bluuebunny/crossref_metadata_2025 huggingface dataset:
Ligature Points and Ligature Types Used by Psychiatric Inpatients Who Die by Hanging
Authors: Hunt Isabelle M. , Windfuhr Kirsten , Shaw Jenny , Appleby Louis , Kapur Nav
Published: February 2012

Background: Approximately three-quarters of patients who die by suicide on psychiatric wards do so by hanging/strangulation. Increased awareness of the methods used by these patients may benefit prevention strategies in mental health services. Aims: To describe the ligature points and ligatures used in ward hangings; to identify any trends over time in ligature points and ligatures used; and to compare these patient characteristics with other inpatient suicides. Methods: A national clinical survey of suicide cases in recent (< 1 year) contact with mental health services in England and Wales (1999–2007). Results: Of the 448 suicides that occured on psychiatric wards, 77% were by hanging. The number of hanging cases, however, has fallen by 74% since 1999. The most common ligature points and ligatures were doors, hooks/handles, windows, and belts or sheets/towels, respectively. Use of shoelaces, doors, and windows increased over time. These patient suicides had had high rates of self-harm, alcohol/drug misuse, and were more likely than other cases to have died early in admission and been formally detained for treatment. Conclusions: Despite the decrease in inpatient suicides by hanging, regular reviews of ward structures are needed, particularly as ligatures and ligature points change over time. Improving the ward environment to engage patients, especially early in admission, may also contribute to reducing risk.
Measuring Working Memory Capacity With Automated Complex Span Tasks
Authors: Redick Thomas S. , Broadway James M. , Meier Matt E. , Kuriakose Princy S. , Unsworth Nash , Kane Michael J. , Engle Randall W.
Published: February 2012

Individual differences in working memory capacity are related to a variety of behaviors both within and outside of the lab. Recently developed automated complex span tasks have contributed to increasing our knowledge concerning working memory capacity by making valid and reliable assessments freely available for use by researchers. Combining the samples from three testing locations yielded data from over 6,000 young adult participants who performed at least one of three such tasks (Operation, Symmetry, and Reading Span). Normative data are presented here for researchers interested in applying cutoffs for their own applications, and information on the validity and reliability of the tasks is also reported. In addition, the data were analyzed as a function of sex and college status. While automated complex span tasks are just one way to measure working memory capacity, the use of a standardized procedure for administration and scoring greatly facilitates comparison across studies.
Is the climate response to CO2 emissions path dependent?
Authors: Zickfeld K. , Arora V. K. , Gillett N. P.
Published: February 2012

Recent studies with coupled climate‐carbon cycle models suggest that global mean temperature change is proportional to cumulative CO2 emissions, independent of the timing of those emissions. This finding has prompted the suggestion that climate stabilization targets, such as the 2°C target adopted by the Copenhagen Accord, can be expressed in terms of cumulative CO2 emissions. Here we examine the simulated response of a range of global and regional climate variables to the same cumulative CO2 emissions (2500 PgC) released along different pathways using a complex Earth system model. We find that the response of most surface climate variables is largely independent of the emissions pathway once emissions cease, with the exception of variables with response timescales of centuries, such as ocean heat content and thermosteric sea level rise. Peak responses of many climate variables, such as global mean temperature, precipitation and sea ice, are also largely independent of the emissions pathway, except for scenarios with cumulative emissions overshoot which require net removal of CO2 from the atmosphere. By contrast, peak responses of atmospheric CO2 and surface ocean pH are found to be dependent on the emissions pathway. We conclude that a CO2mitigation framework based on cumulative emissions is well suited for limiting changes in many impact‐relevant climate variables, but is less effective in avoiding impacts directly associated with atmospheric CO2, whose peak response is dependent on the rate of emissions.
Hydroclimatology of dual‐peak annual cholera incidence: Insights from a spatially explicit model
Authors: Bertuzzo E. , Mari L. , Righetto L. , Gatto M. , Casagrandi R. , Rodriguez‐Iturbe I. , Rinaldo A.
Published: February 2012

Cholera incidence in some regions of the Indian subcontinent may exhibit two annual peaks although the main environmental drivers that have been linked to the disease (e.g., sea surface temperature, zooplankton abundance, river discharge) peak once per year during the summer. An empirical hydroclimatological explanation relating cholera transmission to river flows and to the disease spatial spreading has been recently proposed. We specifically support and substantiate mechanistically such hypothesis by means of a spatially explicit model of cholera transmission. Our framework directly accounts for the role of a model river network in transporting and redistributing cholera bacteria among human communities as well as for spatial and temporal annual fluctuations of river flows. The model is forced by seasonal environmental drivers, namely river flow, temperature and chlorophyll concentration in the coastal environment, a proxy for Vibrio choleraeconcentration. Our results show that these drivers may suffice to generate dual‐peak cholera prevalence patterns for proper combinations of timescales involved in pathogen transport, hydrologic variability and disease unfolding. The model explains the possible occurrence of spatial patterns of cholera incidence characterized by a spring peak confined to coastal areas and a fall peak involving inland regions. Our modeling framework suggests insights on how environmental drivers concert the generation of complex spatiotemporal infections and proposes an explanation for the different cholera patterns (dual or single annual peaks) exhibited by regions that share similar hydroclimatological forcings.
Merging tsunamis of the 2011 Tohoku‐Oki earthquake detected over the open ocean
Authors: Song Y. Tony , Fukumori Ichiro , Shum C. K. , Yi Yuchan
Published: February 2012

