bluuebunny/crossref_metadata_2025 huggingface dataset:
Fully generalised spatial modulation technique for underwater communication
Authors: Hussein H.S. , Esmaiel H. , Jiang D.
Published: May 2018

A novel transmission scheme called fully generalised spatial modulation (FGSM) is proposed for underwater communication, where any subset of available transmitting antennas (Nt) is activated at a time instant to transmit the data constellation symbol and the index of the active antenna is also harnessed to carry information. The FGSM offers better energy efficiency (EE) than previous spatial modulation (SM) and generalised SM systems. The proposed FGSM system is tested in an acoustic underwater multipath channel. Simulation results show that it can significantly improve the average bit error rate (ABER) as well as EE.
Analytical PID control design in time domain with performance‐robustness trade‐off
Authors: Tavakoli S. , Safaei M.
Published: May 2018

This Letter deals with the tuning of series proportional–integral–derivative (PID) controller to provide desired time‐domain specifications. A simple analytical design method based on pole placement is developed. First, the integral and derivative time constants are obtained. Then, a good performance–robustness trade‐off is achieved by suitably choosing the controller gain in the stability range. To evaluate the performance of the proposed method, an illustrative example is presented. Moreover, the simulation results are compared with those given by Skogestad internal model control, a well‐known PID tuning method.
Scope of physiological and behavioural pain assessment techniques in children – a review
Authors: Subramaniam Saranya Devi , Doss Brindha , Chanderasekar Lakshmi Deepika , Madhavan Aswini , Rosary Antony Merlin
Published: May 2018

Pain is an unpleasant subjective experience. At present, clinicians are using self‐report or pain scales to recognise and monitor pain in children. However, these techniques are not efficient to observe the pain in children having cognitive disorder and also require highly skilled observers to measure pain. Using these techniques it is also difficult to choose the analgesic drug dosages to the patients after surgery. Thus, this conceptual work explains the demand for automatic coding techniques to evaluate pain and also it documents some evidence of techniques that act as an alternative approach for objectively determining pain in children. In this review, some good indicators of pain in children are explained in detail; they are facial expressions from an RGB image, thermal image and also feature from well proven physiological signals such as electrocardiogram, skin conductance, body temperature, surgical pleth index, pupillary reflex dilation, analgesia nociception index, photoplethysmography, perfusion index etc.
Multi‐modality‐based Arabic sign language recognition
Authors: Elpeltagy Marwa , Abdelwahab Moataz , Hussein Mohamed E. , Shoukry Amin , Shoala Asmaa , Galal Moustafa
Published: May 2018

With the increase in the number of deaf‐mute people in the Arab world and the lack of Arabic sign language (ArSL) recognition benchmark data sets, there is a pressing need for publishing a large‐volume and realistic ArSL data set. This study presents such a data set, which consists of 150 isolated ArSL signs. The data set is challenging due to the great similarity among hand shapes and motions in the collected signs. Along with the data set, a sign language recognition algorithm is presented. The authors’ proposed method consists of three major stages: hand segmentation, hand shape sequence and body motion description, and sign classification. The hand shape segmentation is based on the depth and position of the hand joints. Histograms of oriented gradients and principal component analysis are applied on the segmented hand shapes to obtain the hand shape sequence descriptor. The covariance of the three‐dimensional joints of the upper half of the skeleton in addition to the hand states and face properties are adopted for motion sequence description. The canonical correlation analysis and random forest classifiers are used for classification. The achieved accuracy is 55.57% over 150 ArSL signs, which is considered promising.
Analysis and control of tundish induction heating power supply using modular multilevel converter
Authors: Yue Yufei , Xu Qianming , Luo An , Guo Peng , He Zhixing , Li Yan
Published: May 2018

Modular multilevel converters (MMCs) provide advantages to reach medium‐voltage operation increasing the power level in industrial applications. In this study, a tundish induction heating power supply based MMC (MMC‐TIHPS) is investigated for heating molten steel. The equivalent model of MMC‐TIHPS is established and the energy in horizontal and vertical directions are analysed. The heating control for molten steel consists of temperature increasing and constant temperature processes (alternatively called transient‐state and steady‐state operation). The main contribution of this study is to propose a direct power feedforward control based load current feedforward strategy for TIHPS. With this strategy, TIHPS can be controlled operating with full power to heat molten steel in transient state and guarantee the insulation effectiveness in steady state. Proper parameters of controllers are designed. Experimental results are conducted to validate the feasibility of MMC‐TIHPS and the effectiveness of the proposed control method.
Optimal sizing of an industrial microgrid considering socio‐organisational aspects
Authors: De Clercq Simon , Zwaenepoel Brecht , Vandevelde Lieven
Published: May 2018

An industrial microgrid can be an effective way to introduce a high percentage of renewable power in the electrical energy supply of an industrial park. An optimal sizing process can be employed in the design phase of such a newly developed hybrid power system to assure the power system's technical and economic efficiency. While optimal sizing algorithms have been developed for different types of hybrid power systems, these often treat stand‐alone systems and do not consider the socio‐organisational drivers for inter‐firm energy supply facilities. Here, a techno‐economic optimisation is carried out using a genetic algorithm to determine the optimal system configuration of a grid‐connected power system. The current development of the project Eiland Zwijnaarde in Ghent provides the basis for a concrete case study. The main results suggest that the optimal configuration consists of a significant share of renewable sources. A cogeneration unit can compensate the renewables’ intermittent behaviour and lower the thermal energy cost. Large‐scale electrical storage is found not to be profitable under the used control structure. A gradual ingress of firms in the park and the subsequent sloped annual energy demand have a negative effect on the power system's fraction of shared facilities.
Day‐ahead demand side management using symbiotic organisms search algorithm
Authors: Niharika  , Mukherjee Vivekananda
Published: May 2018

