bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced dielectricity coupled to spin-crossover in a one-dimensional polymer iron(ii) incorporating tetrathiafulvalene
Authors: Qiu Ya-Ru , Cui Long , Cai Pei-Yu , Yu Fei , Kurmoo Mohamedally , Leong Chanel F. , D'Alessandro Deanna M. , Zuo Jing-Lin
Published: May 2020

A concerted bending–flattening motion of the redox-active TTF within constructed one-dimensional FeII–TTF–Schiff-base chain with bridging 4,4′-bpy enhances the dielectric constant coupled to its spin-crossover transition above room temperature.
Surface controlled pseudo-capacitive reactions enabling ultra-fast charging and long-life organic lithium ion batteries
Authors: Amin Kamran , Zhang Jianqi , Zhou Hang-Yu , Lu Ruichiao , Zhang Miao , Ashraf Nawal , YueLi Cheng , Mao Lijuan , Faul Charl F. J. , Wei Zhixiang
Published: May 2020

To develop ultra-fast charging and long-life lithium ion batteries, a surface-controlled pseudo-capacitive reaction mechanism for organic lithium ion batteries is developed based on a coaxial nanocomposite of an active anthraquinone-based covalent organic framework and CNTs.
Volume transition effects on the correlations and effective interactions among highly charged microgels
Authors: Aguirre-Manzo L. A. , González-Mozuelos P.
Published: May 2020

Microgels shrinkage promotes counterion condensation, which in the highly charged regime markedly inhibits the effective interaction and induces strong counterion–counterion correlations that deviate this potential from the traditional Yukawa shape.
A three-dimensional nitrogen-doped graphene framework decorated with an atomic layer deposited ultrathin V2O5 layer for lithium sulfur batteries with high sulfur loading
Authors: Liu Xiaowei , Li Zhaohuai , Liao Xiaobin , Hong Xufeng , Li Yan , Zhou Cheng , Zhao Yan , Xu Xu , Mai Liqiang
Published: May 2020

Lithium–sulfur batteries with ultra-high theoretical capacity have gradually become candidates to replace existing energy systems.
Double-shelled hollow carbon nanospheres as enclosed electrochemical reactors to enhance the lithium storage performance of silicon nanodots
Authors: Zhu Ruiyu , Hu Xuejiao , Chen Kai , Dang Jie , Wang Xiujuan , Liu Xiaojie , Wang Hui
Published: May 2020

SiNDs@DSHC can effectively improve the lithium storage performance. Furthermore, in situ TEM was used to study the formation of SiNDs@DSHC.
Combinatorial investigation of structural and optical properties of cation-disordered ZnGeN2
Authors: Melamed Celeste L. , Pan Jie , Mis Allison , Heinselman Karen , Schnepf Rekha R. , Woods-Robinson Rachel , Cordell Jacob J. , Lany Stephan , Toberer Eric S. , Tamboli Adele C.
Published: May 2020

Cation-disordered ZnGeN2 is found to exhibit structural and optical tunability with cation off-stoichiometry.
Signalling cost‐aware routing for green networks
Authors: Alizadeh Hadi , Gözüpek Didem
Published: May 2020

Owing to the environmental impact and potential economic benefits, there is an urgent request for green techniques to reduce energy consumption in telecommunication networks. However, green approaches impose signalling overhead on the network. While most research works in the literature focus on minimisation of energy consumption in green networks, the signalling overhead has largely been unexplored. In this work, the authors tackle the trade‐off between energy efficiency and signalling overhead in green routing by formulating an optimisation problem as an integer linear programme (ILP). Their ILP problem minimises signalling overhead with a constraint on the total power consumption of the network. Moreover, their problem introduces the multipath routing feature and takes the flow table sizes of the forwarding devices into account. They prove that the proposed green routing problem is nondeterministic polynomial (NP)‐hard and thus propose a polynomial‐time heuristic algorithm in addition to analysing its time complexity. They evaluate the performance of the heuristic algorithm by comparing its results with those generated by ILP.
Blood flow imaging of high frame rate two‐dimensional vector in cardiovascular ultrasound detection
Authors: Wu Cungang , Huang Chao
Published: May 2020

