidtke B. , Kahlau R. , Bock D. , Meier R. , Micko B. , Kruk D. , Rössler E. A.
Published: January 2013

Although broadly studied, molecular glass formers are not well investigated above their melting point. Correlation times down to 10−12 s are easily accessible when studying low-Tg systems by depolarized light scattering, employing a tandem-Fabry-Perot interferometer and a double monochromator. When combining these techniques with state-of-the-art photon correlation spectroscopy (PCS), broad band susceptibility spectra become accessible which can compete with those of dielectric spectroscopy (DS). Comparing the results with those from DS, optical Kerr effect, and NMR, we describe the evolution of the susceptibilities starting from the boiling point Tb down to Tg, i.e., from simple liquid to glassy dynamics. Special attention is given to the emergence of the excess wing contribution which is also probed by PCS and which signals a crossover of the spectral evolution. The process is attributed to a small-angle precursor process of the α-relaxation, and the apparent probe dependent stretching of the α-process is explained by a probe dependent contribution of the excess wing. Upon cooling, its emergence is linked to a strong decrease of the strength of the fast dynamics which is taken as reorientational analog of the anomaly of the Debye-Waller factor. Many glass formers show in addition a slow β-process which manifests itself rather universally in NMR, in DS, however, with different amplitudes, but not at all in PCS experiments. Finally, a three-parameter function is discussed interpolating τα(T) from Tb to Tg by connecting high- and low-temperature dynamics.
High efficiency coupling of radio frequency beams from the dual frequency gyrotron with a corrugated waveguide transmission system
Authors: Oda Yasuhisa , Kajiwara Ken , Takahashi Koji , Mitsunaka Yoshika , Sakamoto Keishi
Published: January 2013

High efficiency coupling of the millimeter-wave output of the dual-frequency gyrotron with the transmission line was demonstrated. The dual-frequency gyrotron was design to produce similar beam profiles for two operation frequencies (170 GHz and 137 GHz). Using two RF beam reflecting mirrors in a matching optics unit (MOU), which are designed to transform the beam profile of the gyrotron output to the fundamental waveguide mode (HE11 mode) at 170 GHz, high efficiency coupling was demonstrated for two frequencies. The measured mode purity of HE11 mode was 96% at 170 GHz and 94% at 137 GHz operations with the identical mirrors at the fixed mirror position and angle. The results indicate that the significantly simple dual frequency system is realized by the gyrotron designed to output the similar beam profiles at different frequency operation.
Raman spectroscopy of ferroelectric Sn2P2S6 under high pressure up to 40 GPa: Phase transitions and metallization
Authors: Ovsyannikov Sergey V. , Gou Huiyang , Morozova Natalia V. , Tyagur Iryna , Tyagur Yuriy , Shchennikov Vladimir V.
Published: January 2013

We report results of a Raman spectroscopy study of non-oxide ferroelectric tin-hypothiodiphosphate (Sn2P2S6) at ambient temperature under application of high pressure up to 40 GPa. Pressure evolution of the Raman spectra revealed several different compression regimes that are most likely related to phase transitions, with boundaries near <1, ∼5–7, ∼16–19, ∼26–29, and ∼39 GPa. Above 39 GPa, the Raman signal disappeared. Pronounced softening in some phonon modes prior to these crossovers also suggested that these features are related to structural phase transitions. In optical absorption spectroscopy, we confirmed the wide semiconductor band gap Eg of Sn2P2S6, and in particular, found indirect gap of Eg = 2.26 eV and direct one of Eg = 2.42 eV. In visual examinations, we observed that the sample color gradually changed with pressure from yellow to orange, red, and then to opaque. Eventually, at the maximal pressure achieved in our study, the sample demonstrated a metallic luster. Hence, the metallization at 39 GPa was proposed. At decompression, these characteristic features shifted to lower pressures. Thus, besides the known ferroelectric Pn and paraelectric P21/n phases, Sn2P2S6 can adopt several more structures in the pressure range up to 40 GPa, with electronic properties ranging from wide-gap semiconductor to metal. We found that high-pressure behavior of electronic band structure in Sn2P2S6 is, to significant extent, analogous to a case of elemental sulfur.
Efficient methods for including quantum effects in Monte Carlo calculations of large systems: Extension of the displaced points path integral method and other effective potential methods to calculate properties and distributions
Authors: Mielke Steven L. , Dinpajooh Mohammadhasan , Siepmann J. Ilja , Truhlar Donald G.
Published: January 2013

