bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyethyleneimine-facilitated high-capacity boronate affinity membrane and its application for the adsorption and enrichment of cis-diol-containing molecules
Authors: Ma Juan , Wang Chaozhan , Wei Yinmao
Published: April 2016

High capacity boronate affinity membranes were prepared for the first time, the membranes possess good selectivity, faster adsorption and desorption speed towards cis-diol-containing molecules.
A surface confined yttrium(iii) bis-phthalocyaninato complex: a colourful switch controlled by electrons
Authors: Alcón I. , Gonidec M. , Ajayakumar M. R. , Mas-Torrent M. , Veciana J.
Published: April 2016

SAMs of a Y(iii) double-decker complex on ITO have been prepared and their electrical and optical properties explored, exhibiting three accessible stable redox states with characteristic absorption bands in the visible spectra, corresponding to three complementary colors (i.e., green, blue and red).
Dendronized delayed fluorescence emitters for non-doped, solution-processed organic light-emitting diodes with high efficiency and low efficiency roll-off simultaneously: two parallel emissive channels
Authors: Li Yifan , Xie Guohua , Gong Shaolong , Wu Kailong , Yang Chuluo
Published: April 2016

Carbazole-dendronized TADF emitters enable non-doped, solution-processed OLEDs to achieve a high EQE of 13.8% and a low efficiency roll-off simultaneously.
Metal sulfide ion exchangers: superior sorbents for the capture of toxic and nuclear waste-related metal ions
Authors: Manos Manolis J. , Kanatzidis Mercouri G.
Published: April 2016

Metal sulfide ion-exchangers (MSIEs) have emerged as a new class of promising sorbents for the removal of toxic and radioactive metals from wastewater.
Copper-promoted site-selective carbonylation of sp3 and sp2 C–H bonds with nitromethane
Authors: Wu Xuesong , Miao Jinmin , Li Yanrong , Li Guigen , Ge Haibo
Published: April 2016

A copper-promoted site-selective carbonylation of sp2 and sp3 C–H bonds with nitromethane as an unprecedented source of carbonyl carbon is described.
Reversible polypeptide hydrogels from asymmetric telechelics with temperature-dependent and Ni2+-dependent connectors
Authors: Pham Thao T. H. , van der Gucht Jasper , Mieke Kleijn J. , Cohen Stuart Martien A.
Published: April 2016

An asymmetric (‘hybrid’) triblock polypeptide TR4H with two different, orthogonally self-assembling end blocks has been constructed by conjugating a long (37 kDa) random coil block (R4) with a triple helix former T = (Pro-Gly-Pro)9at the N terminus, and a histidine hexamer (‘Histag’, H) at the C terminus.
Self-assembled vesicle and rod-like aggregates of functionalized perylene diimide: reaction-based near-IR intracellular fluorescent probe for selective detection of palladium
Authors: Singh Prabhpreet , Mittal Lalit Singh , Vanita Vanita , Kumar Kapil , Walia Amandeep , Bhargava Gaurav , Kumar Subodh
Published: April 2016

Aggregates ofPS-PDIafter Pd0based depropargylation show de-aggregation and near-IR, ratiometric absorbance changes in water and live HeLa cells.
QSAR modeling for predicting reproductive toxicity of chemicals in rats for regulatory purposes
Authors: Basant Nikita , Gupta Shikha , Singh Kunwar P.
Published: April 2016

The figure shows the prediction performance of (a) DTF-QSAR and (b) DTB-QSAR models for pLOAEL (rat) in training and test data.
Characterization of Drosophila CMP-sialic acid synthetase activity reveals unusual enzymatic properties
Authors: Mertsalov Ilya B. , Novikov Boris N. , Scott Hilary , Dangott Lawrence , Panin Vladislav M.
Published: April 2016

CMP-sialic acid synthetase (CSAS) is a key enzyme of the sialylation pathway. CSAS produces the activated sugar donor, CMP-sialic acid, which serves as a substrate for sialyltransferases to modify glycan termini with sialic acid. Unlike other animal CSASs that normally localize in the nucleus, Drosophila melanogaster CSAS (DmCSAS) localizes in the cell secretory compartment, predominantly in the Golgi, which suggests that this enzyme has properties distinct from those of its vertebrate counterparts. To test this hypothesis, we purified recombinant DmCSAS and characterized its activity in vitro. Our experiments revealed several unique features of this enzyme. DmCSAS displays specificity for N-acetylneuraminic acid as a substrate, shows preference for lower pH and can function with a broad range of metal cofactors. When tested at a pH corresponding to the Golgi compartment, the enzyme showed significant activity with several metal cations, including Zn2+, Fe2+, Co2+ and Mn2+, whereas the activity with Mg2+ was found to be low. Protein sequence analysis and site-specific mutagenesis identified an aspartic acid residue that is necessary for enzymatic activity and predicted to be involved in co-ordinating a metal cofactor. DmCSAS enzymatic activity was found to be essential in vivo for rescuing the phenotype of DmCSAS mutants. Finally, our experiments revealed a steep dependence of the enzymatic activity on temperature. Taken together, our results indicate that DmCSAS underwent evolutionary adaptation to pH and ionic environment different from that of counterpart synthetases in vertebrates. Our data also suggest that environmental temperatures can regulate Drosophila sialylation, thus modulating neural transmission.
SLC transporters as a novel class of tumour suppressors: identity, function and molecular mechanisms
Authors: Bhutia Yangzom D. , Babu Ellappan , Ramachandran Sabarish , Yang Shengping , Thangaraju Muthusamy , Ganapathy Vadivel
Published: April 2016

