bluuebunny/crossref_metadata_2025 huggingface dataset:
Light-induced [2 + 2] cycloadditions for the construction of cyclobutane-fused pyridinyl sulfonyl fluorides
Authors: Liu Jing , Wang Shi-Meng , Qin Hua-Li
Published: May 2020

A photocatalytic [2 + 2] cycloaddition between pyridones or isoquinolones and ethenesulfonyl fluoride was achieved, generating unique cyclobutane-fused pyridinyl sulfonyl fluoride compounds.
Calculation of magnetic response properties of tetrazines
Authors: Orozco-Ic Mesías , Celaya Christian A. , Sundholm Dage
Published: May 2020

Magnetic response properties of 1,2,3,5-tetrazine derivatives including the newly synthesized 4,6-diphenyl-1,2,3,5-tetrazine have been studied computationally at the density functional theory level.
Recent advances in catalytic chain transfer polymerization of isobutylene: a review
Authors: Rajasekhar Tota , Singh Gurmeet , Kapur Gurpreet Singh , Ramakumar S. S. V.
Published: May 2020

This review presents the development of highly reactive polyisobutylene (HRPIB), a major commercial intermediate toward fuel and lubricant additives.
Enhanced performance of lithium–sulfur batteries based on single-sided chemical tailoring, and organosiloxane grafted PP separator
Authors: Zhou Haifeng , Tang Qunli , Xu Qianer , Zhang Yan , Huang Cong , Xu Yali , Hu Aiping , Chen Xiaohua
Published: May 2020

Even after a decade of research and rapid development of lithium–sulfur (Li–S) batteries, the infamous shuttle effect of lithium polysulfide is still the major challenge hindering the commercialization of Li–S batteries.
Spin-chemical effects on intramolecular photoinduced charge transfer reactions in bisphenanthroline copper(i)-viologen dyad assemblies
Authors: Lazorski Megan S. , Schapiro Igor , Gaddie Ross S. , Lehnig Ammon P. , Atanasov Mihail , Neese Frank , Steiner Ulrich E. , Elliott C. Michael
Published: May 2020

Quantum chemical calculations and laser flash spectroscopy probe spin-dynamics of the photoinduced electron transfer mechanism in two donor–acceptor bisphenanthrolinecopper(i) species, marking the influence of spin on solar energy conversion schemes.
Peptide and protein modified metal clusters for cancer diagnostics
Authors: Su Dongdong , Gao Liang , Gao Fuping , Zhang Xiangchun , Gao Xueyun
Published: May 2020

A perspective on the development of peptide and protein modified metal clusters in cancer diagnostic applications.
Outer-sphere effects on ligand-field excited-state dynamics: solvent dependence of high-spin to low-spin conversion in [Fe(bpy)3]2+
Authors: Miller Jennifer N. , McCusker James K.
Published: May 2020

Time-resolved spectroscopic measurements of ground-state recovery for [Fe(bpy)3]2+ reveal that the solvent can induce an outer-sphere reorganization energy effect on excited-state dynamics involving metal-centered ligand-field electronic states.
Chiral structure fluctuations predicted by a coarse-grained model of peptide aggregation
Authors: Szała Beata , Molski Andrzej
Published: May 2020

This work reports on the chiral structure fluctuations of peptide clusters at the early stages of aggregation in a coarse-grained peptide model.
Partition of nanoswimmers between two immiscible phases: a soft and penetrable boundary
Authors: Peng Ying-Shuo , Sheng Yu-Jane , Tsao Heng-Kwong
Published: May 2020

The behavior of run-and-tumble nanoswimmers which can self-propel in two immiscible liquids such as water–oil systems and are able to cross the interface is investigated by dissipative particle dynamics.
Laser-induced formation of “craters” and “hills” in azobenzene-containing polymethacrylate films
Authors: Bobrovsky Alexey , Mochalov Konstantin , Solovyeva Daria , Shibaev Valery , Cigl Martin , Hamplová Vĕra , Bubnov Alexej
Published: May 2020

The work is devoted to the contactless control of the surface topography and formation of the surface features by light irradiation in the amorphousized and liquid crystalline films of azobenzene-containing polymethacrylates.
Fatigue resistant lead-free multilayer ceramic capacitors with ultrahigh energy density
Authors: Wang Ge , Lu Zhilun , Yang Huijing , Ji Hongfen , Mostaed Ali , Li Linhao , Wei Yiqi , Feteira Antonio , Sun Shikuan , Sinclair Derek C. , Wang Dawei , Reaney Ian M.
Published: May 2020

Electrical homogeneity is vital in optimising energy storage performance in BiFeO3–BaTiO3–xBi(Li0.5Nb0.5)O3 ceramic multilayer capacitors, giving rise to high recoverable energy density ∼13.8 J cm−3 under electric field ∼950 kV cm−1 and fatigue resistance behaviour.
Potential and limitations of CsBi3I10 as a photovoltaic material
Authors: Sebastia-Luna Paz , Gélvez-Rueda María C. , Dreessen Chris , Sessolo Michele , Grozema Ferdinand C. , Palazon Francisco , Bolink Henk J.
Published: May 2020

Wide-bandgap, low-toxicity CsBi3I10 is synthesized and deposited as thin films by solvent-free approaches. Its implementation in photovoltaic devices is demonstrated albeit with limited performances. Suggestions to further improve these are given.
Composite sodium metal anodes for practical applications
Authors: Cui Jiayu , Wang Aoxuan , Li Guojie , Wang Donghong , Shu Da , Dong Anping , Zhu Guoliang , Luo Jiayan , Sun Baode
Published: May 2020

