bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular basis for potentiation of Cx36 gap junction channel conductance by n-alcohols and general anesthetics
Authors: Raškevičius Vytautas , Jotautis Vaidas , Rimkutė Lina , Marandykina Alina , Kazokaitė Mintautė , Kairys Visvaldas , Skeberdis Vytenis Arvydas
Published: January 2018

In our recent study, we have demonstrated that short carbon chain n-alcohols (up to octanol) stimulated while long carbon chain n-alcohols inhibited the conductance of connexin (Cx) 36 (Cx36) gap junction (GJ) channels. In contrast, GJ channels composed of other types of Cxs all were inhibited by n-alcohols independent of their carbon chain length. To identify the putative structural domains of Cx36, responsible for the dual effect of n-alcohols, we performed structural modeling of Cx36 protein docking with hexanol and isoflurane that stimulated as well as nonanol and carbenoxolone that inhibited the conductance of Cx36 GJs and revealed their multiple common docking sites and a single pocket accessible only to hexanol and isoflurane. The pocket is located in the vicinity of three unique cysteine residues, namely C264 in the fourth, and C92 and C87 in the second transmembrane domain of the neighboring Cx36 subunits. To examine the hypothesis that disulphide bonding might be involved in the stimulatory effect of hexanol and isoflurane, we generated cysteine substitutions in Cx36 and demonstrated by a dual whole-cell patch-clamp technique that in HeLa (human cervix carcinoma cell line) and N2A (mouse neuroblastoma cell line) cells these mutations reversed the stimulatory effect of hexanol and isoflurane to inhibitory one, typical of other Cxs that lack respective cysteines and a specific docking pocket for these compounds. Our findings suggest that the stimulatory effect of hexanol and isoflurane on Cx36 GJ conductance could be achieved by re-shuffling of the inter-subunit disulphide bond between C264 and C92 to the intra-subunit one between C264 and C87.
NSCT‐PCNN image fusion based on image gradient motivation
Authors: Ding Shifei , Zhao Xingyu , Xu Hui , Zhu Qiangbo , Xue Yu
Published: January 2018

Pulse coupled neural network (PCNN) is widely used in image processing because of its unique biological characteristics, which is suitable for image fusion. When combining PCNN with non‐subsampled contourlet (NSCT) model, it is applied in overcoming the difficulty of coefficients selection for subband of the NSCT model. However in the original model, only the grey values of image pixels are used as input, without considering that the subjective vision of human eyes lacks the sensitivity to the local factors of the image. In this study, the improved pulse‐coupled neural network model has replaced the grey‐scale value of the image and introduced the weighted product of the strength of the gradient of the image and the local phase coherence as the model input. Finally, compared with other multi‐scale decompositions‐based image fusion and other improved NSCT‐PCNN algorithms, the algorithm presented in this study outperforms them in terms of objective criteria and visual appearance.
Perceptual stereoscopic image quality assessment method with tensor decomposition and manifold learning
Authors: Jiang Gangyi , He Meiling , Yu Mei , Shao Feng , Peng Zongju
Published: January 2018

Perceptual quality assessment of stereoscopic images is a challenge in three‐dimensional video systems. Existing studies suggest that simply averaging the quality of left and right views can effectively predict the quality of symmetrically distorted stereoscopic images, but prediction deviation occurs in the case of asymmetrically distorted stereoscopic images. Most previous stereoscopic image quality assessment (SIQA) methods have been based only on the luminance component of the images; in addition, the basis of human visual perception is critical to image quality assessment and lies on the low‐dimensional manifold. Inspired by this, a new perceptual SIQA method is proposed, which includes two stages: training stage and quality prediction stage. In the training stage, the authors apply Tucker decomposition to RGB images to reduce dimensions along colour channels to produce training sets, and the projection matrix is obtained through manifold learning. In the quality prediction stage, considering the binocular visual characteristics of visual perception, the overall stereoscopic estimate depends on the monocular image quality via a local energy ratio based pooling strategy and cyclopean based binocular quality. Extensive experiments on three available benchmark databases demonstrate that the proposed metric has better performance and achieves highly consistent alignment with subjective assessment compared with state‐of‐the‐art SIQA metrics.
Wire segmentation for printed circuit board using deep convolutional neural network and graph cut model
Authors: Qiao Kai , Zeng Lei , Chen Jian , Hai Jinjin , Yan Bin
Published: January 2018

Printed circuit board wire segmentation based on computed tomography (CT) image can help subsequently locate and estimate inner faults of circuit in an automatic and non‐destructive manner. However, CT imaging is prone to suffer from scattered artefacts, metal artefacts and other interference, destroying compact boundary structures of wires. Wires have the characteristic of dense local distribution, and massive vias, pads, and coppers can appear close to wires, resulting in mazy recognition surroundings. The above‐mentioned problems bring great difficulty for high‐accuracy recognition and location of wire segmentation. In this study, considering that deep convolutional neural network (DCNN) with powerful feature representation can recognise wires in confused surroundings, and graph cut (GC) model relying on grayscale and local texture information specialises in protecting edge structures of wires, the authors propose an effective framework called DCNN‐GC that employs DCNN to obtain global semantic prior to guide the GC model to accomplish satisfactory wire segmentation. The authors qualitative and quantitative results demonstrate outstanding performance, and achieve overwhelming intersection over union compared with traditional and DCNN‐based methods.
Range–Doppler reconstruction for frequency agile and PRF‐jittering radar
Authors: Quan Ying‐Hui , Wu Yao‐Jun , Li Ya‐Chao , Sun Guang‐Cai , Xing Meng‐Dao
Published: January 2018