According to the present scenario, as demand for electricity has increased both in terms of base load energy and peak availability, it is vital to emphasise on the concept of demand side management (DSM). DSM assures efficient utilisation of facilities by managing the energy resources of the customers and optimally modifying their energy demand profiles. It is extremely useful for the power industry to integrate the smart grids with a DSM framework for achieving a sustainable energy goal. This study focuses on modelling of DSM using a day‐ahead load shifting approach as a minimisation problem. For optimisation purpose, symbiotic organisms search (SOS) algorithm has been used. A platform independent of the control parameter is unique and exhibits paramount features of this algorithm. The formulated work has been tested on different areas of smart grid applications viz. residential, commercial and industrial types of customers. A comparison of outcomes, obtained from several algorithms with the proposed SOS algorithm, has been carried out on the basis of peak load reduction leading to lessening of a utility bill. Finally, it is proven that demand management, while using the SOS approach, exhibits better accuracy than the other algorithms compared in the present framework.
Synthesis of unequally spaced linear arrays using modified differential evolution algorithm
Authors: Wang Rui‐Qi , Jiao Yong‐Chang , Zhang Huan , Zhou Zhipeng
Published: May 2018

Unequally spaced linear arrays are synthesised for the sidelobe level (SLL) suppression, the null control in some specified directions and the beamwidth (BW) set within predefined limits. Based on the vector mapping method and the position perturbation technique, the constrained vector projection (CVP) is defined to offer flexibility in controlling null depths with multiple constraints. A modified differential evolution (DE) algorithm with the CVP method (in short MDE‐CVP) is then performed in the array synthesis, which effectively reduces the optimisation space, avoids the infeasible solutions and enhances the global search ability. Three examples are presented and the first two results are compared with those obtained by learning particle swarm optimisation, invasive weed optimisation and wind‐driven optimisation and a modified version of the central force optimisation algorithms. Comparison results indicate that the MDE‐CVP algorithm outperforms the existing algorithms in terms of minimum SLL, BW control, null control and convergence characteristics.
Dual‐band CP coplanar waveguide‐fed split‐ring resonator‐loaded G‐shaped slot antenna with wide‐frequency ratio
Authors: Saraswat Kapil , Harish Ayyangar R.
Published: May 2018

This study presents a dual‐band circularly polarised (CP) coplanar waveguide fed split‐ring resonator‐loaded rectangular slot antenna. A wide‐frequency ratio (the ratio of the centre frequencies of the two bands) ranging from 1.2 to 2 can be achieved by changing the dimensions of the resonator. To demonstrate the concept, an antenna having two bands, one at 2.4 GHz and the other at 3.5 GHz, is designed and measured input reflection coefficient, axial ratio, and radiation pattern are compared with the simulation results and they are found to be in good agreement. Measured results show that the proposed antenna operates in two frequency bands with overlapping bandwidths of 32.13% (2.22–3.07 GHz) and 2.17% (3.415–3.49 GHz). The axial ratio and impedance bandwidths are used to compare the performance of the proposed antenna with some of the published dual‐band CP antennas.
DNN‐based approach for fault detection in a direct drive wind turbine
Authors: Teng Wei , Cheng Hao , Ding Xian , Liu Yibing , Ma Zhiyong , Mu Haihua
Published: May 2018

Incipient fault detection of wind turbines is beneficial for making maintenance strategy and avoiding catastrophic result in a wind farm. A deep neural network (DNN)‐based approach is proposed to deal with the challenging task for a direct drive wind turbine, involving four steps: a preprocessing method considering operational mechanism is presented to get rid of the outliers in supervisory control and data acquisition (SCADA); the conventional random forest method is used to evaluate the importance of variables related to the target variable; the historical healthy SCADA data excluding outliers is used to train a deep neural network; and the exponentially weighted moving average control chart is adopted to determine the fault threshold. With the online data being input into the trained deep neural network model of a wind turbine with healthy state, the testing error is regarded as the metric of fault alarm of the wind turbine. The proposed approach is successfully applied to the fault detection of the fall off of permanent magnets in a direct drive wind turbine generator.
Affinely adjustable robust AC–DC optimal power flow considering correlation of wind power
Authors: Tian Yuan , Wang Keyou , Li Guojie , Zhou Ye , Luo Jinshan , Wang Ying
Published: May 2018

Wind power outputs will bring larger computational error in actual operation without considering the correlation. This study presents an affinely adjustable robust optimisation method for AC–DC optimal power flow (AC–DC AAROPF) considering the correlation of wind power. Affine policies are utilised in the re‐dispatch process to ensure the feasibility of the infinite scenarios of uncertainties. After transforming AC–DC AAROPF to a tractable model, a novel approach based on simplified pair copula to consider multiple dependence of wind power is presented. The AC–DC AAROPF is evaluated on the modified AC–DC IEEE 30‐bus and 118‐bus system. Results show a modest increase in expected cost for reasonable levels of uncertainty representing forecast error confidence intervals, which obtains a more robust solution with higher successful rates.
First direct detection of a polarized companion outside a resolved circumbinary disk around CS Chamaeleonis
Authors: Ginski C. , Benisty M. , van Holstein R. G. , Juhász A. , Schmidt T. O. B. , Chauvin G. , de Boer J. , Wilby M. , Manara C. F. , Delorme P. , Ménard F. , Pinilla P. , Birnstiel T. , Flock M. , Keller C. , Kenworthy M. , Milli J. , Olofsson J. , Pérez L. , Snik F. , Vogt N.
Published: May 2018