With its high theoretical capacity (1165 mA h g−1), low reduction potential (−2.71) and abundant resources in the earth's crust, Na anode exhibits great potential in grid-scale energy storage systems and extensive application of electric vehicles.
A biomimetic nanozyme/camptothecin hybrid system for synergistically enhanced radiotherapy
Authors: Zhu Daoming , Lyu Meng , Jiang Wei , Suo Meng , Huang Qinqin , Li Kaiyang
Published: May 2020

Although radiotherapy (RT) has been an effective therapeutic regimen for regulating most solid tumors, its effect is limited by the hypoxic tumor microenvironment and radio-tolerance of tumor cells to a large extent.
Pyridinium-substituted tetraphenylethylene salt-based photosensitizers by varying counter anions: a highly efficient photodynamic therapy for cancer cell ablation and bacterial inactivation
Authors: Xiong Wei , Wang Lingyun , Chen Xiaoli , Tang Hao , Cao Derong , Zhang Guozhen , Chen Wei
Published: May 2020

A highly efficient photodynamic therapy of cancer cell ablation and bacterial inactivation by two AIEgens was reported.
Cobalt-induced structural modulation in multiferroic Aurivillius-phase oxides
Authors: Koval V. , Shi Y. , Skorvanek I. , Viola G. , Bures R. , Saksl K. , Roupcova P. , Zhang M. , Jia Ch. , Yan H.
Published: May 2020

Nanoscale structural modulation with the disordered intergrowth of three- and four-layered Aurivillius phases gives rise to the ferromagnetic clustering of the FeO6 and CoO6 octahedra in cobalt-substituted Bi5FeTi3O15-derived compounds.
Tailoring the molecular geometry of polyfluoride perylene diimide acceptors towards efficient organic solar cells
Authors: Wang Yan , Zhong Hongbin , Hong Yuwen , Shan Tong , Ding Kui , Zhu Lei , Liu Feng , Wei Hao , Yu Chunyang , Zhong Hongliang
Published: May 2020

The molecular geometry of fully fused perylene diimides was tailored by F⋯F repulsion for the optimization of photovoltaic performance in organic solar cells.
Nanorods of a novel highly conductive 2D metal–organic framework based on perthiolated coronene for thermoelectric conversion
Authors: Chen Zhijun , Cui Yutao , Jin Yigang , Liu Liyao , Yan Jie , Sun Yang , Zou Ye , Sun Yimeng , Xu Wei , Zhu Daoben
Published: May 2020

Ni-PTC, a perthiolated coronene-based conducting MOF displays p-type thermoelectric performance with a ZT value of 0.003 at 300 K.
Tailoring liquid crystal honeycombs by head-group choice in bird-like bent-core mesogens
Authors: Li Ya-xin , Cheng Huifang , Zeng Xiangbing , Tao Yuan , Cheng Xiaohong , Ungar Goran
Published: May 2020

New non-centrosymmetric soft honeycomb lattices and superlattices are generated by self-assembly of novel mesogens promising applications as SHG and ferroelectric materials.
Fast multi‐spectral image super‐resolution via sparse representation
Authors: Mullah Helal Uddin , Deka Bhabesh , Prasad A.V.V.
Published: May 2020

Sparse reconstruction is used to solve the inverse problem of single image super‐resolution (SR) as a patch‐based sparsity promoting regularisation problem. A coupled trained overcomplete dictionary from high‐resolution (HR) and low‐resolution (LR) image patches containing significant features is proposed using sparse representation to produce HR patches from their LR counterparts. In this study, the authors develop a multi‐core single image SR technique for LR multi‐spectral images based on patch‐wise sparse representation coupled with morphological component analysis driven feature extraction. Simulations are carried out to evaluate the proposed method using real remote sensing images of a few Indian satellites, RESOURCESAT‐2 and CARTOSAT‐2, as well as other satellites, such as QuickBird etc. Results are also compared with other existing SR methods to establish the superiority of the proposed method in terms of both objective metrics and visual analysis.
Probing the initial conditions of high-mass star formation
Authors: Zhang Chuan-Peng , Li Guang-Xing , Pillai Thushara , Csengeri Timea , Wyrowski Friedrich , Menten Karl M. , Pestalozzi Michele R.
Published: May 2020

Context. The initial stage of star formation is a complex area of study because of the high densities (nH2 > 106 cm−3) and low temperatures (Tdust < 18 K) involved. Under such conditions, many molecules become depleted from the gas phase by freezing out onto dust grains. However, the deuterated species could remain gaseous under these extreme conditions, which would indicate that they may serve as ideal tracers.

Aims. We investigate the gas dynamics and NH2D chemistry in eight massive precluster and protocluster clumps (G18.17, G18.21, G23.97N, G23.98, G23.44, G23.97S, G25.38, and G25.71).

Methods. We present NH2D 111–101 (at 85.926 GHz), NH3 (1, 1), and (2, 2) observations in the eight clumps using the PdBI and the VLA, respectively. We used 3D GAUSSCLUMPS to extract NH2D cores and provide a statistical view of their deuterium chemistry. We used NH3 (1, 1) and (2, 2) data to investigate the temperature and dynamics of dense and cold objects.

