bluuebunny/crossref_metadata_2025 huggingface dataset:
The relativistic polarization propagator for the calculation of electronic excitations in heavy systems
Authors: Pernpointner Markus
Published: February 2014

In this work, we present a new four-component implementation of the polarization propagator for accurate calculations of excited states in heavy systems. Differences to existing nonrelativistic realizations are detailed and the energetically lowest final states of the ns2np6 → ns2np5(n + 1)s1 and ns2np6 → ns2np5(n + 1)p1 transitions in noble gases are calculated and compared with experimental data. Already for the light atoms Ne and Ar spin-orbit coupling leads to noticeable zero field splitting that gradually increases in the heavier homologues and eventually invalidates the LS-based description of singlet and triplet excited states. For all four noble gases Ne through Xe, we observe a very good agreement with experimental transition energies in the considered energetic range where the extended version of the propagator implementation in general yields better excitation energy differences than the strict variant. In the extended version, off-diagonal first-order contributions in the two-particle-two-hole block are included that are not present in the strict variant. In case of Kr and Xe, nonrelativistic approaches already exhibit unacceptable deviations in the reproduction of transition energies and the spectral structure. The obtained excited final states are analyzed in terms of atomic contributions to the donor and acceptor orbitals constituting the corresponding wave functions. The relativistic polarization propagator provides a consistent description of electron correlation and relativistic effects especially relevant for the heavier systems where these two contributions are no longer separable.
Insight into the description of van der Waals forces for benzene adsorption on transition metal (111) surfaces
Authors: Carrasco Javier , Liu Wei , Michaelides Angelos , Tkatchenko Alexandre
Published: February 2014

Exploring the role of van der Waals (vdW) forces on the adsorption of molecules on extended metal surfaces has become possible in recent years thanks to exciting developments in density functional theory (DFT). Among these newly developed vdW-inclusive methods, interatomic vdW approaches that account for the nonlocal screening within the bulk [V. G. Ruiz, W. Liu, E. Zojer, M. Scheffler, and A. Tkatchenko, Phys. Rev. Lett. 108, 146103 (2012)] and improved nonlocal functionals [J. Klimeš, D. R. Bowler, and A. Michaelides, J. Phys.: Condens. Matter 22, 022201 (2010)] have emerged as promising candidates to account efficiently and accurately for the lack of long-range vdW forces in most popular DFT exchange-correlation functionals. Here we have used these two approaches to compute benzene adsorption on a range of close-packed (111) surfaces upon which it either physisorbs (Cu, Ag, and Au) or chemisorbs (Rh, Pd, Ir, and Pt). We have thoroughly compared the performance between the two classes of vdW-inclusive methods and when available compared the results obtained with experimental data. By examining the computed adsorption energies, equilibrium distances, and binding curves we conclude that both methods allow for an accurate treatment of adsorption at equilibrium adsorbate-substrate distances. To this end, explicit inclusion of electrodynamic screening in the interatomic vdW scheme and optimized exchange functionals in the case of nonlocal vdW density functionals is mandatory. Nevertheless, some discrepancies are found between these two classes of methods at large adsorbate-substrate separations.
The adsorption of h-BN monolayer on the Ni(111) surface studied by density functional theory calculations with a semiempirical long-range dispersion correction
Authors: Sun X. , Pratt A. , Li Z. Y. , Ohtomo M. , Sakai S. , Yamauchi Y.
Published: February 2014

The geometric and spin-resolved electronic structure of a h-BN adsorbed Ni(111) surface has been investigated by density functional theory calculations. Two energy minima (physisorption and chemisorption) are obtained when the dispersive van der Waals correction is included. The geometry of N atom on top site and B atom on fcc site is the most energetically favorable. Strong hybridization with the ferromagnetic Ni substrate induces considerable gap states in the h-BN monolayer. The induced π* states are spin-polarized.
Attached cavitation at a small diameter ultrasonic horn tip
Authors: Žnidarčič Anton , Mettin Robert , Cairós Carlos , Dular Matevž
Published: February 2014