Aims. To understand planet formation it is necessary to study the birth environment of planetary systems. Resolved imaging of young planet forming disks allows us to study this environment in great detail and find signs of planet-disk interaction and disk evolution. In the present study we aim to investigate the circumstellar environment of the spectroscopic binary T Tauri star CS Cha. From unresolved mid-to far-infrared photometry it is predicted that CS Cha hosts a disk with a large cavity. In addition, spectral energy distribution modeling suggests significant dust settling, pointing toward an evolved disk that may show signs of ongoing or completed planet formation.

Methods. We observed CS Cha with the high contrast imager SPHERE at the ESO Very Large Telescope (VLT) in polarimetric differential imaging mode to resolve the circumbinary disk in near-infrared scattered light. These observations were followed up by VLT/NACO L-band observations and complemented by archival VLT/NACO K-band and Hubble Space Telescope WFPC2 I-band data.

Results. We resolve the compact circumbinary disk around CS Cha for the first time in scattered light. We find a smooth, low inclination disk with an outer radius of ~55 au (at 165 pc). We do not detect the inner cavity but find an upper limit for the cavity size of ~15 au. Furthermore, we find a faint comoving companion with a projected separation of 210 au from the central binary outside of the circumbinary disk. The companion is detected in polarized light and shows an extreme degree of polarization (13.7 ± 0.4% in the J band). The J- and H-band magnitudes of the companion are compatible with masses of a few MJup. However, K-, L-, and I-band data draw this conclusion into question. We explore with radiative transfer modeling whether an unresolved circum-companion disk can be responsible for the high polarization and complex photometry. We find that the set of observations is best explained by a heavily extincted low-mass (~20 MJup) brown dwarf or high-mass planet with an unresolved disk and dust envelope.
Felsenkeller 5 MV underground accelerator: Towards the Holy Grail of Nuclear Astrophysics 12C(α, γ)16O
Authors: Bemmerer Daniel , Cowan Thomas E. , Grieger Marcel , Hammer Sebastian , Hensel Thomas , Junghans Arnd R. , Koppitz Martina , Ludwig Felix , Müller Stefan E. , Rimarzig Bernd , Reinicke Stefan , Schwengner Ronald , Stöckel Klaus , Szücs Tamás , Takács Marcell P. , Turkat Steffen , Wagner Andreas , Wagner Louis , Zuber Kai
Published: May 2018

Low-background experiments with stable ion beams are an important tool for putting the model of stellar hydrogen, helium, and carbon burning on a solid experimental foundation. The pioneering work in this regard has been done by the LUNA collaboration at Gran Sasso, using a 0.4 MV accelerator. The present contribution reviews the status of the project for a higher-energy underground accelerator in Felsenkeller, Germany. Results from γ-ray, neutron, and muon background measurements in the Felsenkeller underground site in Dresden, Germany, show that the background conditions are satisfactory.

Two tunnels of the Felsenkeller site have recently been refurbished for the installation of a 5MV high-current Pelletron accelerator. Civil construction work has completed in March 2018. The accelerator will provide intense, 50 μA, beams of 1H+, 4He+, and 12C+ ions, enabling research on astrophysically relevant nuclear reactions with unprecedented sensitivity.
g-factor calculations from the generalized seniority approach
Authors: Maheshwari Bhoomika , Jain Ashok Kumar
Published: May 2018

The generalized seniority approach proposed by us to understand the B(E1)/B(E2)/B(E3) properties of semi-magic nuclei has been widely successful in the explanation of the same and has led to an expansion in the scope of seniority isomers. In the present paper, we apply the generalized seniority scheme to understand the behavior of g-factors in semi-magic nuclei. We find that the magnetic moment and the gfactors do show a particle number independent behavior as expected and the understanding is consistent with the explanation of transition probabilities.
Shell Evolution and E2 Collectivity: New Spectroscopic Information
Authors: Pietralla N. , Kremer C. , Beck T. , Witt W. , Gayer U. , von Neumann-Cosel P. , Werner V.
Published: May 2018

New spectroscopic information on electric quadrupole collectivity has recently been obtained. We report on our identification of a coexisting deformed structure in the quasi-doubly closed-shell nucleus 96Zr from our measurement of a corresponding absolute E2 intraband transition strength in electron scattering reactions and its small mixing matrix element with the spherical ground state structure. The even-mass zirconium isotopes exhibit a first order quantum shape phase transition between neutron numbers 58 and 60. We have used photon scattering reactions for a first measurement of the E2 decay strength of the nuclear 1+ scissors mode. Evidence for its 2+ rotational excitation and its extraordinarily large rotational moment of inertia are presented.
Low lying oscillations of deformed nuclei
Authors: Aprahamian Ani , Lesher Shelly R.
Published: May 2018

