bluuebunny/crossref_metadata_2025 huggingface dataset:
Capillary pressure and saturation relations for supercritical CO2 and brine in sand: High‐pressure Pc(Sw) controller/meter measurements and capillary scaling predictions
Authors: Tokunaga Tetsu K. , Wan Jiamin , Jung Jong‐Won , Kim Tae Wook , Kim Yongman , Dong Wenming
Published: May 2013

In geologic carbon sequestration, reliable predictions of CO2 storage require understanding the capillary behavior of supercritical (sc) CO2. Given the limited availability of measurements of the capillary pressure (Pc) dependence on water saturation (Sw) with scCO2 as the displacing fluid, simulations of CO2 sequestration commonly rely on modifying more familiar air/H2O and oil/H2O Pc(Sw) relations, adjusted to account for differences in interfacial tensions. In order to test such capillary scaling‐based predictions, we developed a high‐pressure Pc(Sw) controller/meter, allowing accurate Pc and Sw measurements. Drainage and imbibition processes were measured on quartz sand with scCO2‐brine at pressures of 8.5 and 12.0 MPa (45°C), and air‐brine at 21°C and 0.1 MPa. Drainage and rewetting at intermediate Sw levels shifted to Pc values that were from 30% to 90% lower than predicted based on interfacial tension changes. Augmenting interfacial tension‐based predictions with differences in independently measured contact angles from different sources led to more similar scaled Pc(Sw) relations but still did not converge onto universal drainage and imbibition curves. Equilibrium capillary trapping of the nonwetting phases was determined for Pc = 0 during rewetting. The capillary‐trapped volumes for scCO2 were significantly greater than for air. Given that the experiments were all conducted on a system with well‐defined pore geometry (homogeneous sand), and that scCO2‐brine interfacial tensions are fairly well constrained, we conclude that the observed deviations from scaling predictions resulted from scCO2‐induced decreased wettability. Wettability alteration by scCO2 makes predicting hydraulic behavior more challenging than for less reactive fluids.
Lateral Lymph Node Dissection for Lower Rectal Cancer
Authors: Nakamura T. , Watanabe M.
Published: May 2013

The mainstay of surgical therapy for rectal cancer is colectomy (including lesions) with lymph node dissection. The lymphatic spread of rectal cancer can proceed in two directions: medially toward the origin of the inferior mesenteric artery or laterally toward the pelvis aslong the internal iliac artery. To prevent postoperative recurrence, lymph nodes situated along these two axes should be adequately dissected, leaving no residual cancer cells. In Japan, the standard procedure for advanced lower rectal cancer is mesorectal excision and lateral lymph node dissection with autonomic nerve preservation. In Europe and North America, lateral lymph node dissection used to be performed, but it led to increased blood loss, complications, and dysfunction, with no improvement in survival. Lateral lymph node dissection is thus no longer performed. Instead, multidisciplinary therapy combining mesorectal excision with preoperative chemoradiotherapy is now the standard treatment for advanced rectal cancer. Although lateral lymph node dissection decreases the rate of local recurrence similar to preoperative chemoradiotherapy, whether it contributes to improved survival remains unclear. In addition, it is unlikely that prophylactic lateral lymph node dissection is required in all patients with rectal cancer. Definition of the indications for lateral lymph node dissection is thus an important concern.
Incidental Findings in Trauma Patients: Dedicated Communication with the Primary Care Physician Ensures Adequate Follow‐Up
Authors: Yeh D. Dante , Imam Ayesha M. , Truong Shani H. , McLaughlin Erin L. , Klein Eric N. , Avery Laura L. , Velmahos George C.
Published: May 2013

Background

Frequent use of computed tomography (CT) in trauma patients results in frequent detection of non‐trauma‐related incidental findings (IFs). Inpatient documentation and disclosure at discharge are infrequent, even when they are potentially serious. We aimed to not only identify the incidence of IFs but also to evaluate the effectiveness of an intervention to trigger follow‐up.

Methods

In this before–after study, all trauma patients evaluated by the trauma surgery service who underwent CT were admitted for >24 h, had at least one IF requiring follow‐up, and had a primary care physician (PCP) employed in our health care system were identified. The historical control period was from January 2006 to December 2008. The intervention period was from December 2011 to September 2012. Intervention consisted of notifying the PCP via email or postal letter. The outcome of interest—the rate of follow‐up—was compared between both groups.

Results

During the historical period, 364 (20.5 %) of 1,774 eligible trauma patients had 434 IFs requiring follow‐up. During the study period, 197 (26 %) of 692 trauma patients had 212 IFs requiring follow‐up. Overall, 91 % of study patients with postdischarge PCP follow‐up had documented follow‐up of the IF. There was a significant improvement in the rate of follow‐up in the study group compared to that of the control group (51 vs. 11 %; p < 0.0001).