Ultrasonic horn transducers are frequently used in applications of acoustic cavitation in liquids, for instance, for cell disruption or sonochemical reactions. They are operated typically in the frequency range up to about 50 kHz and have tip diameters from some mm to several cm. It has been observed that if the horn tip is sufficiently small and driven at high amplitude, cavitation is very strong, and the tip can be covered entirely by the gas/vapor phase for longer time intervals. A peculiar dynamics of the attached cavity can emerge with expansion and collapse at a self-generated frequency in the subharmonic range, i.e., below the acoustic driving frequency. Here, we present a systematic study of the cavitation dynamics in water at a 20 kHz horn tip of 3 mm diameter. The system was investigated by high-speed imaging with simultaneous recording of the acoustic emissions. Measurements were performed under variation of acoustic power, air saturation, viscosity, surface tension, and temperature of the liquid. Our findings show that the liquid properties play no significant role in the dynamics of the attached cavitation at the small ultrasonic horn. Also the variation of the experimental geometry, within a certain range, did not change the dynamics. We believe that the main two reasons for the peculiar dynamics of cavitation on a small ultrasonic horn are the higher energy density on a small tip and the inability of the big tip to “wash” away the gaseous bubbles. Calculation of the somewhat adapted Strouhal number revealed that, similar to the hydrodynamic cavitation, values which are relatively low characterize slow cavitation structure dynamics. In cases where the cavitation follows the driving frequency this value lies much higher – probably at Str > 20. In the spirit to distinguish the observed phenomenon with other cavitation dynamics at ultrasonic transducer surfaces, we suggest to term the observed phenomenon of attached cavities partly covering the full horn tip as “acoustic supercavitation.” This reflects the conjecture that not the sound field in terms of acoustic (negative) pressure in the liquid is responsible for nucleation, but the motion of the transducer surface.
Investigating vibrational anharmonic couplings in cyanide-bridged transition metal mixed valence complexes using two-dimensional infrared spectroscopy
Authors: Slenkamp Karla M. , Lynch Michael S. , Van Kuiken Benjamin E. , Brookes Jennifer F. , Bannan Caitlin C. , Daifuku Stephanie L. , Khalil Munira
Published: February 2014

Using polarization-selective two-dimensional infrared (2D IR) spectroscopy, we measure anharmonic couplings and angles between the transition dipole moments of the four cyanide stretching (νCN) vibrations found in [(NH3)5RuIIINCFeII(CN)5]− (FeRu) dissolved in D2O and formamide and [(NC)5FeIICNPtIV(NH3)4NCFeII(CN)5]4− (FePtFe) dissolved in D2O. These cyanide-bridged transition metal complexes serve as model systems for studying the role of high frequency vibrational modes in ultrafast photoinduced charge transfer reactions. Here, we focus on the spectroscopy of the νCN modes in the electronic ground state. The FTIR spectra of the νCN modes of the bimetallic and trimetallic systems are strikingly different in terms of frequencies, amplitudes, and lineshapes. The experimental 2D IR spectra of FeRu and FePtFe and their fits reveal a set of weakly coupled anharmonic νCN modes. The vibrational mode anharmonicities of the individual νCN modes range from 14 to 28 cm−1. The mixed-mode anharmonicities range from 2 to 14 cm−1. In general, the bridging νCN mode is most weakly coupled to the radial νCN mode, which involves the terminal CN ligands. Measurement of the relative transition dipole moments of the four νCN modes reveal that the FeRu molecule is almost linear in solution when dissolved in formamide, but it assumes a bent geometry when dissolved in D2O. The νCN modes are modelled as bilinearly coupled anharmonic oscillators with an average coupling constant of 6 cm−1. This study elucidates the role of the solvent in modulating the molecular geometry and the anharmonic vibrational couplings between the νCN modes in cyanide-bridged transition metal mixed valence complexes.
Electronic structure, magnetic properties, and magnetostructural transformations in rare earth dialuminides
Authors: Paudyal Durga , Pecharsky V. K. , Gschneidner K. A.
Published: February 2014

We report electronic structure, magnetic properties, and magnetostructural transformations of selected rare earth dialuminides calculated by using local spin density approximation (LSDA), including the Hubbard U parameter (LSDA + U) approach. Total energy calculations show that CeAl2 and EuAl2 adopt antiferromagnetic (AFM) ground states, while dialuminides formed by other magnetic lanthanides have ferromagnetic (FM) ground states. The comparison of theoretical and experimental magnetic moments of CeAl2 indicates that the 4f orbital moment of Ce in CeAl2 is quenched. Theoretical calculations confirm that Eu in EuAl2 and Yb in YbAl2 are divalent. PrAl2 exhibits a tetragonal distortion near FM transition. HoAl2 shows a first order magnetostructural transition while DyAl2 shows a second order transformation below magnetic transition. The dialuminides formed by Nd, Tb, and Er are simple ferromagnets without additional anomalies in the FM state.
Recovering position-dependent diffusion from biased molecular dynamics simulations
Authors: Ljubetič Ajasja , Urbančič Iztok , Štrancar Janez
Published: February 2014

All atom molecular dynamics (MD) models provide valuable insight into the dynamics of biophysical systems, but are limited in size or length by the high computational demands. The latter can be reduced by simulating long term diffusive dynamics (also known as Langevin dynamics or Brownian motion) of the most interesting and important user-defined parts of the studied system, termed collective variables (colvars). A few hundred nanosecond-long biased MD trajectory can therefore be extended to millisecond lengths in the colvars subspace at a very small additional computational cost. In this work, we develop a method for determining multidimensional anisotropic position- and timescale-dependent diffusion coefficients (D) by analysing the changes of colvars in an existing MD trajectory. As a test case, we obtained D for dihedral angles of the alanine dipeptide. An open source Mathematica® package, capable of determining and visualizing D in one or two dimensions, is available at https://github.com/lbf-ijs/DiffusiveDynamics. Given known free energy and D, the package can also generate diffusive trajectories.
A new class of topological insulators from I-III-IV half-Heusler compounds with strong band inversion strength
Authors: Zhang X. M. , Xu G. Z. , Du Y. , Liu E. K. , Liu Z. Y. , Wang W. H. , Wu G. H.
Published: February 2014

