bluuebunny/crossref_metadata_2025 huggingface dataset:
Alkaline earth metal and samarium co-doped ceria as efficient electrolytes
Authors: Ali Amjad , Raza Rizwan , Kaleem Ullah M. , Rafique Asia , Wang Baoyuan , Zhu Bin
Published: January 2018

Co-doped ceramic electrolytes M0.1Sm0.1Ce0.8O2−δ (M = Ba, Ca, Mg, and Sr) were synthesized via co-precipitation. The focus of this study was to highlight the effects of alkaline earth metals in doped ceria on the microstructure, densification, conductivity, and performance. The ionic conductivity comparisons of prepared electrolytes in the air atmosphere were studied. It has been observed that Ca0.1Sm0.1Ce0.8O2−δ shows the highest conductivity of 0.124 Scm−1 at 650 °C and a lower activation energy of 0.48 eV. The cell shows a maximum power density of 630 mW cm−2 at 650 °C using hydrogen fuel. The enhancement in conductivity and performance was due to increasing the oxygen vacancies in the ceria lattice with the increasing dopant concentration. The bandgap was calculated from UV-Vis data, which shows a red shift when compared with pure ceria. The average crystallite size is in the range of 37–49 nm. DFT was used to analyze the co-doping structure, and the calculated lattice parameter was compared with the experimental lattice parameter.
A high-resolution photoelectron imaging and theoretical study of CP− and C2P−
Authors: Czekner Joseph , Cheung Ling Fung , Johnson Eric L. , Fortenberry Ryan C. , Wang Lai-Sheng
Published: January 2018

The discovery of interstellar anions has been a milestone in astrochemistry. In the search for new interstellar anions, CP− and C2P− are viable candidates since their corresponding neutrals have already been detected astronomically. However, scarce data exist for these negatively charged species. Here we report the electron affinities of CP and C2P along with the vibrational frequencies of their anions using high-resolution photoelectron imaging. These results along with previous spectroscopic data of the neutral species are used further to benchmark very accurate quartic force field quantum chemical methods that are applied to CP, CP−, C2P, and two electronic states of C2P−. The predicted electron affinities, vibrational frequencies, and rotational constants are in excellent agreement with the experimental data. The electron affinities of CP (2.8508 ± 0.0007 eV) and C2P (2.6328 ± 0.0006 eV) are measured accurately and found to be quite high, suggesting that the CP− and C2P− anions are thermodynamically stable and possibly observable. The current study suggests that the combination of high-resolution photoelectron imaging and quantum chemistry can be used to determine accurate molecular constants for exotic radical species of astronomical interest.
Threshold behavior and uniqueness of ground states for mass critical inhomogeneous Schrödinger equations
Authors: Deng Yinbin , Guo Yujin , Lu Lu
Published: January 2018

We study ground states of mass critical Schrödinger equations with spatially inhomogeneous nonlinearities in R2 by analyzing the associated L2-constraint Gross-Pitaevskii energy functionals. In contrast to the homogeneous case where m(x) ≡ 1, we prove that both the existence and nonexistence of ground states may occur at the threshold a* depending on the inhomogeneity of m(x). Under some assumptions on m(x) and the external potential V(x), the uniqueness and radial symmetry of ground states are analyzed for almost every a ∈ [0, a*). When there is no ground state at the threshold a*, the limit behavior of ground states as a ↗ a* is also investigated if V(x) reaches its global minimum in a domain Ω with positive Lebesgue measure and m(x) attains its global maximum at finite points. We show that all the mass concentrates at a flattest global maximum of m(x) within Ω.
Effects of spatial gradients in thermophysical properties on the topology of turbulence in heated channel flow of supercritical fluids
Authors: Azih Chukwudi , Yaras Metin I.
Published: January 2018

The current literature suggests that large spatial gradients of thermophysical properties, which occur in the vicinity of the pseudo-critical thermodynamic state, may result in significant variations in forced-convection heat transfer rates. Specifically, these property gradients induce inertia- and buoyancy-driven phenomena that may enhance or deteriorate the turbulence-dominated heat convection process. Through direct numerical simulations, the present study investigates the role of coherent flow structures in channel geometries for non-buoyant and buoyant flows of supercritical water, with buoyant configurations involving wall-normal oriented gravitational acceleration and downstream-oriented gravitational acceleration. This sequence of simulations enables the evaluation of the relative contributions of inertial and buoyancy phenomena to heat transfer variations. In these simulations, the state of the working fluid is in the vicinity of the pseudo-critical point. The uniform wall heat flux and the channel mass flux are specified such that the heat to mass flux ratio is 3 kJ/kg, with an inflow Reynolds number of 12 000 based on the channel hydraulic diameter, the area-averaged inflow velocity, and fluid properties evaluated at the bulk temperature and pressure of the inflow plane. In the absence of buoyancy forces, notable reductions in the density and viscosity in close proximity of the heated wall are observed to promote generation of small-scale vortices, with resultant breakdown into smaller scales as they interact with preexisting larger near-wall vortices. This interaction results in a reduction in the overall thermal mixing at particular wall-normal regions of the channel. Under the influence of wall-normal gravitational acceleration, the wall-normal density gradients are noted to enhance ejection motions due to baroclinic vorticity generation on the lower wall, thus providing additional wall-normal thermal mixing. Along the upper wall, the same mechanism generates streamwise vorticity of the opposing sense of rotation in the close vicinity to the respective legs of the hairpin vortices causing a net reduction in thermal mixing. Finally, in the case of downstream-oriented gravitational acceleration, baroclinic vorticity generation as per spanwise density gradients causes additional wall-normal thermal mixing by promoting larger-scale ejection and sweep motions.
Effects of blockage, arrangement, and channel dynamics on performance of turbines in a tidal array
Authors: Gong Xianliang , Li Ye , Lin Zhiliang
Published: January 2018