Conclusions

Detection of IFs is common in trauma patients. A dedicated effort of communicating the presence of an IF to the patient’s PCP triggered a follow‐up for 91 % of patients who saw their PCP after hospital discharge.
Hardy inequalities on Riemannian manifolds and applications
Authors: D'Ambrosio Lorenzo , Dipierro Serena
Published: May 2013

We prove a simple sufficient criterion to obtain some Hardy inequalities on Riemannian manifolds related to quasilinear second order differential operator

\mathrm{\Delta }_{p}u: = \mathrm{div}(|\mathrm{∇}u|^{p−2}\mathrm{∇}u)

. Namely, if

ρ

is a nonnegative weight such that

−\mathrm{\Delta }_{p}\rho ⩾0

, then the Hardy inequality

c\int \limits_{M}\frac{|u|^{p}}{\rho ^{p}}|\mathrm{∇}\rho |^{p}\:dv_{g}⩽\int \limits_{M}|\mathrm{∇}u|^{p}\:dv_{g},\:u \in \mathrm{C}_{0}^{\infty }(M),

holds. We show concrete examples specializing the function

ρ

.

Our approach allows to obtain a characterization of

p

-hyperbolic manifolds as well as other inequalities related to Caccioppoli inequalities, weighted Gagliardo–Nirenberg inequalities, uncertain principle and first order Caffarelli–Kohn–Nirenberg interpolation inequality.
Gaming Democracy: Elite Dominance during Transition and the Prospects for Redistribution
Authors: Albertus Michael , Menaldo Victor
Published: May 2013

Inequality and democracy are far more compatible empirically than social conflict theory predicts. This article speaks to this puzzle, identifying the scope conditions under which democratization induces greater redistribution. Because autocrats sometimes have incentives to expropriate economic elites, who lack reliable institutions to protect their rights, elites may prefer democracy to autocratic rule if they can impose roadblocks to redistribution under democracyex ante. Using global panel data (1972–2008), this study finds that there is a relationship between democracy and redistribution only if elites are politically weak during a transition; for example, when there is revolutionary pressure. Redistribution is also greater if a democratic regime can avoid adopting and operating under a constitution written by outgoing elites and instead create a new constitution that redefines the political game. This finding holds across three different measures of redistribution and instrumental variables estimation. This article also documents the ways in which elites ‘bias’ democratic institutions.
Hegel’s Moral Concept of Evil
Authors: BROWNLEE TIMOTHY
Published: May 2013

The central aim of this article is to set out the essential elements of Hegel’s conception of evil. I demonstrate that Hegel understands evil primarily as a moral phenomenon. In particular, he identifies evil as a pernicious subjectivism and hypocrisy that undermines the social and institutional conditions for ethical action. An appropriate understanding of his conception of evil points to the centrality of trust to ethicality (die Sittlichkeit).
Comparative performance of the stable isotope signatures of carbon, nitrogen and oxygen in assessing early vigour and grain yield in durum wheat
Authors: BORT J. , BELHAJ M. , LATIRI K. , KEHEL Z. , ARAUS J. L.
Published: May 2013

The present paper studied the performance of the stable isotope signatures of carbon (δ13C), nitrogen (δ15N) and oxygen (δ18O) in plants when used to assess early vigour and grain yield (GY) in durum wheat growing under mild and moderate Mediterranean stress conditions. A collection of 114 recombinant inbred lines was grown under rainfed (RF) and supplementary irrigation (IR) conditions. Broad sense heritabilities (H2) for GY and harvest index (HI) were higher under RF conditions than under IR. Broad sense heritabilities forδ13C were always above 0·60, regardless of the plant part studied, with similar values for IR and RF trials. Some of the largest genetic correlations with GY were those shown by theδ13C content of the flag leaf blade and mature grains. Under both water treatments, mature grains showed the highest negative correlations betweenδ13C and GY across genotypes. Flag leafδ13C was negatively correlated with GY only under RF conditions. Theδ13C in seedlings was negatively correlated, under IR conditions only, with GY but also with early vigour. The sources of variation in early vigour were studied by stepwise analysis using the stable isotope signatures measured in seedlings. Theδ13C was able to explain almost 0·20 of this variation under RF, but up to 0·30 under IR. In addition, nitrogen concentration in seedlings accounted for another 0·05 of variation, increasing the amount explained to 0·35. The sources of variation in GY were also studied through stable isotope signatures and biomass of different plant parts:δ13C was always the first parameter to appear in the models for both water conditions, explainingc. 0·20 of the variation. The second parameter (δ15N or N concentration of grain, or biomass at maturity) depended on the water conditions and the plant tissue being analysed. Oxygen isotope composition (δ18O) was only able to explain a small amount of the variation in GY. In this regard, despite the known and previously described value ofδ13C as a tool in breeding,δ15N is confirmed as an additional tool in the present study. Oxygen isotope composition does not seem to offer any potential, at least under the conditions of the present study.
Love in dark times: Iris Murdoch on openness and the void
Authors: MILLIGAN TONY
Published: May 2013

After situating Iris Murdoch's promotion of openness to love within a broadly Platonic ethic, I outline a familiar suspicion about such openness in the context of grief, where the finding of a new and intimate love may seem inappropriate. By drawing upon her treatment of spiritual crisis and grief as parallel instances of the void, I respond to this suspicion by arguing that love in the context of spiritual crisis offers a way to resist the dangers of the void and that similar considerations apply in the parallel case (grief). If we accept Murdoch's overall position we will then lack justification for rejecting love as a morally defensible pathway out of grief.
Are naturalism and moral realism incompatible?
Authors: PEELS RIK
Published: May 2013