Agility radar with the carrier frequency random hopping and the pulse repetition frequency (PRF) staggering from pulse to pulse achieves superior performance against the electromagnetic jamming. This novel scheme leads to the discontinuity of phase in a coherent processing interval, thus the fast Fourier transform‐based method is no longer a valid way to estimate the velocity of a target. A novel sparse optimisation method based on compressed sensing is proposed for high‐resolution range–Doppler reconstruction from random frequency hopping and PRF‐jittering pulses. The performance of moving target detection of the proposed method for frequency agile and PRF‐jittering radar is analysed by comparing it with parameters‐fixed pulse Doppler radar. Both simulation and field experimental results demonstrate the effectiveness of the proposal.
Transient behaviour of grounding electrodes in uniform and in vertically stratified soil using state space representation
Authors: Chiheb Sofiane , Kherif Omar , Teguar Madjid , Mekhaldi Abdelouahab , Harid Noureddine
Published: January 2018

This investigation is devoted to study, in time domain, the transient behaviour of vertical and horizontal grounding conductors submitted to impulse current using state space representation‐based transmission line method. This study has been carried out with and without incorporating soil ionisation and mutual coupling between conductor elements for soils of low and high resistivities. The results are focused on the time‐domain solution of the electrode's transient potential rise and its impulse performance parameters. The results show the importance of including the mutual coupling between segments of the same electrode and soil ionisation. The results are compared with both published theoretical approaches and experimental measurements, and show acceptable agreement. This method has been applied to compute the transient potential of horizontal electrodes buried in vertically stratified soil, a situation which can occur where long horizontal counterpoise is buried in a highly contrasting soil along its length.
Simultaneous broadband observations and high-resolution X-ray spectroscopy of the transitional millisecond pulsar PSR J1023+0038
Authors: Coti Zelati F. , Campana S. , Braito V. , Baglio M. C. , D’Avanzo P. , Rea N. , Torres D. F.
Published: January 2018

We report on the first simultaneousXMM–Newton,NuSTAR, andSwiftobservations of the transitional millisecond pulsar PSR J1023+0038 in the X-ray active state. Our multi-wavelength campaign allowed us to investigate with unprecedented detail possible spectral variability over a broad energy range in the X-rays, as well as correlations and lags among emissions in different bands. The soft and hard X-ray emissions are significantly correlated, with no lags between the two bands. On the other hand, the X-ray emission does not correlate with the UV emission. We refine our model for the observed mode switching in terms of rapid transitions between a weak propeller regime and a rotation-powered radio pulsar state, and report on a detailed high-resolution X-ray spectroscopy using allXMM–NewtonReflection Grating Spectrometer data acquired since 2013. We discuss our results in the context of the recent discoveries on the system and of the state of the art simulations on transitional millisecond pulsars, and show how the properties of the narrow emission lines in the soft X-ray spectrum are consistent with an origin within the accretion disc.
Thermal response of Moroccan lakes to climatic warming: first results
Authors: Haddout Soufiane , Priya K.L. , Boko Michel
Published: January 2018

Water temperature plays a primary role in controlling a wide range of physical, geochemical and ecological processes in lakes, with considerable influences on lake water quality and ecosystem functioning. In this paper, we report on the ability of the one-dimensional lake model to simulate the water temperature of Moroccan lakes, i.e., Sidi Boughaba and Sidi Ali lakes, over a 35 yrs period from 1979 to 2014, affected by climate change and based on a freshwater lake model (FLake). During the study periods, two variables are studied, the epilimnion and metalimnion temperatures. The result analysis shows that epilimnion temperatures increased, while metalimnion temperatures decreased. Additionally, we calculate significant air temperature, wind speed and water temperature variation and illustrate, using a sequential t test analysis of regime shifts (STARS) based on the Rodionov method, a substantial increase in annually averaged of all variables, in response to an abrupt shift in the climate. Schmidt stability showed a significant increase for Sidi Ali Lake and near 0 for Sidi Boughaba Lake. On the other hand, the sensitivity analysis (i.e., one-at-a-time (OAT) method) of the atmospheric variable is discussed. The results show good agreement with water temperature observations that suggests that the predictive model can be used to obtain a first-order estimation of water temperature in Moroccan lakes. Hence, it is possible to apply this model in other Moroccan lakes to simulate the behavior of temperature and to investigate the potential future warming of the water column in lakes, affected by climate change.
Are cyanobacteria total, specific and trait abundance regulated by the same environmental variables?
Authors: Frau Diego , de Tezanos Pinto Paula , Mayora Gisela
Published: January 2018