Tsunamis often travel long distances without losing power and severely devastate some coastal areas while leaving others with little damage. This unpredictable situation has been a major challenge for accurate and timely tsunami forecasting to facilitate early‐warning and possible evacuations of affected coastal communities without disturbing the lives of others. Here we show evidence from satellite altimetry observations of the 2011 Tohoku‐Oki earthquake‐induced tsunami that sheds light on this issue. Three satellites observed the same tsunami front, and for the first time, one of them recorded a tsunami height about twice as high as that of the other two. Model simulations, based on the GPS‐derived earthquake source and constrained by measurements of seafloor motions near the hypocenter, confirm that the amplified tsunami is one of several jets formed through topographic refraction when tsunamis travel along ocean ridges and seamount chains in the Pacific Ocean. This process caused the tsunami front to merge as it propagates, resulting in the doubling of the wave height and destructive potential in certain directions. We conclude that the potential of merging tsunamis should be emphasized in mapping tsunami hazards and assessing risk levels at key coastal facilities.
Study of the North West Cape electron belts observed by DEMETER satellite
Authors: Li Xinqiao , Ma Yuqian , Wang Ping , Wang Huanyu , Lu Hong , Zhang Xuemin , Huang Jianping , Shi Feng , Yu Xiaoxia , Xu Yanbing , Meng Xiangcheng , Wang Hui , Zhao Xiaoyun , Parrot M.
Published: February 2012

We analyzed observation data collected by the Instrument for the Detection of Particles (IDP) on board the DEMETER satellite during a period of 17 months in 2007 and 2008. In the meantime, the VLF transmitter located at North West Cape (NWC) ground station was shut down during 7 months and working for a total of 10 months. By an (on‐off) method, our analysis for the first time revealed in detail the transient properties of the space electron precipitation belt which is induced by the man‐made VLF wave emitted from NWC. We mapped the electron flux distribution and figured out the space regions that the NWC belt covered. The NWC electron spectrograms have been investigated in a wide range of the McIlwain parameter L (1.1–3.0). Furthermore, we obtained the averaged energy spectra of the NWC electrons within the drift loss cone and compared their characteristics during daytime and nighttime. Our results confirm the previous studies of the enhancement of NWC electrons, the wisp structure, and the day/night difference of the electron flux. In addition, more detailed information is provided. We provide not only evidence of a momentary flux enhancement up to 3 orders of magnitude but also a flux reduction at higher L shells with a maximum up to 60% of the original value. For the first time, the energy spectra of NWC electrons covering the entire IDP energy band are presented for both nighttime and daytime and are quantitatively compared. At the end, our results are discussed, and their agreement with the theory of wave‐particle interactions is checked.
Modeling intragranular diffusion in low‐connectivity granular media
Authors: Ewing Robert P. , Liu Chongxuan , Hu Qinhong
Published: February 2012

Characterizing the diffusive exchange of solutes between bulk water in an aquifer and water in the intragranular pores of the solid phase is still challenging despite decades of study. Many disparities between observation and theory could be attributed to low connectivity of the intragranular pores. The presence of low connectivity indicates that a useful conceptual framework is percolation theory. The present study was initiated to develop a percolation‐based finite difference (FD) model, and to test it rigorously against both random walk (RW) simulations of diffusion starting from nonequilibrium, and data on Borden sand published by Ball and Roberts (1991a,b) and subsequently reanalyzed by Haggerty and Gorelick (1995) using a multirate mass transfer (MRMT) approach. The percolation‐theoretical model is simple and readily incorporated into existing FD models. The FD model closely matches the RW results using only a single fitting parameter, across a wide range of pore connectivities. Simulation of the Borden sand experiment without pore connectivity effects reproduced the MRMT analysis, but including low pore connectivity effects improved the fit. Overall, the theory and simulation results show that low intragranular pore connectivity can produce diffusive behavior that appears as if the solute had undergone slow sorption, despite the absence of any sorption process, thereby explaining some hitherto confusing aspects of intragranular diffusion.
TCR‐mediated Erk activation does not depend on Sos and Grb2 in peripheral human T cells
Authors: Warnecke Nicole , Poltorak Mateusz , Kowtharapu Bhavani S , Arndt Boerge , Stone James C , Schraven Burkhart , Simeoni Luca
Published: February 2012

Sos proteins are ubiquitously expressed activators of Ras. Lymphoid cells also express RasGRP1, another Ras activator. Sos and RasGRP1 are thought to cooperatively control full Ras activation upon T‐cell receptor triggering. Using RNA interference, we evaluated whether this mechanism operates in primary human T cells. We found that T‐cell antigen receptor (TCR)‐mediated Erk activation requires RasGRP1, but not Grb2/Sos. Conversely, Grb2/Sos—but not RasGRP1—are required for IL2‐mediated Erk activation. Thus, RasGRP1 and Grb2/Sos are insulators of signals that lead to Ras activation induced by different stimuli, rather than cooperating downstream of the TCR.
Soft magnetic properties of bulk FeCoMoPCBSi glassy core prepared by copper mold casting
Authors: Zhang Mingxiao , Kong Fanli , Wang Anding , Chang Chuntao , Shen Baolong
Published: February 2012