The role of plasma membrane transporters in cancer is receiving increasing attention in recent years. Several transporters for essential nutrients are up-regulated in cancer and serve as tumour promoters. Transporters could also function as tumour suppressors. To date, four transporters belonging to the SLC gene family have been identified as tumour suppressors. SLC5A8 is a Na+-coupled transporter for monocarboxylates. Among its substrates are the bacterial fermentation products butyrate and propionate and the ubiquitous metabolite pyruvate. The tumour-suppressive function of this transporter relates to the ability of butyrate, propionate and pyruvate to inhibit histone deacetylases (HDAC). SLC5A8 functions as a tumour suppressor in most tissues studied thus far, and provides a molecular link to Warburg effect, a characteristic feature in most cancers. It also links colonic bacteria and dietary fibre to the host. SLC26A3 as a tumour suppressor is restricted to colon; it is a Cl−/HCO−3 exchanger, facilitating the efflux of HCO−3. The likely mechanism for the tumour-suppressive function of SLC26A3 is related to intracellular pH regulation. SLC39A1 is a Zn2+ transporter and its role in tumour suppression has been shown in prostate. Zn2+ is present at high concentrations in normal prostate where it elicits its tumour-suppressive function. SLC22A18 is possibly an organic cation transporter, but the identity of its physiological substrates is unknown. As such, there is no information on molecular pathways responsible for the tumour-suppressive function of this transporter. It is likely that additional SLC transporters will be discovered as tumour suppressors in the future.
Sexual dimorphism in the osmopressor response following water ingestion
Authors: Mendonca Goncalo V. , Teodósio Carolina , Lucena Rui , Pereira Fernando D.
Published: April 2016

There is conflicting evidence as to whether water drinking elicits a pressor response in healthy young adults. The inclusion of a variable number of women may have contributed to the discrepancies found in past research. Thus, we aimed at exploring whether the osmopressor response follows a sexually dimorphic pattern. In a randomized fashion, 31 healthy adults (16 men; 15 women, aged 18–40 years) ingested 50 and 500 ml of water before completing a resting protocol on two separate days. Arterial blood pressure, heart rate and spectral heart rate variability were measured in the seated position at pre- and post-25 min of water ingestion. Women responded to 500 ml of water with a greater proportion of change in diastolic and mean arterial pressure (MAP) (P<0.05). Conversely, the percent change in systolic blood pressure (SBP) and heart rate was not different between sexes after 500 ml of water. Overall, women demonstrated lower blood pressure, but higher resting heart rate compared with men (P<0.05). In contrast, heart rate variability was similar between sexes before and after ingesting either volume of water. There was a bradycardic effect of water and, irrespectively of sex; this was accompanied by increased high frequency power (HF) (P<0.05). We conclude that women display a greater magnitude of pressor response than men post-water ingestion. Accordingly, we provide direct evidence of sexual dimorphism in the haemodynamic response to water intake in young healthy adults.
Management of Persistent Cognitive Symptoms After Sport-Related Concussion
Authors: Sohlberg McKay Moore , Ledbetter Alexander K.
Published: April 2016

Purpose

This case review examines treatments speech-language pathologists at our clinic delivered to middle school, high school, and college students for the management of persistent cognitive symptoms after sport-related concussion. The goal is to examine a range of treatment options, describe clinical rationale for selecting those treatments, and report outcomes in order to identify feasible interventions for systematic evaluation through efficacy research.

Method

Review of clinic intake data identified 63 cases referred for cognitive rehabilitation over a 36-month period. Twenty-four cases (14 women and 10 men) met selection criteria, including documented sport-related concussion, postconcussion symptoms persisting at least 2 months with deleterious effect on school performance, and enrollment in secondary or postsecondary education. The authors independently coded demographics, treatment approaches, functional goal domains, and outcomes.

Results

Treatment approaches fell into 4 broad categories: direct attention training, metacognitive strategy training, training assistive technology for cognition, and psychoeducational supports. Eighty-three percent of clients achieved self-selected functional goals.

Conclusions

Research has focused primarily on return to play and provision of academic accommodations in the initial weeks following concussion. Findings from this case series suggest that speech-language pathologists can deliver individualized interventions that lead to positive clinical outcomes. The authors hope findings encourage efficacy research.
Does Excessive Attention to Speech Contribute to Stuttering? A Preliminary Study With a Reading Comprehension Task
Authors: Iimura Daichi , Uehara Shintaro , Yamamoto Shinji , Aihara Tsuyoshi , Kushiro Keisuke
Published: April 2016

People who stutter (PWS) presumably pay excessive attention to monitoring their speech, possibly exacerbating speech fluency. Using a reading comprehension task, we investigated whether or not PWS devote excessive attention to their speech.

Methods

Eleven PWS and 11 people who do not stutter (PNS) read passages in silent and oral reading conditions with and without noise masking, then answered comprehension questions. For PWS, auditory noise masking and silent reading would presumably divert their attention away from their speech.