In this study we analyzed if cyanobacteria total, specific and trait abundance are regulated by the same environmental variables in a Neotropical urban lake that recurrently suffers harmful cyanobacteria blooms. To assess the predictor variables for cyanobacteria total and species density we performed a multiple regression (GLM) and a redundancy analysis (RDA), respectively. Temperature and oxygen were the main predictor variables for both total and species abundance. Conductivity was an exclusive predictor for cyanobacteria total density (GLM) and light availability (Zd:Zeu) for species abundance (RDA). Nutrients were unnoticeable predictor variables for both. Cyanobacteria blooms showed high recurrence (8 blooms in 12 months) and occurred within 17–28 °C. Blooms were mostly dominated by one species, and less frequently co-dominated by two species. These blooms were more recurrently dominated by dispersive non-fixing filamentous species (mainly Raphidiopsis curvata) linked to lower light availability. Less frequently, blooms were dominated by filamentous nitrogen fixers which develop scum blooms (mainly Anabaenopsis arnoldii) related to better light availability and lower dissolved oxygen concentration. The nitrogen fixing species showed high heterocyte density, suggesting nitrogen fixing behavior and probably giving this an advantage when inorganic nitrogen was low. Our results indicate that in absence of nutrients limitation, cyanobacteria total and species abundance can be regulated by different environmental variables. These results also show that species phylogenetically related (R. curvata and A. arnoldii) can respond differently to the prevailing environmental variables; highlighting the importance of considering cyanobacteria to a specific level when assessing their possible control factors.
The Rational Design and Synthesis of Water-Soluble Thiourea Ligands for Recoverable Pd-Catalyzed Aerobic Aqueous Suzuki–Miyaura Reactions at Room Temperature
Authors: Chen Wei , Lu Xiao-Yan , Xu Bei-Hua , Yu Wei-guo , Zhou Zi-niu , Hu Ying
Published: January 2018

Eight precatalysts containing carboxylic-functionalized thiourea ligands are prepared and their activities and recyclability are evaluated in aerobic aqueous Suzuki–Miyaura reactions. A bulky monothiourea–Pd complex, functionalized with four carboxylic groups, shows the best activity and recyclability in the coupling of aryl bromides with arylboronic acids. The catalyst can be reused at least five times without any significant reduction in its catalytic activity. TEM analysis and the confirmed catalytic activity of the observed black precipitate reveal that Pd nanoparticles are formed during the reactions and are stabilized by the carboxylic-functionalized thiourea ligands.
Screening for Developmental Disorders in 4 to 60 Months Old Children in Iran (2015–2016)
Authors: Ahmadipour Shokoufeh , Mohammadzadeh Morteza , Birjandi Mehdi , Almasian Mohammad , Mohsenzadeh Azam
Published: January 2018

Developmental delay occurs when children fail to reach their developmental milestones at the appropriate time. The aim of this study was to determine the prevalence of developmental disorders as well as their correlations with selected demographic factors affecting development in children 4 to 60 months old in Khorramabad, Iran from 2015 to 2016. In this cross-sectional study, 500 children from 4 to 60 months of age and visiting health service centers were selected. Developmental status was measured using the Ages and Stages Questionnaire, and supplementary data were collected by separate questionnaires. Data were analyzed by the SPSS software using the independent t-test, chi-square test, and Mann–Whitney U test. Note that 8.6% of the children assessed in this study had developmental disorders. The mean age of the children in the normal group was 21.95 ± 16.42 months and in the developmental delay group was 16 ± 13.46 months. The highest prevalence of developmental delay was in the fine motor area (4.2%) and the lowest was in the personal–social area (1.4%). There were correlations between developmental disorder and the child's age (p = 0.006), birth order (p = 0.02), mother's education (p = 0.007), and father's education (p = 0.002). The parents' age, familial marriage, history of developmental disorders in the family, and the child's gender were not correlated with developmental disorders. Due to the high prevalence of developmental disorders and the importance of early identification and intervention, it is necessary to diagnose developmental disorders at early ages.
Imaging of Tendons of the Knee: Much More than just the Extensor Mechanism
Authors: Chang Connie , Palmer William , Husseini Jad
Published: January 2018

The tendons of the knee play a critical role in the motion and stability of the knee. Knee pain, a common clinical complaint, can frequently be attributed to pathology of these structures. While the cornerstones of the radiological evaluation of the knee are radiography and magnetic resonance imaging, ultrasound can also play an important diagnostic role and can be useful for guided interventional procedures. Understanding the utility of each modality in the assessment for tendon pathology and a familiarity with the normal and abnormal imaging appearance of these structures are crucial for accurate diagnosis.
Akute Larynxläsionen nach endotrachealer Intubation bei Kindern
Authors: Koscielny Sven
Published: January 2018

Manica D et al. Association of endotracheal tube repositioning and acute laryngeal lesions during mechanical ventilation in children. Eur
Arch Otorhinolaryngol 2017; 274: 2871–2876