Bulk Fe66Co10Mo3.5P10C4B4Si2.5 glassy core of 10 mm in outer diameter, 6 mm in inner diameter, and 1 mm in thickness was successfully prepared by copper mold casting. The effects of annealing treatments on magnetic properties and microstructure of these cores were investigated. After an optimum annealing treatment, the resulting bulk glassy core exhibits good magnetic properties, i.e., high saturation magnetic flux density of 1.23 T, low coercive force of 1.0 A/m, high maximum permeability of 450 000, respectively. In addition, the glassy core also shows low core loss of 0.4 W/kg at 50 Hz and at maximum magnetic flux density of 1 T. The synthesis of bulk glassy core with excellent magnetic properties is encouraging for enlarging the application field of ferromagnetic bulk glassy alloys.
Vacuum insulation of the high energy negative ion source for fusion application
Authors: Kojima A. , Hanada M. , Hilmi A. , Inoue T. , Watanabe K. , Taniguchi M. , Kashiwagi M. , Umeda N. , Tobari H. , Kobayashi S. , Yamano Y. , Grisham L. R.
Published: February 2012

Vacuum insulation on a large size negative ion accelerator with multiple extraction apertures and acceleration grids for fusion application was experimentally examined and designed. In the experiment, vacuum insulation characteristics were investigated in the JT-60 negative ion source with >1000 apertures on the grid with the surface area of ∼2 m2. The sustainable voltages varied with a square root of the gap lengths between the grids, and decreased with number of the apertures and with the surface area of the grids. Based on the obtained results, the JT-60SA (super advanced) negative ion source is designed to produce 22 A, 500 keV D− ion beams for 100 s.
Development of a composite material with high magnetic permeability and low loss factor for high frequency application
Authors: Roy Debangsu , Anil Kumar P. S.
Published: February 2012

A flexible composite suitable for MHz frequency application has been developed by combining Fe3O4 and polyvinyl alcohol (PVA). The loss factor and the permeability have been evaluated. At an optimum weight percentage of Fe3O4 in the PVA matrix, the frequency at which the loss factor gives a minimum shifts to the MHz region. The loss factor has been found to be lower by one order of magnitude at 70 MHz compared to the presently used nickel zinc ferrite. The Henkel plot and the Cole-Cole plot have been obtained for the understanding of the high magnetic permeability and the low loss factor.
Tailoring magnetocrystalline anisotropy of FePt by external strain
Authors: Lukashev Pavel V. , Horrell Nathan , Sabirianov Renat F.
Published: February 2012

We propose using strain assisted reduction in anisotropy of FePt to control magnetization reversal in the writing on the magnetic storage devices. Our first-principles calculations show 21% decrease of the magnetocrystalline anisotropy energy (MAE) with application of 1.5% tensile biaxial strain. The reduction of MAE is primarily due to the change of the c/a ratio and to some extent due to the increase in volume. We propose building bilayer (or heterostructure) of FePt and piezoelectric film. This system is expected to allow the control of anisotropy constant by applying electric field to the system. Finally, we discuss the possibility of forming medium using bi-layer of FePt and soft magnetic material with the gradient of anisotropy constant.
Magnetism of BaB6 thin films synthesized by pulsed laser deposition
Authors: Ackland K. , Venkatesan M. , Coey J. M. D.
Published: February 2012

Amorphous BaB6 films synthesized by pulsed laser deposition show ferromagnetic-like signals for substrate temperatures in the range 450–550 °C. The magnetization is virtually anhysteretic, isotropic, and independent of temperature down to 4 K. Less than 4.5% of the volume fraction of the films is magnetically ordered, consistent with models where the magnetism is due to defects, interfaces, or grain boundaries.
High temperature x ray diffraction determination of the body-centered-cubic–face-centered-cubic transformation temperature in (Fe70Ni30)88Zr7B4Cu1 nanocomposites
Authors: Ipus J. J. , Herre P. , Ohodnicki P. , McHenry M. E.
Published: February 2012

In situ high-temperature x ray diffraction and magnetization measurements were performed on a melt-spun (Fe70Ni30)88Zr7B4Cu1 amorphous alloy to follow its structural evolution. At 728 K, a bcc-FeNi phase was observed as the primary crystallization product followed by transformation to an fcc phase ∼773 K. During cooling to room temperature, the fcc-to-bcc transformation was not observed, and the metastable fcc-NiFe phase was retained at room temperature.
Vector magnetic properties of Fe-based amorphous sheets under alternating flux condition
Authors: Ueno S. , Todaka T. , Enokizono M.
Published: February 2012

This paper presents measured vector magnetic properties of Fe-based amorphous sheets under alternating flux conditions in arbitrary direction. It is well known that amorphous material has usually isotropic magnetic property; however it is changeable by heat-treatment and shows complicated aspects. In this paper, the relationship between the magnetic flux density and field strength vector and iron loss under alternating flux conditions is measured by using a vector magnetic property measurement system. Moreover, the iron losses depending on the exciting frequency are discussed. The results show a weak anisotropy in plane and the frequency dependence of the iron losses shows different tendency in each direction.
Radiative diagnostics for sub-Larmor scale magnetic turbulence
Authors: Reynolds Sarah J. , Medvedev Mikhail V.
Published: February 2012