Traditional cardiovascular ultrasound detection using focused ultrasound can cause a decrease in frame rate, which affects the results of the diagnosis. In order to improve the effect of cardiovascular ultrasound detection, this study used ultrasound vector blood flow imaging technology to improve the image frame rate and introduce planar high frame rate imaging technology. Simultaneously, this work studies the parameters of the image through parameter analysis and combines the advantages of various methods to improve the analysis. In addition, this work proposes a high frame rate blood flow imaging method, and designs simulation experiments to analyse the effectiveness of the method. The results show that the proposed algorithm has a certain effect in two‐dimensional vector blood flow imaging, which can be applied to clinical practice, and can provide theoretical reference for subsequent related research.
Bio‐inspired metaheuristic framework for clustering optimisation in VANETs
Authors: Alsuhli Ghada H. , Fahmy Yasmine A. , Khattab Ahmed
Published: May 2020

Vehicular ad‐hoc network (VANET) is a key enabling technology of intelligent transportation systems. VANETs are characterised by the rapidly changing topology and the unbounded network size. These characteristics present a range of challenges to different VANET applications such as routing and security. Clustering has strongly presented itself as an efficient solution to such challenges. In this study, the authors formulate the clustering algorithm as a many‐objective optimisation problem. Then, they propose a unified framework to optimise the configuration parameters arbitrary clustering algorithms. Three many‐objective metaheuristic optimisation techniques, ESPEA, MOEA/DD and NSGA‐III, are compared in context of this framework, and various commonly used quality indicators are utilised to identify the metaheuristic with the best quality of solutions. The proposed framework is then used to optimise a recent clustering algorithm. Using the optimal configuration resulting from the proposed framework significantly improves the performance of the clustering algorithm under‐test compared to the non‐optimised algorithm as well as other clustering approaches. This is demonstrated by the simulation results which showed up to 182% improvement in the cluster head lifetime and a reduction of 36% in the clustering packets overhead in the highway environment.
Flux and torque ripple minimisation for permanent magnet synchronous motor by finite‐set hybrid direct torque control
Authors: Navardi Mohammad‐Javad , Milimonfared Jafar , Talebi Heidar‐Ali
Published: May 2020

A hybrid direct torque control (DTC) method is proposed in this study for a permanent magnet synchronous motor (PMSM) drive based on the finite‐set control (FSC). After selecting the optimal voltage vectors, the steady‐state torque and flux ripple is minimised using the conventional DTC and the most efficient and dynamically‐fast mode of the control algorithm. The philosophy of the control approach proposed is based on the FSC and DTC. In other words, the process of optimisation relies on a combination of FSC DTC. Compared to conventional PMSM drive control, the proposed technique optimises the switching state of the inverter and minimises the cost function by adopting measures resembling DTC. In addition, the sensitivity of this method to motor parameters is very low, and it is computationally simple. The results obtained from the experiments and simulations validated the applicability of this method to PMSM drives by suggesting that the proposed model provides dynamically‐fast responses to low torque and flux ripples using a simple‐to‐implement hybrid structure.
Cooperative optimisation strategy of comprehensive vulnerability of activedistribution network considering information interrupted
Authors: Liu Wenxia , Ma Tie , Xu Yahui
Published: May 2020

As the scale of distributed generations connecting to the power system increases continuously, communication system considering the requirements of real‐time control is becoming much more important in active distribution system. Therefore, in order to improve the responsiveness of the distribution network during the communication interruption, an offline backup strategy is proposed considering the combined output of distributed generations and energy storage systems involving the characteristics of the active distribution system. Based on a typical set of clusters which describe the features of wind turbines and photovoltaics, the strategy analyses operational vulnerability combining structural characteristics of the active distribution system and solves the output level of each distributed generation according to the improved algorithm. A numerical case study is presented to demonstrate the effectiveness of this model.
Estimation of PV module parameters from the manufacturer's datasheet for MPP estimation
Authors: Changmai Papul , Nayak Sisir Kumar , Metya Sanjeev Kumar
Published: May 2020