Akute Larynxverletzungen zählen zu den Hauptrisikofaktoren der erworbenen subglottischen Stenose (SGS) bei Kindern nach
intensivmedizinischer Behandlung. Manica und Kolleginnen/ Kollegen haben nun in einer prospektiven klinischen Studie an 231 Kindern
untersucht, welche Faktoren das Risiko akuter Läsionen durch endotracheale Intubation über 24 Stunden beeinflussen können.
A Self-Microemulsifying Formulation of Oxyresveratrol Prevents Amyloid Beta Protein-Induced Neurodegeneration in Mice
Authors: Sangsen Yaowaporn , Sooksawate Thongchai , Likhitwitayawuid Kittisak , Sritularak Boonchoo , Wiwattanapatapee Ruedeekorn
Published: January 2018

The polyphenol compound, oxyresveratrol (OXY) possesses potent antioxidant and neuroprotective properties of potential utility in the treatment of Alzheimerʼs disease. However, the low oral bioavailability limits its neuroprotective effect and clinical application. The neuroprotective effect of orally administered OXY-loaded self-microemulsifying drug delivery system (OXY-SMEDDS) was compared with free OXY in vivo. Mice were orally administered either free OXY or OXY-SMEDDS once daily at a dose of 90, 180, or 360 mg/kg for 14 d. Mice received a single intracerebroventricular injection of the neurotoxic amyloid β (Aβ)25 – 35 peptide at day 8 during oral treatment. The OXY-SMEDDS formulation resulted in four-times reduction of the free OXY dose required for prevention of neurotoxicity effects due to Aβ
25 – 35 peptide as demonstrated by a significant decline in behavior impairments, lipid oxidation levels, and neuronal cell loss in all hippocampal subfields (p < 0.0001). These results indicate the potential of OXY-SMEDDS by oral delivery to improve the efficacy of this compound in the treatment of Alzheimerʼs disease.
THz generation by laser coupling to carbon nanotube array
Authors: Malik Rakhee , Uma R.
Published: January 2018

A viable scheme of THz radiation generation by beating of two lasers (ω1, k→1; ω2, k→2) in a nanotube array, mounted on a dielectric substrate, is proposed and studied. The free electrons of the nanotubes acquire a large oscillatory velocity and experience a beat frequency ponderomotive force that turns nanotubes into oscillating dipole antennae emitting THz radiation. The THz power peaks in directions where a phase difference between fields due to successive nanotubes is integral multiple of 2π. The THz power is large when the beat frequency equals ωp/2 (where ωp is the electron plasma frequency) and surface plasmon resonance occurs. For our set of laser and carbon nanotube parameters, the generated THz is about 0.1 kW for CO2 laser power of 10 GW and pulse length of a few picoseconds.
Theory of relativistic radiation reflection from plasmas
Authors: Gonoskov Arkady
Published: January 2018

We consider the reflection of relativistically strong radiation from plasma and identify the physical origin of the electrons' tendency to form a thin sheet, which maintains its localisation throughout its motion. Thereby, we justify the principle of relativistic electronic spring (RES) proposed in [Gonoskov et al., Phys. Rev. E 84, 046403 (2011)]. Using the RES principle, we derive a closed set of differential equations that describe the reflection of radiation with arbitrary variation of polarization and intensity from plasma with an arbitrary density profile for an arbitrary angle of incidence. We confirm with ab initio PIC simulations that the developed theory accurately describes laser-plasma interactions in the regime where the reflection of relativistically strong radiation is accompanied by significant, repeated relocation of plasma electrons. In particular, the theory can be applied for the studies of plasma heating and coherent and incoherent emissions in the RES regime of high-intensity laser-plasma interaction.
Dynamics of delay-coupled FitzHugh-Nagumo neural rings
Authors: Mao Xiaochen , Sun Jianqiao , Li Shaofan
Published: January 2018

This paper studies the dynamical behaviors of a pair of FitzHugh-Nagumo neural networks with bidirectional delayed couplings. It presents a detailed analysis of delay-independent and delay-dependent stabilities and the existence of bifurcated oscillations. Illustrative examples are performed to validate the analytical results and to discover interesting phenomena. It is shown that the network exhibits a variety of complicated activities, such as multiple stability switches, the coexistence of periodic and quasi-periodic oscillations, the coexistence of periodic and chaotic orbits, and the coexisting chaotic attractors.
On system behaviour using complex networks of a compression algorithm
Authors: Walker David M. , Correa Debora C. , Small Michael
Published: January 2018

We construct complex networks of scalar time series using a data compression algorithm. The structure and statistics of the resulting networks can be used to help characterize complex systems, and one property, in particular, appears to be a useful discriminating statistic in surrogate data hypothesis tests. We demonstrate these ideas on systems with known dynamical behaviour and also show that our approach is capable of identifying behavioural transitions within electroencephalogram recordings as well as changes due to a bifurcation parameter of a chaotic system. The technique we propose is dependent on a coarse grained quantization of the original time series and therefore provides potential for a spatial scale-dependent characterization of the data. Finally the method is as computationally efficient as the underlying compression algorithm and provides a compression of the salient features of long time series.
Nonlinear eigen-structures in star-forming gyratory nonthermal complex molecular clouds
Authors: Karmakar Pralay Kumar , Dutta Pranamika
Published: January 2018