Low-lying oscillations of the intrinsic deformed shape of a nucleus remain an open challenge in nuclear structure. The question or challenge revolves around the viability of single or multiple quanta of vibrational excitations superimposed on the equilibrium, deformed shape of a nucleus. The K=2 or “γ” vibrations are fairly widespread and nominally conform to expectations whereas the existence of the K=0 or “β” vibrational excitation is yet to be distinguished from other possible origins including the coexistence of other potential minima.
Nuclear shapes: Quest for triaxiality in 86Ge and the shape of 98Zr
Authors: Werner V. , Lettmann M. , Lizarazo C. , Witt W. , Cline D. , Carpenter M. , Doornenbal P. , Obertelli A. , Pietralla N. , Savard G. , Söderström P.-A. , Wu C.-Y. , Zhu S.
Published: May 2018

The region of neutron-rich nuclei above the N = 50 magic neutron shell closure encompasses a rich variety of nuclear structure, especially shapeevolutionary phenomena. This can be attributed to the complexity of sub-shell closures, their appearance and disappearance in the region, such as the N = 56 sub shell or Z = 40 for protons. Structural effects reach from a shape phase transition in the Zr isotopes, over shape coexistence between spherical, prolate, and oblate shapes, to possibly rigid triaxial deformation. Recent experiments in this region and their main physics viewpoints are summarized.
Nuclear shapes studied with low-energy Coulomb excitation
Authors: Zielińska Magda , Hadyńska-Klȩk Katarzyna
Published: May 2018

Coulomb excitation is one of the rare methods available to obtain information on static electromagnetic moments of short-lived excited nuclear states, including collective non-yrast levels. It is thus an ideal tool to study shape coexistence and shape evolution throughout the nuclear chart. Historically, these experiments were limited to stable isotopes, however the advent of new facilities, providing intense beams of short-lived radioactive species, has opened the possibility to apply this powerful technique to a much wider range of nuclei. Here, we present some recent complex Coulomb-excitation studies and use the example of superdeformed states in 42Ca to demonstrate the sensitivity of the method to second-order effects such as relative signs of electromagnetic matrix elements and quadrupole moments.
Isomers and shell evolution in neutron-rich nuclei below the doubly magic nucleus 132Sn
Authors: Watanabe Hiroshi
Published: May 2018

The level structures of the very neutron-rich nuclei 128Pd82 and 126Pd80 have been investigated for the first time. A new isomer with a half-life of 5.8(8) μs in 128Pd is proposed to have a spin and parity of 8+ and is associated with a maximally aligned configuration arising from the g9/2Pd proton subshell with seniority υ = 2. The level sequence below the 8+ isomer is similar to that in the N = 82 isotone 130Cd, but the electric quadrupole transition that depopulates the 8+ isomer is more hindered in 128Pd than in 130Cd, as expected in the seniority scheme for a semi-magic, spherical nucleus. For 126Pd, three new isomers with Jπ = (5-), (7-), and (10+) have been identified with half-lives of 0.33(4) μs, 0.44(3) μs, and 23.0(8) ms, respectively. The smaller energy difference between the 10+ and 7- isomers in 126Pd than in the heavier N = 80 isotones can be interpreted as being ascribed to the monopole shift of the h11/2 neutron orbit. The nature of the N = 82 shell closure scrutinized with these characteristic isomers is discussed.
Probing the E2 properties of the scissors mode with real photons
Authors: Beck Tobias , Pietralla Norbert , Beller Jacob , Derya Vera , Löher Bastian , Savran Deniz , Tornow Werner , Werner Volker , Zilges Andreas
Published: May 2018

The E2/M1 multipole mixing ratio δ1→2 of the 1+ sc → 2+ 1 γ-ray transition of 156Gd and 164Dy has been measured using the linearly polarized photon beams of the HIγS facility. The employed method of photonscattering experiments in combination with polarized, quasi-monochromatic beams and a dedicated detector setup is highly sensitive to the electric quadrupole-decay properties of the scissors mode.
β-γ and isomeric decay spectroscopy of 168Dy
Authors: Zhang G.X. , Watanabe H. , Kondev F.G. , Lane G.J. , Regan P.H. , Söderström P.-A. , Walker P.M. , Kanaoka H. , Korkulu Z. , Lee P.S , Liu J.J , Nishimura S. , Wu J. , Yagi A. , Ahn D.S. , Alharbi T. , Baba H. , Browne F. , Bruce A.M. , Carroll R.J. , Chae K.Y. , Dombradi Zs. , Doornenbal P. , Estrade A. , Fukuda N. , Griffin C. , Ideguchi E. , Inabe N. , Isobe T. , Kanaya S. , Kojouharov I. , Kubo T. , Kubono S. , Kurz N. , Kuti I. , Lalkovski S. , Lee C.S. , Lee E.J. , Lorusso G. , Lotay G. , Moon C.-B , Nishizuka I. , Nita C.R. , Odahara A. , Patel Z. , Phong V.H. , Podolyák Zs. , Roberts O.J. , Sakurai H. , Schaffner H. , Shand C.M. , Shimizu Y. , Sumikama T. , Suzuki H. , Takeda H. , Terashima S. , Vajta Zs. , Valiente-Dóbon J.J. , Xu Z.Y.
Published: May 2018

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.
Strong coupling in 65,67Mn
Authors: Liu Xiaoyu , Liu Zhong , Ding Bing
Published: May 2018