Results. We find that the distribution between deuterium fractionation and kinetic temperature shows a number density peak at around Tkin = 16.1 K and the NH2D cores are mainly located at a temperature range of 13.0 to 22.0 K. The 3.5 mm continuum cores have a kinetic temperature with a median width of 22.1 ± 4.3 K, which is obviously higher than the temperature in NH2D cores. We detected seven instances of extremely high deuterium fractionation of 1.0 ≤ Dfrac ≤ 1.41. We find that the NH2D emission does not appear to coincide exactly with either dust continuum or NH3 peak positions, but it often surrounds the star-formation active regions. This suggests that the NH2D has been destroyed by the central young stellar object (YSO) due to heating. The detected NH2D lines are very narrow with a median width of 0.98 ± 0.02 km s−1, which is dominated by non-thermal broadening. The extracted NH2D cores are gravitationally bound (αvir < 1), they are likely to be prestellar or starless, and can potentially form intermediate-mass or high-mass stars in future. Using NH3 (1, 1) as a dynamical tracer, we find evidence of very complicated dynamical movement in all the eight clumps, which can be explained by a combined process with outflow, rotation, convergent flow, collision, large velocity gradient, and rotating toroids.

Conclusions. High deuterium fractionation strongly depends on the temperature condition. Tracing NH2D is a poor evolutionary indicator of high-mass star formation in evolved stages, but it is a useful tracer in starless and prestellar cores.
The ALPINE-ALMA [C II] survey
Authors: Schaerer D. , Ginolfi M. , Béthermin M. , Fudamoto Y. , Oesch P. A. , Le Fèvre O. , Faisst A. , Capak P. , Cassata P. , Silverman J. D. , Yan Lin , Jones G. C. , Amorin R. , Bardelli S. , Boquien M. , Cimatti A. , Dessauges-Zavadsky M. , Giavalisco M. , Hathi N. P. , Fujimoto S. , Ibar E. , Koekemoer A. , Lagache G. , Lemaux B. C. , Loiacono F. , Maiolino R. , Narayanan D. , Morselli L. , Méndez-Hernàndez H. , Pozzi F. , Riechers D. , Talia M. , Toft S. , Vallini L. , Vergani D. , Zamorani G. , Zucca E.
Published: May 2020

The [C II] 158μm line is one of the strongest IR emission lines, which has been shown to trace the star formation rate (SFR) of galaxies in the nearby Universe, and up toz ∼ 2. Whether this is also the case at higher redshift and in the early Universe remains debated. The ALPINE survey, which targeted 118 star-forming galaxies at 4.4 <  z <  5.9, provides a new opportunity to examine this question with the first statistical dataset. Using the ALPINE data and earlier measurements from the literature, we examine the relation between the [C II] luminosity and the SFR over the entire redshift range fromz ∼ 4 − 8. ALPINE galaxies, which are both detected in [C II] and in dust continuum, show good agreement with the localL([CII])–SFR relation. Galaxies undetected in the continuum by ALMA are found to be over-luminous in [C II] when the UV SFR is used. After accounting for dust-obscured star formation, by an amount of SFR(IR) ≈ SFR(UV) on average, which results from two different stacking methods and SED fitting, the ALPINE galaxies show anL([CII])–SFR relation comparable to the local one. When [C II] non-detections are taken into account, the slope may be marginally steeper at high-z, although this is still somewhat uncertain. When compared homogeneously, thez >  6 [C II] measurements (detections and upper limits) do not behave very differently to thez ∼ 4 − 6 data. We find a weak dependence ofL([CII])/SFR on the Lyαequivalent width. Finally, we find that the ratioL([CII])/LIR∼ (1 − 3) × 10−3for the ALPINE sources, comparable to that of “normal” galaxies at lower redshift. Our analysis, which includes the largest sample (∼150 galaxies) of [C II] measurements atz > 4 available so far, suggests no or little evolution of the [C II]–SFR relation over the last 13 Gyr of cosmic time.
CHANG-ES
Authors: Krause Marita , Irwin Judith , Schmidt Philip , Stein Yelena , Miskolczi Arpad , Carolina Mora-Partiarroyo Silvia , Wiegert Theresa , Beck Rainer , Stil Jeroen M. , Heald George , Li Jiang-Tao , Damas-Segovia Ancor , Vargas Carlos J. , Rand Richard J. , West Jennifer , Walterbos Rene A. M. , Dettmar Ralf-Jürgen , English Jayanne , Woodfinden Alex
Published: May 2020

Context. The magnetic field in spiral galaxies is known to have a large-scale spiral structure along the galactic disk and is observed as X-shaped in the halo of some galaxies. While the disk field can be well explained by dynamo action, the three-dimensional structure of the halo field and its physical nature are still unclear.

Aims. As first steps towards understanding the halo fields, we want to clarify whether or not the observed X-shaped field is a wide-spread pattern in the halos of spiral galaxies. We also aim to investigate whether these halo fields are simply turbulent fields ordered by compression or shear (anisotropic turbulent fields), or have a large-scale regular structure.

Methods. Analysis of the Faraday rotation in the halo is used as a tool to distinguish anisotropic turbulent fields from large-scale magnetic fields. However, this has been challenging until recently because of the faint halo emission in linear polarization. Our sensitive VLA broadband observations in C-band and L-band of 35 spiral galaxies seen edge-on (called CHANG-ES) allowed us to perform rotation measure synthesis (RM synthesis) in their halos and to analyze the results. We further accomplished a stacking of the observed polarization maps of 28 CHANG-ES galaxies in C-band.

Results. Though the stacked edge-on galaxies were of different Hubble type, and had differing star formation activity and interaction activity, the stacked image clearly reveals an X-shaped structure of the apparent magnetic field. We detected a large-scale (coherent) halo field in all 16 galaxies that have extended polarized emission in their halos. We detected large-scale field reversals in all of their halos. In six galaxies, these are along lines that are approximately perpendicular to the galactic midplane (vertical RMTL) with about 2 kpc separation. Only in NGC 3044 and possibly in NGC 3448 did we observe vertical giant magnetic ropes (GMR) similar to those detected recently in NGC 4631.