The performance and economics of turbines in a tidal array are largely dependent on the power per turbine, and so, approaches that can increase this power are crucial for the development of tidal energy. In this paper, we combine a two-scale partial array model and a one-dimensional channel model to investigate the effects of blockage, turbine arrangement, and channel dynamics on tidal turbines. The power per turbine is obtained as the product of two parameters: a power coefficient measuring the power acquired from the instantaneous flow and an environment coefficient showing the response of the channel to added drag. The results suggest that taking account of channel dynamics will decrease the predicted power and the optimal induction factor. The model also shows that when the number of turbines in a row is increased, the power per turbine may monotonically increase or decrease or attain a maximum value at a certain global blockage. These different results depend on two characteristic parameters of the channel: α and λD. Furthermore, we find that besides turbine density (blockage), the arrangement of the turbines should also be considered if we want to obtain an efficient array. Appropriate arrangements can enhance the performance of turbines in tidal channels although the beneficial effects will be partly offset by reduced velocities. The turbine arrangement also has an effect on the optimal global blockage at which the power attains its maximum value. As the rate of increase of the power per turbine from an array spanning the whole channel width to the optimal partial array diminishes with increasing blockage, the optimal global blockage will also decrease.
Near-infrared in situ generation of the higher-energy trans conformer of tribromoacetic acid: Observation of a large-scale matrix-site changing mediated by conformational conversion
Authors: Apóstolo Rui F. G. , Bazsó Gábor , Ogruc-Ildiz Gulce , Tarczay György , Fausto Rui
Published: January 2018

The first observation of the higher-energy conformer of tribromoacetic acid (trans-TBAA) is reported. The conformer was produced in cryogenic matrices (Ar, Kr, and N2) by in situ selective narrowband near-infrared excitation of the lower-energy cis-TBAA conformer and characterized both structurally and vibrationally. The novel trans-TBAA conformer is shown to spontaneously decay to the most stable cis-TBAA form in all studied matrix media, by tunneling, and the measured decay rates in the different matrices were compared with those of the trans conformers of other carboxylic acids in similar experimental conditions. In the N2 matrix, where trans-TBAA establishes a specific stabilizing intermolecular interaction with the host N2 molecules via its OH group and is about 11 times more stable than in rare gas matrices, the effect of changing the irradiation wavenumber within the 2νOH absorption profile was investigated in detail. An interesting phenomenon of matrix-site changing mediated by conformational conversion was observed in the N2 matrix: vibrational excitation of cis-TBAA in the 2νOH wavenumber range predominantly converts the molecules located in a specific “matrix site” into trans-TBAA; then, relaxation (by tunneling) of the produced higher-energy conformer back to the cis form populates almost exclusively another “matrix site.” The experimental studies received support from quantum chemistry calculations, which allowed a detailed characterization of the relevant regions of the potential energy surface of the molecule and the detailed assignment of the infrared spectra of the two conformers in the various matrices.
A laser heating facility for energy-dispersive X-ray absorption spectroscopy
Authors: Kantor I. , Marini C. , Mathon O. , Pascarelli S.
Published: January 2018

A double-sided laser heating setup for diamond anvil cells installed on the ID24 beamline of the ESRF is presented here. The setup geometry is specially adopted for the needs of energy-dispersive X-ray absorption spectroscopic (XAS) studies of materials under extreme pressure and temperature conditions. We illustrate the performance of the facility with a study on metallic nickel at 60 GPa. The XAS data provide the temperature of the melting onset and quantitative information on the structural parameters of the first coordination shell in the hot solid up to melting.
Thermal detection of single e-h pairs in a biased silicon crystal detector
Authors: Romani R. K. , Brink P. L. , Cabrera B. , Cherry M. , Howarth T. , Kurinsky N. , Moffatt R. A. , Partridge R. , Ponce F. , Pyle M. , Tomada A. , Yellin S. , Yen J. J. , Young B. A.
Published: January 2018

We demonstrate that individual electron-hole pairs are resolved in a 1 cm2 by 4 mm thick silicon crystal (0.93 g) operated at ∼35 mK. One side of the detector is patterned with two quasiparticle-trap-assisted electro-thermal-feedback transition edge sensor arrays held near ground potential. The other side contains a bias grid with 20% coverage. Bias potentials up to ±160 V were used in the work reported here. A fiber optic provides 650 nm (1.9 eV) photons that each produce an electron-hole (e– h+) pair in the crystal near the grid. The energy of the drifting charges is measured with a phonon sensor noise σ ∼0.09 e– h+ pair. The observed charge quantization is nearly identical for h+s or e–s transported across the crystal.
G-factor and well width variations for the two-dimensional hole gas in surface conducting diamond
Authors: Akhgar Golrokh , Creedon Daniel L. , Willems van Beveren Laurens H. , Stacey Alastair , Hoxley David I. , McCallum Jeffrey C. , Ley Lothar , Hamilton Alex R. , Pakes Christopher I.
Published: January 2018