Excited states in 63,65,67Mn were studied via in-beam γ-ray spectroscopy following knockout reactions from 68Fe. Similar level schemes, consisting of the 11/2−, 9/2−, 7/2− and 5/2−g,s. level sequence, connected by I → I–1 transitions, were established. Their level structures show features consistent with strongly-coupled rotational bands with K = 5/2.
One-nucleon pickup reactions and compound-nuclear decays
Authors: E. Escher J. , T. Burke J. , J. Casperson R. , O. Hughes R. , D. Scielzo N.
Published: May 2018

One-nucleon transfer reactions, long used as a tool to study the structure of nuclei, are potentially valuable for determining reaction cross sections indirectly. This is significant, as many reactions of interest to astrophysics and other applications involve short-lived isotopes and cannot be measured directly. We describe a procedure for obtaining constraints for calculations of neutron capture cross sections using observables from experiments with transfer reactions. As a first step toward demonstrating the method, we outline the theory developments used to properly describe the production of the compound nucleus88Y*via the one-nucleon pickup reaction89Y(p,d)88Y*and test the description with data from a recent experiment. We indicate how this development can be used to extract the unknown87Y(n,γ) cross section from89Y(p,dγ) data. The example illustrates a more generally applicable method for determining unknown cross sections via a combination of theory and transfer (or inelastic scattering) experiments.
Selection of different reaction channels in 6Li induced fusion reaction by a powerful combination of a charged particle array and a high-resolution gamma spectrometer
Authors: Zhang G. X. , Hu S. P. , Zhang G. L. , Zhang H. Q. , Yao Y. J. , Huang Z. , Wang M. L. , Sun H. B. , Valiente-Dobòn J. J. , Testov D. , Goasduff A. , John P. R. , Siciliano M. , Galtarosa F. , Francesco R. , Mengoni D. , Bazzacco D. , Li E. T. , Hao X.
Published: May 2018

Investigation of the breakup and transfer effect of weakly bound nuclei on the fusion process has been an interesting research topic in the past several years. In comparison with radioactive ion beam (RIB), the beam intensities of stable weakly bound nuclei such as 6,7Li and 9Be, which have significant breakup probability, are orders of magnitude higher. Precise fusion measurements induced by these nuclei have already been performed. However, the conclusion of reaction dynamics was not clear and has contradiction. In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, the 6Li+89Y experiment with incident energies of 22 MeV and 34 MeV was performed on Galileo array in combination with Si-ball EUCLIDES at Legnaro National Laboratory (LNL) in Italy. Using the coincidence by the charged particles and γ-rays, the different reaction channels can be clearly identified.
The Gogny-HFB+QRPA dipole strength function and its application to radiative neutron capture cross section
Authors: Goriely Stephane , Hilaire Stephane , Péru Sophie
Published: May 2018

Valuable theoretical predictions of nuclear dipole excitations in the whole chart are of great interest for different nuclear applications, including in particular nuclear astrophysics. Here we extend our large-scale calculations of the E1 and M1 absorption γ-ray strength function obtained in the framework of the axially-symmetric deformed quasiparticle random phase approximation (QRPA) based on the finite-range D1M Gogny force to the determination of the de-excitation strength function. To do so, shell-model calculations of the de-excitation dipole strength function as well as experimental data are considered to provide insight in the low-energy limit and to complement the QRPA estimate phenomenologically. We compare our final prediction of the E1 and M1 strengths with available experimental data at low energies and show that a relatively good agreement can be obtained. Its impact on the average radiative width as well as radiative neutron capture cross section is discussed.
The Great Wall: Urca Cooling Layers in the Accreted NS Crust
Authors: Meisel Zach
Published: May 2018

Accreting neutron stars host a number of astronomical observables which can be used to infer the properties of the underlying dense matter. These observables are sensitive to the heating and cooling processes taking place in the accreted neutron star (NS) crust. Within the past few years it has become apparent that electron-capture/beta-decay (urca) cycles can operate within the NS crust at high temperatures. Layers of nuclei undergoing urca cycling can create a thermal barrier, or Great Wall, between heating occurring deep in the crust and the regions above the urca layers. This paper briefly reviews the urca process and the implications for observables from accreting neutron stars.
Nuclear Neutrino Spectra in Late Stellar Evolution
Authors: Misch G. Wendell , Sun Yang , Fuller George
Published: May 2018

Neutrinos are the principle carriers of energy in massive stars, beginning from core carbon burning and continuing through core collapse and after the core bounce. In fact, it may be possible to detect neutrinos from nearby pre-supernova stars. Therefore, it is of great interest to understand the neutrino energy spectra from these stars. Leading up to core collapse, beginning around core silicon burning, nuclei become dominant producers of neutrinos, particularly at high neutrino energy, so a systematic study of nuclear neutrino spectra is desirable. We have done such a study, and we present our sd-shell model calculations of nuclear neutrino energy spectra for nuclei in the mass number range A = 21 – 35. Our study includes neutrinos produced by charged lepton capture, charged lepton emission, and neutral current nuclear deexcitation. Previous authors have tabulated the rates of charged current nuclear weak interactions in astrophysical conditions, but the present work expands on this not only by providing neutrino energy spectra, but also by including the heretofore untabulated neutral current de-excitation neutrino pairs.
Experimental measurement of the 12C+16O fusion cross sections at astrophysical energies
Authors: Fang X. , Tan W. P. , Beard M. , deBoer R. J. , Gilardy G. , Jung H. , Liu Q. , Lyons S. , Robertson D. , Setoodehnia K. , Seymour C. , Stech E. , Vande Kolk B. , Wiescher M. , de Souza R. , Hudan S. , Singh V. , Tang X. D. , Uberseder E.
Published: May 2018