Radiative diagnostics of high-energy density plasmas is addressed in this paper. We propose that the radiation produced by energetic particles in small-scale magnetic field turbulence, which can occur in laser-plasma experiments, collisionless shocks, and during magnetic reconnection, can be used to deduce some properties of the turbulent magnetic field. Particles propagating through such turbulence encounter locally strong magnetic fields but over lengths much shorter than a particle gyroradius (that is λB≪γmν/q⟨B⊥⟩). Consequently, the particle does not gyrate but undergoes a series of transverse accelerations reflective of the magnetic field variations it encounters.In the limit of small deflection angle, the particle is accelerated but never substantially deviated from a straight line path. We develop the general jitter radiation solutions for this case and show that the resulting radiation is directly dependent upon the spectral distribution of the magnetic field through which the particle propagates. We demonstrate the power of this approach in considering the radiation produced by particles moving through a region in which a (Weibel-like) filamentation instability grows magnetic fields randomly oriented in a plane transverse to counterstreaming particle populations. We calculate the spectrum as would be seen from the original particle population and as could be seen by using a quasi-monoenergetic electron beam to probe the turbulent region at various angles to the filamentation axis.
Secondary crystallization in (Fe65Co35)79.5+xB13Nb4−xSi2Cu1.5 and (Fe65Co35)83B10Nb4Si2Cu1 nanocomposite alloys
Authors: Kernion Samuel J. , Keylin Vladimir , Huth Joe , McHenry Michael E.
Published: February 2012

Here, secondary crystallization kinetics of high induction, low loss HTX002-type nanocomposite alloys with the compositions (Fe65Co35)79.5+xB13Nb4−xSi2Cu1.5 (x = 0-4) and (Fe65Co35)83B10Nb4Si2Cu1 are reported. The magnetization of the alloys was measured through the thermal cycle of 50 °C-700 °C-300 °C-800 °C-300 °C-900 °C-200 °C by vibrating sample magnetometry. In (Fe65Co35)79.5+xB13Nb4−xSi2Cu1.5 alloys, the stability of the (Fe,Co,Nb)23B6 (23-6) phase is increased with increasing Nb content. In the x = 4 alloy, (Fe,Nb)2B is the only secondary crystalline phase to form, demonstrating that Nb is necessary for the 23-6 phase to form. The (Fe65Co35)83B10Nb4Si2Cu1 alloy forms the 23-6 phase more readily than the x = 0 alloy, likely due to the lower B content. The kinetics of secondary crystallization are important to assess long-term ageing effects on the metastable microstructure at elevated temperatures.
Crystal nucleation and the solid–liquid interfacial free energy
Authors: Baidakov Vladimir G. , Tipeev Azat O.
Published: February 2012

We present the results of molecular dynamics simulation of crystal nucleation in a supercooled Lennard–Jones liquid. Temperature and baric dependences of the nucleation rate, the Zeldovich factor, nucleus size diffusion coefficient, the radius, and the pressure in a critical crystal nucleus are defined in computer simulation. The data obtained have been used in the framework of classical nucleation theory to calculate the effective surface energy of crystal nuclei γe. It is shown that the value of γe at T = const exceeds the value of the interfacial free energy at a flat crystal–liquid interface γ∞ and γe < γ∞ at p = const.
Effects of dust particles on the dynamics of blobs in the scrape off layer II
Authors: Jovanović D. , de Angelis U.
Published: February 2012

A detailed analysis is performed of the results of numerical simulations of the dynamics of plasma blobs, obtained within the model of the nonlinear interchange mode, including the effects of the dissipation by dust, in tokamak scrape-off layer plasmas. The maximum distances that a plasma blob may travel in the radial direction are calculated under physical conditions characteristic for several large tokamaks that are presently in operation, and it is found that a relatively small amount of 30 nm carbon dust particulates, corresponding to only a few grams of dust in the entire scrape-off layer, may dissipate the blobs and prevent them from reaching the tokamak wall.
Optimization on a three-level heat engine working with two noninteracting fermions in a one-dimensional box trap
Authors: Wang Jianhui , He Jizhou
Published: February 2012

We setup a three-level heat engine model that works with two noninteracting fermions in a one-dimensional box trap. Besides two quantum adiabatic processes, the quantum heat engine cycle consists of two isoenergetic processes, along which the particles are coupled to energy baths at a high constant energy EH and a low constant energy EC, respectively. Based on the assumption that the potential wall moves at a very slow speed and there exists a heat leakage between two energy baths, we derive the expressions of the power output and the efficiency, and then obtain the optimization region for the heat engine cycle. Finally, we present a brief performance analysis of a Carnot engine between a hot and a cold bath at temperatures TH and TC, respectively. We demonstrate that under the same conditions, the efficiency η=1-(EC/EH) of the engine cycle is bounded from above the Carnot efficiency ηc=1-(TC/TH).
Finger tapping movements of Parkinson’s disease patients automatically rated using nonlinear delay differential equations
Authors: Lainscsek C. , Rowat P. , Schettino L. , Lee D. , Song D. , Letellier C. , Poizner H.
Published: February 2012