Hydrogen-terminated diamond possesses a quasi two-dimensional, sub-surface hole accumulation layer with a strong and tunable spin-orbit coupling due to surface transfer doping. We report a magnetoresistance study of the phase coherent backscattering (weak localization and antilocalization) at low temperatures. The response to an external magnetic field is highly anisotropic, confirming the 2D nature of the carriers despite the short mean free path. By simultaneously applying perpendicular and parallel magnetic fields, we are able to probe the Zeeman interaction and microroughness of the quantum well at the diamond surface. From a quantitative analysis of magnetoresistance curves at 2.5 K, we derive a hole g-factor of 2.6±0.1 and rms fluctuations in the width of the hole quantum well of about 3 nm over the phase coherence length of 33 nm. Well width fluctuations are ascribed to surface roughness and to lateral fluctuations in carrier density, which self-consistently determines the width of the confining potential.
On the difference between variational and unitary coupled cluster theories
Authors: Harsha Gaurav , Shiozaki Toru , Scuseria Gustavo E.
Published: January 2018

There have been assertions in the literature that the variational and unitary forms of coupled cluster theory lead to the same energy functional. Numerical evidence from previous authors was inconsistent with this claim, yet the small energy differences found between the two methods and the relatively large number of variational parameters precluded an unequivocal conclusion. Using the Lipkin Hamiltonian, we here present conclusive numerical evidence that the two theories yield different energies. The ambiguities arising from the size of the cluster parameter space are absent in the Lipkin model, particularly when truncating to double excitations. We show that in the symmetry adapted basis under strong correlation, the differences between the variational and unitary models are large, whereas they yield quite similar energies in the weakly correlated regime previously explored. We also provide a qualitative argument rationalizing why these two models cannot be the same. Additionally, we study a generalized non-unitary and non-hermitian variant that contains excitation, de-excitation, and mixed operators with different amplitudes and show that it works best when compared to the traditional, variational, unitary, and extended forms of coupled cluster doubles theories.
Characterization of fast deuterons involved in the production of fusion neutrons in a dense plasma focus
Authors: Kubes P. , Paduch M. , Sadowski M. J. , Cikhardt J. , Cikhardtova B. , Klir D. , Kravarik J. , Munzar V. , Rezac K. , Zielinska E. , Skladnik-Sadowska E. , Szymaszek A. , Tomaszewski K. , Zaloga D.
Published: January 2018

This paper considers regions of a fast deuteron production in a correlation with an evolution of ordered structures inside a pinch column of a mega-ampere plasma focus discharge. Ion pinhole cameras equipped with plastic PM-355 track-detectors recorded fast deuterons escaping in the downstream and other directions (up to 60° to the z-axis). Time-integrated ion images made it possible to estimate sources of the deuteron acceleration at the known magnetic field and deuteron energy values. The images of the fast deuterons emitted in the solid angle ranging from 0° to 4° showed two forms: central spots and circular images. The spots of 1–2 cm in diameter were produced by deuterons from the central pinch regions. The circular-shaped images of a radius above 3 cm (or their parts) were formed by deuterons from the region surrounding the dense pinch column. The ion pinhole cameras placed at angles above 20° to the z-axis recorded the ion spots only, and the ring-images were missing. The central region of the deuteron acceleration could be associated mainly with plasmoids, and the circular images could be connected with ring-shaped regions of the radius corresponding to tops of the plasma lobules outside the dense pinch column. The deuteron tracks forming ring-shaped images of a smaller (0.5–1) cm radius could be produced by deflections of the fast deuterons, which were caused by a magnetic field inside the dense pinch column.
Elastic wave generated by granular impact on rough and erodible surfaces
Authors: Bachelet Vincent , Mangeney Anne , de Rosny Julien , Toussaint Renaud , Farin Maxime
Published: January 2018

The elastic waves generated by impactors hitting rough and erodible surfaces are studied. For this purpose, beads of variable materials, diameters, and velocities are dropped on (i) a smooth PMMA plate, (ii) stuck glass beads on the PMMA plate to create roughness, and (iii) the rough plate covered with layers of free particles to investigate erodible beds. The Hertz model validity to describe impacts on a smooth surface is confirmed. For rough and erodible surfaces, an empirical scaling law that relates the elastic energy to the radius Rb and normal velocity Vz of the impactor is deduced from experimental data. In addition, the radiated elastic energy is found to decrease exponentially with respect to the bed thickness. Lastly, we show that the variability of the elastic energy among shocks increases from some percents to 70% between smooth and erodible surfaces. This work is a first step to better quantify seismic emissions of rock impacts in natural environment, in particular on unconsolidated soils.
First-principles calculations of lattice dynamics and thermodynamic properties for Yb14MnSb11
Authors: Wang Yi , Hu Yong-Jie , Firdosy Samad A. , Star Kurt E. , Fleurial Jean-Pierre , Ravi Vilupanur A. , Chen Long-Qing , Shang Shun-Li , Liu Zi-Kui
Published: January 2018