This paper deals with the nonlinear gravito-electrostatic fluctuations in star-forming rotating complex partially ionized dust molecular clouds, evolutionarily well-governed by a derived pair of the Korteweg–de Vries (KdV) equations of a unique analytical shape, in a bi-fluidic-model fabric. The lighter constituent species, such as electrons and ions, are considered thermo-statistically as the nonthermal ones in nature, governed by the anti-equilibrium kappa-distribution laws, due to inherent nonlocal gradient effects stemming from large-scale inhomogeneity. The heavier species, such as the constitutive identical neutral and charged dust micro-spheres, are treated as separate turbulent viscous fluids in the Larson logatropic tapestry. Application of a standard technique of multiple scale analysis over the nonlinearly perturbed cloud procedurally yields the pair KdV system. It comprises of the gravitational KdV and electrostatic KdV equations with exclusive constructs of diversified multi-parametric coefficients. A numerical constructive platform is provided to see the excitation and propagatory dynamics of gravitational rarefactive periodic soliton-trains and electrostatic rarefactive aperiodic damped soliton-trains of distinctive patterns as the pair-KdV-supported discrete coherent eigen-mode structures illustratively. The varied key stabilizing and tonality destabilizing factors behind the cloud dynamics are identified. An elaborated contrast of the eigen-mode conjugacy is reconnoitered. The main implications and applications of the semi-analytical results explored here are summarily outlined in the real astro-space-cosmic statuses.
Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe
Authors: Milotti Valeria , Pietsch Manuel , Strunk Karl-Philipp , Melzer Christian
Published: January 2018

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.
Deep-ultraviolet light emission from 4H-AlN/4H-GaN short-period superlattice grown on 4H-SiC(112¯)
Authors: Kaneko M. , Ueta S. , Horita M. , Kimoto T. , Suda J.
Published: January 2018

AlN/GaN short-period superlattices (SPSLs) were grown on 4H-SiC(112¯0) substrates with a 4H-AlN template layer. The thickness of the GaN layers was controlled to be less than 1 nm to suppress the generation of extended defects. The stacking fault and threading dislocation density were found to be 3 × 105 cm−1 and 6 × 107 cm−2, respectively, which were as low as those for a 4H-AlN single layer. The superlattice replicated the polytype of the underlying 4H-AlN layer (4H-SiC substrate), meaning that a 4H-AlN/4H-GaN SPSL was grown. Room-temperature cathodoluminescence measurements revealed that the 4H-AlN/4H-GaN SPSLs exhibited intense luminescence in the deep ultraviolet region of 4.4–5.0 eV, depending on the GaN layer thickness. The emission wavelengths of the SPSLs fairly agreed with the estimation based on the Kronig-Penney model.
Thermal transport in semicrystalline polyethylene by molecular dynamics simulation
Authors: Lu Tingyu , Kim Kyunghoon , Li Xiaobo , Zhou Jun , Chen Gang , Liu Jun
Published: January 2018

Recent research has highlighted the potential to achieve high-thermal-conductivity polymers by aligning their molecular chains. Combined with other merits, such as low-cost, corrosion resistance, and light weight, such polymers are attractive for heat transfer applications. Due to their quasi-one-dimensional structural nature, the understanding on the thermal transport in those ultra-drawn semicrystalline polymer fibers or films is still lacking. In this paper, we built the ideal repeating units of semicrystalline polyethylene and studied their dependence of thermal conductivity on different crystallinity and interlamellar topology using the molecular dynamics simulations. We found that the conventional models, such as the Choy-Young's model, the series model, and Takayanagi's model, cannot accurately predict the thermal conductivity of the quasi-one-dimensional semicrystalline polyethylene. A modified Takayanagi's model was proposed to explain the dependence of thermal conductivity on the bridge number at intermediate and high crystallinity. We also analyzed the heat transfer pathways and demonstrated the substantial role of interlamellar bridges in the thermal transport in the semicrystalline polyethylene. Our work could contribute to the understanding of the structure–property relationship in semicrystalline polymers and shed some light on the development of plastic heat sinks and thermal management in flexible electronics.
Compressive ion acoustic double layer and its transitional properties for a two electron temperature warm, multi-ion plasma
Authors: Steffy S. V. , Ghosh S. S.
Published: January 2018