In this paper, by first principle calculations, we investigate systematically the band topology of a new half-Heusler family with composition of I(A)-III(A)-IV(A). The results clearly show that many of the I-III-IV half-Heusler compounds are in fact promising to be topological insulator candidates. The characteristic feature of these new topological insulators is the naturally strong band inversion strength (up to −2 eV) without containing heavy elements. Moreover, we found that both the band inversion strength and the bulk insulating gap of the compounds can be tailored through strain engineering, and therefore would be grown epitaxially in the form of thin films, and useful in spintronics and other applications.
Effect of the energy barrier in the base of the transistor laser on the recombination lifetime
Authors: Bambery R. , Wang C. , Dallesasse J. M. , Feng M. , Holonyak N.
Published: February 2014

Data are presented to quantify the effect of the conduction band energy barrier (ΔEC,B) in the base region of the transistor laser on the minority carrier transport dynamics, recombination lifetime in the base region, and frequency response of the device. A greater ΔEC,B results in lower transistor current gain (β) and higher optical output power, indicating increased carrier confinement and recombination in the base. For a device with ΔEC,B = 41 meV, the measured bias-dependent optical frequency response and subsequent data fitting yield a short recombination lifetime of 30 ps in the base and a small resonance peak of 1.5 dB. A device with ΔEC,B = 82 meV exhibits a longer recombination lifetime of 70 ps and a larger resonance peak of 4 dB.
Reconfigurable modified surface layers using plasma capillaries around the neutral inclusion regime
Authors: Varault S. , Gabard B. , Crépin T. , Sokoloff J. , Bolioli S.
Published: February 2014

We show both theoretically and experimentally reconfigurable properties achieved by plasma inclusions placed in modified surface layers generally used to tailor the transmission and beaming properties of electromagnetic bandgap based waveguiding structures. A proper parametrization of the plasma capillaries allows to reach the neutral inclusion regime, where the inclusions appear to be electromagnetically transparent, letting the surface mode characteristics unaltered. Varying the electron density of the plasma inclusions provoques small perturbations around this peculiar regime, and we observe significant modifications of the transmission/beaming properties. This offers a way to dynamically select the enhanced transmission frequency or to modify the radiation pattern of the structure, depending on whether the modified surface layer is placed at the entrance/exit of the waveguide.
Magnetic properties of grain oriented electrical steel in model transformer under direct current-biased magnetization
Authors: Inoue Hirotaka , Okabe Seiji
Published: February 2014

Iron losses and acoustic noises of the model transformer under DC-biased magnetization were empirically investigated. To clarify the influence of magnetic properties of transformer core materials, two types of grain oriented electrical steels—high permeability grade (HGO) and conventional grade (CGO)—were used as core materials. Iron losses increased with superimposing DC-bias magnetic field (HDC) in both materials, and the iron loss increment in HGO was larger than that in CGO. Acoustic noises increased with increasing HDC in both materials; however, noises emitted from the core of HGO were smaller than those of CGO.
1-nm-thick graphene tri-layer as the ultimate copper diffusion barrier
Authors: Nguyen Ba-Son , Lin Jen-Fin , Perng Dung-Ching
Published: February 2014

We demonstrate the thinnest ever reported Cu diffusion barrier, a 1-nm-thick graphene tri-layer. X-ray diffraction patterns and Raman spectra show that the graphene is thermally stable at up to 750 °C against Cu diffusion. Transmission electron microscopy images show that there was no inter-diffusion in the Cu/graphene/Si structure. Raman analyses indicate that the graphene may have degraded into a nanocrystalline structure at 750 °C. At 800 °C, the perfect carbon structure was damaged, and thus the barrier failed. The results of this study suggest that graphene could be the ultimate Cu interconnect diffusion barrier.
Two-surface-plasmon-polariton-absorption based lithography using 400 nm femtosecond laser
Authors: Li Yunxiang , Liu Fang , Ye Yu , Meng Weisi , Cui Kaiyu , Feng Xue , Zhang Wei , Huang Yidong
Published: February 2014

The two-surface-plasmon-polariton-absorption (TSPPA) at the vacuum wavelength of 400 nm is observed, and the subwavelength lithography, by using this nonlinear phenomenon, is demonstrated. Resist patterns with the period of ∼138 nm have been obtained by exciting the SPP at the Al/resist interface with the 400 nm femtosecond laser. By altering the exposure time, the exposure linewidth reduces from ∼90 nm to ∼55 nm, which explores the ability of the TSPPA based lithography at the short wavelength. The factors limiting the performance of the proposed TSPPA based lithography are discussed in detail.
Serrated flow behaviors of a Zr-based bulk metallic glass by nanoindentation
Authors: Cheng L. , Jiao Z. M. , Ma S. G. , Qiao J. W. , Wang Z. H.
Published: February 2014