Results

The comprehension performance of PWS was lower in the oral-no-masking condition than the oral-masking and silent-no-masking conditions. In contrast, there were no significant differences in the comprehension performance of PNS between the four conditions.

Conclusions

PWS had poor comprehension when listening to their speech, suggesting excessive attention to speech and limited attention to concurrent cognitive tasks.
Vision‐based position computation from in‐vehicle video log images for road sign inventory
Authors: Hu Zhaozheng , Li Na
Published: April 2016

Computing the positions of road signs from in‐vehicle video log images is one of the most fundamental tasks for intelligent sign inventory. This study analysed vision‐based positioning methods from video log images and proposed an analytic model of road sign positioning (AM‐RSP) based on error propagation and first‐order approximation. Both image noises and camera calibration errors were modelled as two error sources. The AM‐RSP model can evaluate and quantify the positioning uncertainties for both single view and stereo vision‐based methods. Moreover, it can quantitatively establish the relationship between the positioning uncertainties and the various parameters of the vehicle and the camera,such as camera focal length, view angle, baseline width, height, image acquisition interval, vehicle distance to the road edge etc. Hence, the proposed AM‐RSP model can be applied to configure the parameters of the camera and the vehicle to meet some specific computation requirement such as RSP accuracy. The proposed AM‐RSP model has been validated with real video log image data collected in the field. These results show that the AM‐RSP model is accurate and reliable to compute sign positioning uncertainties.
Experimental analysis of multistatic multiband radar signatures of wind turbines
Authors: Fioranelli Francesco , Ritchie Matthew , Balleri Alessio , Griffiths Hugh
Published: April 2016

This study presents the analysis of recent experimental data acquired using two radar systems at S‐band and X‐band to measure simultaneous monostatic and bistatic signatures of operational wind turbines near Shrivenham, UK. Bistatic and multistatic radars are a potential approach to mitigate the adverse effects of wind farm clutter on the performance of radar systems, which is a well‐known problem for air traffic control and air defence radar. This analysis compares the simultaneous monostatic and bistatic micro‐Doppler signatures of two operational turbines and investigates the key differences at bistatic angles up to 23°. The variations of the signature with different polarisations, namely vertical transmitted and vertical received and horizontal transmitted and horizontal received, are also discussed.
Dynamics and robustness of the cardiac progenitor cell induced pluripotent stem cell network during cell phenotypes transition
Authors: Yao Yuangen , Ma Chengzhang , Deng Haiyou , Liu Quan , Cao Wei , Gui Rong , Feng Tianquan , Yi Ming
Published: April 2016

Robustness is a fundamental characteristic of biological systems since all living systems need to adapt to internal or external perturbations, unpredictable environments, stochastic events and unreliable components, and so on. A long‐term challenge in systems biology is to reveal the origin of robustness underlying molecular regulator network. In this study, a simple Boolean model is used to investigate the global dynamic properties and robustness of cardiac progenitor cell (CPC) induced pluripotent stem cell network that governs reprogramming and directed differentiation process. It is demonstrated that two major attractors correspond to source and target cell phenotypes, respectively, and two dominating attracting trajectories characterise the biological pathways between two major cell phenotypes. In particular, the experimentally observed transition between different cell phenotypes can be reproduced and explained theoretically. Furthermore, the robustness of major attractors and trajectories is largely maintained with respect to small perturbations to the network. Taken together, the CPC‐induced pluripotent stem cell network is extremely robustly designed for their functions.
Optimisations in machine type communications for sensor data networking
Authors: Husain Syed , Prasad Athul , Kunz Andreas , Song JaeSeung , Koshimizu Takeshi
Published: April 2016

Currently, many sensor data networks are managed using machine‐to‐machine (M2M) or machine type communications (MTCs) technologies. One of the key factors for the success of sensor data networks is in developments of international M2M/MTC standards. As third generation partnership project (3GPP) and oneM2M are actively working on standardising M2M/MTC specifications for 3GPP core networks and M2M common service layer, this study reviews the ongoing activities in 3GPP and oneM2M standardisation bodies, in the area of machine type or M2M communications, focusing on enhancing device, service platform, and mobile network technologies that can be useful in achieving cost efficiencies in sensor data networks.
Developing intelligent software interface for wireless monitoring of vehicle speed and management of associated data
Authors: Ahsan Mominul , Haider Julfikar , McManis Jennifer , Hashmi M. Saleem J.
Published: April 2016

The aim of this work is to develop an intelligent wireless system for monitoring vehicle speed, identify speeding vehicles and imposing penalty for the speeding offenders. A prototype system has been developed in a laboratory environment to generate random speed data using a mechanical wheel (acts as a vehicle), measure the speed data with a Shimmer wireless sensor and transfer the data wirelessly to a server computer for further analysis. Software interface has been developed using Java based socket‐programming to monitor the vehicle speed in a server computer and to send the data associated with a speeding vehicle to a remotely placed client computer. The functionality of the software has been tested by experimenting different traffic scenarios. If the vehicle speed is higher than the set speed limit for the road, the system automatically detects it and generates a report with the time of speeding, vehicle number, vehicle speed, etc. The report is saved in a central database (client computer) in order to take further necessary actions for the speeding offender. The experimental evaluation results show that the system can measure and monitor the vehicle speeds wirelessly and manage the speeding data automatically.
Certified Descent Algorithm for shape optimization driven by fully-computablea posteriorierror estimators
Authors: Giacomini Matteo , Pantz Olivier , Trabelsi Karim
Published: April 2016