Parkinson’s disease is a degenerative condition whose severity is assessed by clinical observations of motor behaviors. These are performed by a neurological specialist through subjective ratings of a variety of movements including 10-s bouts of repetitive finger-tapping movements. We present here an algorithmic rating of these movements which may be beneficial for uniformly assessing the progression of the disease. Finger-tapping movements were digitally recorded from Parkinson’s patients and controls, obtaining one time series for every 10 s bout. A nonlinear delay differential equation, whose structure was selected using a genetic algorithm, was fitted to each time series and its coefficients were used as a six-dimensional numerical descriptor. The algorithm was applied to time-series from two different groups of Parkinson’s patients and controls. The algorithmic scores compared favorably with the unified Parkinson’s disease rating scale scores, at least when the latter adequately matched with ratings from the Hoehn and Yahr scale. Moreover, when the two sets of mean scores for all patients are compared, there is a strong (r = 0.785) and significant (p<0.0015) correlation between them.
Microstructured silicon with two impurity bands for solar cells
Authors: He Huili , Chen Changshui , Liu Songhao
Published: February 2012

A low-cost, large area, random, maskless texturing scheme independent of crystal orientation is expected to have an impact on terrestrial photovoltaic technology significantly. We investigated microstructured silicon formed by irradiating the surface of a Si wafer with femtosecond laser pulses in the presence of a sulfur-bearing gas. It is widely believed that microstructured silicon is a potential material for efficient multi intermediate bands silicon solar cell. Using a four-band model, the loss of sunlight for silicon with two different chalcogenide impurity bands was analyzed, and the levels of the minimum loss of sunlight can be found. Then the effect of the position at which the intermediate bands that have minimum sunlight loss rate on the theoretical conversion efficiency of the corresponding solar cell was discussed with the Detailed Balance Theory. After that, the influence of impact ionization on the efficiency of four-band Solar Cells was analyzed in detail. Finally, problems that need to be resolved in making intermediate band solar cell based on femtosecond laser microstructured silicon are pointed out with great emphasis.
Phase transformation and crystallization kinetics of a-Ge/Cu bilayer for blue-ray recording under thermal annealing and pulsed laser irradiation
Authors: Her Yung-Chiun , Tu Wei-Ting , Tsai Ming-Hsin
Published: February 2012

Similar phase formation and crystallization behaviors have been observed in the a-Ge/Cu bilayer under thermal annealing and pulsed laser irradiation. The Cu3Ge phase would form prior to the crystallization of a-Ge. The crystallization temperature and activation energy for crystallization of a-Ge were reduced to 310 °C and 2.75 eV, respectively, due to the fast Ge diffusion in the already formed germanide phases. The reaction exponent m of ∼2.0 for the a-Ge/Cu bilayer corresponds to a crystallization process in which grain growth occurs with nucleation, and the nucleation rate decreases with the progress of the grain growth process. Under pulsed laser irradiation, the maximum data-transfer-rates of 44, 56, 74, and 112 Mbit/s can be achieved in the write-once blue-ray disk at the recording powers of 3, 4, 5, and 6 mW, respectively. The a-Ge/Cu bilayer also demonstrated sufficient optical contrast and adequate absorptance for low power and high speed write-once blue-ray recording.
Large-scale molecular dynamics study of jet breakup and ejecta production from shock-loaded copper with a hybrid method
Authors: Durand O. , Soulard L.
Published: February 2012

Ejecta production from the free surface of metals under shock loading is investigated using large-scale molecular dynamics (MD) simulations performed with a new (hybrid) method. A copper crystal, in contact with vacuum and with a sinusoidal surface finish representative of the roughness produced by a machine polishing, is divided in two zones, bulk and surface, calculated with, respectively, Hugoniostat and NVE ensembles. The bulk part is simulated using the Hugoniostat technique, which allows a very large number of particles to reach a Hugoniot equilibrium state in a short physical time by the mean of a quasi-equilibrium MD simulation. The surface part is simulated with the NVE ensemble (microcanonical ensemble in which the total number N of particles, the total volume V, and the total energy E of the system are constant) in order to account for the non-equilibrium character of the ejection process. With this method, the morphology and the size distribution of the ejecta cloud generated by a system with 125 × 106 atoms are studied over 1 ns. The simulations show that the ejection phenomenon tends toward a steady state on long times (typically above 200 ps). The ejected particles remain spherical with time and their size distribution exhibits a power law scaling followed by a large-size residual in the large size limit. This behavior is in good agreement with most of distributions measured in fragmentation processes. In particular, the power law scaling reflects a self-similar behavior which seems to be successfully reproduced within the framework of a 2D percolation model although a direct analogy is still difficult to establish.
Collection of solid and gaseous samples to diagnose inertial confinement fusion implosions
Authors: Stoyer M. A. , Velsko C. A. , Spears B. K. , Hicks D. G. , Hudson G. B. , Sangster T. C. , Freeman C. G.
Published: February 2012