Instrumented nanoindentation tests were used to investigate the mechanical properties of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass. The corresponding loading strain rates were ranged from 0.002 s−1, 0.02 s−1 to 0.2 s−1. Plastic flow of this material exhibited remarkable serrations at low strain rates and increasingly became weakening until disappearance with increasing indentation strain rate, implying strong rate sensitivity. A significant pile-up around the indents was observed through atomic force microscopy, which suggested a highly localized plastic deformation. Mechanism governing the deformation was tentatively discussed in terms of the increasing process of free volume with a negligible temperature rise under low strain rate, which well explained the declining trend of elastic modulus and hardness with an increase of indentation depth.
Dynamics of the magneto structural phase transition in La(Fe0.9Co0.015Si0.085)13 observed by magneto-optical imaging
Authors: Kuepferling M. , Bennati C. , Laviano F. , Ghigo G. , Basso V.
Published: February 2014

We investigate the temperature induced ferromagnetic to paramagnetic phase transition in Co substituted La(FexCoySi1−x−y)13 with x = 0.9 and low Co content of y = 0.015 (Tc≃200 K) by means of magneto-optical imaging with indicator film and by calorimetry at very low temperature rates. We were able to visualize the motion of the ferromagnetic (FM)/paramagnetic (PM) front which is forming reproducible patterns independently of the temperature rate. The average velocity of the FM/PM front was calculated to be 10−4 m/s during the continuous propagation and 4×10−3 m/s during an avalanche. The heat flux was measured at low temperature rates by a differential scanning calorimeter and shows a reproducible sequence of individual and separated avalanches which occurs independently of the rate. We interpret the observed effects as the result of the athermal character of the phase transition.
GaAs buffer layer technique for vertical nanowire growth on Si substrate
Authors: Xu Xiaoqing , Li Yang , Parizi Kokab B. , Huo Yijie , Kang Yangsen , Philip Wong H.-S.
Published: February 2014

Gold catalyzed vapor-liquid-solid method is widely applied to III–V nanowire (NW) growth on Si substrate. However, the easy oxidation of Si, possible Si contamination in the NWs, high defect density in the NWs, and high sensitivity of the NW morphology to growth conditions largely limit its controllability. In this work, we developed a buffer layer technique by introducing a GaAs thin film with predefined polarity as a template. It is found that samples grown on these buffer layers all have high vertical NW yields in general, due to the single-orientation of the buffer layers. Low temperature buffer with smoother surface leads to highest yield of vertical NWs, while high temperature (HT) buffer with better crystallinity results in perfect NW quality. The defect-free property we observed here is very promising for optoelectronic device applications based on GaAs NW. Moreover, the buffer layers can eliminate Si contamination by preventing Si-Au alloy formation and by increasing the thickness of the Si diffusion barrier, thus providing more flexibility to vertical NW growth. The buffer layer technique we demonstrated here could be easily extended to other III-V on Si system for electronic and photonic applications.
Measurement of the transmission magnetic circular dichroism of Ga1−x
MnxAs epilayers using a built-in p-i-n photodiode
Authors: He Z. X. , Zheng H. Z. , Wang H. L. , Zhao J. H.
Published: February 2014

By constructing a GaMnAs epilayer/semi-insulating In0.2Ga0.8As/(001) n+-GaAs substrate layer structure as a built-in p-i-n photodiode, we developed a scheme for on-chip measurements of transmission magnetic circular dichroism (T-MCD). Both the hysteresis loops in the magnetic field sweeps and the wavelength scans at saturated magnetic fields measured using the new T-MCD scheme, illustrated the same features as those previously measured on the freestanding GaMnAs thin films by conventional T-MCD. Because a large group of epitaxially grown magnetic film/semiconductor heterostructures, such as Fe, NiFe, CoFeAl, and MnGa films on semiconductor substrates, are becoming important new building blocks for semiconductor-based spin field-effect transistor, perpendicular magnetic tunnel junction (p-MTJ) and lateral MTJ devices, the new T-MCD scheme can be applied to tests of their magnetic properties by forming either p-i-n or Schottky photodiodes.
Effects of growth process on the optical and electrical properties in Al-doped ZnO thin films
Authors: Prabhakar Tejas , Dai Lingling , Zhang Lin , Yang Rong , Li Liwei , Guo Ted , Yan Yanfa
Published: February 2014

Aluminum doped zinc oxide (AZO) has attained prominence as being a very good transparent conducting oxide for optoelectronics and photovoltaic applications. In this work, we report on the synthesis and characterization of AZO films with c-axis preferred orientation using magnetron radio frequency (RF) sputtering. It was found that the degree of the c-axis preferred orientation can be controlled by varying the growth conditions, such as working pressure, RF power, and substrate temperatures. The preferred orientation increased as the working pressure decreased, while it increased as the RF power and substrate temperature increased. Electrical and optical measurements have revealed that the growth conditions and c-axis preferred orientation have strong influence on the physical properties of the synthesized AZO thin films. The thin films with increased c-axis preferred orientation exhibited enhanced carrier mobility.
Current induced doping in graphene-based transistor with asymmetrical contact barriers
Authors: Chen Wei , Qin Shiqiao , Zhang Xue-Ao , Zhang Sen , Fang Jingyue , Wang Guang , Wang Chaocheng , Wang Li , Chang Shengli
Published: February 2014