Systematic first-principles calculations were performed to study the lattice dynamics of Yb14MnSb11 and hence to obtain a wide range of its thermodynamic properties at high temperatures. The calculated results were analyzed in terms of the lattice contribution and the electronic contribution, together with a comparison with a collection of experimental thermochemical data. At 0 K, the electronic density of states showed the typical feature of a p-type semiconductor—a small amount of unoccupied electronic states exclusively made of the major spin by a range of ∼0.6 eV above the Fermi energy. It showed that the Mn atom had a ferromagnetic spin moment of ∼4 μB. As a semiconductor, it was found that the electronic contribution to the heat capacity was substantial, with an electronic heat capacity coefficient of ∼0.0006 J/mole-atom/K2.
Polyaniline-based memristive microdevice with high switching rate and endurance
Authors: Lapkin D. A. , Emelyanov A. V. , Demin V. A. , Erokhin V. V. , Feigin L. A. , Kashkarov P. K. , Kovalchuk M. V.
Published: January 2018

Polyaniline (PANI) based memristive devices have emerged as promising candidates for hardware implementation of artificial synapses (the key components of neuromorphic systems) due to their high flexibility, low cost, solution processability, three-dimensional stacking capability, and biocompatibility. Here, we report on a way of the significant improvement of the switching rate and endurance of PANI-based memristive devices. The reduction of the PANI active channel dimension leads to the increase in the resistive switching rate by hundreds of times in comparison with the conventional one. The miniaturized memristive device was shown to be stable within at least 104 cyclic switching events between high- and low-conductive states with a retention time of at least 103 s. The obtained results make PANI-based memristive devices potentially widely applicable in neuromorphic systems.
Direct enrichment of pathogens from physiological samples of high conductivity and viscosity using H-filter and positive dielectrophoresis
Authors: Cai Dongyang , Yi Qiaolian , Shen Chaohua , Lan Ying , Urban Gerald , Du Wenbin
Published: January 2018

The full potential of microfluidic techniques as rapid and accurate methods for the detection of disease-causing agents and foodborne pathogens is critically limited by the complex sample preparation process, which commonly comprises the enrichment of bacterial cells to detectable levels. In this manuscript, we describe a microfluidic device which integrates H-filter desalination with positive dielectrophoresis (pDEP) for direct enrichment of bacterial cells from physiological samples of high conductivity and viscosity, such as cow's milk and whole human blood. The device contained a winding channel in which electrolytes in the samples continuously diffused into deionized (DI) water (desalination), while the bacterial cells remained in the samples. The length of the main channel was optimized by numerical simulation and experimentally evaluated by the diffusion of fluorescein into DI water. The effects of another three factors on H-filter desalination were also investigated, including (a) the flow rate ratio between the sample and DI water, (b) sample viscosity, and (c) non-Newtonian fluids. After H-filter desalination, the samples were withdrawn into the dielectrophoresis chamber in which the bacterial cells were captured by pDEP. The feasibility of the device was demonstrated by the direct capture of the bacterial cells in 1× PBS buffer, cow's milk, and whole human blood after H-filter desalination, with the capture efficiencies of 70.7%, 90.0%, and 80.2%, respectively. We believe that this simple method can be easily integrated into portable microfluidic diagnosis devices for rapid and accurate detection of disease-causing agents and foodborne pathogens.
Engineering a simple lateral flow device for animal blood coagulation monitoring
Authors: Li Hua , Han Daewoo , Pauletti Giovanni M. , Steckl Andrew J.
Published: January 2018

Increasing numbers of animals are diagnosed with thromboembolism, requiring anticoagulation treatment to prevent thrombotic events. Frequent and periodic coagulation monitoring is critical to ensure treatment effectiveness and patient safety by limiting blood coagulation ability within the desired therapeutic range. Point-of-care diagnostics is an ideal candidate for frequent coagulation monitoring due to rapid test results and no need for laboratory setting. This article reports the first utilization of no-reaction lateral flow assay (nrLFA) device for simple and low-cost animal blood coagulation monitoring in resource-limited setting. The nrLFA device consists of sample pad, analytical membrane and wicking pad, without conjugate pad, reagent printing or membrane drying. Citrated and heparinized animal blood were utilized to mimic different blood coagulation abilities in vitro by adding reversal agents CaCl2 and protamine sulfate. The travel distance of red blood cells (RBCs) on the nrLFA after a pre-determined test time serves as endpoint marker. Upon adding 500 mM CaCl2 solution to citrated bovine, canine, rabbit and equine blood, the average travel distance decreases from 10.9 to 9.4 mm, 8.8 to 5.7 mm, 12.6 to 9 mm, and 15.3 to 11.3 mm, respectively. For heparinized bovine and rabbit blood, the average distance decreases from 14.5 to 11.4 mm and from 9.8 to 7.2 mm, respectively, when adding 300 mg/l protamine sulfate solution. The effect of hematocrit on RBC travel distance in the nrLFA was also investigated. The nrLFA device will potentially improve treatment efficiency, patient safety, quality of life, and satisfaction for both animal patients and their owners.
A new ultrasonic transducer sample cell for in situ small-angle scattering experiments
Authors: Gupta Sudipta , Bleuel Markus , Schneider Gerald J.
Published: January 2018