Collection of representative samples of debris following inertial confinement fusion implosions in order to diagnose implosion conditions and efficacy is a challenging endeavor because of the unique conditions within the target chamber such as unconverted laser light, intense pulse of x-rays, physical chunks of debris, and other ablative effects. We present collection of gas samples following an implosion for the first time. High collection fractions for noble gases were achieved. We also present collection of solid debris samples on flat plate collectors. Geometrical collection efficiencies for Au hohlraum material were achieved and collection of capsule debris (Be and Cu) was also observed. Asymmetric debris distributions were observed for Au and Be samples. Collection of Be capsule debris was higher for solid collectors viewing the capsule through the laser entrance hole in the hohlraum than for solid collectors viewing the capsule around the waist of the hohlraum. Collection of Au hohlraum material showed the opposite pattern: more Au debris was collected around the waist than through the laser entrance hole. The solid debris collectors were not optimized for minimal Cu backgrounds, which limited the conclusions about the symmetry of the Cu debris. The quality of the data limited conclusions on chemical fractionation effects within the burning, expanding, and then cooling plasma.
Mechanical cleaning of graphene
Authors: Goossens A. M. , Calado V. E. , Barreiro A. , Watanabe K. , Taniguchi T. , Vandersypen L. M. K.
Published: February 2012

Contamination of graphene due to residues from nanofabrication often introduces background doping and reduces electron mobility. For samples of high electronic quality, post-lithography cleaning treatments are therefore needed. We report that mechanical cleaning based on contact mode atomic force microscopy removes residues and significantly improves the electronic properties. A mechanically cleaned dual-gated bilayer graphene transistor with hexagonal boron nitride dielectrics exhibited a mobility of ∼36 000 cm2/Vs at low temperature.
Transient state kinetic investigation of ferritin iron release
Authors: Ciasca G. , Papi M. , Chiarpotto M. , Rodio M. , Campi G. , Rossi C. , De Sole P. , Bianconi A.
Published: February 2012

Increased iron concentration in tissues appears to be a factor in the genesis and development of inflammatory and degenerative diseases. By means of real-time small angle x-ray scattering measurements, we studied the kinetics of iron release from the ferritin inorganic core as a function of time and distance from the iron core centre. Accordingly, the iron release process follows a three step model: (i) a defect nucleation in the outer part of the mineral core, (ii) the diffusion of the reducing agent towards the inner part of the core, and (iii) the erosion of the core from the inner to the outer part.
Well-to-well non-uniformity in InGaN/GaN multiple quantum wells characterized by capacitance-voltage measurement with additional laser illumination
Authors: Kim Tae-Soo , Ahn Byung-Jun , Dong Yanqun , Park Ki-Nam , Lee Jin-Gyu , Moon Youngboo , Yuh Hwan-Kuk , Choi Sung-Chul , Lee Jae-Hak , Hong Soon-Ku , Song Jung-Hoon
Published: February 2012

We experimentally investigated well-to-well non-uniformity in InGaN/GaN multiple quantum well (MQW) structures by using capacitance-voltage measurements with additional laser illumination. By varying the illuminating power of the resonant excitation, well-to-well non-uniformity through the MQWs was clearly revealed. The quantum wells (QWs) close to the n-GaN side show higher carrier accumulations and larger position shift as the excitation power is increased, relative to the p-side QWs. Both results were attributed to the existence of stronger piezoelectric fields in the n-side QWs induced by subsequent partial relaxation of strain through the MQWs.
Fiber delivered two-color picosecond source through nonlinear spectral transformation for coherent Raman scattering imaging
Authors: Wang Ke , Xu Chris
Published: February 2012

We demonstrate a two-color, fiber-delivered picosecond source for coherent Raman scattering (CRS) imaging through nonlinear spectral transformation. The wavelength tunable picosecond pump is generated by nonlinear spectral compression of a prechirped femtosecond pulse in a fiber wavelength division multiplexer (WDM). The 1064-nm synchronized picosecond Stokes pulse is generated through pulse carving of a continuous wave laser, nonlinear spectral broadening in 100-m standard single-mode fiber, and subsequent dispersive compression with a fiber compressor. The pump and Stokes beams are combined and delivered by the fiber WDM. CRS imaging of mouse skin is performed to demonstrate the practicality of this source.
Dirac cones at k→= in acoustic crystals and zero refractive index acoustic materials
Authors: Liu Fengming , Huang Xueqin , Chan C. T.
Published: February 2012

We show that two-dimensional acoustic crystals (ACs) can be designed to exhibit Dirac cone dispersion at k→=0. Effective medium theory finds that some of these ACs can have effectively zero reciprocal of bulk modulus 1/κeff and zero mass density ρeff, and thus zero refractive indices at the Dirac point. Numerical simulations are used to demonstrate various phenomena associated with the zero spatial phase change inside such materials.
Characteristics of polarization-doped N-face III-nitride light-emitting diodes
Authors: Dong Kexiu , Chen Dunjun , Liu Bin , Lu Hai , Chen Peng , Zhang Rong , Zheng Youdou
Published: February 2012