The metal/graphene contacts play a very important role in the performance of graphene-based devices. We report here a unique observation of current-induced doping in graphene transistors. The charge carrier type and the concentration in graphene can be manipulated by the current flowing through the graphene device, arising from the asymmetrical metal/graphene barriers between the source and drain electrodes and the accompanied current crowding effect.
Pressure-driven fast reaction and recovery of peptide receptor for an electronic nose application
Authors: Yoo Yong Kyoung , Lee Sang-Myung , Chae Myung-Sic , Yoon Kang Ji , Song Kim Tae , Seon Hwang Kyo , Hoon Lee Jeong
Published: February 2014

Combining a highly sensitive sensor platform with highly selective recognition elements is essential for micro/nanotechnology-based electronic nose applications. Particularly, the regeneration sensor surface and its conditions are key issues for practical e-nose applications. We propose a highly sensitive piezoelectric-driven microcantilever array chip with highly selective peptide receptors. By utilizing the peptide receptor, which was discovered by a phase display screening process, we immobilized a dinitrotoluene (DNT) specific peptide as well as a DNT nonspecific peptide on the surface of the cantilever array. The delivery of DNT gas via pressure-driven flow led to a greater instant response of ∼30 Hz, compared to diffusion only (∼15 Hz for 15 h). Using a simple pressure-driven air flow of ∼50 sccm, we confirmed that a ratio of ∼70% of the specific-bounded sites from DNT gas molecules could be regenerated, showing re-usability of the peptide receptor in on-site monitoring for electronic nose applications.
Perspective: Towards environmentally acceptable criteria for downstream fish passage through mini hydro and irrigation infrastructure in the Lower Mekong River Basin
Authors: Baumgartner Lee J. , Daniel Deng Z. , Thorncraft Garry , Boys Craig A. , Brown Richard S. , Singhanouvong Douangkham , Phonekhampeng Oudom
Published: February 2014

Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstream fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries.
Sensitivity studies for the weak r process: neutron capture rates
Authors: Surman R. , Mumpower M. , Sinclair R. , Jones K. L. , Hix W. R. , McLaughlin G. C.
Published: February 2014

Rapid neutron capture nucleosynthesis involves thousands of nuclear species far from stability, whose nuclear properties need to be understood in order to accurately predict nucleosynthetic outcomes. Recently sensitivity studies have provided a deeper understanding of how the r process proceeds and have identified pieces of nuclear data of interest for further experimental or theoretical study. A key result of these studies has been to point out the importance of individual neutron capture rates in setting the final r-process abundance pattern for a ‘main’ (A ∼ 130 peak and above) r process. Here we examine neutron capture in the context of a ‘weak’ r process that forms primarily the A ∼ 80 r-process abundance peak. We identify the astrophysical conditions required to produce this peak region through weak r-processing and point out the neutron capture rates that most strongly influence the final abundance pattern.
Pre-rigor carcass stretching counteracts the negative effects of high rigor temperature on tenderness and water-holding capacity – using lamb muscles as a model
Authors: Warner R. D. , Kerr M. , Kim Y. H. B. , Geesink G.
Published: February 2014

High pre-rigor muscle temperature has negative consequences on quality and has been predominantly studied in the excised longissimus muscle of beef and lamb carcasses. There is little data on other muscles, the application in whole carcasses or potential amelioration techniques such as stretching. This study evaluated the effects of electrical stimulation, high pre-rigor temperature and stretching of lamb sides on quality traits and protein denaturation in four leg muscles [gluteus medius (GM), rectus femoris (RF), semimembranosus (SM) and semitendinosus (ST)]. Twenty lamb carcasses were used with two electrical stimulation treatments (stimulated or non-stimulated, +/−) and two pre-rigor temperature treatments (chilled at 2°C directly after slaughter, or held in 37°C water for 4.5 h before transfer to a 2°C chiller) applied. One side of each carcass was suspended from the Achilles tendon, whereas the other side was stretched by allowing the leg to drop and tying it to the ribs. Electrical stimulation did not influence the different traits except for pH fall post slaughter and myosin denaturation. Stretching resulted in greater muscle and sarcomere lengths for the GM, SM and ST, but a decrease in sarcomere length for the RF. For the non-stretched GM and SM, the 37°C treatment resulted in tougher meat at 1 and 8 days post mortem compared with the 2°C treatment. In contrast, the stretched 37°C treatment resulted in more tender meat for the GM, SM and ST at 1 day post mortem compared with the 2°C treatment. For all muscles, the 37°C treatment resulted in a decrease in the water-holding capacity (increased purge, surface exudate and cooking losses). The magnitude of this effect was generally diminished by stretching for the GM, SM and ST, but for the RF, (which was not stretched by the treatment) this effect was reversed. The 37°C treatment resulted in paler meat (increased L*-values) for the GM, SM and ST relative to the 2°C treatment. The observed effects of the 37°C treatment on water-holding capacity and colour could be explained by the effects of this treatment on indicators of protein denaturation (sarcoplasmic protein solubility and myofibrillar ATPase activity), which were decreased for the GM, SM and ST. The response to both temperature and stretching varied between the muscles, due to different anatomical location and also due to postulated differences in the fibre types. In conclusion, pre-rigor stretching of lamb sides can counteract the negative effects of high early post-mortem temperature on tenderness and water-holding capacity for those muscles that are stretched as a result of this hanging method.
Factors influencing the incidence of high rigor temperature in beef carcasses in Australia
Authors: Warner R. D. , Dunshea F. R. , Gutzke D. , Lau J. , Kearney G.
Published: February 2014