The emergence of the compressive ion acoustic double layer has been investigated for a two electron temperature warm, multi-ion plasma by the Sagdeev pseudopotential technique. It shows that the ambient cooler electron concentration plays a deterministic role in initiating the transition process of a compressive ion acoustic solitary wave to its double layer. Incorporating the derivative analysis for the pseudopotential, the transitional phase was further quantified by assigning a critical value for the ambient cooler electron concentration. It has been observed that, beyond that critical value, the width of the solitary wave increases rapidly with the increasing amplitude which coincides with the aforementioned transitional phase, manifesting a change in the internal microphysics of the structure for that region. A comparison with the satellite observation revealed good agreement validating the present model. The model will be useful in interpreting the observed monopolar structures in the auroral acceleration region.
Anisotropy of the ferromagnetic L1 phase in the Mn-Al-C alloys induced by high-pressure spark plasma sintering
Authors: Tyrman Muriel , Ahmim Smail , Pasko Alexandre , Etgens Victor , Mazaleyrat Frédéric , Quetel-Weben Simon , Perrière Loïc , Guillot Ivan
Published: January 2018

The metastable τ-phase of MnAl equi-atomic compound belongs to a family of ferromagnetic alloys with L10 crystal structure. Stabilization of the phase by adding 2 at. % using manganese carbide (Mn23C6) enhances the magnetization in relation with the increase in lattice volume. It is thus a promising candidate for rare-earth-free permanent magnets. Coercivity of Mn-Al-C alloys being still weak, there is an interest to see to which extend sintering/transformation of the ϵ-phase by Spark Plasma Sintering (SPS) can increase the coercivity and the anisotropy. The structural and the magnetic properties were studied for samples sintered at 550 °C under uniaxial pressure of 100, 200, 300 and 400 MPa. Coercivity, remanence and anistotropy appears with the sintering pressure. The high pressure applied while sintering produces preferential orientation of the flake-shaped grains which influences the remanence.
Monitoring local redox processes in LiNi0.5Mn1.5O4 battery cathode material by in operando EPR spectroscopy
Authors: Niemöller Arvid , Jakes Peter , Eurich Svitlana , Paulus Anja , Kungl Hans , Eichel Rüdiger-A. , Granwehr Josef
Published: January 2018

Despite the multitude of analytical methods available to characterize battery cathode materials, identifying the factors responsible for material aging is still challenging. We present the first investigation of transient redox processes in a spinel cathode during electrochemical cycling of a lithium ion battery by in operando electron paramagnetic resonance (EPR). The battery contains a LiNi0.5Mn1.5O4 (LNMO) spinel cathode, which is a material whose magnetic interactions are well understood. The evolution of the EPR signal in combination with electrochemical measurements shows the impact of Mn3+ on the Li+ motion inside the spinel. Moreover, state of charge dependent linewidth variations confirm the formation of a solid solution for slow cycling, which is taken over by mixed models of solid solution and two-phase formation for fast cycling due to kinetic restrictions and overpotentials. Long-term measurements for 480 h showed the stability of the investigated LNMO, but also small amounts of cathode degradation products became visible. The results point out how local, exchange mediated magnetic interactions in cathode materials are linked with battery performance and can be used for material characterization.
Raman and photoluminescence spectroscopy of SiGe layer evolution on Si(100) induced by dewetting
Authors: Shklyaev A. A. , Volodin V. A. , Stoffel M. , Rinnert H. , Vergnat M.
Published: January 2018

High temperature annealing of thick (40–100 nm) Ge layers deposited on Si(100) at ∼400 °C leads to the formation of continuous films prior to their transformation into porous-like films due to dewetting. The evolution of Si-Ge composition, lattice strain, and surface morphology caused by dewetting is analyzed using scanning electron microscopy, Raman, and photoluminescence (PL) spectroscopies. The Raman data reveal that the transformation from the continuous to porous film proceeds through strong Si-Ge interdiffusion, reducing the Ge content from 60% to about 20%, and changing the stress from compressive to tensile. We expect that Ge atoms migrate into the Si substrate occupying interstitial sites and providing thereby the compensation of the lattice mismatch. Annealing generates only one type of radiative recombination centers in SiGe resulting in a PL peak located at about 0.7 and 0.8 eV for continuous and porous film areas, respectively. Since annealing leads to the propagation of threading dislocations through the SiGe/Si interface, we can tentatively associate the observed PL peak to the well-known dislocation-related D1 band.
Reduced dependence of thermal conductivity on temperature and pressure of multi-atom component crystalline solid solutions
Authors: Giri Ashutosh , Braun Jeffrey L. , Hopkins Patrick E.
Published: January 2018

We investigate the effect of mass disorder, temperature, and pressure on the spectral thermal conductivity of multicomponent crystalline solid solutions via molecular dynamics simulations. The thermal conductivities of Lennard-Jones based solid solutions with one to five different atomic components in the crystalline lattice are simulated at a range of uniaxial strain levels and temperatures. Our results show that for multicomponent alloys, increasing only the mass impurity scattering by adding atoms with different masses in the solid solution does not lead to significant changes in the spectral contributions to thermal conductivity. However, increasing the impurity concentration or changing the local force-field of the impurity atoms in the solid solution has a relatively significant impact on the spectral contributions to thermal conductivity. The effect of chemical order in these alloys is shown to drastically alter the temperature dependence due to the different scattering mechanisms dictating thermal conductivities in the ordered and disordered states. Furthermore, in comparison to a homogeneous solid, crystalline solid solutions (especially the disordered states) show a reduced pressure dependence on thermal conductivity, which becomes more prominent as the number of components is increased. This is attributed to the fact that while anharmonic effects in homogeneous solids lead to the large temperature and pressure dependencies in their thermal conductivities, impurity scattering in solid solutions leads to a largely reduced dependence on pressure and temperature.
Numerical study of the current-convective instability driven by asymmetry of detachment in inner and outer divertors
Authors: Stepanenko A. A. , Krasheninnikov S. I.
Published: January 2018