The electrical and optical performances of N-face GaN-based light-emitting diodes (LEDs) with polarization-induced p-type doping are investigated theoretically. In comparison with the polarization-doped metal-face LED, the N-face one exhibits significant improvements in the hole injection efficiency and electroluminescence intensity when the applied forward voltage exceeds a certain value. Simultaneously, a reversed quantum confined Stark effect is observed in the polarization-doped N-face LED. The detailed physical mechanisms are explained in terms of the calculated energy band diagrams, carrier transport, and distribution of electric field containing polarization filed and free-carrier screening field.
Spatially resolved spectral mapping of phase mixing and charge transfer excitons in bulk heterojunction solar cell films
Authors: Riisness I. , Carach C. , Gordon M. J.
Published: February 2012

Donor-acceptor phase mixing and charge transfer excitons (CTXs) in bulk heterojunction solar cell films have been imaged using confocal photoluminescence (PL) and Raman microscopy. Spatially resolved spectral analysis of PL was used to map fullerene diffusion and agglomeration as well as detect local changes in interfacial contact between donor and acceptor domains due to thermal annealing. CTX emission was most intense at the periphery of micron-sized fullerene agglomerates, which correlates with fullerene depletion in the surrounding film. Raman scattering indicates that the polymer phase is essentially immobile during the annealing process and that fullerene agglomerates reside atop a polymer-rich underlayer.
Rocksalt MgS solar blind ultra-violet detectors
Authors: Lai Ying-Hoi , Cheung Wai-Yip , Lok Shu-Kin , Wong George K. L. , Ho Sut-Kam , Tam Kam-Weng , Sou Iam-Keong
Published: February 2012

Studies using in-situ Auger electron spectroscopy and reflection high energy electron diffraction, and ex-situ high resolution X-ray diffraction and electron backscatter diffraction reveal that a MgS thin film grown directly on a GaAs (100) substrate by molecular beam epitaxy adopts its most stable phase, the rocksalt structure, with a lattice constant of 5.20 Å. A Au/MgS/n+-GaAs (100) Schottky-barrier photodiode was fabricated and its room temperature photoresponse was measured to have a sharp fall-off edge at 235 nm with rejection of more than three orders at 400 nm and higher than five orders at 500 nm, promising for various solar-blind UV detection applications.
Assessment of changes in the state of the rangelands of Inner Mongolia, China between 1998 and 2007 using remotely sensed data
Authors: Hu Z. M. , Li S. G. , Dong J. W. , Fan J. W.
Published: February 2012

The spatial annual patterns of aboveground net primary productivity (ANPP) and precipitation-use efficiency (PUE) of the rangelands of the Inner Mongolia Autonomous Region of China, a region in which several projects for ecosystem restoration had been implemented, are described for the years 1998–2007. Remotely sensed normalised difference vegetation index and ANPP data, measured in situ, were integrated to allow the prediction of ANPP and PUE in each 1 km2 of the 12 prefectures of Inner Mongolia. Furthermore, the temporal dynamics of PUE and ANPP residuals, as indicators of ecosystem deterioration and recovery, were investigated for the region and each prefecture. In general, both ANPP and PUE were positively correlated with mean annual precipitation, i.e. ANPP and PUE were higher in wet regions than in arid regions. Both PUE and ANPP residuals indicated that the state of the rangelands of the region were generally improving during the period of 2000–05, but declined by 2007 to that found in 1999. Among the four main grassland-dominated prefectures, the recovery in the state of the grasslands in the Erdos and Chifeng prefectures was highest, and Xilin Gol and Chifeng prefectures was 2 years earlier than Erdos and Hunlu Buir prefectures. The study demonstrated that the use of PUE or ANPP residuals has some limitations and it is proposed that both indices should be used together with relatively long-term datasets in order to maximise the reliability of the assessments.
Citizenship, participation, and CMD
Authors: Chiluwa Innocent
Published: February 2012

NaijaPals and Nolitics, respectively a hosting site and a discussion forum by and for Nigerians, provide an opportunity for the citizens’ social and political participation. As a hosting website with social networking and blogging activities, NaijaPals maintains an online community, with Nolitics as a discussion forum solely dedicated to social and political debate. Members exchange information and engage in critical analysis of Nigeria’s political system. A total of 104 ‘posts’ are analyzed in the framework of Computer-Mediated Discourse Analysis (CMDA) and Critical Discourse Analysis (CDA). The analysis highlights the roles of political discourse in Nolitics, mainly as social critique, with the aim of shaping political leadership and involving the citizens in political governance. Discourse in this context is viewed as discursive practice, in the form of political propaganda; anti-corruption campaigns; socio-political mobilization; and recommendations for growth — all of these mediated in written texts. The analyses also show that metaphors, directive speech acts and questioning are used as discursive strategies.
“The baby dey CHUK CHUK”
Authors: Odebunmi Akin
Published: February 2012