In a recent paper, Alvin Plantinga has argued that there is good reason to think that naturalism and moral realism are incompatible. He has done so by arguing that the most important argument for the compatibility of these two theses, which has been provided by Frank Jackson, fails and that any other argument that serves the same purpose is likely to fail for the same reason. His argument against the compatibility of naturalism and moral realism, then, isindirect: he argues against it by refuting the most important argument for it. In this article, I argue that Plantinga's argument is unconvincing for at least two reasons. First, Jackson's argument can be revised in such a way that it meets Plantinga's worry. Second, there is another way of arguing for the compatibility of two propositions which Plantinga does not consider. If the naturalist takes this alternative route, she does not face the problem identified by Plantinga. I thus show not only that Plantinga's argument does not count against the compatibility of naturalism and moral realism, but that there is even good reason to think that naturalism and moral realism are in fact compatible.
Moving from Ambivalence to Certainty: Older Same-Sex Couples Marry in Canada
Authors: Humble Áine M.
Published: May 2013

Une étude qualitative, dans la perspective du parcours de vie, a exploré la transition vers le mariage pour les couples de même sexe au milieu ou plus tard dans la vie. Vingt personnes (soit 11 couples) ont été intérrogées – 12 lesbiennes, sept hommes gais, et une homme bisexuel. Au moment de leurs mariages, les participants avaient de 42 à 72 ans (âge moyen: 54), et avaient vécu avec leurs partenaires entre six mois à 19 ans (moyen: 7,5 ans). Trois thèmes soulignent la manière dont les expériences de ces couples de même sexe, en décidant de se marier, ont été influencés par les expériences dans leurs parcours de vie. Premièrement,l’intégration: les individus ont dû integrer le mariage dans leur psychisme. Deuxièmement,la justification: ils ont dû demander pourquoi ils se marient avec leurs partenaires spécifiques. Le troisième thème étaitla déliberation: les participants à l’étude ont demontré comment leurs expériences de planification de mariage et les caractéristiques de leurs noces etaient impregnées à la suite de leurs expériences conscientes de vie en ce qui concerne l’homophobie et/ou l’hétérosexisme.
Overview of seismic research activities in the Southern Ocean - quantifying the environmental impact
Authors: Breitzke Monika
Published: May 2013

Understanding the regional and seasonal distribution of seismic research surveys in the Southern Ocean is essential for assessing their acoustic impact on the marine environment. An analysis of the navigation data and cruise table in the Seismic Data Library System for Cooperative Research (SDLS) shows that a fairly extensive network of seismic lines is now available for the Southern Ocean. However, line spacing ranges from tens to hundreds of kilometres, and some almost unsurveyed areas still exist. The seasonal distribution of the seismic profile lengths shows periods with increased survey activity between 1976/77 and 2001/02, but only moderate levels of activity between 2002/03 and 2010/11. The corresponding line spacing is large, and lines are widely distributed over the Southern Ocean. None of the eight Antarctic regions considered here have experienced seismic survey activity during all summer seasons in the last 35 years. Instead, periods with survey activity are interspersed by periods with no survey activity. The average survey length ranges from ∼2600 km per season off the Antarctic Peninsula to ∼260 km per season off Enderby Land. Compared to the industrial seismic exploration off Norway the acoustic impact of the seismic research activity in the Southern Ocean is at least ∼150 times lower.
Performance of Older Japanese American Adults on Selected Cognitive Instruments
Authors: Kemmotsu Nobuko , Enobi Yurika , Murphy Claire
Published: May 2013

This study examined cognitive test performance of second- and third-generation Japanese American (JA) adults, a relatively homogeneous Asian American subgroup. Sixty-five JA and 65 non-Hispanic White (NHW) adults, ages between 45 and 91, were administered the Boston Naming Test-2 (BNT), Letter Fluency Test, Semantic Fluency Test, California Verbal Learning Test (CVLT), Brief Visuospatial Memory Test-Revised (BVMT-R), and Trail Making Test. Levels of acculturation, quality of educational attainment, and generation status in the United States, were also collected. There were no significant differences in the scores between the two groups on the tests administered. JA and NHW groups, however, differed in the patterns of the associations between some of the test performance and demographic variables. JA adults showed a stronger age-score relationship on BNT, CVLT, and the BVMT-R. Furthermore, second-generation JA adults performed lower than the third-generation adults even after controlling for basic demographic variables on CVLT and Trail Making Test. Acculturation on the other hand did not explain score differences once demographic variables were considered. Our results suggest the importance of considering unique history and characteristics of ethnic groups, and interactions of the aging process and culture on tasks with different cognitive demands. (JINS, 2013, 19, 1–9)
Report of the Investment Products for Retirement Savings Working Party: “Is there a place in the UK Defined Contribution pensions market for a guaranteed savings product?” ‐ Abstract of the London discussion
Authors: Eason Scott
Published: May 2013

This abstract relates to the following paper:

EasonS., BarkerP., ForoughiG., HarsantJ., HunterD., JarvisS., JonesG., KnavaV., MurphyP., MurrayK., MuthulingamJ., OdoziN., PageT., WashomaK. & WebbA.Is there a place in the UK Defined Contribution pensions market for a guaranteed savings product?British Actuarial Journal, doi:10.1017/S135732171300024X
Prevention of overweight in children younger than 2 years old: a pilot cluster-randomized controlled trial
Authors: Verbestel Vera , De Coen Valerie , Van Winckel Myriam , Huybrechts Inge , Maes Lea , De Bourdeaudhuij Ilse
Published: May 2013

Objective

The aim of the present study was to evaluate the effects of a 1-year family-based healthy lifestyle intervention implemented through day-care centres on toddlers’ BMIZ-scores and reported activity- and dietary-related behaviours.