The total cross sections of the 12C+16O fusion have been experimentally determined at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam was produced by the 5MV pelletron accelerator at the University of Notre Dame impinging on a thick ultra-pure graphite target. Protons and γ-rays were measured simultaneously in the center-of-mass energy range from 3.64 to 5.01 MeV, using strip silicon and HPGe detectors. Statistical model calculations were employed to interpret the experimental results. A new broad resonance-like structure is observed for the 12C+16O reaction, and a decreasing trend of its S-factor towards low energies is found.
Shape phase transition and shape coexistence in the Bose-Fermi system
Authors: Zhang Yu , Dong Wenting , Jiang He
Published: May 2018

A classical analysis of shape phase transition and shape coexistence in odd-even nuclei has been carried within the interacting boson-fermion model. The results indicate that shape coexistence can be taken as a signature of shape phase transition in odd-even nuclei.
Gamma-widths, lifetimes and fluctuations in the nuclear quasi-continuum
Authors: Guttormsen M. , Larsen A. C. , Midtbø J. E. , Crespo Campo L. , Görgen A. , Ingeberg V. W. , Renstrøm T. , Siem S. , Tveten G. M. , Zeiser F. , Kirsch L. E.
Published: May 2018

Statistical γ-decay from highly excited states is determined by the nuclear level density (NLD) and the γ-ray strength function (γSF). These average quantities have been measured for several nuclei using the Oslo method. For the first time, we exploit the NLD and γSF to evaluate the γ-width in the energy region below the neutron binding energy, often called the quasi-continuum region. The lifetimes of states in the quasi-continuum are important benchmarks for a theoretical description of nuclear structure and dynamics at high temperature. The lifetimes may also have impact on reaction rates for the rapid neutron-capture process, now demonstrated to take place in neutron star mergers.
Developing reliable reaction gamma-ray data
Authors: Dimitriou Paraskevi , Belgya T. , Cho Y-S. , Filipescu D. , Firestone R. , Goriely S. , Iwamoto N. , Kawano T. , Kopecky J. , Krticka M. , Plujko V. , Siem S. , Schwengner R. , Utsunomiya H. , Vlarlamov V. , Wiedeking M. , Xu R.
Published: May 2018

We report on efforts to develop reliable photonuclear cross section and photon strength function data by measuring, compiling, assessing, evaluating the available data, and producing tables of Giant Dipole Resonance parameters and global models for use in basic sciences and applications.
Error analysis of a FVEM for fractional order evolution equations with nonsmooth initial data
Authors: Karaa Samir , Pani Amiya K.
Published: May 2018

In this paper, a finite volume element (FVE) method is considered for spatial approximations of time fractional diffusion equations involving a Riemann-Liouville fractional derivative of order α ∈ (0, 1) in time. Improving upon earlier results [Karaa et al., IMA J. Numer. Anal. 37 (2017) 945–964], error estimates in L2 (Ω)- and H1 (Ω)-norms for the semidiscrete problem with smooth and mildly smooth initial data, i.e., v ∈ H2(Ω) ∩ H01(Ω) and v ∈ H01(Ω) are established. For nonsmooth data, that is, v  ∈  L2 (Ω), the optimal L2 (Ω)-error estimate is shown to hold only under an additional assumption on the triangulation, which is known to be satisfied for symmetric triangulations. Superconvergence result is also proved and as a consequence, a quasi-optimal error estimate is established in the L∞ (Ω)-norm. Further, two fully discrete schemes using convolution quadrature in time generated by the backward Euler and the second-order backward difference methods are analyzed, and error estimates are derived for both smooth and nonsmooth initial data. Based on a comparison of the standard Galerkin finite element solution with the FVE solution and exploiting tools for Laplace transforms with semigroup type properties of the FVE solution operator, our analysis is then extended in a unified manner to several time fractional order evolution problems. Finally, several numerical experiments are conducted to confirm our theoretical findings.
Oxidative C–C Bond Cleavage for the Synthesis of Aryl Carboxylic Acids from Aryl Alkyl Ketones
Authors: Li Meichao , Shen Zhenlu , Xu Liang , Wang Shengpeng , Chen Bajin , Hu Xinquan , Hu Baoxiang , Jin Liqun , Sun Nan
Published: May 2018

A metal-free and one-pot two-step synthesis of aryl carboxylic acids from aryl alkyl ketones has been achieved. The reactions were performed with iodine as the catalyst, DMSO and TBHP as the oxidants. Under the optimal reaction conditions, a number of aryl alkyl ketones could be converted into their corresponding aryl carboxylic acids in good to excellent yields (up to 94%).
Co-occurrence of Noonan and Cardiofaciocutaneous Syndrome Features in a Patient with KRAS Variant
Authors: Vallejos Carla , Bolanos-Garcia Víctor , Ponce Diana , Unanue Nancy , Garay Francisco , Cassorla Fernando , Aracena Mariana , Rodríguez Fernando
Published: May 2018