In this paper we introduce a novel certified shape optimization strategy – named Certified Descent Algorithm (CDA) – to account for the numerical error introduced by the Finite Element approximation of the shape gradient. We present a goal-oriented procedure to derive a certified upper bound of the error in the shape gradient and we construct a fully-computable, constant-freea posteriorierror estimator inspired by the complementary energy principle. The resulting CDA is able to identify a genuine descent direction at each iteration and features a reliable stopping criterion. After validating the error estimator, some numerical simulations of the resulting certified shape optimization strategy are presented for the well-known inverse identification problem of Electrical Impedance Tomography.
Transoral Segmental Resection and Disarticulation of Mandible with Immediate Nonvascularized Reconstruction: A Case Report
Authors: Gupta Hemant , Singh Deepak , Gupta Sumit , Mehra Hemant , Singh Jasmeet , Mishra Ravish
Published: April 2016

Disarticulation resections are required for treatment of variety of pathologies of the jaws. These resections are mostly carried out through extraoral approach, which bear significant postoperative morbidity. The transoral approach may be used for this purpose in benign pathological cases of the mandible to limit the postoperative morbidity of extraoral approach, as it provides sufficient access not only for resection and disarticulation but also for immediate reconstruction. This article shares our experience with transoral approach for resection and disarticulation in a case of kerato cystic odontogenic tumor and simultaneous reconstruction. Excellent cosmetic and functional results were observed in 6-month follow-up.
Critical gender studies and international development studies: interdisciplinarity, intellectual agility and inclusion
Authors: Underhill-Sem Yvonne
Published: April 2016

Critical gender studies and international development studies are both interdisciplinary, but intellectual agility can ensure they are inclusive sites of knowledge production. To develop intellectual agility, which underpins progressive interdisciplinarity, students must paradoxically venture into more closely defined disciplinary traditions in the social sciences, the humanities and the sciences. Intellectual agility begins by being fully cognizant of epistemological and theoretical framings in substantive debates, such as, for instance, the perpetuation of violence against women or the entrenchment of poverty. I argue that by explicitly tethering ideas to disciplinary traditions, interdisciplinary research and teaching can more successfully address pressing international development concerns in an inclusive manner. International development studies can easily be seen as utilitarian and instrumental just as critical gender studies can easily be seen as impractical and vague. Here, I show how I have worked critical gender studies into international development studies so that students can develop intellectual agility. Underpinning this is the call for progressive interdisciplinary research and teaching delinked from the defensive claims of long-standing scholarly traditions or the aspirational ambitions of newly cast bodies of knowledge. This article is published as part of a thematic collection dedicated to multi- and interdisciplinary perspectives on gender studies.
Input-output analysis of high-speed axisymmetric isothermal jet noise
Authors: Jeun Jinah , Nichols Joseph W. , Jovanović Mihailo R.
Published: April 2016

We use input-output analysis to predict and understand the aeroacoustics of high-speed isothermal turbulent jets. We consider axisymmetric linear perturbations about Reynolds-averaged Navier-Stokes solutions of ideally expanded turbulent jets with jet Mach numbers 0.6 < Mj < 1.8. For each base flow, we compute the optimal harmonic forcing function and the corresponding linear response using singular value decomposition of the resolvent operator. In addition to the optimal mode, input-output analysis also yields sub-optimal modes associated with smaller singular values. For supersonic jets, the optimal response closely resembles a wavepacket in both the near-field and the far-field such as those obtained by the parabolized stability equations (PSE), and this mode dominates the response. For subsonic jets, however, the singular values indicate that the contributions of sub-optimal modes to noise generation are nearly equal to that of the optimal mode, explaining why the PSE do not fully capture the far-field sound in this case. Furthermore, high-fidelity large eddy simulation (LES) is used to assess the prevalence of sub-optimal modes in the unsteady data. By projecting LES source term data onto input modes and the LES acoustic far-field onto output modes, we demonstrate that sub-optimal modes of both types are physically relevant.
A universal preconditioner for simulating condensed phase materials
Authors: Packwood David , Kermode James , Mones Letif , Bernstein Noam , Woolley John , Gould Nicholas , Ortner Christoph , Csányi Gábor
Published: April 2016

We introduce a universal sparse preconditioner that accelerates geometry optimisation and saddle point search tasks that are common in the atomic scale simulation of materials. Our preconditioner is based on the neighbourhood structure and we demonstrate the gain in computational efficiency in a wide range of materials that include metals, insulators, and molecular solids. The simple structure of the preconditioner means that the gains can be realised in practice not only when using expensive electronic structure models but also for fast empirical potentials. Even for relatively small systems of a few hundred atoms, we observe speedups of a factor of two or more, and the gain grows with system size. An open source Python implementation within the Atomic Simulation Environment is available, offering interfaces to a wide range of atomistic codes.
Orbit-based analysis of nonlinear energetic ion dynamics in tokamaks. II. Mechanisms for rapid chirping and convective amplification
Authors: Bierwage Andreas , Shinohara Kouji
Published: April 2016