Ultrasound irradiation is a commonly used technique for nondestructive diagnostics or targeted destruction. We report on a new versatile sonication device that fits in a variety of standard sample environments for neutron and X-ray scattering instruments. A piezoelectric transducer permits measuring of the time-dependent response of the sample in situ during or after sonication. We use small-angle neutron scattering (SANS) to demonstrate the effect of a time-dependent perturbation on the structure factor of micelles formed from sodium dodecyl sulfate surfactant molecules. We observe a substantial change in the micellar structure during and after exposure to ultrasonic irradiation. We also observe a time-dependent relaxation to the equilibrium values of the unperturbed system. The strength of the perturbation of the structure factor depends systematically on the duration of sonication. The relaxation behavior can be well reproduced after multiple times of sonication. Accumulation of the recorded intensities of the different sonication cycles improves the signal-to-noise ratio and permits reaching very short relaxation times. In addition, we present SANS data for the micellar form factor on alkyl-poly (ethylene oxide) surfactant molecules irradiated by ultrasound. Due to the flexibility of our new in situ sonication device, different experiments can be performed, e.g., to explore molecular potentials in more detail by introducing a systematic time-dependent perturbation.
Global existence and finite time blow-up for a parabolic system on hyperbolic space
Authors: Wu Hui , Yang Xiaoping
Published: January 2018

In this paper, we study the global existence and finite time blow-up of positive solutions for a parabolic system on hyperbolic space. Using the heat semigroup and constructing subsolutions and supersolutions, we obtain the Fujita type results. In the case of a critical exponent, the critical exponent is not a blow-up exponent.
Computation of electron transport and relaxation properties in gases based on improved multi-term approximation of Boltzmann equation
Authors: Cai X. J. , Wang X. X. , Zou X. B. , Lu Z. W.
Published: January 2018

An understanding of electron kinetics is of importance in various applications of low temperature plasmas. We employ a series of model and real gases to investigate electron transport and relaxation properties based on improved multi-term approximation of the Boltzmann equation. First, a comparison of different methods to calculate the interaction integrals has been carried out; the effects of free parameters, such as vmax, lmax, and the arbitrary temperature Tb, on the convergence of electron transport coefficients are analyzed. Then, the modified attachment model of Ness et al. and SF6 are considered to investigate the effect of attachment on the electron transport properties. The deficiency of the pulsed Townsend technique to measure the electron transport and reaction coefficients in electronegative gases is highlighted when the reduced electric field is small. In order to investigate the effect of external magnetic field on the electron transport properties, Ar plasmas in high power impulse sputtering devices are considered. In the end, the electron relaxation properties of the Reid model under the influence of electric and magnetic fields are demonstrated.
Phonon signal in cryogenic detector discriminates single electron-hole pair
Authors: Leahy Rhys
Published: January 2018

Phonon-based detectors capable of resolving single charges could enhance the search for dark matter.
Evolution of vertical and oblique transmission under fluctuating selection
Authors: Ram Yoav , Liberman Uri , Feldman Marcus W.
Published: January 2018

Significance

Evolutionary dynamics of phenotypes in populations depend on how the traits are transmitted across generations and how the environments that cause selection on the traits fluctuate over time. We show that, under periodically fluctuating selection, a gene that increases the rate of vertical transmission is disfavored when the periods are short but approaches an intermediate stable rate for longer periods. This stable rate differs markedly from the rate that maximizes the geometric mean fitness. The evolution of learning rules thus differs qualitatively from the evolution of genetically modified rules of genetic transmission.
New method for preparing micron porous aluminium via powder metallurgy
Authors: Liu Chao , Liu Yang , Yang Yuling , Ma Yunzhu , Liu Wensheng , Tang Siwei , Liu Bing , Cai Qingshan
Published: January 2018

In this work, micron porous aluminium (Al) specimens with various porosities were successfully prepared via a cold pressing-vacuum sintering-dissolution process (SDP) with water-soluble granules as space holders. Effects of the parameters of the sintering process on microstructure, density, and hardness were investigated. Results show that SDP was used to synthesise open-cell porous aluminium with uniform holes and enabled easy control of the microstructure porosity of porous aluminium. We also found that vacuum sintering and the addition of magnesium (Mg) improved the sintered behaviours. Based on our findings, the optimised sintering parameters (temperature and time) for porous aluminium are 650°C and 270 min, respectively.
Wear resistance of cold sprayed Al alloys for aeronautical repairs
Authors: Cruz David , Garrido Miguel Ángel , Rico Álvaro , Múnez Claudio J. , Poza Pedro
Published: January 2018

Al–Cu alloys, like Al 2024, and Al–Si alloys, like Al F357 and Al C355, are used in aeronautic gearboxes and fuselage parts operating in severe conditions. It is necessary to develop maintenance and overhaul technologies to extend the life of metallic components used in the aeronautical sector. Cold Spray (CS) could be an alternative as it is real solid-state processing technique. However, the repaired component should exhibit similar properties as the original substrate. This paper evaluates the wear performance of Al coatings CS onto the same Al substrates in sliding and oscillating conditions. The results were compared with the corresponding substrates. The wear rate of coatings processed using new conditions, developed to enhance the coatings performance, was similar or smaller than that measured in the substrate bulk alloys. For Al 2024 and Al C355 CS could be used for repairing, from the tribological point of view.
Greek primary school teachers’ awareness of the special features of scientific language: implications for science curricula and teachers’ professional development
Authors: Sagiannis Spyridon , Dimopoulos Kostas
Published: January 2018