We present a procedure to calculate ensemble averages, thermodynamic derivatives, and coordinate distributions by effective classical potential methods. In particular, we consider the displaced-points path integral (DPPI) method, which yields exact quantal partition functions and ensemble averages for a harmonic potential and approximate quantal ones for general potentials, and we discuss the implementation of the new procedure in two Monte Carlo simulation codes, one that uses uncorrelated samples to calculate absolute free energies, and another that employs Metropolis sampling to calculate relative free energies. The results of the new DPPI method are compared to those from accurate path integral calculations as well as to results of two other effective classical potential schemes for the case of an isolated water molecule. In addition to the partition function, we consider the heat capacity and expectation values of the energy, the potential energy, the bond angle, and the OH distance. We also consider coordinate distributions. The DPPI scheme performs best among the three effective potential schemes considered and achieves very good accuracy for all of the properties considered. A key advantage of the effective potential schemes is that they display much lower statistical sampling variances than those for accurate path integral calculations. The method presented here shows great promise for including quantum effects in calculations on large systems.
Vortex core size in unconventional superconductors
Authors: Zakharchuk I. , Belova P. , Safonchik M. , Traito K. B. , Lähderanta E.
Published: January 2013

Influence of the order parameter symmetries on the cutoff parameter ξh and vortex core size ξ2 (the distance from the vortex center at which the current density reaches the maximum value) in the mixed state are investigated in the framework of Eilenberger theory for unconventional superconductors. The cutoff parameter determines the field distribution in the generalized London equation obtained as a projection of the quasiclassical theory. It is used for the fitting of the μSR and small-angle neutron scattering experimental data. Anisotropic dx2−y2 and isotropic s±-wave superconducting pairings are studied. These pairing symmetries can be realized in iron pnictide superconductors. Conventional s++ pairing mediated electron-phonon interaction is also considered. Temperature, field, and impurity scattering dependences of ξh/ξc2 are obtained. It is found that normalized ξ2/ξc2(B/Bc2) dependence is increasing with pair breaking impurity scattering (interband scattering for s±-wave and intraband impurity scattering for d-wave superconductors). Here, ξc2 is the Ginzburg-Landau coherence length determined from the relation Bc2=Φ0/2πξc22, where Bc2 is an upper critical field and Φ0 is a flux quantum. Two types of ξ2/ξc2(B/Bc2) dependences are obtained for s± superconductors. It has minimum at low temperatures and small impurity scattering transforming in monotonously decreasing function at strong scattering and high temperatures. The second kind of this dependence was also found for d-wave superconductors at intermediate and high temperatures. In contrast, impurity scattering results in decreasing of ξ2/ξc2 field dependence in s++ superconductors.
Direct imaging of the distortions of MnO6 octahedra in La0.4Ca2.6Mn2O7
Authors: Wang Y. M. , Yu R. C. , Ge B. H.
Published: January 2013

The distortions of MnO6 octahedra in layered manganites La0.4Ca2.6Mn2O7, which play a key role in the structure transformations and physical properties, were investigated by using a 200 kV high-resolution transmission electron microscope. Tetragonal, orthorhombic (superstructure), and monoclinic phases were found to coexist in the form of microdomains. In particular, the distortions of MnO6 octahedra in the orthorhombic and monoclinic phases were revealed directly at atomic resolution by means of image deconvolution. The differences of the Mn atomic columns in position, size, and contrast among the tetragonal, orthorhombic, and monoclinic phases, caused by the rotation or tilt of the MnO6 octahedra, were directly obtained from the corresponding structure projection maps.
Calculation of interface roughness scattering-limited vertical and horizontal mobilities in InAs/GaSb superlattices as a function of temperature
Authors: Szmulowicz F. , Brown G. J.
Published: January 2013