We report the case of a 3-year-old girl, who is the third child of nonconsanguineous parents, with short stature, hypertrophic cardiomyopathy, and mild dysmorphic features; all suggestive of Noonan syndrome. In addition, the patient presents with feeding difficulties, deep palmar and plantar creases, sparse hair, and delayed psychomotor and language development, all characteristics frequently observed in cardiofaciocutaneous syndrome. Molecular analysis of the Ras/ MAPK pathway genes using high-resolution melting curve analysis and gene sequencing revealed a de novo KRAS amino acid substitution of leucine to tryptophan at codon 53 (p.L53W). This substitution was recently described in an Iranian patient with Noonan syndrome. The findings described in this report expand the phenotypic heterogeneity observed in RASopathy patients harboring a KRAS substitution, and advocate for the inclusion of genes with low mutational frequency in genetic screening protocols for Noonan syndrome and other RASopathies.
Electron energy distribution function in a low-power Hall thruster discharge and near-field plume
Authors: Tichý M. , Pétin A. , Kudrna P. , Horký M. , Mazouffre S.
Published: May 2018

Electron temperature and plasma density, as well as the electron energy distribution function (EEDF), have been obtained inside and outside the dielectric channel of a 200 W permanent magnet Hall thruster. Measurements were carried out by means of a cylindrical Langmuir probe mounted onto a compact fast moving translation stage. The 3D particle-in cell numerical simulations complement experiments. The model accounts for the crossed electric and magnetic field configuration in a weakly collisional regime where only electrons are magnetized. Since only the electron dynamics is of interest in this study, an artificial mass of ions corresponding to mi = 30 000me was used to ensure ions could be assumed at rest. The simulation domain is located at the thruster exit plane and does not include the cathode. The measured EEDF evidences a high-energy electron population that is superimposed onto the low energy bulk population outside the channel. Inside the channel, the EEDF is close to Maxwellian. Both the experimental and numerical EEDF depart from an equilibrium distribution at the channel exit plane, a region of high magnetic field. We therefore conclude that the fast electron group found in the experiment corresponds to the electrons emitted by the external cathode that reach the thruster discharge without experiencing collision events.
Fiber-optic Lorentz force magnetometer based on a gold-graphene composite membrane
Authors: Liu Zeng-yong , Cao Hong-qian , Xu Fei
Published: May 2018

Because of its outstanding mechanical and electronic properties and unique transfer flexibility, graphene is ideal for miniature all-in-fiber nanoelectromechanical systems (NEMS) in ultrasensitive sensing applications; however, its application in magnetic detection is limited because of the lack of magnetic-optic response. Here, we demonstrate a high spatial resolution fiber-optic magnetic field sensor based on Lorentz force in a pseudo–magnetic-response quasi-static graphene NEMS. The ultra-compact design of this all-fiber-based sensor is achieved by integrating a hybrid gold-graphene membrane and two gold electrodes onto the hollow endface of a single-mode fiber. An electrical current flowing through the suspended membrane in a perpendicular magnetic field can generate Lorentz force to cause a nanoscale deformation of the membrane. The sensor has a much higher spatial resolution, which is nanometer-scale longitudinally, compared with conventional optical fiber magnetic sensors.
Controlling coulomb interactions in infrared stereometamaterials for unity light absorption
Authors: Mudachathi Renilkumar , Moritake Yuto , Tanaka Takuo
Published: May 2018

We investigate the influence of near field interactions between the constituent 3D split ring resonators on the absorbance and resonance frequency of a stereo metamaterial based perfect light absorber. The experimental and theoretical analyses reveal that the magnetic resonance red shifts and broadens for both the decreasing vertical and lateral separations of the constituents within the metamaterial lattice, analogous to plasmon hybridization. The strong interparticle interactions for higher density reduce the effective cross-section per resonator, which results in weak light absorption observed in both experimental and theoretical analyses. The red shift of the magnetic resonance with increasing lattice density is an indication of the dominating electric dipole interactions and we analyzed the metamaterial system in an electrostatic point of view to explain the observed resonance shift and decreasing absorption peak. From these analyses, we found that the fill factor introduces two competing factors determining the absorption efficiency such as coulomb interactions between the constituent resonators and their number density in a given array structure. We predicted unity light absorption for a fill factor of 0.17 balancing these two opposing factors and demonstrate an experimental absorbance of 99.5% at resonance with our 3D device realized using residual stress induced bending of 2D patterns.
Electrical properties of phosphorene systems doped with fourth-period elements
Authors: Wang Ke , Wang Hai , Zhang Min , Liu Yan , Zhao Wei
Published: May 2018

In this work, we use a first-principles calculation to investigate the structure, binding energies, and electrical properties of monolayer phosphorene systems doped with fourth-period main group elements at a doping concentration of 6.25%. The calculation results reveal that, although large deformations exist, all doped systems are stable and non-spin polarized. In addition, the Ca, Se, and Br atoms are electron acceptors in the doped systems, whereas the Ga, Ge and As atoms are donors. Thus, there is an ionic bonding character between the dopants and neighboring phosphorus atoms in the Ca-, Ga-, Ge-, As-, Se-, and Br-doped systems. From band structures, we find that the K-, Ga-, As-, and Br-doped systems present semiconducting states with indirect gaps, whereas the Ca-, Ge-, and Se-doped systems have metallic states. We conclude that the metallicity of a phosphorene system doped with main-group elements depends on the number of valence electrons of the dopant. This investigation provides directions for manipulating the electrical properties of phosphorene by substitutional doping, which would broaden its possible applications in optoelectronics.
The effects of particle recycling on the divertor plasma: A particle-in-cell with Monte Carlo collision simulation
Authors: Chang Mingyu , Sang Chaofeng , Sun Zhenyue , Hu Wanpeng , Wang Dezhen
Published: May 2018