The nonlinear interactions between shear Alfvén modes and tangentially injected beam ions in the 150–400 keV range are studied numerically in realistic geometry for a JT-60U tokamak scenario. In Paper I, which was reported in the companion paper, the recently developed orbit-based resonance analysis method was used to track the resonant frequency of fast ions during their nonlinear evolution subject to large magnetic and electric drifts. Here, that method is applied to map the wave-particle power transfer from the canonical guiding center phase space into the frequency-radius plane, where it can be directly compared with the evolution of the fluctuation spectra of fast-ion-driven modes. Using this technique, we study the nonlinear dynamics of strongly driven shear Alfvén modes with low toroidal mode numbers n = 1 and n = 3. In the n = 3 case, both chirping and convective amplification can be attributed to the mode following the resonant frequency of the radially displaced particles, i.e., the usual one-dimensional phase locking process. In the n = 1 case, a new chirping mechanism is found, which involves multiple dimensions, namely, wave-particle trapping in the radial direction and phase mixing across velocity coordinates.
Study of clathrate hydrates via equilibrium molecular-dynamics simulation employing polarisable and non-polarisable, rigid and flexible water models
Authors: Burnham Christian J. , English Niall J.
Published: April 2016

Equilibrium molecular-dynamics (MD) simulations have been performed on metastable sI and sII polymorphs of empty hydrate lattices, in addition to liquid water and ice Ih. The non-polarisable TIP4P-2005, simple point charge model (SPC), and polarisable Thole-type models (TTM): TTM2, TTM3, and TTM4 water models were used in order to survey the differences between models and to see what differences can be expected when polarisability is incorporated. Rigid and flexible variants were used of each model to gauge the effects of flexibility. Power spectra are calculated and compared to density-of-states spectra inferred from inelastic neutron scattering (INS) measurements. Thermodynamic properties were also calculated, as well as molecular-dipole distributions. It was concluded that TTM models offer optimal fidelity vis-à-vis INS spectra, together with thermodynamic properties, with the flexible TTM2 model offering optimal placement of vibrational modes.
Weak intramolecular interaction effects on the torsional spectra of ethylene glycol, an astrophysical species
Authors: Boussessi R. , Senent M. L. , Jaïdane N.
Published: April 2016

An elaborate variational procedure of reduced dimensionality based on explicitly correlated coupled clusters calculations is applied to understand the far infrared spectrum of ethylene-glycol, an astrophysical species. This molecule can be classified in the double molecular symmetry group G8 and displays nine stable conformers, gauche and trans. In the gauche region, the effect of the potential energy surface anisotropy due to the formation of intramolecular hydrogen bonds is relevant. For the primary conformer, stabilized by a hydrogen bond, the ground vibrational state rotational constants are computed to be A0 = 15 369.57 MHz, B0 = 5579.87 MHz, and C0 = 4610.02 MHz corresponding to differences of 6.3 MHz, 7.2 MHz, and 3.5 MHz from the experimental parameters. Ethylene glycol displays very low torsional energy levels whose classification is not straightforward and requires a detailed analysis of the torsional wavefunctions. Tunneling splittings are significant and unpredictable due to the anisotropy of the potential energy surface PES. The ground vibrational state splits into 16 sublevels separated ∼142 cm−1. The splitting of the “G1 sublevels” was calculated to be ∼0.26 cm−1 in very good agreement with the experimental data (0.2 cm−1 = 6.95 MHz). Transitions corresponding to the three internal rotation modes allow assignment of previously observed Q branches. Band patterns, calculated between 362.3 cm−1 and 375.2 cm−1, 504 cm−1 and 517 cm−1, and 223.3 cm−1 and 224.1 cm−1, that correspond to the tunnelling components of the v21 fundamental (v21 = OH-torsional mode), are assigned to the prominent experimental Q branches.
Note: “Exact” quantum Monte Carlo calculations of the barrier for the H + H2 reaction at the sub-microhartree level
Authors: Anderson James B.
Published: April 2016

We report the third in a series of ’exact’ quantum Monte Carlo calculations for the potential energy of the saddle point of the barrier for the reaction H + H2 → H2 + H. The barrier heights determined are 9.61 ± 0.01 in 1992/94, 9.608 ± 0.001 in 2003, and 9.6089 ± 0.0001 in 2016 (this work), all in kcal/mole and successively a factor of ten more accurate. The new value is below the lowest value from explicitly correlated Gaussian calculations and within the estimated limits of extrapolated multireference configuration calculations.
Generalized interactions supported on hypersurfaces
Authors: Exner Pavel , Rohleder Jonathan
Published: April 2016

We analyze a family of singular Schrödinger operators with local singular interactions supported by a hypersurface Σ ⊂ ℝn, n ≥ 2, being the boundary of a Lipschitz domain, bounded or unbounded, not necessarily connected. At each point of Σ the interaction is characterized by four real parameters, the earlier studied case of δ- and δ′-interactions being particular cases. We discuss spectral properties of these operators and derive operator inequalities between those referring to the same hypersurface but different couplings and describe their implications for spectral properties.
Edge localized mode rotation and the nonlinear dynamics of filaments
Authors: Morales J. A. , Bécoulet M. , Garbet X. , Orain F. , Dif-Pradalier G. , Hoelzl M. , Pamela S. , Huijsmans G. T. A. , Cahyna P. , Fil A. , Nardon E. , Passeron C. , Latu G.
Published: April 2016