Superlattice transport has acquired new relevance owing to the current interest in InAs/GaSb and other superlattices (SL) for third-generation infrared detector focal plane arrays. Interface-roughness scattering (IRS) is known to limit carrier mobilities at low temperatures. Whereas horizontal (in-plane) transport measurements are standard, perpendicular transport measurements (across SL layers)—the ones relevant to the operation of infrared sensors—are non-routine and seldom performed; vertical SL transport is also less well studied theoretically. Therefore, we extend our previous work on low-temperature SL transport by studying horizontal and vertical IRS-limited transport in InAs/GaSb SLs as a function of temperature, SL parameters, and the degree of roughness. Electron mobilities are calculated by solving the Boltzmann equation with temperature-dependent bands and carrier screening, and the results are discussed by analyzing the behavior of the relaxation rates and spectral mobilities, defined as mobilities as a function of carrier energy. New computational tools are devised to handle the implicit integral equation for the horizontal relaxation rates. We find that the behavior of the relaxation rates and spectral mobilities undergoes a change for energies below and above the conduction band bandwidth, which dictates the ultimate behavior of mobilities as a function of temperature. The calculated mobilities are found to display a rich variety of behaviors as a function of temperature, either increasing, decreasing, or remaining relatively constant, depending on the correlation length of interface roughness, Λ, and the conduction band bandwidth. Since the horizontal mobility is a double-valued function of Λ, the temperature dependence of mobilities can be used to eliminate this indeterminacy in order to assess the degree of interface roughness.
Emission enhancement mechanism of GaN:Eu by Mg codoping
Authors: Sekiguchi Hiroto , Takagi Yasufumi , Otani Tatsuki , Okada Hiroshi , Wakahara Akihiro
Published: January 2013

Mg codoping into Eu-doped GaN strongly affects the two dominant optical sites A (620.3 nm) and B (622.3 nm) and dramatically improves the optical characteristics obtained from Eu3+ ions. To clarify the mechanism of the enhanced emission, the effects of the Mg concentration on the excitation and emission processes were evaluated by considering the excitation power dependence of photoluminescence (PL) and time-resolved PL at various temperatures. The excitation cross section σex, which reflected the excitation process, did not depend on the Mg concentration but strongly on the optical site, which was attributed to the different energy transfer processes of the two optical sites. σex for site A was three times larger than that for site B, indicating higher excitation efficiency for site A. Mg codoping dramatically increased the number of Eu ions in site A that remain active at room temperature (RT) and the 5D0 lifetime at RT, indicating the suppression of nonradiative components during the emission process. Therefore, the optical properties were markedly enhanced by Mg codoping.
The vibrational spectrum of CaCO3 aragonite: A combined experimental and quantum-mechanical investigation
Authors: Carteret Cédric , De La Pierre Marco , Dossot Manuel , Pascale Fabien , Erba Alessandro , Dovesi Roberto
Published: January 2013

The vibrational properties of CaCO3 aragonite have been investigated both theoretically, by using a quantum mechanical approach (all electron Gaussian type basis set and B3LYP HF-DFT hybrid functional, as implemented in the CRYSTAL code) and experimentally, by collecting polarized infrared (IR) reflectance and Raman spectra. The combined use of theory and experiment permits on the one hand to analyze the many subtle features of the measured spectra, on the other hand to evidentiate limits and deficiencies of both approaches. The full set of TO and LO IR active modes, their intensities, the dielectric tensor (in its static and high frequency components), and the optical indices have been determined, as well as the Raman frequencies. Tools such as isotopic substitution and graphical animation of the modes are available, that complement the analysis of the spectrum.
${\cal N}=2$
N
=
2
gauge theories: Congruence subgroups, coset graphs, and modular surfaces
Authors: He Yang-Hui , McKay John
Published: January 2013