Conclusions. The observed X-shaped structure of the halo field seems to be an underlying feature of spiral galaxies. It can be regarded as the two-dimensional projection of the regular magnetic field which we found to have scales of typically 1 kpc or larger observed over several kiloparsecs. The ordered magnetic field extends far out in the halo and beyond. We detected large-scale magnetic field reversals in the halo that may indicate that GMR are more or less tightly wound. With these discoveries, we hope to stimulate model simulations for the halo magnetic field that should also explain the determined asymmetry of the polarized intensity (PI).
Thermal evolution of protoplanetary disks: from β-cooling to decoupled gas and dust temperatures
Authors: Vorobyov Eduard I. , Matsukoba Ryoki , Omukai Kazuyuki , Guedel Manuel
Published: May 2020

Aims. We explore the long-term evolution of young protoplanetary disks with different approaches to computing the thermal structure determined by various cooling and heating processes in the disk and its surroundings.

Methods. Numerical hydrodynamics simulations in the thin-disk limit were complemented with three thermal evolution schemes: a simplified β-cooling approach with and without irradiation, where the rate of disk cooling is proportional to the local dynamical time; a fiducial model with equal dust and gas temperatures calculated taking viscous heating, irradiation, and radiative cooling into account; and a more sophisticated approach allowing decoupled dust and gas temperatures.

Results. We found that the gas temperature may significantly exceed that of dust in the outer regions of young disks thanks to additional compressional heating caused by the infalling envelope material in the early stages of disk evolution and slow collisional exchange of energy between gas and dust in low-density disk regions. However, the outer envelope shows an inverse trend, with the gas temperatures dropping below that of dust. The global disk evolution is only weakly sensitive to temperature decoupling. Nevertheless, separate dust and gas temperatures may affect the chemical composition, dust evolution, and disk mass estimates. Constant-β models without stellar and background irradiation fail to reproduce the disk evolution with more sophisticated thermal schemes because of the intrinsically variable nature of the β-parameter. Constant-β models with irradiation more closely match the dynamical and thermal evolution, but the agreement is still incomplete.

Conclusions. Models allowing separate dust and gas temperatures are needed when emphasis is placed on the chemical or dust evolution in protoplanetary disks, particularly in subsolar metallicity environments.
Understanding the contribution of groove resonance to tire-road noise on different surfaces under various operating conditions
Authors: Pinay Julien , Saito Yoshinori , Mignot Christian , Gauterin Frank
Published: May 2020

Reducing tire-road noise is now becoming more and more important during the tire development process. Tread profile randomization is used to avoid tonal components and reduce groove resonance noise. To better understand the groove resonance contribution to tire-road noise, we performed acoustic measurements on a test bench with two serial tires. We filled the grooves with acoustic foam to highlight the groove resonance’s contribution. We then varied the road surface, the tire load and the driving speed. In the end, we used a multiple linear regression to quantify the interaction between the varying parameters and the groove resonance noise. We show that groove resonance contributes an average of 1.7 dBA to the tire rolling noise of passenger car tires. Groove resonance noise also increases with the driving speed. While the tread pattern and the tire load are responsible for the spectral content of the groove resonance noise, the orientation of the road surface’s texture mainly influences the noise level of the groove resonance. The tire manufacturers should carefully consider these findings when developing noise-optimized patterns. This is especially true for tire approval tests, which take place on tracks and usually have a relatively low texture level that is oriented negatively.
Low frequency sound field reconstruction in a non-rectangular room using a small number of microphones
Authors: Pham Vu Thach , Lissek Hervé
Published: May 2020

An accurate knowledge of the sound field distribution inside a room is required to identify and optimally locate corrective measures for room acoustics. However, the spatial recovery of the sound field would result in an impractically high number of microphones in the room. Fortunately, at low frequencies, the possibility to rely on a sparse description of sound fields can help reduce the total number of measurement points without affecting the accuracy of the reconstruction. In this paper, the use of Greedy algorithm and Global curve-fitting techniques are proposed, in order to first recover the modal parameters of the room, and then to reconstruct the entire enclosed sound field at low frequencies, using a reasonably low set of measurements. First, numerical investigations are conducted on a non-rectangular room configuration, with different acoustic properties, in order to analyze various aspects of the reconstruction frameworks such as accuracy and robustness. The model is then validated with an experimental study in an actual reverberation chamber. The study yields promising results in which the enclosed sound field can be faithfully reconstructed using a practically feasible number of microphones, even in complex-shaped and damped rooms.
A brief review on the techniques used for the enhancement of luminescence of red emitting thin film
Authors: Vini Kalathil , Aparna Cheruvathur adukkathayar , Nissamudeen Kavukuzhi Meerasahib
Published: May 2020

In the past few years, red emitting thin film activated by Eu3+ has received much attention. Europium has a peculiar property that it exhibits both types of emission on the basis of their valencies. In this review, we try to make a full list of known methods which may be useful for the enhancement of luminescence. It has been found that luminescence can be enhanced by increasing substrate temperature, film roughness, changing the morphology etc. Finally we discuss the mechanism of co-doping with different elements for the enhancement of luminescence.
Research on Hydrodynamic Characteristics of Blended Wing Body Underwater Glider with Rudder
Authors: Ma Yunlong , Pan Guang , Huang Qiaogao , Li Jinglu
Published: May 2020