Nigerian Pidgin is a popular informal communicative code in Nigerian social, economic and political experience. It is sometimes spoken in formal situations in the hospital setting when participants find it pragmatically convenient. Despite its communicative significance, little research has been carried out on the use of Pidgin in conversational interactions in Nigerian hospitals, a gap this study fills by investigating how Pidgin is used in constructing emotions relating to social and medical conditions in hospitals. Seventy five (75) interactions between doctors and clients in Nigerian Pidgin were sampled; the data analysis was based centrally on relevance theory. Nigerian Pidgin evokes negative and positive emotions. Negative emotions manifest as pain and fear, while positive emotions appear as excitement and relief. Doctors and clients gain access to each other’s intentions through their shared knowledge of Pidgin, their co-construction of ailments, and their contextually based local interactional resources. They thus negotiate emotions as cue-dependent variables that are steered with the help of cognitive processes.
Research Priorities in Forensic Mental Health
Authors: Hodgins Sheilagh
Published: February 2012

This article identifies research priorities for the field of forensic mental health. What is known about the association between mental disorders, retardation, brain damage and offending and violence is briefly reviewed. It is noted that while some of the correlates of offending are common to both non-disordered and disordered offenders, others characterize specific subgroups of mentally disordered offenders. The evidence is consistent in showing that most mentally disordered offenders have multiple problems that have been present, in many cases, since childhood. Knowledge about effective treatments for mentally disordered, mentally retarded, and brain damaged offenders is highlighted. It is concluded that there is a lack of information about the organization, legal powers, and content of treatment, management, and rehabilitation programs that have been shown to impact on recidivism, relapse, and autonomous functioning. Almost nothing is known about the impact of various social services. Future research should be designed to contribute to (1) improving the efficacy of models of service organization; (2) improving the efficacy of treatment, management, and rehabilitation programs; (3) improving the efficacy of the multiple components included in treatment, management, and rehabilitation programs; (4) integrating risk assessment of violent behavior into treatment, management, and rehabilitation programs and improving the accuracy of prediction; (5) identifying the etiologies of offending and violence among persons with mental disorders, mental retardation, and brain damage; and (6) preventing offending and violence among children at risk for mental disorders.
Perceived Relevance of Factors for Violence Risk Assessment: A Survey of Clinicians
Authors: Elbogen EricB. , Mercado CynthiaCalkins , Scalora MarioJ. , Tomkins AlanJ.
Published: February 2012

Although there has been extensive research on violence risk assessment in the past decade, it has not been examined whether clinicians in actual practice consider violence risk factors that researchers suggest should be utilized. The purpose of this study was to investigate clinicians' perceptions of factors derived from research on violence risk assessment. One hundred thirty-four clinicians from four psychiatric facilities completed surveys in which they rated the relevance of research risk factors as well as additional behavioral variables. The analyses indicated that while clinicians perceived research risk factors to be relevant, they perceived behavioral variables not subjected to empirical scrutiny as significantly more relevant for violence risk assessment. The findings have implications for dissemination of risk assessment research and the development and implementation of risk assessment measures.
Violence Risk Assessment: Using Structured Clinical Guides Professionally
Authors: Webster ChristopherD. , Müller-Isberner Rüdiger , Fransson Göran
Published: February 2012

The HCR-20 has gained considerable acceptance by mental health, forensic, and criminal justice professionals since its initial publication only seven and a half years ago. Scientific evidence has gradually accrued to show that the guide can be used reliably and validly. Yet the scheme is sometimes misapplied. It is important that HCR-20 item definitions be kept anchored to the text to prevent “drift” that the guide be seen as a vehicle to promote discussion among colleagues rather than being viewed as capable of offering violence risk estimates that necessarily approach full accuracy; that would-be users should receive practice in coding case examples; and that, as urged in the basic manual, clinicians and researchers make all possible effort to avoid omitting items. The paper offers suggestions about conceptual and research work that needs to be completed in the future and offers one concrete example of a project in progress.
Judicial Decision Thresholds for Violence Risk Management
Authors: Monahan John , Silver Eric
Published: February 2012

To affect violence risk management decisions, it is necessary to apply a decision threshold to the estimates that actuarial violence risk assessments generate. Despite widespread agreement that the choice of decision threshold is a matter of policy rather than of science, no one has actually asked policy makers about their choices. A survey was conducted asking 26 judges where they would set the decision threshold for instituting short-term civil commitment as a “danger to others.” The five risk assessment options communicated to the judges were the Risk Classes obtained in the MacArthur Study. Results showed great variability among judges. As a group, however, judges chose Risk Class 3 – a 0.26 likelihood of committing a violent act – as their decision threshold for short-term civil commitment.
Multiple Facets of Risk for Violence: The Impact of Judgmental Specificity on Structured Decisions About Violence Risk
Authors: Douglas KevinS. , Ogloff JamesR. P.
Published: February 2012

Among the many advances that have occurred in the field of violence risk assessment over the past decade has been the realization that violence is multifaceted. Violence and the risk for violence include many facets including the severity, density, imminence, target and nature of violence. Despite advances in the understanding and conceptualization of violence and risk, very few empirical risk assessment studies have considered the multifaceted nature of violence. Using a structured professional judgment model of risk assessment, the present study evaluated whether more highly specific judgments of violence (i.e., low, moderate, or high risk for short-term violence, or serious violence, versus violence generally) could be made with reasonable reliability and incremental validity. The findings suggested that more specific judgments about particular facets of violence were not made with the same reliability and validity as either the numerical scores or the omnibus structured clinical risk ratings for general violence. The possible reasons for the findings are discussed with suggestions for future research to continue to study this important area.