We establish a correspondence between generalized quiver gauge theories in four dimensions and congruence subgroups of the modular group, hinging upon the trivalent graphs, which arise in both. The gauge theories and the graphs are enumerated and their numbers are compared. The correspondence is particularly striking for genus zero torsion-free congruence subgroups as exemplified by those which arise in Moonshine. We analyze in detail the case of index 24, where modular elliptic K3 surfaces emerge: here, the elliptic j-invariants can be recast as dessins d'enfant, which dictate the Seiberg-Witten curves.
Spectroscopic and thermochemical properties of the c-C6H7 radical: A high-level theoretical study
Authors: Bargholz Arne , Oswald Rainer , Botschwina Peter
Published: January 2013

The electronic ground state ($\tilde X{}^2B_1$X̃2B1) of the cyclohexadienyl radical (c-C6H7) has been studied by explicitly correlated coupled cluster theory at the RCCSD(T)-F12x (x = a, b) level, partly in combination with the double-hybrid density functional method B2PLYP. An accurate equilibrium structure has been established and the ground-state rotational constants are predicted to be A0 = 5347.3 MHz, B0 = 5249.7 MHz, and C0 = 2692.5 MHz. The calculated vibrational wavenumbers agree well with the recent p-H2 matrix IR data [M. Bahou, Y.-J. Wu, and Y.-P. Lee, J. Chem. Phys. 136, 154304 (2012)10.1063/1.3703502] and several predictions have been made. A low value of 6.803 ± 0.005 eV is predicted for the adiabatic ionization energy of c-C6H7. Owing to a moderately large change in the equilibrium structure upon ionization, the first band of the photoelectron spectrum is dominated by the adiabatic peak (100%) and only the peaks corresponding to excitation of the two lowest totally symmetric vibrations (ν12 and ν11) by one vibrational quantum have relative intensities of more than 15%. The C6H6-H dissociation energy is calculated to be D0 = 85.7 kJ mol−1, with an estimated error of ∼2 kJ mol−1.
The electronic structure of gas phase croconic acid compared to the condensed phase: More insight into the hydrogen bond interaction
Authors: Bisti F. , Stroppa A. , Perrozzi F. , Donarelli M. , Picozzi S. , Coreno M. , de Simone M. , Prince K. C. , Ottaviano L.
Published: January 2013

The electronic structure of croconic acid in the gas phase has been investigated by means of core level and valence band photoemission spectroscopy and compared with hybrid Heyd-Scuseria-Ernzerhof density functional theory calculations. The results have been compared with the corresponding ones of the condensed phase. In the gas phase, due to the absence of hydrogen bond intermolecular interactions, the O 1 s core level spectrum shows a shift of binding energy between the hydroxyl (O–H) and the carbonyl group (C=O) of 2.1  eV, which is larger than the condensed phase value of 1.6  eV. Interestingly, such a shift decreases exponentially with the increase of the O–H distance calculated from theory. The significant differences between the gas and condensed phase valence band spectra highlight the important role played by the hydrogen bonding in shaping the electronic structure of the condensed phase.
Revisiting the mechanisms involved in Line Width Roughness smoothing of 193 nm photoresist patterns during HBr plasma treatment
Authors: Brihoum M. , Ramos R. , Menguelti K. , Cunge G. , Pargon E. , Joubert O.
Published: January 2013

HBr plasma treatments are widely used in nanoscale lithographic technologies to increase the plasma etch resistance of 193 nm photoresist masks as well as to decrease their Line Width Roughness (LWR). VUV irradiation of the photoresist is known to play a major role in this process by inducing polymer chains rearrangement and finally LWR reduction. However, in the plasma environment (i.e., with radical and ion bombardment), the interaction layer formed at the resist surface perturbs this mechanism and a lower LWR reduction is achieved compared to VUV only treatment. So far the nature of the interaction layer, its formation mechanism and its relation with the resist pattern LWR were all unclear. In this paper, we show that a graphite-like layer is formed on the resist patterns by the redeposition of carbon-based species originating from the plasma dissociation of outgassed photo-etched resist moieties. We show that the presence of this layer inhibits the LWR minimization and causes an increase in the LWR when it becomes thick enough (i.e., a few nanometers). We present evidences that the difference in the mechanical properties of the graphite-like top layer which coats the resist patterns and the bulk of the resist patterns is correlated to the LWR after plasma treatment. We can conclude that the optimization of an HBr cure process relies on the minimization of the carbon redeposition while keeping a significant VUV light flux and we show that this can be achieved by using pulsed plasma processes.
Portable atomic layer deposition reactor for in situ synchrotron photoemission studies
Authors: Methaapanon R. , Geyer S. M. , Hagglund C. , Pianetta P. A. , Bent S. F.
Published: January 2013