In order to improve the maneuverability and stability of the Blended Wing Body (BWB) underwater glider, the trailing edge rudder is integrated into its shape design in this paper. Through the numerical simulation of CFD, the variation laws of the hydraulic parameters such as lift, drag, lift-to-drag ratio with the angle of attack and rudder angle are given. Compared with the traditional underwater glider, the BWB underwater glider not only has high loading capacity, but also has a maximum lift-to-drag ratio three times that of the former, resulting in higher energy efficiency. At the same time, by adding trailing edge rudders, the maneuverability of the BWB underwater glider is improved, and the lift-to-drag ratio under the same large rudder angle is increased by more than 30% compared with the variable-wing underwater glider. Finally, through the analysis of the numerical results and the cloud image, the difference interaction extent between the rudder and the body of the BWB underwater glider and the traditional torpedo or AUV is illustrated.
Study on Operation Strategy of Solar-Powered UAV Based on Longest Endurance
Authors: Wang Chunyang , Zhou Zhou , Wang Rui
Published: May 2020

Aiming at the problem of energy collection and consumption of solar-powered UAV under different maneuvers, an energy collection model combining solar-powered UAV attitude and solar radiation was established. Firstly, the ASHRAE model was used as the solar radiation estimation model in the flight environment. Secondly, the energy harvesting model of the solar-powered UAV is deduced by the relationship between the attitude of the UAV, the relative position of the sun and the earth. The experimental data was used to establish the energy consumption model of solar-powered UAV in different flight states. Finally, the flight time of the same mission path under different operating modes is obtained through simulation. Simulation results show that when the solar-powered UAV is hovering at a height of 3 000 meters and a radius of 50 meters, the flight time of aileron operation is 7.19% longer than power differential operation; when hovering at a radius of 170 meters, the flight time of the two operations is almost equal; when hovering at a radius of 600 meters and flying in a line, the flight time of the power differential operation is about 1.08% longer than that of the aileron operation.
A Link Distance Division Based Time Division Multiple Access Protocol for Directional Aeronautical Relay Networks
Authors: Yan Zhongjiang , Li Qianqian , Li Bo , Yang Mao
Published: May 2020

In directional aeronautical relay networks, the airplane relay explores the advantages of the directional antenna, in terms of long transmission distance, low transmission power, small interference range and so on, to help the ground nodes transmitting data. However, data transmission delay extension problem occurs when the distance of the transmission link extends, where the wireless signal transmission time approximates the data transmission time such that the wireless signal transmission time cannot be omitted. To address the data transmission delay extension problem, a link distance division based time division multiple access protocol, LDD-TDMA, is proposed in this paper. Different from the traditional TDMA protocol, where the time slots are equal and are determined by the longest transmission link, the length of the time slots are different and are determined by different transmission links. Furthermore, the concept of communication coverage ring is proposed where the nodes located in the same ring communicate with the relay utilizing the same time slot length. The relationships between the number of rings, the ring radius and the transmission range of the LDD-TDMA are modelled and derived as a closed formula, where the ring radius are optimized such that the gain is maximized. Simulation results show that LDD-TDMA outperforms TDMA by 13.37% when the transmission range is 200 km and the ring number is 4.
The Hessian Riemannian flow and Newton’s method for effective Hamiltonians and Mather measures
Authors: Gomes Diogo A. , Yang Xianjin
Published: May 2020

Effective Hamiltonians arise in several problems, including homogenization of Hamilton–Jacobi equations, nonlinear control systems, Hamiltonian dynamics, and Aubry–Mather theory. In Aubry–Mather theory, related objects, Mather measures, are also of great importance. Here, we combine ideas from mean-field games with the Hessian Riemannian flow to compute effective Hamiltonians and Mather measures simultaneously. We prove the convergence of the Hessian Riemannian flow in the continuous setting. For the discrete case, we give both the existence and the convergence of the Hessian Riemannian flow. In addition, we explore a variant of Newton’s method that greatly improves the performance of the Hessian Riemannian flow. In our numerical experiments, we see that our algorithms preserve the non-negativity of Mather measures and are more stable than related methods in problems that are close to singular. Furthermore, our method also provides a way to approximate stationary MFGs.
Optimality and duality in nonsmooth vector optimization with non-convex feasible set
Authors: Sharma Sunila , Yadav Priyanka
Published: May 2020

For a convex programming problem, the Karush–Kuhn–Tucker (KKT) conditions are necessary and sufficient for optimality under suitable constraint qualification. Recently, Suneja et al. [Am. J. Oper. Res. 6 (2013) 536–541] proved KKT optimality conditions for a differentiable vector optimization problem over cones in which they replaced the cone-convexity of constraint function by convexity of feasible set and assumed the objective function to be cone-pseudoconvex. In this paper, we have considered a nonsmooth vector optimization problem over cones and proved KKT type sufficient optimality conditions by replacing convexity of feasible set with the weaker condition considered by Ho [Optim. Lett. 11 (2017) 41–46] and assuming the objective function to be generalized nonsmooth cone-pseudoconvex. Also, a Mond–Weir type dual is formulated and various duality results are established in the modified setting.
Anaerobic and Agility Parameters of Salonists in Laboratory and Field
Tests
Authors: da Cruz João Pedro , Messias Leonardo Henrique Dalcheco , Cetein Rafael Lucas , Rasteiro Felipe Marroni , Gobatto Claudio Alexandre , Manchado-Gobatto Fúlvia Barros
Published: May 2020