Edge Localized Modes (ELMs) rotating precursors were reported few milliseconds before an ELM crash in several tokamak experiments. Also, the reversal of the filaments rotation at the ELM crash is commonly observed. In this article, we present a mathematical model that reproduces the rotation of the ELM precursors as well as the reversal of the filaments rotation at the ELM crash. Linear ballooning theory is used to establish a formula estimating the rotation velocity of ELM precursors. The linear study together with nonlinear magnetohydrodynamic simulations give an explanation to the rotations observed experimentally. Unstable ballooning modes, localized at the pedestal, grow and rotate in the electron diamagnetic direction in the laboratory reference frame. Approaching the ELM crash, this rotation decreases corresponding to the moment when the magnetic reconnection occurs. During the highly nonlinear ELM crash, the ELM filaments are cut from the main plasma due to the strong sheared mean flow that is nonlinearly generated via the Maxwell stress tensor.
Complex formation between polyelectrolytes and oppositely charged oligoelectrolytes
Authors: Zhou Jiajia , Barz Matthias , Schmid Friederike
Published: April 2016

We study the complex formation between one long polyanion chain and many short oligocation chains by computer simulations. We employ a coarse-grained bead-spring model for the polyelectrolyte chains and model explicitly the small salt ions. We systematically vary the concentration and the length of the oligocation and examine how the oligocations affects the chain conformation, the static structure factor, the radial and axial distribution of various charged species, and the number of bound ions in the complex. At low oligocation concentration, the polyanion has an extended structure. Upon increasing the oligocation concentration, the polyanion chain collapses and forms a compact globule, but the complex still carries a net negative charge. Once the total charge of the oligocations is equal to that of the polyanion, the collapse stops and is replaced by a slow expansion. In this regime, the net charge on the complexes is positive or neutral, depending on the microion concentration in solution. The expansion can be explained by the reduction of the oligocation bridging. We find that the behavior and the structure of the complex are largely independent of the length of oligocations, and very similar to that observed when replacing the oligocations by multivalent salt cations, and conclude that the main driving force keeping the complex together is the release of monovalent counterions and coions. We speculate on the implications of this finding for the problem of controlled oligolyte release and oligolyte substitution.
Rashba splitting of 100 meV in Au-intercalated graphene on SiC
Authors: Marchenko D. , Varykhalov A. , Sánchez-Barriga J. , Seyller Th. , Rader O.
Published: April 2016

Intercalation of Au can produce giant Rashba-type spin-orbit splittings in graphene, but this has not yet been achieved on a semiconductor substrate. For graphene/SiC(0001), Au intercalation yields two phases with different doping. We observe a 100 meV Rashba-type spin-orbit splitting at 0.9 eV binding energy in the case of p-type graphene after Au intercalation. We show that this giant splitting is due to hybridization and much more limited in energy and momentum space than for Au-intercalated graphene on Ni.
Synchronization criteria for generalized reaction-diffusion neural networks via periodically intermittent control
Authors: Gan Qintao , Lv Tianshi , Fu Zhenhua
Published: April 2016

In this paper, the synchronization problem for a class of generalized neural networks with time-varying delays and reaction-diffusion terms is investigated concerning Neumann boundary conditions in terms of p-norm. The proposed generalized neural networks model includes reaction-diffusion local field neural networks and reaction-diffusion static neural networks as its special cases. By establishing a new inequality, some simple and useful conditions are obtained analytically to guarantee the global exponential synchronization of the addressed neural networks under the periodically intermittent control. According to the theoretical results, the influences of diffusion coefficients, diffusion space, and control rate on synchronization are analyzed. Finally, the feasibility and effectiveness of the proposed methods are shown by simulation examples, and by choosing different diffusion coefficients, diffusion spaces, and control rates, different controlled synchronization states can be obtained.
Difficulty of carrier generation in orthorhombic PbO
Authors: Liao Min , Takemoto Seiji , Xiao Zewen , Toda Yoshitake , Tada Tomofumi , Ueda Shigenori , Kamiya Toshio , Hosono Hideo
Published: April 2016

Polycrystalline β-PbO films were grown by pulsed laser deposition in atmospheres ranging from oxygen-poor (the oxygen pressure of 0.01 Pa) to oxygen-rich (13 Pa) conditions, and the oxygen chemical potential was further enhanced by ozone annealing to examine hole doping. It was found that each of the as-grown β-PbO films showed poor electrical conductivity, σ < 1.4 × 10−7 S cm−1, regardless of the oxygen pressure. The density functional calculations revealed that native defects including Pb and O vacancies have deep transition levels and extremely high formation enthalpies, which indicates difficulty of carrier generation in β-PbO and explains the experimentally observed poor electrical conductivity. The analysis of the electronic structures showed that the interaction between Pb 6s and O 2p orbitals is weak due to the deep energy level of Pb 6s and does not raise the valence band maximum (VBM) level unlike that observed in SnO, which is also supported by ultraviolet photoemission spectroscopy measurements. The deep acceptor transition levels of the native defects are attributed to the deep VBM of β-PbO. On the other hand, annealing β-PbO films in reactive oxygen-containing atmospheres (i.e., O3) led to a significantly enhanced electrical conductivity (i.e., σ > 7.1 × 102 S cm−1) but it is the result of the formation of an n-type PbO2 phase because oxygen chemical potential exceeded the phase boundary limit. The striking difference in carrier generation between PbO and SnO is discussed based on the electronic structures calculated by density functional theory.
Kr photoionized plasma induced by intense extreme ultraviolet pulses
Authors: Bartnik A. , Wachulak P. , Fiedorowicz H. , Skrzeczanowski W.
Published: April 2016