We report the design of a portable atomic layer deposition (ALD) reactor that can be integrated into synchrotron facilities for in situ synchrotron photoemission studies. The design allows for universal installation of the system onto different beam line end stations. The ALD reactor operates as a fully functional, low vacuum deposition system under the conditions of a typical ALD reactor while allowing the samples to be analyzed in an ultrahigh vacuum (UHV) chamber through a quick transfer without vacuum break. This system not only minimizes the exposure of the UHV chamber to the ALD reactants, but it also eliminates the necessity of a beam alignment step after installation. The system has been successfully installed at the synchrotron and tested in the mechanistic studies of platinum ALD following individual half reaction cycles.
Ion drag force on a dust grain in a weakly ionized collisional plasma
Authors: Semenov I. L. , Zagorodny A. G. , Krivtsun I. V.
Published: January 2013

The problem of calculating the ion drag force acting on a dust grain immersed in a weakly ionized collisional plasma is studied using an approach based on the direct numerical solution of the Vlasov-Bhatnagar-Gross-Krook kinetic equations. A uniform subthermal flow of argon plasma past a spherical dust grain is considered. The numerical computations are performed for a wide range of plasma pressures. On the basis of the obtained results, the effect of ion-neutral collisions on the ion drag force is analyzed in a wide range of ion collisionality. In the collisionless limit, our results are shown to be in good agreement with the results obtained by the binary collision approach. As the ion collisionality increases, the ion drag force is found to decrease sharply and even become negative, i.e., directed oppositely to the plasma flow. A qualitative explanation of this effect is presented and a comparison of our results with those obtained using the drift diffusion approach is discussed. The velocity dependence of the ion drag force in the highly collisional regime is examined. The relationship between the ion and the neutral drag forces in the highly collisional limit is analyzed and the possibility of a superfluid-like behavior of dust grains is discussed.
Reciprocal Damon-Eshbach-type spin wave excitation in a magnonic crystal due to tunable magnetic symmetry
Authors: Huber R. , Krawczyk M. , Schwarze T. , Yu H. , Duerr G. , Albert S. , Grundler D.
Published: January 2013

We report spin-wave (SW) propagation in a one-dimensional magnonic crystal (MC) explored by all electrical spectroscopy. The MC consists of a periodic array of 255 nm wide permalloy nanowires with a small edge-to-edge separation of 45 nm. Provoking antiparallel alignment of the magnetization of neighboring nanowires, we unexpectedly find reciprocal excitation of Damon-Eshbach type SWs. The characteristics are in contrast to ferromagnetic thin films and controlled via, both, the external magnetic field and magnetic states. The observed reciprocal excitation is a metamaterial property for SWs and attributed to the peculiar magnetic symmetry of the artificially tailored magnetic material. The findings offer great perspectives for nanoscale SW interference devices.
Development of eddy current testing system for inspection of combustion chambers of liquid rocket engines
Authors: He D. F. , Zhang Y. Z. , Shiwa M. , Moriya S.
Published: January 2013

An eddy current testing (ECT) system using a high sensitive anisotropic magnetoresistive (AMR) sensor was developed. In this system, a 20 turn circular coil with a diameter of 3 mm was used to produce the excitation field. A high sensitivity AMR sensor was used to measure the magnetic field produced by the induced eddy currents. A specimen made of copper alloy was prepared to simulate the combustion chamber of liquid rocket. Scanning was realized by rotating the chamber with a motor. To reduce the influence of liftoff variance during scanning, a dual frequency excitation method was used. The experimental results proved that ECT system with an AMR sensor could be used to check liquid rocket combustion chamber.