Design

Pilot cluster-randomized controlled trial.

Setting

Seventy child-care centres in three different intervention communities and three paired-matched control communities in Flanders, Belgium.

Subjects

A sample of 203 Belgian toddlers aged 9–24 months was included in the study. Objectively assessed weight and height were used to calculate BMIZ-scores. A parental-report questionnaire was used to assess children's lifestyle behaviours.

Results

Positive intervention effects were found on BMIZ-score. No intervention effects were found for activity- and dietary-related behaviours targeted by the intervention. In both intervention and control groups, daily consumption of water, soft drinks, sweets and savoury snacks increased while daily consumption of fruit and vegetables decreased over 1 year. Daily physical activity remained stable but screen-time behaviour increased in both groups over time.

Conclusions

The study showed that a family-based healthy lifestyle intervention implemented through day-care centres can lead to healthier weight outcomes in toddlers. In both groups, an unhealthier lifestyle pattern was observed over 1 year which underlines the importance of the early childhood period as the focus of future behavioural interventions.
Selective Intrauterine Growth Restriction in Monochorionic Twin Pregnancies: Markers of Endothelial Damage and Metabolomic Profile
Authors: Cosmi Erich , Visentin Silvia , Favretto Donata , Tucci Marianna , Ragazzi Eugenio , Viel Guido , Ferrara Santo Davide
Published: May 2013

The aim of this study was to assess the aorta–intima thickness (aIT) and serum metabolomic profile in selective intrauterine growth-restricted (sIUGR) monochorionic diamniotic (MCDA) twin fetuses presenting Doppler velocimetry alterations. Fetal abdominal aIT was measured by ultrasound at 32 weeks of gestation, enrolling 24 MCDA twin fetuses (8 sIUGR and 16 controls). sIUGR twin fetuses were classified into two groups: Group 1 consisted of sIUGR with abnormal umbilical artery (UA) Doppler waveforms and Group 2 included sIUGR with normal UA Doppler. Group 3 were control fetuses appropriate for gestational age (AGA). Fetal blood samples were obtained from the umbilical vein immediately after fetal extraction. A non-targeted metabolomic profiling investigated fetal metabolism alterations by using liquid chromatography–high-resolution mass spectrometry (LC-HRMS). Median fetal aIT was significantly larger in Group 1 (median value = 0.9 mm; range = 0.8–1.0 mm;p< .002) and Group 2 (median value = 0.8 mm; range = 0.7–0.8 mm;p< .002) than in AGA Group 3 (median value = 0.5 mm; range = 0.4–0.6 mm;p< .002). Metabolomic analyses, performed on four sIUGR cases (Group 1) compared with four AGA co-twins, showed an upregulation of phenylalanine, sphingosine, glycerophosphocholine, and choline, and a downregulation of valine, tryptophan, isoleucine, and proline sIUGR Group 1 compared with AGA. Although for metabolomics data only a statistical tendency (and not a statistical significance) was reached due to the small sample size, we believe that our results represent a valid starting point for further in-depth metabolomic and proteomic investigations of sIUGR in MCDA fetuses.
The role of histone deacetylases in rheumatoid arthritis fibroblast-like synoviocytes
Authors: Hawtree Sarah , Muthana Munitta , Wilson Anthony G.
Published: May 2013

RA (rheumatoid arthritis) is an inflammatory disease of synovial joints affecting approximately 1% of the population. One of the main cell types involved in damage to RA joint tissue is the FLSs (fibroblast-like synoviocytes). These have a semi-transformed, auto-aggressive phenotype typified by loss of contact inhibition, reduced apoptosis and the production of matrix-degrading enzymes. The mechanisms involved in the development of this phenotype are unclear; however, increasing evidence implicates alterations in the epigenetic regulation of gene expression. Reduced acetylation of amino acids in the tails of histone proteins is an epigenetic mark associated with transcriptional repression and is controlled by the HDAC (histone deacetylase) enzyme family. To date, evidence has implicated HDACs in the auto-aggressive phenotype of FLSs, and administration of HDAC inhibitors to both animal models of RA and individuals with juvenile arthritis has shown efficacy in attenuating inflammation and tissue damage. This highlights a role for HDACs in disease pathogenesis and, more importantly, that HDACs are potential novel therapeutic targets.
Ab initio and classical molecular dynamics studies of the structural and dynamical behavior of water near a hydrophobic graphene sheet
Authors: Rana Malay Kumar , Chandra Amalendu
Published: May 2013