Irradiation of any gas with an intense EUV (extreme ultraviolet) radiation beam can result in creation of photoionized plasmas. The parameters of such plasmas can be significantly different when compared with those of the laser produced plasmas (LPP) or discharge plasmas. In this work, the photoionized plasmas were created in a krypton gas irradiated using an LPP EUV source operating at a 10 Hz repetition rate. The Kr gas was injected into the vacuum chamber synchronously with the EUV radiation pulses. The EUV beam was focused onto a Kr gas stream using an axisymmetrical ellipsoidal collector. The resulting low temperature Kr plasmas emitted electromagnetic radiation in the wide spectral range. The emission spectra were measured either in the EUV or an optical range. The EUV spectrum was dominated by emission lines originating from Kr III and Kr IV ions, and the UV/VIS spectra were composed from Kr II and Kr I lines. The spectral lines recorded in EUV, UV, and VIS ranges were used for the construction of Boltzmann plots to be used for the estimation of the electron temperature. It was shown that for the lowest Kr III and Kr IV levels, the local thermodynamic equilibrium (LTE) conditions were not fulfilled. The electron temperature was thus estimated based on Kr II and Kr I species where the partial LTE conditions could be expected.
Noisy coupled logistic maps in the vicinity of chaos threshold
Authors: Tirnakli Ugur , Tsallis Constantino
Published: April 2016

We focus on a linear chain of N first-neighbor-coupled logistic maps in the vicinity of their edge of chaos in the presence of a common noise. This model, characterised by the coupling strength ϵ and the noise width σmax, was recently introduced by Pluchino et al. [Phys. Rev. E 87, 022910 (2013)]. They detected, for the time averaged returns with characteristic return time τ, possible connections with q-Gaussians, the distributions which optimise, under appropriate constraints, the nonadditive entropy, Sq, basis of nonextensive statistics mechanics. Here, we take a closer look on this model, and numerically obtain probability distributions which exhibit a slight asymmetry for some parameter values, in variance with simple q-Gaussians. Nevertheless, along many decades, the fitting with q-Gaussians turns out to be numerically very satisfactory for wide regions of the parameter values, and we illustrate how the index q evolves with (N,τ,ϵ,σmax). It is nevertheless instructive on how careful one must be in such numerical analysis. The overall work shows that physical and/or biological systems that are correctly mimicked by this model are thermostatistically related to nonextensive statistical mechanics when time-averaged relevant quantities are studied.
Screening charge localization at LiNbO3 surface with Schottky junction
Authors: Nagata Takahiro , Chikyow Toyohiro , Kitamura Kenji
Published: April 2016

Screening charge localization was demonstrated by using a Schottky contact with LiNbO3 (LN). A Cr/LN stack structure with a 2 μm diameter hole array penetrating the Cr layer localized the screening charge of LN in the hole, although the Al/LN stack structure exhibited no surface charge localization behavior. X-ray photoelectron spectroscopy revealed that Cr formed a Schottky contact with LN, which prevents the screening charge from escaping from the hole arrays. The screening charge localization was enhanced by inserting SiO2 between the metal and LN, which moved the position of the Fermi level to mid gap.
Superhydrophobicity on nanostructured porous hydrophilic material
Authors: Jiang Hong-Ren , Chan Deng-Chi
Published: April 2016

By applying laser oxidation, ablation, and plasma treatment to modify a surface of polydimethylsiloxane, we show that creating hydrophobic sites on an originally superhydrophilic nanostructured porous surface greatly changes the wetting properties of the surface. The modified surface may even become superhydrophobic while the ratio of added hydrophobic site to the surface is relatively low. The relation between the contact angles and the effect of hydrophobic sites is further tested in blade scraping method and a similar result is also obtained. This method to achieve superhydrophobicity on the hydrophilic nanostructured porous material may open possibilities for achieving superhydrophobicity and enable functional superhydrophobic surfaces with heterogeneous components.
High-sensitivity two-terminal magnetoresistance devices using InGaAs/AlGaAs two-dimensional channel on GaAs substrate
Authors: Wu Di-Cheng , Pan You-Wei , Wu Jenq-Shinn , Lin Shih-Wei , Lin Sheng-Di
Published: April 2016