A study has been performed to extract the unknown parameters of a photovoltaic (PV) module using mathematical model‐driven analysis. Neglecting the less significant terms, the number of non‐linear exponential terms are reduced to develop a simplified algorithm to estimate five unknown parameters such as diode ideality factor, series resistance, shunt resistance, diode saturation current and photogenerated current of a single diode model PV module accurately with less computational complexities from the manufacturer's datasheet values. Substituting the estimated values of the unknown parameters, the PV module output power is obtained at different irradiance and temperature, which shows close co‐ordination with the datasheet values. To improve the accuracy in the estimation of the PV module output using the proposed model, the nominal operating cell temperature (NOCT) is considered. The results of the proposed model are verified with the experimental output of two (one 315 Wp and another 3 Wp) PV modules, which shows better correlation with the proposed model considering NOCT. The measurement uncertainty to obtain the output power experimentally is not more than 6.88%.
Sensorless variable speed operation of doubly‐fed reluctance wind generators
Authors: Jovanović Milutin , Ademi Sul , Binns Richard
Published: May 2020

An improved and more robust flux vector orientated control scheme for an emerging doubly‐fed reluctance generator without a shaft angular position or velocity sensor has been proposed, computer‐simulated, and experimentally verified. Whilst retaining the cost and other advantages of using a fractional power electronics converter rating, this promising medium‐speed brushless machine technology has been viewed by research and industrial communities as an appealing economical solution for the compromised reliability and high maintenance requirements associated with the presence of slip rings, brushes, and the failures prone three‐stage gearbox of conventional wound rotor doubly‐fed induction generators, traditionally deployed for commercial wind turbines. The comprehensive comparative simulation and test results obtained have been shown to agree very well undoubtedly demonstrating the good overall performance of the sensorless controller. A precise speed reference tracking with smooth, intrinsically decoupled real and reactive power responses of the grid‐connected winding has been achieved for the typical variable loading profiles and narrow speed ranges (e.g. around or so) of a laboratory emulated wind turbine.
Quickest attack detection in smart grid based on sequential Monte Carlo filtering
Authors: Chen Leian , Wang Xiaodong
Published: May 2020

Quick and accurate detection of cyber‐attacks is key to the normal operation of the smart grid system. In this study, joint state estimation and sequential attack detection method for a given bus with grid frequency drift is proposed that utilises the commonly monitored output voltage. In particular, based on a non‐linear state‐space model derived from the three‐phase sinusoidal voltage equations, the authors employ the sequential Monte Carlo (SMC) filtering to estimate the system state. The output of the SMC filter is fed into a cumulative sum control chart test to detect the attack in the fastest way. Moreover, an adaptive sampling strategy is proposed to reduce the rate of taking measurements and communicating with the controller. Extensive simulation results demonstrate that the proposed method achieves high adaptivity and efficient detection of various types of attacks in power systems.
HRIPCB: a challenging dataset for PCB defects detection and classification
Authors: Huang Weibo , Wei Peng , Zhang Manhua , Liu Hong
Published: May 2020

To cope with the difficulties in inspection and classification of defects in printed circuit board (PCB), many methods have been proposed in previous work. However, few of them publish their datasets before, which hinders the introduction and comparison of new methods. In this study, HRIPCB, a synthesised PCB dataset that contains 1386 images with 6 kinds of defects is proposed for the use of detection, classification and registration tasks. Besides, a reference‐based method is adopted to inspect and an end‐to‐end convolutional neural network is trained to classify the defects, which are collectively referred to as the RBCNN approach. Unlike conventional approaches that require pixel‐by‐pixel processing, the RBCNN method proposed in this study firstly locates the defects and then classifies them by deep neural networks, which shows superior performance on the dataset.
Strong Hα emission and signs of accretion in a circumbinary planetary mass companion from MUSE
Authors: Eriksson Simon C. , Asensio Torres Rubén , Janson Markus , Aoyama Yuhiko , Marleau Gabriel-Dominique , Bonnefoy Mickael , Petrus Simon
Published: May 2020

Context. Intrinsic Hα emission can be advantageously used to detect substellar companions because it improves contrasts in direct imaging. Characterising this emission from accreting exoplanets allows for the testing of planet formation theories.

Aims. We characterise the young circumbinary planetary mass companion 2MASS J01033563-5515561 (AB)b (Delorme 1 (AB)b) through medium-resolution spectroscopy.

Methods. We used the new narrow-field mode for the MUSE integral-field spectrograph, located on the ESO Very Large Telescope, during science verification time to obtain optical spectra of Delorme 1 (AB)b.