The behavior of water near a graphene sheet is investigated by means of ab initio and classical molecular dynamics simulations. The wetting of the graphene sheet by ab initio water and the relation of such behavior to the strength of classical dispersion interaction between surface atoms and water are explored. The first principles simulations reveal a layered solvation structure around the graphene sheet with a significant water density in the interfacial region implying no drying or cavitation effect. It is found that the ab initio results of water density at interfaces can be reproduced reasonably well by classical simulations with a tuned dispersion potential between the surface and water molecules. Calculations of vibrational power spectrum from ab initio simulations reveal a shift of the intramolecular stretch modes to higher frequencies for interfacial water molecules when compared with those of the second solvation later or bulk-like water due to the presence of free OH modes near the graphene sheet. Also, a weakening of the water-water hydrogen bonds in the vicinity of the graphene surface is found in our ab initio simulations as reflected in the shift of intermolecular vibrational modes to lower frequencies for interfacial water molecules. The first principles calculations also reveal that the residence and orientational dynamics of interfacial water are somewhat slower than those of the second layer or bulk-like molecules. However, the lateral diffusion and hydrogen bond relaxation of interfacial water molecules are found to occur at a somewhat faster rate than that of the bulk-like water molecules. The classical molecular dynamics simulations with tuned Lennard-Jones surface-water interaction are found to produce dynamical results that are qualitatively similar to those of ab initio molecular dynamics simulations.
Influence of anneal atmosphere on ZnO-nanorod photoluminescent and morphological properties with self-powered photodetector performance
Authors: Hatch S. M. , Briscoe J. , Sapelkin A. , Gillin W. P. , Gilchrist J. B. , Ryan M. P. , Heutz S. , Dunn S.
Published: May 2013

ZnO nanorods synthesised using an aqueous pH 11 solution are shown to exhibit surface-sensitive morphology post-annealing in oxygen, air, and nitrogen as shown by scanning electron microscopy and transmission electron microscopy analysis. Raman analysis confirms the nanorods were nitrogen-doped and that nitrogen incorporation takes place during the synthesis procedure in the form of N-Hx. A strong green photoluminescence is observed post-annealing for all samples, the intensity of which is dependent on the atmosphere of anneal. This luminescence is linked to zinc vacancies as recent reports have indicated that these defects are energetically favoured with the annealing conditions used herein. ZnO-nanorod/CuSCN diodes are fabricated to examine the effect of material properties on photodetector device performance. The devices exhibit a photocurrent at zero bias, creating a self-powered photodetector. A photocurrent response of 30 μA (at 6 mW cm−2 irradiance) is measured, with a rise time of ∼25 ns, and sensitivity to both UV and visible light (475–525 nm).
A microscopic picture of surface charge trapping in semiconductor nanocrystals
Authors: Mooney Jonathan , Krause Michael M. , Saari Jonathan I. , Kambhampati Patanjali
Published: May 2013

Several different compositions of semiconductor nanocrystals are subjected to numerous spectroscopic techniques to elucidate the nature of surface trapping in these systems. We find a consistent temperature-dependent relationship between core and surface photoluminescence intensity and marked differences in electron-phonon coupling for core and surface states based on ultrafast measurements and Resonance Raman studies, respectively. These results support a minimal model of surface charge trapping applicable to a range of nanocrystal systems involving a single surface state in which the trapped charge polarization leads to strong phonon couplings, with transitions between the surface and band edge excitonic states being governed by semiclassical electron-transfer theory.
Dynamics of discrete semiflexible chains under dihedral constraints: Analytic results
Authors: Dolgushev Maxim , Blumen Alexander
Published: May 2013

Here we consider the dynamics of semiflexible polymers subject both to angular and to dihedral constraints. We succeed in obtaining analytically the dynamical matrix of such systems by extending the formalism developed by Dolgushev and Blumen [J. Chem. Phys. 131, 044905 (2009)10.1063/1.3184797]. This leads to a set of Langevin equations whose eigenvalues determine many dynamical properties. Exemplarily, we display the mechanical relaxation loss moduli [G″(ω)] as a function of several, distinct sets of microscopic stiffness parameters; it turns out that such differences lead to macroscopically distinct patterns.
Direct numerical simulation of sediment entrainment in turbulent channel flow
Authors: Ji C. , Munjiza A. , Avital E. , Ma J. , Williams J. J. R.
Published: May 2013

In this paper, the entrainment and movement of coarse particles on the bed of an open channel is numerically investigated. Rather than model the sediment transport using a concentration concept, this study treats the sediment as individual particles and investigates the interaction between turbulent coherent structures and particle entrainment. The applied methodology is a combination of the direct numerical simulation of turbulent flow, the combined finite-discrete element modeling of particle motion and collision, and the immersed boundary method for the fluid-solid interaction. In this study, flow over a water-worked rough-bed consisting of 2-3 layers of densely packed spheres is adopted and the Shields function is 0.065 which is just above the entrainment threshold to give a bed-load regime. Numerical results for turbulent flow, sediment entrainment statistics, hydrodynamic forces acting on the particles, and the interaction between turbulence coherent structures and particle entrainment are presented. It is shown that the presence of entrained particles significantly modifies the mean velocity and turbulence quantity profiles in the vicinity of a rough-bed and that the instantaneous lift force can be larger than a particle's submerged weight in a narrow region above the effective bed location, although the mean lift force is always smaller than the submerged weight. This, from a hydrodynamic point of view, presents strong evidence for a close cause-and-effect relationship between coherent structures and sediment entrainment. Furthermore, instantaneous numerical results on particle entrainment and the surrounding turbulent flow are reported which show a strong correlation between sediment entrainment and sweep events and the underlying mechanisms are discussed.
Theoretical considerations for mapping activation in human cardiac fibrillation
Authors: Rappel Wouter-Jan , Narayan Sanjiv M.
Published: May 2013