A Particle-In-Cell (PIC) with Monte Carlo Collision (MCC) model is applied to study the effects of particle recycling on divertor plasma in the present work. The simulation domain is the scrape-off layer of the tokamak in one-dimension along the magnetic field line. At the divertor plate, the reflected deuterium atoms (D) and thermally released deuterium molecules (D2) are considered. The collisions between the plasma particles (e and D+) and recycled neutral particles (D and D2) are described by the MCC method. It is found that the recycled neutral particles have a great impact on divertor plasma. The effects of different collisions on the plasma are simulated and discussed. Moreover, the impacts of target materials on the plasma are simulated by comparing the divertor with Carbon (C) and Tungsten (W) targets. The simulation results show that the energy and momentum losses of the C target are larger than those of the W target in the divertor region even without considering the impurity particles, whereas the W target has a more remarkable influence on the core plasma.
Torque analysis of incoherent spin rotation in the presence of ordered defects
Authors: Koulialias D. , Charilaou M. , Mensing C. , Löffler J. F. , Gehring A. U.
Published: May 2018

Defects in magnetic systems often have a drastic impact on the magnetic state, particularly the anisotropy. In this letter, we show that magnetic torque analysis with appropriate phenomenological theoretical treatment can be used to analyze in detail the magnetic state in complex heterogeneous materials. We base our study on the Fe7S8 omission structure, which exhibits a non-trivial temperature dependence of magnetic anisotropy, involving incoherent out-of-plane spin rotation due to an elaborate defect distribution.
A simple microdevice for single cell capture, array, release, and fast staining using oscillatory method
Authors: Cheng Dantong , Yu Yang , Han Chao , Cao Mengjia , Yang Guang , Liu Jingquan , Chen Xiang , Peng Zhihai
Published: May 2018

Microchips that perform single cell capture, array, and identification have become powerful tools for single cell studies, which can reveal precise underlying mechanisms among bulk cell populations. However, current single cell capture and on-chip immunostaining methods consume more time and reagent than desired. To optimize this technology, we designed a novel trap structure for single cell capture, array, and release, and meanwhile an oscillatory method was used to perform rapid on-chip cell immunostaining. The trap structure array used equal distribution of lateral flow to achieve single cell array in high velocity flows and decrease the risk of clogging. A length of glass capillary with a sealed bubble was inserted into the outlet so that it could act in a manner analogous to that of a capacitor in an RC circuit. By applying one periodic air pressure to the inlet, oscillation motion was generated, which significantly enhanced the on-chip reaction efficiency. In addition, the oscillation performance could be easily regulated by changing the length of the capillary. The trapped cells could maintain their positions during oscillation; hence, they were able to be tracked in real time. Through our trap microchip, 12 μm microbeads were successfully trapped to form a microarray with a capture efficiency of ∼92.7% and 2 μm microbeads were filtered. With an optimized oscillation condition (Ppush = 0.03 MPa, f = 1 Hz, L = 3 cm), fast on-chip immunostaining was achieved with the advantages of less time (5 min) and reagent (2 μl) consumption. The effectiveness of this method was demonstrated through quantitative microbead and qualitative Caco-2 cell experiments. The device is simple, flexible, and efficient, which we believe provides a promising approach to single cell heterogeneity studies, drug screening, and clinical diagnosis.
Observation of FeGe skyrmions by electron phase microscopy with hole-free phase plate
Authors: Kotani Atsuhiro , Harada Ken , Malac Marek , Salomons Mark , Hayashida Misa , Mori Shigeo
Published: May 2018

We report application of hole-free phase plate (HFPP) to imaging of magnetic skyrmion lattices. Using HFPP imaging, we observed skyrmions in FeGe, and succeeded in obtaining phase contrast images that reflect the sample magnetization distribution. According to the Aharonov-Bohm effect, the electron phase is shifted by the magnetic flux due to sample magnetization. The differential processing of the intensity in a HFPP image allows us to successfully reconstruct the magnetization map of the skyrmion lattice. Furthermore, the calculated phase shift due to the magnetization of the thin film was consistent with that measured by electron holography experiment, which demonstrates that HFPP imaging can be utilized for analysis of magnetic fields and electrostatic potential distribution at the nanoscale.
Proton acceleration measurements using fs laser irradiation of foils in the target normal sheath acceleration regime
Authors: Batani D. , Boutoux G. , Burgy F. , Jakubowska K. , Ducret J. E.
Published: May 2018

We present experimental results obtained at the CELIA laboratory using the laser ECLIPSE to study proton acceleration from ultra-intense laser pulses. Several types of targets were irradiated with different laser conditions (focusing and prepulse level). Proton emission was characterized using time-of-flight detectors (SiC and diamond) and a Thomson parabola spectrometer. In all cases, the maximum energy of observed protons was of the order of 260 keV with a large energy spectrum. Such characteristics are typical of protons emitted following the target normal sheath acceleration mechanism for low-energy short-pulse lasers like ECLIPSE.
Cavities coupled for brilliant Brillouin lasing
Authors: Patrick Chris
Published: May 2018

Using mode splitting of coupled microcavities achieves Brillouin lasing without having to precisely control the microcavity dimensions.