This exploratory study aims at investigating first the extent to which Greek primary school teachers recognize the features of scientific language (an archetype for the academic language employed in all school disciplines), and second and most importantly the functional role they attribute to these features in the construction of scientific discourse. Semi‐structured interviews were conducted with 30 teachers. Two versions of a one‐page extract, varying in linguistic specialization, were used as stimuli‐materials. Teachers correctly recognized the linguistically highly specialized version, but they were less able to spontaneously mention specific features (mainly syntactic complexity and terminology) contributing to this specialization. Worse still, they failed to recognize syntactic complexity as a feature of the specialized extract even after they were explicitly probed to do so. Moreover, teachers were found to only be partially aware of the functional role these features play in constructing the scientific world‐view. Specifically, teachers seem to put emphasis on the communicative rather than the epistemological role of the corresponding linguistic features. These findings stress the need for certain interventions both at initial and in‐service level of teacher education as well as at the level of science curricula.
Variations in macrobenthic community at two stations in the southern Yellow Sea and relation to climate variability (2000–2013)
Authors: Xu Yong , Sui Jixing , Li Xinzheng , Wang Hongfa , Zhang Baolin
Published: January 2018

Decadal variations (2000–2013) in the macrobenthic community of the southern Yellow Sea were investigated based on the analysis of the community at two stations located basically along the 70 m depth contour. Significant decadal variations in community structure were found through cluster analysis, nMDS ordination and one-way ANOSIM. SIMPER analysis showed that the decadal community variations could be roughly attributed to the decrease of two species of Mollusks (Thyasira tokunagai and Nucula tenuis) and the increase of one echinoderm (Ophiura sarsii vadicola), one polychaete (Notomastus latericeus) and one bivalve (Portlandia japonica) at both stations. Redundancy analysis showed that the Pacific Decadal Oscillation and the Southern Oscillation Index were significant climate indices influencing the macrobenthic community structure in the southern Yellow Sea. Most of the species collected in 2000s showed a positive correlation with Pacific Decadal Oscillation at both stations, especially for cold water species Thyasira tokunagai, while most species in 2010s were positively correlated to Southern Oscillation Index, e.g. Portlandia japonica and Notomastus latericeus at station 1 and Sigambra bassi and Aricidea fragilis at station 2.
A cross-sectional analysis of ex-smokers and characteristics associated with quitting smoking: The Polish Norwegian Study (PONS)
Authors: Manczuk Marta , Lobaszewski Jakub , Sulkowska Urszula , Hashim Dana , Boffetta Paolo
Published: January 2018

Tobacco smoking remains a number one preventable risk factor of premature death worldwide. Findings of recent research show concurrent trends of lung cancer deaths in males and females in Europe. Although lung cancer death rates are consistently decreasing in male population, in women an upward trend is observed. The burden of tobacco-related harm can be prevented by smoking cessation. The main goal of this analysis is to identify the crucial correlates of successful smoking cessation in the middle-aged Polish population. The data came from 13 172 survey participants south-eastern part of Poland as part of the PONS cohort study established in 2010. A total of 6998 records of those who were either ex-smokers or current smokers at baseline were analyzed. We applied logistic regression and adjusted for sociodemographic covariates and health determinants. Characteristics related to being an ex-smoker as opposed to a current smoker included: older age [men: odds ratio (OR)=1.03, 95% confidence interval (CI)=1.01–1.05; women: OR=1.05, 95% CI=1.03–1.07], being married or living together, having secondary (OR=1.51, 95% CI=1.14–1.99) or higher (OR=2.30, 95% CI=1.75–3.18) education (women), full-time employment (men), alcohol consumer (women), being overweight (men: OR=2.85, 95% CI=2.26–3.59; women: OR=1.60, 95% CI=1.36–1.87) or obese (men: OR=3.47, 95% CI=2.67–4.51; women: OR=2.99, 95% CI=2.45–3.65), having normal fasting glucose and cholesterol blood level without any treatment (women), assessing their own health highly (9–10, on the scale from 1 to 10) and having at least one accompanying chronic disease (women, OR=1.25, 95% CI=1.07–1.45). These findings provide valuable information on characteristics of ex-smokers as well as behavioral and sociodemographic predictors of successful cessation. Such data expand our knowledge and can be used to design a more comprehensive and targeted group-specific tobacco control policy focused on increasing the number of ex-smokers.
Artificial intelligence estimates the impact of human papillomavirus types in influencing the risk of cervical dysplasia recurrence: progress toward a more personalized approach
Authors: Bogani Giorgio , Ditto Antonino , Martinelli Fabio , Signorelli Mauro , Chiappa Valentina , Leone Roberti Maggiore Umberto , Taverna Francesca , Lombardo Claudia , Borghi Chiara , Scaffa Cono , Lorusso Domenica , Raspagliesi Francesco
Published: January 2018