This study aimed to investigate the relationship between mechanical parameters
from the Running-based Anaerobic Sprint Test (RAST2×17.5),
agility performance from the Illinois Agility Test (IAT) and all-out 30-second
tethered running (AO30) in college futsal athletes. It also investigates whether
these protocols are capable of identifying differences between sexes. Twenty
subjects were evaluated. The IAT was applied on a specific course and
performance was considered as the total time (T.T). The
RAST2×17.5 consisted of six maximum efforts in a shuttle
exercise of 2x17.5 m per bout. The AO30 was conducted under maximal effort on a
non-motorized treadmill. Maximum, mean and minimum power were determined for
RAST2×17.5 and AO30. Mean power from
RAST2×17.5 was inversely and significantly correlated to
T.T regardless of sex (male: r=–0.76; p=0.010; female:
r=–0.89; p=0.010). A similar association was noticed for
maximum power for females (r=–0.94; p=0.001). The AO30
maximum and mean power were significantly correlated with T.T (male:
r=–0.67; p=0.031 and r=–0.66;
p=0.035, respectively; female: r=–0.64; p=0.046
and r=0.66; p=0.035, respectively). Maximum power from
RAST2×17.5 and AO30 were significantly correlated (male:
r=0.68; p=0.030; female: r=0.72; p=0.019). Our
results reinforce the adoption of field-based tests like
RAST2×17.5 and IAT for futsal, since significant
relationships among these parameters and AO30 results were obtained. Moreover,
these protocols differentiated male and female athletes by mechanical and
agility parameters, proving their application under specific field
evaluation.
Antebrachial Angular Deformities Using Computer-Assisted Hexapod External Fixator Systems in Dogs
Authors: Şengöz Şirin Özlem , Peirone Bruno , Piras Lisa Adele , Bilgili Hasan
Published: May 2020

Objective The aim of this study was to investigate the applicability of computer-assisted hexapod fixators in dogs and to consider the advantages and disadvantages during implementation.

Materials and Methods This was a prospective study. The study material consisted of 11 deformed extremities of 6 dogs. The correction plans were defined according to multiple extremity radiographs of the dog and the clinical evaluation of deformities. All measurements were uploaded to Click2Correct software program. Latent, correction and consolidation periods of each dog were recorded. The hexapod external fixators were removed after completion of the correction.

Results Data were adapted to the radiographic navigation software to be used during operation and postoperative period. The latent period ranged from 3 to 20 days, the correction period ranged from 7 to 20 days and the consolidation period ranged from 39 to 81 days. It was concluded that special fixators can be used in dogs with complex antebrachial deformities.

Clinical significance The ability to perform six axes correction at the same time has a considerable advantage, especially in dogs with complex antebrachial deformities. It is practical to use this fixation system in dogs with antebrachial deformities.
A Bond-Weakening Borinate Catalyst that Improves the Scope of the Photoredox α-C–H Alkylation of Alcohols
Authors: Oisaki Kounosuke , Kanai Motomu , Sakai Kentaro
Published: May 2020

The development of catalyst-controlled, site-selective C(sp3)–H functionalization reactions is currently a major challenge in organic synthesis. In this paper, a novel bond-weakening catalyst that recognizes the hydroxy group of alcohols through formation of a borate is described. An electron-deficient borinic acid–ethanolamine complex enhances the chemical yield of the α-C–H alkylation of alcohols when used in conjunction with a photoredox catalyst and a hydrogen atom transfer catalyst under irradiation with visible light. This ternary hybrid catalyst system can, for example, be applied to functional-group-enriched­ peptides.
Regioselective Synthesis of Pyrazolyl-pyrimidine Hybrids of Pharmacological Interest
Authors: Zanatta Nilo , Camargo Adriano F. , Marangoni Mário A. , de Moraes Paulo A. , Nogara Pablo A. , Afolabi Blessing A. , Bencke Carlos E. , Rocha João B. T. , Bonacorso Helio G. , Martins Marcos A. P.
Published: May 2020

The regioselective synthesis of twenty novel [3-substituted 5-hydroxy-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-1-yl][6-aryl-(2-methylthio)pyrimidin-4-yl]methanones from the cyclocondensation reactions of new 6-aryl-2-(methylthio)pyrimidine-4-carbohydrazides with 4-substituted 1,1,1-trifluorobut-3-en-2-ones is reported. Human acetylcholinesterase (HsAChE) and butyrylcholinesterase (HsBChE) inhibition tests were performed on selected products in order to explore the possible pharmacological applications of these compounds. Two compounds showed significant and selective inhibitory activity for BChE.
Knowledge and Attitude of Dentists and Patients Toward Use and Health Safety of Dental Amalgam in Saudi Arabia
Authors: Al-Nahedh Hend N. , El-hejazi Ahmed A , Habib Syed Rashid
Published: May 2020

Objective The aim of this study was to assess: (1) the perceptions of dentists in Saudi Arabia concerning the amalgam controversy, (2) their attitude toward the ethical responsibility of patient information, and (3) patients’ knowledge and attitude toward the use of dental amalgam.

Materials and Methods A total of 1,139 dentists were sampled on convenience by electronic survey. The questionnaire contained questions about the safety of dental amalgam, use of amalgam, case selection, alternate materials, and informing their patients about risks of amalgam. Also, 425 patients were sampled on convenience and information collected on their knowledge about amalgam and its acceptance in their oral cavities.

Results A total of 201 dentists and 425 patients participated in the study. A total of 60% of dentists and specialists declared it safe. A total of 32.4% (31) of general dental practitioners and 41% (43) specialists considered it a moral obligation to inform patients about the potential health risks associated with amalgam. Mercury toxicity was identified as the most common health hazard. About 57.3% dentists and 36.2% specialists opted for superior longevity as the principle advantage. Majority of patients (52.2%) in Saudi Arabia had no knowledge about dental amalgam. While 23.1% (98) had concern about poor color, 8.7% (30) knew it contained silver while only 7.8% (27) patients were aware of its mercury content.