Defining mechanisms for cardiac fibrillation is challenging because, in contrast to other arrhythmias, fibrillation exhibits complex non-repeatability in spatiotemporal activation but paradoxically exhibits conserved spatial gradients in rate, dominant frequency, and electrical propagation. Unlike animal models, in which fibrillation can be mapped at high spatial and temporal resolution using optical dyes or arrays of contact electrodes, mapping of cardiac fibrillation in patients is constrained practically to lower resolutions or smaller fields-of-view. In many animal models, atrial fibrillation is maintained by localized electrical rotors and focal sources. However, until recently, few studies had revealed localized sources in human fibrillation, so that the impact of mapping constraints on the ability to identify rotors or focal sources in humans was not described. Here, we determine the minimum spatial and temporal resolutions theoretically required to detect rigidly rotating spiral waves and focal sources, then extend these requirements for spiral waves in computer simulations. Finally, we apply our results to clinical data acquired during human atrial fibrillation using a novel technique termed focal impulse and rotor mapping (FIRM). Our results provide theoretical justification and clinical demonstration that FIRM meets the spatio-temporal resolution requirements to reliably identify rotors and focal sources for human atrial fibrillation.
Domain wall control in wire-tube nanoelements
Authors: Neumann R. F. , Bahiana M. , Vargas N. M. , Altbir D. , Allende S. , Görlitz D. , Nielsch K.
Published: May 2013

The possibility of a three-state nanoelement, composed by a wire and a tube, is investigated by means of Monte Carlo simulations. The desired behavior may be identified by a step or plateau in the hysteresis curve, corresponding to a partial pinning of the domain wall at the interface between wire and tube sections. This step may be augmented in segmented nanoelements with large coercivity difference between the sections. Different possibilities, such as geometry and choice of materials, are explored.
Experimental characterization of multiscale and multifield turbulence as a critical gradient threshold is surpassed in the DIII-D tokamak
Authors: Hillesheim J. C. , DeBoo J. C. , Peebles W. A. , Carter T. A. , Wang G. , Rhodes T. L. , Schmitz L. , McKee G. R. , Yan Z. , Staebler G. M. , Burrell K. H. , Doyle E. J. , Holland C. , Petty C. C. , Smith S. P. , White A. E. , Zeng L.
Published: May 2013

A critical gradient for long wavelength (kθρs≲0.4) electron temperature fluctuations has been observed in an experiment in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)], where below a threshold value of LTe−1=|∇Te|/Te electron temperature fluctuations are constant and above they steadily increase. Above the critical gradient, the electron heat flux inferred by power balance also increases rapidly. Critical gradients are a predicted attribute of turbulence arising from linear instabilities and are thought to be related to transport stiffness. The presented results are the first direct, systematic demonstration of critical gradient behavior in turbulence measurements in a tokamak. The experiment was performed by changing the deposition location of electron cyclotron heating shot-to-shot to locally scan LTe−1 at r/a = 0.6 in L-mode plasmas; rotation was also varied by changing the momentum input from neutral beam injection. Temperature fluctuations were measured with a correlation electron cyclotron emission (CECE) radiometry system. In addition to the CECE measurements, an array of turbulence measurements were acquired to characterize fluctuations in multiple fields and at multiple scales as LTe−1 and rotation were modified: long wavelength (kθρs≲0.5) density fluctuations were acquired with beam emission spectroscopy, the phase angle between electron temperature and density fluctuations was measured by coupling the CECE system and a reflectometer, intermediate scale (kθρs∼0.8) density fluctuations were measured with a Doppler backscattering (DBS) system, and low frequency flows were also measured with DBS. The accumulated measurements and trends constrain identification of the instability responsible for the observed critical gradient to the ∇Te-driven trapped electron mode.
Bottom-up modeling of Al/Ni multilayer combustion: Effect of intermixing and role of vacancy defects on the ignition process
Authors: Hemeryck A. , Ducéré J.-M. , Lanthony C. , Estève A. , Rossi C. , Djafari-Rouhani M. , Estève D.
Published: May 2013

Vapor deposited multilayered aluminum/oxide and bimetallics are promising materials for Micro Electro Mechanical System technologies as energy carriers, for instance, microinitiators or heat microsources in biological or chemical applications. Among these materials, the Al/Ni couple has received much attention both experimentally and theoretically. However, the detailed relation between the chemical composition of the intermixed interfacial regions and its impact on the ignition capabilities remains elusive. In this contribution, we propose a two-fold strategy combining atomistic density functional theory (DFT) calculations and a macroscopic 1D model of chemical kinetics. The DFT calculations allow the description of the elementary chemical processes (involving Al, Ni atoms and vacancies basic ingredients) and to parameterize the macroscopic model, in which the system is described as a stack of infinite layers. This gives the temporal evolution of the system composition and temperature. We demonstrate that the amount of vacancies, originating from the deposition process and the Al and Ni lattice mismatch, plays a critical role on both the ignition time and the temperature. The presence of vacancies enhances the migration of atoms between layers and so dramatically speeds up the atomic mixing at low temperatures far below ignition temperature, also pointing to the relation between experimental deposition procedures and ageing of the nanolaminates.
Characteristics of a tapered capillary plasma waveguide for laser wakefield acceleration
Authors: Kim M. S. , Jang D. G. , Lee T. H. , Nam I. H. , Lee I. W. , Suk H.
Published: May 2013