We demonstrate experimentally the two-terminal magnetic sensors exhibiting an extraordinary magneto-resistance effect by using an InGaAs quantum well channel with a metal-shunting structure. A high magneto-resistance of 17.3% and a sensitivity of 488.1 Ω/T have been obtained at 1 T and room temperature with our geometrical design. The two-contact configuration and the high-mobility electron transistor-compatible epitaxy structure make the devices promising for high-sensitivity magnetic sensing integration and applications.
Melt front propagation in dielectrics upon femtosecond laser irradiation: Formation dynamics of a heat-affected layer
Authors: Garcia-Lechuga Mario , Solis Javier , Siegel Jan
Published: April 2016

Several studies in dielectrics have reported the presence of a thin heat-affected layer underneath the ablation crater produced by femtosecond laser irradiation. In this work, we present a time-resolved microscopy technique that is capable of monitoring the formation dynamics of this layer and apply it to the study of a phosphate glass exposed to single pulses below the ablation threshold. A few nanoseconds after laser excitation, a melt front interface can be detected, which propagates into the bulk, gradually slowing down its speed. By means of image analysis combined with optical modeling, we are able to determine the temporal evolution of the layer thickness and its refractive index. Initially, a strong transient decrease in the refractive index is observed, which partially recovers afterwards. The layer resolidifies after approximately 1 μs after excitation, featuring a maximum thickness of several hundreds of nanometers.
Understanding the difference in cohesive energies between alpha and beta tin in DFT calculations
Authors: Legrain Fleur , Manzhos Sergei
Published: April 2016

The transition temperature between the low-temperature alpha phase of tin to beta tin is close to the room temperature (Tαβ = 130C), and the difference in cohesive energy of the two phases at 0 K of about ΔEcoh =0.02 eV/atom is at the limit of the accuracy of DFT (density functional theory) with available exchange-correlation functionals. It is however critically important to model the relative phase energies correctly for any reasonable description of phenomena and technologies involving these phases, for example, the performance of tin electrodes in electrochemical batteries. Here, we show that several commonly used and converged DFT setups using the most practical and widely used PBE functional result in ΔEcoh ≈0.04 eV/atom, with different types of basis sets and with different models of core electrons (all-electron or pseudopotentials of different types), which leads to a significant overestimation of Tαβ. We show that this is due to the errors in relative positions of s and p –like bands, which, combined with different populations of these bands in α and β Sn, leads to overstabilization of alpha tin. We show that this error can be effectively corrected by applying a Hubbard +U correction to s –like states, whereby correct cohesive energies of both α and β Sn can be obtained with the same computational scheme. We quantify for the first time the effects of anharmonicity on ΔEcoh and find that it is negligible.
An Organobase (TBD)-Anchored Mesoporous Silica Nanoparticle-Catalyzed Green Synthesis of Dihydropyrano[2,3-c]pyrazoles
Authors: Karmakar Bikash
Published: April 2016

An efficient, mild, and environmental friendly method has been developed for the synthesis of dihydropyrano[2,3-c]pyrazole in ethanolic water over 1,5,7-triazabicyclo-[4,4,0]-dec-1-ene (TBD)-anchored mesoporous silica nanoparticle catalyst. The method involves the assembly of ethyl acetoacetate, hydrazine hydrate, different aldehydes, and malononitrile. It affords the corresponding product in high yield with short reaction times, while employing a very low loading of catalyst. The catalyst was reused several times without significant loss in activity.
Mass dependent processes can generate an isotope anomaly: the effect of ordinary diffusion on Δ17O in solids
Authors: Campisi Laura Donatella
Published: April 2016

Environmental contextThe nitrate oxygen isotope anomaly has been suggested as a tool for quantifying the atmospheric input of this essential nutrient to terrestrial environments. However, it is calculated that the most important transport process in minerals, diffusion, may also be responsible for measurable anomalies. The signal in Chilean nitrate minerals could be associated with diffusion during crystal growth so the belief that the nitrate is entirely of atmospheric origin is therefore questioned.
AbstractCalculated diffusion profiles assuming the classical mass dependence of diffusion coefficients indicate that important Δ17O gradients could be measured in geological samples. The belief that the MIF (mass independent fractionation) signature can be used as a tracer of atmospheric processes because mass dependent processes cannot significantly alter the signal is therefore questioned. Oxygen delta values in a three-isotope plot could lie on a straight line of slope 0.5 or 1 when diffusion is approximately a linear process. Diffusion during nitratine (NaNO3) growth could be partially responsible for measured Δ17O in nitrate deposits from Atacama Desert (Chile) and Turpan-Hami Basin (China).
Developmental evidence for obstetric adaptation of the human female pelvis
Authors: Huseynov Alik , Zollikofer Christoph P. E. , Coudyzer Walter , Gascho Dominic , Kellenberger Christian , Hinzpeter Ricarda , Ponce de León Marcia S.
Published: April 2016

Significance

The obstetrical dilemma hypothesis states that the human female pelvis represents a compromise between designs most suitable for childbirth and bipedal locomotion, respectively. This hypothesis has been challenged recently on biomechanical, metabolic, and biocultural grounds. Here we provide evidence for the pelvis’ developmental adaptation to the problem of birthing large-headed/large-bodied babies. We show that the female pelvis reaches its obstetrically most adequate morphology around the time of maximum fertility but later reverts to a mode of development similar to that of males, which significantly reduces the dimensions of the birth canal. These developmental changes are likely mediated by hormonal changes during puberty and menopause, indicating “on-demand” adjustment of pelvic shape to the needs of childbirth.