One of the possible mechanisms responsible for strong radiation fluctuations observed in recent experiments with detached plasmas at ASDEX Upgrade [Potzel et al., Nucl. Fusion 54, 013001 (2014)] can be related to the onset of the current-convective instability (CCI) driven by strong asymmetry of detachment in the inner and outer divertors of the tokamak [S. Krasheninnikov and A. Smolyakov, Phys. Plasmas 23, 092505 (2016)]. In this study, we present the physical model, used to simulate the CCI, and the first numerical results of modeling of the CCI dynamics in ASDEX Upgrade-like conditions. The simulation results provide frequency spectra of turbulent divertor plasma oscillations showing reasonably good agreement with the available experimental data.
Vision sensor and dual MEMS gyroscope integrated system for attitude determination on moving base
Authors: Guo Xiaoting , Sun Changku , Wang Peng , Huang Lu
Published: January 2018

To determine the relative attitude between the objects on a moving base and the base reference system by a MEMS (Micro-Electro-Mechanical Systems) gyroscope, the motion information of the base is redundant, which must be removed from the gyroscope. Our strategy is to add an auxiliary gyroscope attached to the reference system. The master gyroscope is to sense the total motion, and the auxiliary gyroscope is to sense the motion of the moving base. By a generalized difference method, relative attitude in a non-inertial frame can be determined by dual gyroscopes. With the vision sensor suppressing accumulative drift of the MEMS gyroscope, the vision and dual MEMS gyroscope integration system is formed. Coordinate system definitions and spatial transform are executed in order to fuse inertial and visual data from different coordinate systems together. And a nonlinear filter algorithm, Cubature Kalman filter, is used to fuse slow visual data and fast inertial data together. A practical experimental setup is built up and used to validate feasibility and effectiveness of our proposed attitude determination system in the non-inertial frame on the moving base.
Experimental evaluation of fatty acid composition influence on Jatropha biodiesel physicochemical properties
Authors: Reddy A. N. R. , Saleh A. A. , Islam M. S. , Hamdan S. , Rahman Md. Rezaur , Masjuki H. H.
Published: January 2018

The physiochemical properties of biodiesel are significantly influenced by its fatty acid composition (FAC). This research investigates FAC of Jatropha biodiesel (JB) synthesized using feedstocks originated from the east (JBEM) and west (JBWM) Malaysian regions together with biofuel properties. The critical properties of pure biodiesels and blends were analysed according to ASTM D6751/EN 14214 standards. The JB properties were precisely regulated by its FAC features such as saturated fatty acids (SFAs), unsaturated fatty acids (USFAs), degree of unsaturation, and long chain saturated factor. The influence of SFA and USFA was inversely associated over biodiesel properties. The presence of higher SFA greatly affects biodiesel properties like the cetane number, cold filter plugging point, kinematic viscosity, density, cloud point, and pour point; conversely, the fuel properties such as oxidation stability, iodine value, acid value, water content, and flash point were improving with USFA contents. Blending of biofuels with petro diesels considerably improved their fuel properties.
Concurrent wafer-level measurement of longitudinal and transverse effective piezoelectric coefficients (d33,f and e31,f) by double beam laser interferometry
Authors: Sivaramakrishnan S. , Mardilovich P. , Schmitz-Kempen T. , Tiedke S.
Published: January 2018

In a recently published paper [S. Sivaramakrishnan et al., Appl. Phys. Lett. 103, 132904 (2013)], the electrode-size dependence of the longitudinal effective piezoelectric coefficient (d33,f) of piezoelectric thin films measured by double beam laser interferometry was shown to be due to the substrate clamping effects. It was also shown that the true d33,f is measured when the ratio of the electrode size to the substrate thickness is approximately unity, in the case of a substrate with isotropic elastic properties and a Poisson's ratio of ∼0.3. In this paper, we further investigate the dependence of the critical ratio (rc) of the electrode size to the substrate thickness at which the true d33,f is measured on the substrate Poisson's ratio for isotopic substrates and for the important case of the anisotropic Si substrate. It turns out that it is the out-of-plane Poisson's ratio (-s13/s11) that is relevant for this measurement technique and not the in-plane Poisson's ratio which is highly anisotropic for the (001) oriented Si. Furthermore, we show that the transverse effective piezoelectric coefficient (e31,f) can also be determined from the same measurement of the electrode size dependence of d33,f. This provides a convenient non-destructive wafer-level measurement technique for the determination of both the piezoelectric coefficients simultaneously. Moreover, this technique is also capable of measuring e31,f under varying electric field excitation which is important for many applications such as actuators.
Second-mode waves produce hypersonic boundary layer heating
Authors: Wolverton Mark
Published: January 2018