We developed a gas-filled capillary with a tapered density for laser wakefield acceleration, of which the tapering was realized by employing gas feed-lines with different cross-sections. Plasma diagnostics show that the capillary plasma has a significant longitudinal density tapering and a transverse parabolic profile. By using the tapered capillary plasma, high transmission (over 90%) of laser beams, meaning good optical guiding, was observed. These results demonstrate the potential of the tapered plasma source for high-energy laser wakefield acceleration, where the dephasing problem is minimized.
The effect of high/low permittivity in bilayer HfO2/BN resistance random access memory
Authors: Huang Jen-Wei , Zhang Rui , Chang Ting-Chang , Tsai Tsung-Ming , Chang Kuan-Chang , Lou J. C. , Young Tai-Fa , Chen Jung-Hui , Chen Hsin-Lu , Pan Yin-Chih , Huang Xuan , Zhang Fengyan , Syu Yong-En , Sze Simon M.
Published: May 2013

This letter investigated the electrical characteristics of resistance random access memory (RRAM) with HfO2/BN bilayer structures. By adopting the high/low permittivity structure, we obtained the excellent device characteristics such as uniform distribution of switching voltage and more stable resistance switching properties of RRAM. The current conduction mechanism of low resistance state in the HfO2/BN device was transferred to space-charge-limited current conduction from Ohmic conduction owing to space electric effect concentrated by the high/low permittivity bilayer structures. The electric field in the bilayer can be verified by comsol simulation software.
Formation behavior of BexZn1−xO alloys grown by plasma-assisted molecular beam epitaxy
Authors: Chen Mingming , Zhu Yuan , Su Longxing , Zhang Quanlin , Chen Anqi , Ji Xu , Xiang Rong , Gui Xuchun , Wu Tianzhun , Pan Bicai , Tang Zikang
Published: May 2013

We report the phase formation behavior of BexZn1−xO alloys grown by plasma-assisted molecular beam epitaxy. We find the alloy with low- and high-Be contents could be obtained by alloying BeO into ZnO films. X-ray diffraction measurements shows the c lattice constant value shrinks, and room temperature absorption shows the energy band-gap widens after Be incorporated. However, the alloy with intermediate Be composition are unstable and segregated into low- and high-Be contents BeZnO alloys. We demonstrate the phase segregation of BexZn1−xO alloys with intermediate Be composition resulted from large internal strain induced by large lattice mismatch between BeO and ZnO.
First-principle prediction of single-carrier avalanche multiplication in chalcopyrite semiconductors
Authors: Rubel O. , Darbandi A.
Published: May 2013

A critical requirement for high gain and low noise avalanche photodiodes is the single-carrier avalanche multiplication. We propose that the single-carrier avalanche multiplication can be achieved in materials with a limited width of the valence band resulting in a restriction of kinetic energy for holes while allowing electrons to participate in the multiplication cascade. This feature of the electric structure is not common to the majority of technologically relevant semiconductors, but it can be anticipated in chalcopyrite Cu(AlGa)Se2 alloys based on the presented electric structure calculations.
Temperature-dependent dielectric nonlinearity of relaxor ferroelectric Pb0.92La0.08Zr0.52Ti0.48O3 thin films
Authors: Ma Beihai , Hu Zhongqiang , Liu Shanshan , Tong Sheng , Narayanan Manoj , Koritala Rachel E. , Balachandran Uthamalingam
Published: May 2013

Rayleigh analysis has been used to investigate the temperature dependence of the dielectric response of relaxor ferroelectric Pb0.92La0.08Zr0.52Ti0.48O3 films grown on platinized silicon substrates by chemical solution deposition. The irreversible contribution to dielectric permittivity maximizes at 50 °C and decreases with further temperature increase; while the intrinsic/reversible contribution is weakly dependent on temperature. The relaxor ferroelectric transition temperature Tm increases from 160 °C to 172 °C when the frequency increases from 1 kHz to 100 kHz. The dielectric nonlinearity decreases with temperature: falling from 0.012 cm/kV at room temperature to 0.005 cm/kV at 225 °C in tests at 1 kHz.
Onset of the crystalline phase in small assemblies of colloidal particles
Authors: Sehgal Ray M. , Cogan Joshua G. , Ford David M. , Maroudas Dimitrios
Published: May 2013

We report the findings of a computational study designed to determine the onset of a stable crystalline phase in assemblies of small numbers (13–32) of colloidal particles that interact via a depletion-based short-ranged attractive potential. Using Monte Carlo umbrella sampling with coarse graining in two order parameters, we generate free-energy landscapes that can indicate coexistence between fluid-like and crystalline phases. The emergence of a stable crystalline phase is observed as the number of particles in the assembly increases beyond a critical value. We find that the critical cluster size for crystallization onset decreases with increasing strength of the interparticle attraction.
Electrical stress in CdS thin film transistors using HfO2 gate dielectric
Authors: García R. , Mejia I. , Molinar-Solis J. E. , Salas-Villasenor A. L. , Morales A. , García B. , Quevedo-Lopez M. A. , Alemán M.
Published: May 2013

During thin film transistor (TFT) operation, gate dielectric is under a bias stress condition. In this work, bias stress effect for CdS TFT using HfO2 as gate dielectric is analyzed. Threshold voltage, Ion/Ioff ratio, and subthreshold slope were studied in order to understand changes produced at the dielectric semiconductor interface. We observed that threshold voltage shift is related with negative charge trapping in the dielectric/semiconductor interface and for this phenomenon we propose a trapping charge model. Finally, the TFT output characteristic was modeled considering a shift in the threshold voltage for each gate voltage curve.
Realization of an extraordinary transmission window for a seamless Ag film based on metal-insulator-metal structures
Authors: Zhao Ding , Gong Hanmo , Yang Yuanqing , Li Qiang , Qiu Min
Published: May 2013