Beef carcasses undergoing rapid pH fall while the loin muscle temperature is still high are described as heat-shortened, heat-toughened or ‘high rigor temperature’ carcasses, with subsequent negative effects on quality traits. The aim of the study was to quantify the occurrence of high rigor temperature in beef carcasses across Australia and to identify the causative factors. Data was collected over 4–5 days at each of seven beef processing plants from 1512 beef carcasses. The beef carcasses were from both grass- and grain-fed cattle ranging in days on grain feeding from 0 (grass-fed) to 350 days and the category of cattle ranged from veal to ox and cow. Data collected on the day of slaughter included the duration of electrical inputs at the immobiliser, electrical stimulation and hide puller, longissimus muscle pH and temperature decline, hot carcass weight and P8 fat depth. At grading, ultimate pH, eye muscle area, wetness of the loin surface and colour score were also collected. The temperature at pH 6 was calculated and if it was >35°C, the carcass was defined as ‘high rigor temperature’. Modelling of the data was conducted using GLMM and REML. The occurrence of high rigor temperature across all seven beef processing plants was 74.6% ranging from 56 to 94% between beef processing plants. Increasing days in the feedlot and heavier carcass weights were highly correlated and both caused an increase in the predicted temperature at pH 6 and in the % high rigor temperature (P < 0.05 for both). Longer duration of electrical inputs at the hide puller, fatter grass-fed cattle and fatter male (castrate) carcasses had a higher temperature at pH 6 and higher % high rigor temperature. Modelling showed that if the time to reach pH 6 in the longissimus muscle was 65 v. 105 min, the % high rigor temperature carcasses reduced from 98 to 19% in grain-fed cattle and 93 to 7% in grass-fed cattle. Higher plasma insulin levels at slaughter were associated with a higher temperature at pH 6 (rigor temperature) (P < 0.001). In conclusion, in order to reduce the incidence of high rigor temperature in grain-fed beef carcasses, methods for identifying high rigor temperature carcasses will be required and while some management strategies can be implemented now, others require further research.
Syntheses, Structures, Characterisation, and Spectroscopic Properties of CuI and AgI Complexes with Extended C–H···π and π···π Interactions
Authors: Huang Ting-Hong , Zhang Min-Hua
Published: February 2014

Based on the ligands N,N′-bis(pyridin-2-ylmethylene)benzene-1,4-diamine (pmb) and N,N′-bis(pyridin-2-ylmethylene)biphenyl-4,4′-diamine (pmbb), the three compounds [Cu2(pmb) (PPh3)2(Cl)2] (1), [Cu2(pmbb)(CH3CN)2(PPh3)2](BF4)2·2DMF (2), and [Ag2(pmbb)(PPh3)2] (ClO4)2 (3) have been synthesised and characterised. Structural analysis reveals that all of these complexes contain 1D supramolecular arrays, with different variations in π-stacking patterns and intermolecular C–H···π interactions. Crystal structures of 1 and 2 contain 1D tape-like arrays formed by C–H···π and π···π interactions, and an ordered-layer-lattice of DMF and BF4– in 2 is located between the one-dimensional array. For 3, π-stacking interactions lead to the construction of 1D supramolecular arrays and a 2D network. The results indicate that C–H···π and π···π interactions play an important role in the construction of the supramolecular structure. In addition, the absorption peaks of complexes 1 and 3 in the solid state at room temperature show intraligand charge transfer and metal-to-ligand charge transfer absorptions. The optical and fluorescent properties of 2 were also studied in acetonitrile solution at room temperature.
Mothers, fathers, and gender: Parental narratives about children
Authors: Peterson Carole
Published: February 2014

This was an exploratory study assessing how parents talk about salient child experiences, namely injuries serious enough to require hospital ER treatment. Preschool-aged (2–5 years) and school-aged (8–13 years) children were recruited from a hospital ER, and their parents were interviewed a few days later about their children's experience. The free recall portion of interviews are assessed here. Narratives of mothers and fathers differed little, but both parents were more elaborative, i.e., more descriptive and informative, when they talked about the injury of their daughters vs. their sons. Narratives about daughters were also more cohesive and included more context-setting information, i.e., orientation to where and when events occurred. Narratives about older children were also longer, more elaborative, more cohesive, and more contextually embedded than were those about younger children. Although the amount of explicit emotion descriptors did not differ, fathers tended to emphasize the absence of an emotional reaction by their sons, but not their daughters. Results were discussed in terms of concordance with gender stereotypes that describe males as tough and females as fragile. (Narratives, Gender, Parents, Story-telling)
Shared experiences and narrative positionings in the classroom
Authors: Poveda David
Published: February 2014