Researchers use second mode instability to explain heat-transfer peaks observed ahead of laminar-to-turbulence transitions.
Pairwise comparisons across species are problematic when analyzing functional genomic data
Authors: Dunn Casey W. , Zapata Felipe , Munro Catriona , Siebert Stefan , Hejnol Andreas
Published: January 2018

Significance

Comparisons of genome function between species are providing important insight into the evolutionary origins of diversity. Here, we show that comparative functional genomics studies can come to the wrong conclusions if they do not take the relationships of species into account and instead rely on pairwise comparisons between species, as is common practice. We reexamined two previously published studies and found problems with pairwise comparisons that draw both their original conclusions into question. One study found support for the ortholog conjecture, and the other concluded that evolution of gene expression differed in pattern and process between animal phyla vs. within animal phyla. Our results show that, to answer evolutionary questions about genome function, it is critical to consider evolutionary relationships.
Impact and cost-effectiveness of snail control to achieve disease control targets for schistosomiasis
Authors: Lo Nathan C. , Gurarie David , Yoon Nara , Coulibaly Jean T. , Bendavid Eran , Andrews Jason R. , King Charles H.
Published: January 2018

Significance

Schistosomiasis is an infectious disease that affects over 240 million people living in low- and middle-income countries, and is caused by parasitic worms that require snail hosts to complete its lifecycle. To improve public health control of this disease, there is growing interest in using chemical-based snail control that kills snail populations in environmental water sources, which will reduce infection rate in people. We modeled transmission of schistosomiasis and cost-effectiveness of various strategies with data from low- and high-prevalence rural Kenyan communities. Adding snail control alongside conventional mass treatment programs (instead of mass treatment programs alone) was found to be cost-effective, especially in settings with high disease burden and nonparticipation in mass treatment programs.
Molecular determinants of pH regulation in the cardiac Na+–Ca2+ exchanger
Authors: John Scott , Kim Brian , Olcese Riccardo , Goldhaber Joshua I. , Ottolia Michela
Published: January 2018

The cardiac Na+–Ca2+ exchanger (NCX) plays a critical role in the heart by extruding Ca2+ after each contraction and thus regulates cardiac contractility. The activity of NCX is strongly inhibited by cytosolic protons, which suggests that intracellular acidification will have important effects on heart contractility. However, the mechanisms underlying this inhibition remain elusive. It has been suggested that pH regulation originates from the competitive binding of protons to two Ca2+-binding domains within the large cytoplasmic loop of NCX and requires inactivation by intracellular Na+ to fully develop. By combining mutagenesis and electrophysiology, we demonstrate that NCX pH modulation is an allosteric mechanism distinct from Na+ and Ca2+ regulation, and we show that cytoplasmic Na+ can affect the sensitivity of NCX to protons. We further identify two histidines (His 124 and His 165) that are important for NCX proton sensitivity and show that His 165 plays the dominant role. Our results reveal a complex interplay between the different allosteric mechanisms that regulate the activity of NCX. Because of the central role of NCX in cardiac function, these findings are important for our understanding of heart pathophysiology.
Study of pyrolysed acid and based treated coconut coir as green photocatalyst substrate
Authors: Asim Nilofar , Emdadi Zeynab , Abdullah N A , Mohammad Masita , Badiei Marzieh , Sopian Kamaruzzaman
Published: January 2018

This study investigates the possible contribution to sustainable development by utilizing agriculture waste materials to prepare a substrate for photo-catalysis application. The photocatalytic performance of impregnated TiO2 on acid and base- treated coconut coir (CC) and their pyrolysed form have been studied. The photocatalytic performance of impregnated TiO2 on acid treated CC improved compared to bare TiO2. However, the pyrolysed samples showed higher thermal stability and porosity compared to only treated CC, their catalytic performance was decreased. It seems that impregnated TiO2 undergo interaction with treated CC during pyrolysis. More investigations to reveal exact reason of this behavior is in progress.
Cross-national Differences in Intergenerational Family Relations: The Influence of Public Policy Arrangements
Authors: Dykstra Pearl A
Published: January 2018

Focusing mostly on Europe, this overview reveals how the research on cross-national differences in intergenerational family relations has moved from basic descriptions to a focus on understanding how support exchanges are shaped by macro-level processes. A key issue concerns generational interdependence, the extent to which public policy arrangements impose reliance on older and younger family members or enable individual autonomy. Real theoretical progress is visible in three areas of research. The first pertains to analyses at the micro level of how family members actually respond to the incentives that different macro contexts provide. The generosity or restrictedness of public provisions variably releases or necessitates normative obligations in interdependent family relationships. The second area of progress involves analyses of the implications of specific policies rather than policy packages for gender and socioeconomic inequality. The third area of progress is a more nuanced view on the familialism–individualism divide. These three areas provide inspiring examples for future investigations.