A polarization-sensitive, wide-angle operating antireflection coating based on a metal-insulator-metal structure is investigated. In both visible and near-infrared regions, it dramatically reduces the reflection and enhances the transmission through a seamless Ag film near a specifically designed frequency due to the surface plasmon resonance. By achieving above 70% transmission through a 20 nm-thickness Ag film theoretically, this antireflection coating is able to open an extraordinary transmission window for a metallic layer without any slits or holes.
Intrinsic photoinduced anomalous Hall effect in insulating GaAs/AlGaAs quantum wells at room temperature
Authors: Yu J. L. , Chen Y. H. , Liu Y. , Jiang C. Y. , Ma H. , Zhu L. P. , Qin X. D.
Published: May 2013

The photocurrent spectra of the inter-band photoinduced anomalous Hall effect (PAHE) in insulating GaAs/AlGaAs quantum wells have been observed at room temperature. The PAHE current changes linearly with the varied longitudinal electric fields. The anomalous Hall conductivity corresponding to excitonic state 1HH-1E (the first valence subband of heavy hole to the first conduction) has the same sign with that of excitonic state 1LH-1E (the first valence subband of light hole to the first conduction), while under uniaxial strain along the ⟨110⟩ axes, they have different signs. The PAHE current of 1HH-1E decreases linearly, but that of 1LH-1E increases linearly with shear strain. The linearly dependence of the PAHE current on uniaxial strain along the ⟨110⟩ axes suggests that the dominant mechanism is intrinsic, which has not yet been confirmed in our previous work [Yu et al., Appl. Phys. Lett. 100, 142109 (2012)].
The “Shim-a-ring” magnet: Configurable static magnetic fields using a ring magnet with a concentric ferromagnetic shim
Authors: Nath P. , Chandrana C. K. , Dunkerley D. , Neal J. A. , Platts D.
Published: May 2013

We introduce a permanent magnet assembly that can be configured to obtain uniform, gradient, or tunable field distribution. The design is composed of a single ring shaped permanent magnet and a concentric ferromagnetic shim. Magnetic field is configured by changing the shape of the air gap inside the ring magnet. Circular cross-section produces up to 0.54 T uniform field, whereas rectangular or triangular cross-sections result in gradient magnetic field distributions. Tunable field from a given ring magnet is obtained by changing the thickness of the ferromagnetic shim or the spacing between the shim and the permanent magnet.
Standing out in the Crowd: The Rise of Exclusivity-Based Strategies to Compete in the Contemporary Marketplace for Music and Fashion
Authors: Hracs Brian J , Jakob Doreen , Hauge Atle
Published: May 2013

Geographers have studied the complex relationships between cultural production, consumption, and space for some time, but the marketplace for cultural products is being reconfigured by digital technologies and broader societal trends. For producers of fashion and music the contemporary marketplace is a double-edged sword featuring lower entry barriers and fierce competition from an unprecedented number of producers and ubiquitous substitutes. Global firms and local entrepreneurs struggle to stand out in the crowd and command monopoly rents for their unique goods and services. This paper examines how independent cultural producers use ‘exclusivity’ to generate attention and distinction. Drawing on qualitative research with independent musicians and fashion designers in Toronto, Stockholm, Berlin, and New York it presents three mechanisms through which exclusivity can be created. These include exploiting consumer demand for uniqueness, enrolling consumers into the production and promotion process, and manipulating physical and virtual space.
The writing of modern Turkey
Authors: Danforth Nicholas
Published: May 2013

In its title, Uğrur Ümit Üngör'sMaking of Modern Turkey(2011) offers an elegant indication of how much has changed in the academic literature on Turkey since Bernard Lewis's 1961Emergence of Modern Turkey.Lewis believed modern Turkey emerged; Üngör reminds us it was made. The cover pictures tell the rest of the story: where my copy of Lewis's book shows a bustling street scene, Üngör's boldly offers the ruins of an abandoned Armenian church. If it is an exaggeration to say that modern Turkey no longer represents the triumph of progress, but instead a systematic act of destruction, it is increasingly clear that younger historians, both Turkish and non-Turkish, have shifted their focus from what was gained with the advent of the republic to what was lost.
The Relationship between Drug Use and Crime among Police Detainees: Does Gender Matter?
Authors: Swan AngelineC. , Goodman-Delahunty Jane
Published: May 2013

Research has shown a relationship between substance use and offending, but the nature of this relationship remains unclear, especially for women. To explore this, 867 female police detainees in New South Wales were interviewed to examine the temporal order of substance use and offending, correlates of substance use and offending, and relationships between social background, substance use, and offending. Offenses relating to substance use, such as possession, were excluded. Canonical correlations revealed a significant association between substance use and offending. Results of t-tests showed that substance use significantly preceded criminal offending. Younger, less-educated women self-reported more heroin and cannabis dependency. Women who self-reported drug dependency had higher levels of offending than those who did not. These results are markedly different from patterns observed in most male offenders. We review the implications of these findings for crime prevention, rehabilitation and substance abuse treatment.