The objective of this study was to determine whether the pretreatment human papillomavirus (HPV) genotype might predict the risk of cervical dysplasia persistence/recurrence. Retrospective analysis of prospectively collected data of consecutive 5104 women who underwent the HPV-DNA test were matched with retrospective data of women undergoing either follow-up or medical/surgical treatment(s) for genital HPV-related infection(s). Artificial neuronal network (ANN) analysis was used in order to weight the importance of different HPV genotypes in predicting cervical dysplasia persistence/recurrence. ANN simulates a biological neuronal system from both the structural and functional points of view: like neurons, ANN acquires knowledge through a learning-phase process and allows weighting the importance of covariates, thus establishing how much a variable influences a multifactor phenomenon. Overall, 5104 women were tested for HPV. Among them, 1273 (25%) patients underwent treatment for HPV-related disorders. LASER conization and cervical vaporization were performed in 807 (59%) and 386 (30%) patients, respectively, and secondary cervical conization in 45 (5.5%). ANN technology showed that the most important genotypes predicting cervical dysplasia persistence/recurrence were HPV-16 (normalized importance: 100%), HPV-59 (normalized importance: 51.2%), HPV-52 (normalized importance: 47.7%), HPV-18 (normalized importance: 32.8%) and HPV-45 (normalized importance: 30.2%). The pretreatment diagnosis of all of those genotypes, except HPV-45, correlated with an increased risk of cervical dysplasia persistence/recurrence; the pretreatment diagnosis was also arrived at using standard univariate and multivariable models (P<0.01). Pretreatment positivity for HPV-16, HPV-18, HPV-52 and HPV-59 might correlate with an increased risk of cervical dysplasia persistence/recurrence after treatment. These data might be helpful during patients’ counseling and to implement new vaccination programs.
Breast Cancer Stage at Diagnosis in a New Jersey Cancer Education and Early Detection Site
Authors: Jerome-D’Emilia Bonnie , Kushary Debashis , Burrell Sherry A. , Suplee Patricia D. , Hansen Katherine
Published: January 2018

Objectives:

The National Breast and Cervical Cancer Early Detection Program provides free or low-cost screening to uninsured or underinsured women and has had positive results; however, only a few state programs have been evaluated. This study will provide a first snapshot of the effectiveness of the New Jersey program, by comparing stage at diagnosis for enrollees as compared with nonenrollees who received definitive treatment for breast cancer at the same academic medical center.

Materials and Methods:

A retrospective analysis of 5 years of breast cancer data abstracted from the Cancer Registry of a large urban hospital in the Northeast United States. Bivariate analysis and logistic regression were utilized.

Results:

One thousand forty women were screened for and diagnosed with breast cancer at this site; they were more likely to be racially (P<0.001) and ethnically (P<0.002) diverse as compared with nonenrollees. Enrollees were more likely to be symptomatic at diagnosis (P<0.001), and diagnosed at a late stage when compared with nonenrollees (odds ratio, 1.88; 95% confidence interval, 1.07-3.29).

Conclusions:

This national program was developed to serve low income, under and uninsured women who may otherwise have limited access to cancer screening services. It appears that many women enroll in this program needing diagnostic rather than screening services, after breast symptoms were noted. This finding helps to emphasize the fact that just providing free screening services is not enough to make up for the lack of a usual source of preventive care for low income and uninsured women.
Value of FDG–PET/CT Volumetry After Chemoradiotherapy in Rectal Cancer
Authors: Okuno Takayuki , Kawai Kazushige , Koyama Keitaro , Takahashi Miwako , Ishihara Soichiro , Momose Toshimitsu , Morikawa Teppei , Fukayama Masashi , Watanabe Toshiaki
Published: January 2018

BACKGROUND:

Neoadjuvant chemoradiotherapy followed by an optimal surgery is the standard treatment for patients with locally advanced rectal cancer. FDG-PET/CT is commonly used as the modality for assessing the effect of chemoradiotherapy.

OBJECTIVE:

The purpose of this study was to investigate whether PET/CT-based volumetry could contribute to the prediction of pathological complete response or prognosis after neoadjuvant chemoradiotherapy.

DESIGN:

This was a retrospective cohort study.

SETTINGS:

This study was conducted at a single research center.

PATIENTS:

Ninety-one consecutive patients with locally advanced rectal cancer were enrolled between January 2005 and December 2015.

INTERVENTION:

Patients underwent PET/CT before and after neoadjuvant chemoradiotherapy.

MAIN OUTCOME MEASURES:

Maximum standardized uptake value and total lesion glycolysis on PET/CT before and after neoadjuvant chemoradiotherapy were calculated using isocontour methods. Correlations between these variables and clinicopathological factors and prognosis were assessed.

RESULTS:

PET/CT-associated variables before chemoradiotherapy were not correlated with either clinicopathological factors or prognosis. Maximum standardized uptake value was associated with pathological complete response, but total lesion glycolysis was not. Maximum standardized uptake value correlated with ypT, whereas total lesion glycolysis correlated with both ypT and ypN. High total lesion glycolysis was associated with a considerably poorer prognosis; the 5-year recurrence rate was 65% and the 5-year mortality rate 42%, whereas in lesions with low total lesion glycolysis, these were 6% and 2%. On multivariate analysis, high total lesion glycolysis was an independent risk factor for recurrence (HR = 4.718; p = 0.04).