Conclusion Majority of dentists in Saudi Arabia found it safe to use amalgam while the patients had little knowledge about the possible issues with amalgam. It is recommended to improve public awareness about impact of mercury containing products on the environment.
Effect of Sodium Bicarbonate Mouth Wash on Salivary pH and Interleukin-1β Levels among Smokers
Authors: Hamza Syed Ameer , Wahid Arsalan , Afzal Nadeem , Asif Saba , Imran Mian Farrukh , Khurshid Zohaib , Bokhari Syed Akhtar Hussain
Published: May 2020

Objective Smoking induces changes in salivary pH and inflammatory biomarker levels associated with oral diseases. This study examined the effect of alkaline oral rinse to modify this effect of smoking on salivary study parameters.

Materials and Methods A double-blind randomized controlled trial (RCT) on systemically healthy smokers was conducted. A total of 78 smokers, aged 18 to 40 years, were enrolled as per exclusion/inclusion criteria. An alkaline mouthwash was provided to the intervention group and a placebo to control group. Salivary pH and inflammatory biomarker interleukin (IL)-1β levels were evaluated at baseline and at follow-up (14 ± 2 days).

Statistical Analysis Chi-squared test, independaent t-test, and paired t-test were used to observe the changes in parameters among and between groups before and after intervention using SPSS v16 with a significance level of p≤0.050.

Results Sixty eight salivary samples were analyzed. All study parameters of the study sample were statistically insignificant between both intervention and control groups at baseline. pH level was 6.56 ± 0.53 at baseline and 6.62 ± 0.45 at follow-up in the intervention group; respective values for control group were 6.70 ± 0.36 and 6.83 ± 0.44 and the changes were not significant (p≥0.071). IL-1β level was 9.39 ± 10.23 pg/µL at baseline and 5.40 ± 6.62 pg/µL at a follow-up in the intervention group and the change was significant (p = 0.001); respective values for the control group were 10.63 ± 11.50, and 9.33 ± 11.73 and the difference was nonsignificant (p = 0.076).

Conclusion This randomized trial indicated that sodium bicarbonate mouth rinse is effective in decreasing IL-1β levels and increasing salivary pH favorable for prevention of oral diseases.
Flexural Performance of Direct Resin Composite Restorative Materials Past Expiration Date
Authors: Nagaoka Hiroko , Bishop Susan , Roberts Howard
Published: May 2020

Objective This study' s purpose was to examine the flexural properties of five direct restorative resin composites stored up to 30 months after the expiration date.

Materials and Methods Ambient-stored materials had pre-expiration date baseline flexure strength values as per ISO 4049 (n = 20). All materials were used per manufacturer guidelines, photopolymerized on both sides using a LED-based visible light curing unit, and stored in 0.2M phosphate buffered saline. At 24 hours, specimens were stressed to failure in three-point bend at a 0.5 mm/min cross head speed. Additional samples were made at 3, 6, 9, 12, 15, 18, 24, and 30 months past expiration date. Young’s modulus (flexural) was ascertained using the linear slope of the stress-stain curve.

Statistical Analysis The mean data was found to contain a non-normal distribution and irregular variance which was compared using Kruskal–Wallis with Dunn’s posthoc testing.

Also, Pearson’s correlation analysis was used to identify possible similar degradation behavior between products within both flexure strength and modulus determinations. A 95% level of confidence (α = 0.05) was used.

Results Materials maintained similar to baseline flexure strength and modulus for up to 15 months past expiration date with two materials being similar at 30 months. However, clinicians were still advised to follow expiration dates, as resin composite degradation mechanisms are complex and vital constituents might degrade that are not overtly identified by clinical handling characteristics. No dental shelf life standards exist and manufacturers are requested to provide protocol information used in determining shelf life expiration.
A Proposed Plan for Prenatal Care to Minimize Risks of COVID-19 to Patients and Providers: Focus on Hypertensive Disorders of Pregnancy
Authors: Barton John R. , Saade George R. , Sibai Baha M.
Published: May 2020

Hypertensive disorders are the most common medical complications of pregnancy and a major cause of maternal and perinatal morbidity and death. The detection of elevated blood pressure during pregnancy is one of the cardinal aspects of optimal antenatal care. With the outbreak of novel coronavirus disease 2019 (COVID-19) and the risk for person-to-person spread of the virus, there is a desire to minimize unnecessary visits to health care facilities. Women should be classified as low risk or high risk for hypertensive disorders of pregnancy and adjustments can be accordingly made in the frequency of maternal and fetal surveillance. During this pandemic, all pregnant women should be encouraged to obtain a sphygmomanometer. Patients monitored for hypertension as an outpatient should receive written instructions on the important signs and symptoms of disease progression and provided contact information to report the development of any concern for change in status. As the clinical management of gestational hypertension and preeclampsia is the same, assessment of urinary protein is unnecessary in the management once a diagnosis of a hypertensive disorder of pregnancy is made. Pregnant women with suspected hypertensive disorders of pregnancy and signs and symptoms associated with the severe end of the disease spectrum (e.g., headaches, visual symptoms, epigastric pain, and pulmonary edema) should have an evaluation including complete blood count, serum creatinine level, and liver transaminases (aspartate aminotransferase and alanine aminotransferase). Further, if there is any evidence of disease progression or if acute severe hypertension develops, prompt hospitalization is suggested. Current guidelines from the American College of Obstetricians and Gynecologists (ACOG) and The Society for Maternal-Fetal Medicine (SMFM) for management of preeclampsia with severe features suggest delivery after 34 0/7 weeks of gestation. With the outbreak of COVID-19, however, adjustments to this algorithm should be considered including delivery by 30 0/7 weeks of gestation in the setting of preeclampsia with severe features.