Results. We report the discovery of very strong Hα and Hβ emission, accompanied by He I emission. This is consistent with an active accretion scenario. We provide accretion rate estimates obtained from several independent methods and find a likely mass of 12−15 MJup for Delorme 1 (AB)b. This is also consistent with previous estimates.

Conclusions. Signs of active accretion in the Delorme 1 system might indicate a younger age than the ∼30−40 Myr expected from a likely membership in Tucana-Horologium (THA). Previous works have also shown the central binary to be overluminous, which gives further indication of a younger age. However, recent discoveries of active discs in relatively old (∼40 Myr), very low-mass systems suggests that ongoing accretion in Delorme 1 (AB)b might not require in and of itself that the system is younger than the age implied by its THA membership.
Quasistatic evolution for dislocation-free finite plasticity
Authors: Kružík Martin , Melching David , Stefanelli Ulisse
Published: May 2020

We investigate quasistatic evolution in finite plasticity under the assumption that the plastic strain is compatible. This assumption is well-suited to describe the special case of dislocation-free plasticity and entails that the plastic strain is the gradient of a plastic deformation map. The total deformation can be then seen as the composition of a plastic and an elastic deformation. This opens the way to an existence theory for the quasistatic evolution problem featuring both Lagrangian and Eulerian variables. A remarkable trait of the result is that it does not require second-order gradients.
Pourquoi et comment peser l’antimatière ?
Authors: Sacquin Yves , Hilico Laurent
Published: May 2020

Au Cern, trois expériences (ALPHA-g, AEg- IS et GBAR) sont en concurrence pour mesurer le comportement gravitationnel de l’antimatière. Ces collaborations rassemblent des chercheurs et ingénieurs aux compétences extrêmement variées en physique des particules, détection, physique atomique, lasers, ions froids, accélérateurs, ultravide, cryogénie&

Au-delà de la prouesse technique, l’enjeu de cette mesure est considérable pour notre compréhension de l’Univers.
Hemostatic spray powder TC-325 in the primary endoscopic treatment of peptic ulcer-related bleeding: multicenter international registry
Authors: Hussein Mohamed , Alzoubaidi Durayd , Lopez Miguel-Fraile , Weaver Michael , Ortiz-Fernandez-Sordo Jacobo , Bassett Paul , Rey Johannes W. , Hayee Bu Hussain , Despott Edward , Murino Alberto , Moreea Sulleman , Boger Philip , Dunn Jason , Mainie Inder , Graham David , Mullady Daniel K. , Early Dayna S. , Ragunath Krish , Anderson John T. , Bhandari Pradeep , Goetz Martin , Kiesslich Ralf , Coron Emmanuel , Lovat Laurence B. , Haidry Rehan
Published: May 2020

Background Upper gastrointestinal bleeding (UGIB) is a leading cause of morbidity and is associated with a 2 % – 17 % mortality rate in the UK and USA. Bleeding peptic ulcers account for 50 % of UGIB cases. Endoscopic intervention in a timely manner can improve outcomes. Hemostatic spray is an endoscopic hemostatic powder for GI bleeding. This multicenter registry was created to collect data prospectively on the immediate endoscopic hemostasis of GI bleeding in patients with peptic ulcer disease when hemostatic spray is applied as endoscopic monotherapy, dual therapy, or rescue therapy.

Methods Data were collected prospectively (January 2016 – March 2019) from 14 centers in the UK, France, Germany, and the USA. The application of hemostatic spray was decided upon at the endoscopist’s discretion.

Results 202 patients with UGIB secondary to peptic ulcers were recruited. Immediate hemostasis was achieved in 178/202 patients (88 %), 26/154 (17 %) experienced rebleeding, 21/175 (12 %) died within 7 days, and 38/175 (22 %) died within 30 days (all-cause mortality). Combination therapy of hemostatic spray with other endoscopic modalities had an associated lower 30-day mortality (16 %, P < 0.05) compared with monotherapy or rescue therapy. There were high immediate hemostasis rates across all peptic ulcer disease Forrest classifications.