LIMITATIONS:

The gain in fluoro-2-deoxy-d-glucose uptake may differ between scanners, thus the general applicability of this threshold should be validated.

CONCLUSIONS:

In patients with locally advanced rectal cancer, high total lesion glycolysis after neoadjuvant chemoradiotherapy is strongly associated with a worse prognosis. Total lesion glycolysis after chemoradiotherapy may be a promising preoperative predictor of recurrence and death. See Video Abstract at http://links.lww.com/DCR/A464.
Hyaluronic Acid Filler Injections Under the Metatarsal Heads Provide a Significant and Long-Lasting Improvement in Metatarsalgia From Wearing High-Heeled Shoes
Authors: Foumenteze Jean Paul , Simpson Helen , Kerrouche Nabil
Published: January 2018

BACKGROUND

Metatarsalgia is a common overuse injury that may be caused by wearing high-heeled shoes.

OBJECTIVE

To evaluate the decrease in metatarsalgia using a hyaluronic acid dermal filler.

METHODS

A 6-month, open study was conducted in 15 subjects with metatarsalgia because of regularly wearing high-heeled shoes. Hyaluronic acid (20 mg/mL) with lidocaine hydrochloride (3 mg/mL) was injected under the metatarsal heads at baseline. Pain (on a 0–10 scale) under the metatarsal heads when walking in high heels was recorded in a weekly subject diary.

RESULTS

At 6 months after injections, 5 subjects (33.3%) reported no metatarsalgia pain. For subjects with pain, they were able to wear high heels for significantly longer than before the injections (7.2 hours at 6 months vs 3.4 hours at baseline). Significant improvements from baseline were observed at Month 6 for time to onset of pain (3.5 hours longer), time between onset of pain and intolerable pain (1.9 hours longer), and pain sensation (−2.2 grades at onset and −3.8 grades at shoe removal). No adverse events were reported.

CONCLUSION

Injection of hyaluronic acid filler to the forefeet provided a significant effective, long-lasting, and well-tolerated improvement in metatarsalgia because of wearing high-heeled shoes.
Combination of Melolabial Interpolation Flap and Nasal Sidewall and Cheek Advancement Flaps Allows for Repair of Complex Compound Defects
Authors: Patel Payal M. , Greenberg Judah N. , Kreicher Kathryn L. , Burkemper Nicole M. , Bordeaux Jeremy S. , Maher Ian A.
Published: January 2018

BACKGROUND

The paramedian forehead flap (PMFF) is the repair of choice for large nasal defects involving multiple cosmetic subunits. However, the PMFF may not be optimal for all patients. The combination of a melolabial interpolation flap (MLIF) and a nasal sidewall flap may serve as an alternative.

OBJECTIVE

To present the surgical technique and aesthetic outcomes of the alternative reconstruction for surgical defects of the lower nose.

MATERIALS AND METHODS

Fourteen patients with multisubunit nasal Mohs defects reconstructed alternatively were identified from 2 academic centers in this retrospective case series. Illustrations and photographs were used to demonstrate surgical technique and outcomes. Final aesthetic results were analyzed using the Patient and Observer Scar Assessment Scale.

RESULTS

The physician observer rated the scar outcome a mean score of 10.9 ± 3.3. Patients rated their results as a mean of 9.1 ± 4.7. The mean “Patient” Overall Opinion score was 2.3 ± 2.6 and the mean “Observer” Overall Opinion score was 1.9 ± 0.9. No patients reported problems with nasal airflow or obstruction, and cosmetic complications such as pincushioning or alar buckling were not observed.

CONCLUSION

The combined MLIF and nasal sidewall flap is an alternative repair for complex distal nasal defects.
Measurement and Simulation of the Counting Efficiency of a Whole-body Counter Using a BOMAB Phantom Inserted with Rod Sources Containing Mixed Radionuclides
Authors: Park MinSeok , Yoo Jaeryong , Ha Wi-Ho , Park Sunhoo , Jin Young Woo
Published: January 2018

The examination of internal contamination is important for providing an adequate medical response during a radiological emergency. A whole-body counting system can assess gamma-emitting radionuclides in a human body when monitoring internal contamination. It is necessary to calibrate whole-body counting systems by using a calibration phantom, such as a Bottle Manikin Absorption phantom, to properly assess internal contamination. However, the total weight of the Bottle Manikin Absorber phantom is high, and there can be leakage of radioactive sources, which are disadvantages of using such a phantom. This study proposes a calibration phantom that is designed to overcome these disadvantages. The proposed phantom consists of rod sources that are inserted in each part of the phantom. The counting efficiency of the rod-source-inserted calibration phantom was acquired using a Monte Carlo simulation method, but the results were evaluated by comparing the experimental efficiencies with those of a conventional Bottle Manikin Absorption phantom by using two commercial whole-body counting systems (stand-up type and bed type). The efficiency curve of the rod-source-inserted phantom matched well that of the conventional calibration phantom. The relative deviation between the efficiencies of the conventional Bottle Manikin Absorption phantom and the proposed calibration phantom in both whole-body counting systems was less than 11%, and the total weight of the phantom was also reduced. These results suggest that the proposed phantom can be manipulated more easily and replace the conventional Bottle Manikin Absorption calibration phantom for these two types of whole-body counting systems.