This article examines the different positionings that preschool children develop towards the collective narrating of a school field trip to an educational farm in which only about half the class participated. The report of this excursion took place during the morningronda(the Spanish equivalent to sharing time or news sessions) and organized the children and the teacher in two groups of participants, those who went on the field trip and those who stayed home. I argue that these children displayed four discursive strategies towards the narrative and narrated events: (a) children who participated in the field trip couldincludeorexcludethe rest of the class from their narrative space; (b) children who did not participate in the field trip couldaffiliatewith orresistthe narrated events. The episode is discussed as exceptional in a classroom where precisely it has been argued thatrondaconversations play a key role in developing group identity, and shows how children have resources to develop varied stances towards school initiatives and even question the institutional and socio-economic arrangements that configure these activities. (Classroom Discourse, Ethnography of Communication, Narrative Inequality, Positioning)
Making visible an ideological dilemma in an interview narrative about social trauma
Authors: Cavallaro Johnson Greer
Published: February 2014

This article builds on contemporary understandings that identity is accomplished interactionally and discursively through storyteller/interviewer engagement inside the telling of the story. It introduces a new notion of narrative inquiry through the concept of “transactional positioning” to achieve an imagined interaction between a listener outside the institutional interview context and a tale told in an interview narrative some time ago. Texts are arranged by a select listener in a pre-thought out way to imaginatively fill gaps between what the narrator said and what he could have said during the interview but did not. The intertextual activity on the part of the listener aims to expand, retrospectively, the positioning of the interviewee so as to make more visible his ideological dilemma, uncovered through conversation analysis and critical discourse analysis of an interview narrative about the social trauma of being an Italian-Australian interned during World War II.
The elementary forms of narrative coherence in young children’s storytelling
Authors: Nicolopoulou Ageliki
Published: February 2014

This article argues for rethinking and reorientation in the study of narrative coherence and its development in young children. The most influential model guiding current research in this area (a) tends to equate narrative coherence with causal linkages between events and (b) suggests that the primary (or exclusive) strategy used by children to achieve coherence is to embed causally-connected event sequences in the goal-directed actions of a single major protagonist. Despite its undoubted contributions, this approach is misleadingly narrow in several respects, and it has not been able to reconstruct the actual dynamics and trajectories of young children’s narrative development. A first step toward overcoming these limitations is to undertake the foundational work of reconstructing and examining the range of actual modes and strategies of narrative coherence used by children, beginning with young children, which must include delineating the different narrative purposes and intentions these embody and the distinctive ways that they integrate events and event structures with the depiction and coordination of characters and relations between characters. I offer some theoretical and methodological proposals along these lines, illustrated with empirical examples.
Identity negotiation in small stories among German adolescent girls
Authors: Spreckels Janet
Published: February 2014

In recent years, a change in narrative and identity analysis, which Georgakopoulou has called “a ‘new’ narrative turn” (2006, p. 129), has been observed. This term refers to a shift of focus from the traditional “big stories”, i.e., narratives as a well-defined and delineated genre with an identifiable structure, towards non-canonical “small stories” (Bamberg, 2004). In this article, I will discuss a “small story” in terms of identity negotiation. The data are taken from a larger ethnographic conversation-analytical study of a group of German adolescent girls, who interactively negotiate and construe group and gender identity through their categorization and disaffiliation from various out-groups. I will illustrate this phenomenon by drawing on concepts such as positioning analysis (Davies & Harré, 1990), identities-in-interaction (Antaki & Widdicombe, 1998), and membership categorization (Sacks, 1992). Besides discussing content-related aspects of the sequence the small story is embedded in, I will analyze the structure of it employing elements of traditional narrative models such as that proposed by Labov and Waletzky (1967) and combine them with elements that belong exclusively to the interactive construction of “small stories”. At the end of my analysis, I will draw on Quasthoff’s model of narratives-in-interaction (2001) to argue that in close-knit groups of friends, small stories at times only minimally deviate from the ongoing turn-by-turn-talk.
La Vie d'Ésope: un prologue original du recueil de fables de Julien Macho
Authors: Boivin Jeanne-Marie
Published: February 2014

En tête de la dernière grande collection de fables médiévales réunie par Heinrich Steinhowel et adaptée en français par Julien Macho, apparaî un texte ancien, mais nouveau en Europe, la Vita Esopi qui venait d’être traduite du grec. Sa position dans le recueil et sa dimension réflexive l’apparentent aux prologues des collections antérieures. La Vie d’Ésope entre en résonance avec la définition de l’apologue héritée du vieux Romulus par les isopets en prose et avec les questions poétiques débattues, à partir du Romulus de Nevelet, par les isopets en vers.
Langage du pouvoir, pouvoir du langage
Authors: Cobby Anne
Published: February 2014