Key Points
Comparison of Two Novel Techniques for Iris Centering in Ocular Prosthesis
Authors: Arora Dhananjay , Singla Shefali , Kumar Lalit , Sehgal Komal , Sharma Puneet
Published: May 2020

Eyes are among the first features of the face to be noticed. Loss of an eye due to congenital, traumatic, or pathologic etiologies causes disfigurement and loss of sensory feedback. It leaves a psychological impact on the patient; thus, prosthesis should be provided at the earliest to raise the spirits of the afflicted. Iris positioning is one of the important steps in fabricating customized ocular prosthesis. In facial asymmetry cases, comparison of both irises together can be a major disadvantage. This case report illustrates the use of a regular eyeglass in one technique and the use of a bioart facebow in the second technique for centering of iris in a customized ocular prosthesis to overcome the disadvantages of earlier used standard techniques (McArthur’s ocular locator and fixed calliper, pupillometer, visual judgement, and graph grid) of iris centering.
Spin transfer and proximity effects in case of FePt (L1) nanoparticles coated with P3HT
Authors: Gutoiu Simona , Leostean Cristian , Soran Maria-Loredana , Stefan Maria , Macavei Sergiu , Toloman Dana , Popa Adriana , Stegarescu Adina , Pana Ovidiu
Published: May 2020

Nanocomposites based on half-metallic FePt (L10) magnetic nanoparticles coated with the semiconducting conjugated polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) show a significant reduction in the magnetic coercivity. This study adopts a physical approach based on chemical potential equalization at the interface. The underlying charge/spin transfer mechanism unveils an imbalance: only spin-down polarized electrons are allowed to be transferred from the semiconductor to the half-metal (spin-down) conduction band, while spin-up states remain blocked at the interface. This process determines an excess of spin-up states on the P3HT side, and due to a RKKY mechanism, this effective spin system becomes ferromagnetic polarized. Due to this proximity effect, the conjugate polymer becomes exchange coupled to the hard magnetic FePt (L10) phase, thus reducing the coercivity of the half-metal. These processes make this type of composite suitable for magnetic recording applications.
Effects of temperature fluctuations on a SQUID-based superconducting gravimeter
Authors: Yu Jiao , Hu Xianjun , Liu Xikai , Ma Dong , Liu Xiangdong , Zhang Ning , Chen Liang
Published: May 2020

A superconducting gravimeter based on the superconducting quantum interference device system is under development. As the main source of low-frequency noise, temperature fluctuations affect the resolution of superconducting gravimeters. In this study, a set of experimental devices was built to investigate the primary coupling processes of temperature fluctuations in superconducting gravimeters. Under the temperature modulation method, the effects of temperature fluctuations can be expressed as dΦ/dT = 342(2)Φ0/K, which, according to theoretical analysis, corresponds to a displacement change of (1.38 ± 0.04) × 10−7 m/K. Based on these results, the ambient temperature is controlled to within ±100 µK, and the equivalent effect of temperature fluctuations on our superconducting gravimeter is 0.5 μGal.
Evidence of double-loop hysteresis in disordered ferroelectric crystal
Authors: Parravicini Jacopo , Fornasari Lucia , DelRe Eugenio , Marabelli Franco , Agranat Aharon J. , Parravicini Gianbattista
Published: May 2020

Double-loop electric-field vs polarization hysteresis is investigated in a depoled compositionally disordered lithium-enriched potassium tantalate niobate crystal. Comparing electro-optic response and dielectric spectroscopy indicates that the anomalous response occurs for those temperatures in which the sample also manifests a temperature hysteresis in the low-frequency dielectric function. An electric-field hysteresis at concurrent temperatures suggests an underlying role of reorienting mesoscopic polar regions that accompany the nonergodic phase.
Infrared emission bands and thermal effects for 440-nm-emitting GaN-based laser diodes
Authors: Mao Feng , Hong Jin , Wang Han , Chen Ye , Jing Chengbin , Yang Pingxiong , Tomm Jens W. , Chu Junhao , Yue Fangyu
Published: May 2020

Broad emission bands due to defects in (In,Ga,Al)N laser diodes operating at 440 nm are investigated using continuous-wave and pulsed currents. In addition to known yellow–green and short-wave infrared bands, defect emissions were observed even in the medium-wave infrared range. A separation from thermal radiation is possible. When using pulsed currents, a super-linearly increasing emission occurs at ∼1150 nm, which could be attributed to amplified spontaneous emission mainly due to the electroluminescence of deep defects in the optically active region. These results may be useful in interpreting the output power bottleneck of GaN-based lasers compared to mature GaAs-based lasers.
Metal–oxide–semiconductor interface properties of TiN/Y2O3/Si0.62Ge0.38 gate stacks with high temperature post-metallization annealing
Authors: Lee Tsung-En , Ke Mengnan , Kato Kimihiko , Takenaka Mitsuru , Takagi Shinichi
Published: May 2020

We investigate the influence of an interfacial layer (IL) formed by plasma pre-oxidation on atomic layer deposition TiN/Y2O3/Si0.62Ge0.38 metal–oxide–semiconductor (MOS) gate stacks on the electrical characteristics of the MOS interfaces in order to examine the physical mechanism of the interface trap density (Dit) of SiGe MOS interfaces. The post-metallization annealing (PMA) temperature significantly decreases Dit. It is found that, at any PMA temperature, Dit at the MOS interfaces without pre-oxidation is lower than that with pre-oxidation. The low Dit value of 7 × 1011 eV−1 cm−2 is obtained for TiN/Y2O3/SiGe without pre-oxidation after PMA at 450 °C. It is revealed that the ILs of TiN/Y2O3 stacks with and without pre-oxidation after PMA consist mainly of YSiOx/SiGeOx and YSiOx, respectively. The physical origins of reduction in Dit without pre-oxidation and after PMA are attributable to the reduction in the amount of Ge–O bonds at the interface and an annealing effect of distorted Ge–O bonds, respectively.