L’interdépendance du langage et du pouvoir, thèmes fondamentaux des fabliaux, se laisse étudier de façon complémentaire dans ces deux textes. DansConstant du Hamelles faibles résistent à la domination des puissants et la subvertissent au moyen de la parole, parole choisie pour répondre point pour point aux attaques que subit le couple fidèle. Après l’analyse des échanges et des renversements, j’examine quelques détails dans l’emploi de certains mots-clés pour montrer comment le poète donne de la solidité à son intrigue par un réseau d’échos lourds de sens. DansLes Trois Aveugles de Compiegnec’est la parole qui domine: à chaque étape le protagoniste choisit son langage en fonction de son interlocuteur, choix auquel la langue du narrateur fait écho; l’importance essentielle du langage dans ce fabliau est soulignée par des jeux rhétoriques.
Les animaux à travers les stalles, reflets des comportements humains?
Authors: Leme Kristiane
Published: February 2014

Les animaux sculptés sur les stalles sont souvent présentés comme porteurs d’un message moral, voire moralisateur. Une enquête menée parmi 73 ensembles de la fin du Moyen Âge (1450–1550 environ) dans le nord-ouest de l’Europe (Grande-Bretagne exclue) montre tout d’abord que les animaux ne sont pas si nombreux qu’on pourrait le croire, par rapport à d’autres sujets iconographiques. En outre, la plupart d’entre eux ne sont pas animés d’une intention moralisatrice, mais font tout simplement partie de la vie quotidienne. Il en est toutefois qui se moquent des défauts humains, en illustrant un proverbe: le chien, le cochon, le singe et Renart ont fréquemment inspiré les sculpteurs, qui donnent parfois une interprétation curieuse des proverbes médiévaux.
Le moniage du loup
Authors: Librová Bohdana
Published: February 2014

Le grand rôle dramatique du loup — clerc dansl’Ysengrimuset dansl’Ecbasis, de même que son intervention dans deux branches duRoman de Renartont relégué à la marge des récits d’une envergure plus modeste, fables,exemplaet expressions gnomiques. Malgré la fixité des motifs caractéristique de la littérature moralisatrice, le thème y connaîtra tout au long du Moyen Âge, un certain nombre de variations. D’autre part, la tendance à la fixation des motifs au sein des récits brefs, marquante dès le XIIIesiècle, atteint

attient à son paroxysme dans des expressions figées, sous la forme desquelles le thème, pourvu d’un sens référentiel fixe, se propage en dehors de son contexte exclusief, la littérature parénétique. Les adaptations tardives du poèmeDe lupopermettent d’entrevoir un aspect inédit de cette évolution lorsque, en intégrant ces expressions en guise de moralité, elles les replacent dans le cadre contextuel analogue à celui qui les a fait naîre.
La parodie des chansons de geste dans le Roman de Renart
Authors: Takana Yasufumi
Published: February 2014

Dans l’épisode en question de la branche I, on trouve l’agglomération de la conjonctionquantcommençant une phrase. Cette tournure se trouve également à la tête d’une proportion peu négligeable des laisses épiques où d’enchaîement narratif aussi bien que l’auteur de la branche tout au long de son oeuvre. Par la méthode statistique et comparatiste, nous sommes arrivés à découvrir l’intention parodique de l’auteur de donner à cet épisode une allure des chansons de geste en dramatisant le changement de fortune de Renart.
Attitudes towards lexical borrowing and intra-sentential code-switching among Spanish-English bilinguals
Authors: Anderson Tyler Kimball , Toribio Almeida Jacqueline
Published: February 2014

The present study seeks to evaluate bilinguals’ attitudes towards the contact forms that are manifested in the speech of Spanish-English bilinguals in the United States, and the factors that contribute to this linguistic assessment. Towards that end, bilinguals of diverse proficiencies are presented with five versions of the fairytale Little Red Riding Hood/La Caperucita Roja: a normative Spanish text, two Spanish texts that contrast in the type of English lexical insertions made, and two code-switched texts, differentiated by type of intra-sentential alternation represented. Multiple measures are used to evaluate participants’ attitudes, including scalar judgments on personality characteristics of the authors of the texts. Data from fifty-three participants unveil a continuum of preferences that largely confirms the hypotheses posited: Spanish-English bilinguals evaluate single-noun insertions more positively than code-switching and report more fine-grained distinctions — differentiating specific versus core noun insertions and felicitous versus infelicitous code-switching — as commensurate with social and linguistic factors, such as language heritage and linguistic competence.
Towards strategies for processing relationships between multiple relation participants in knowledge patterns
Authors: Marshman Elizabeth
Published: February 2014

Knowledge patterns are an effective tool for automatically or semi-automatically locating specific types of information — such as conceptual relations — in text corpora. However, pattern-based approaches are vulnerable to a number of types of variation; one of these is the expression of multiple participants in a single occurrence of a relation. Despite the challenges posed by this phenomenon, however, such cases may be particularly rich in useful information about the principal relation expressed and/or others involving the relation participants. Strategies that allow for formal evaluation and processing of such cases can enable pattern-based applications to capitalize on this information. This article will present a description, in English and French, of the types of relation occurrences in which multiple participants in CAUSE–EFFECT and ASSOCIATION relations are named, and the information that each can offer in addition to these primary relations. In addition, some strategies and challenges for processing these cases automatically will be discussed, and the phenomena as observed in the two languages will be briefly compared.