Conclusions This is the largest case series of outcomes of peptic ulcer bleeding treated with hemostatic spray, with high immediate hemostasis rates for bleeding peptic ulcers.
Effects of acoustic softening on thermal conductivity beyond group velocity
Authors: Gerboth M. D. , Walker D. G.
Published: May 2020

We model the highly reduced thermal conductivity of nanostructured materials observed in nanoribbons. For highly scaled structures, such as wires with diameters on the order of 20nm, physical effects beyond classical boundary scattering, including acoustic softening, become important. To date, work on acoustic softening has focused on reductions in group velocity. However, a reduction in the group velocity implies that the phonon dispersion is modified. Here, we investigate how changes in the phonon dispersion manifest in the mean free path, heat capacity, and group velocity. Including these effects in the modeling of thermal conductivity, we find that softening increases low-temperature thermal conductivity while reducing high temperature thermal conductivity. We further compare the model to experimental data.
Stochastic equation of motion approach to fermionic dissipative dynamics. I. Formalism
Authors: Han Lu , Ullah Arif , Yan Yun-An , Zheng Xiao , Yan YiJing , Chernyak Vladimir
Published: May 2020

In this work, we establish formally exact stochastic equation of motion (SEOM) theory to describe the dissipative dynamics of fermionic open systems. The construction of the SEOM is based on a stochastic decoupling of the dissipative interaction between the system and fermionic environment, and the influence of environmental fluctuations on the reduced system dynamics is characterized by stochastic Grassmann fields. Meanwhile, numerical realization of the time-dependent Grassmann fields has remained a long-standing challenge. To solve this problem, we propose a minimal auxiliary space (MAS) mapping scheme with which the stochastic Grassmann fields are represented by conventional c-number fields along with a set of pseudo-levels. This eventually leads to a numerically feasible MAS-SEOM method. The important properties of the MAS-SEOM are analyzed by making connection to the well-established time-dependent perturbation theory and the hierarchical equations of motion theory. The MAS-SEOM method provides a potentially promising approach for the accurate and efficient simulation of fermionic open systems at ultra-low temperatures.
Stochastic equation of motion approach to fermionic dissipative dynamics. II. Numerical implementation
Authors: Ullah Arif , Han Lu , Yan Yun-An , Zheng Xiao , Yan YiJing , Chernyak Vladimir
Published: May 2020

This paper provides a detailed account of the numerical implementation of the stochastic equation of motion (SEOM) method for the dissipative dynamics of fermionic open quantum systems. To enable direct stochastic calculations, a minimal auxiliary space (MAS) mapping scheme is adopted, with which the time-dependent Grassmann fields are represented by c-number noises and a set of pseudo-operators. We elaborate on the construction of the system operators and pseudo-operators involved in the MAS-SEOM, along with the analytic expression for the particle current. The MAS-SEOM is applied to study the relaxation and voltage-driven dynamics of quantum impurity systems described by the single-level Anderson impurity model, and the numerical results are benchmarked against those of the highly accurate hierarchical equations of motion method. The advantages and limitations of the present MAS-SEOM approach are discussed extensively.
Passive micropumping in microfluidics for point-of-care testing
Authors: Xu Linfeng , Wang Anyang , Li Xiangpeng , Oh Kwang W.
Published: May 2020

Suitable micropumping methods for flow control represent a major technical hurdle in the development of microfluidic systems for point-of-care testing (POCT). Passive micropumping for point-of-care microfluidic systems provides a promising solution to such challenges, in particular, passive micropumping based on capillary force and air transfer based on the air solubility and air permeability of specific materials. There have been numerous developments and applications of micropumping techniques that are relevant to the use in POCT. Compared with active pumping methods such as syringe pumps or pressure pumps, where the flow rate can be well-tuned independent of the design of the microfluidic devices or the property of the liquids, most passive micropumping methods still suffer flow-control problems. For example, the flow rate may be set once the device has been made, and the properties of liquids may affect the flow rate. However, the advantages of passive micropumping, which include simplicity, ease of use, and low cost, make it the best choice for POCT. Here, we present a systematic review of different types of passive micropumping that are suitable for POCT, alongside existing applications based on passive micropumping. Future trends in passive micropumping are also discussed.
Phase transition of non-Hermitian topological edge states in microwave regime
Authors: Yu Ye , Song Wange , Chen Chen , Chen Tao , Ye Hongmei , Shen Xiaopeng , Cheng Qingqing , Li Tao
Published: May 2020

Recent advances in non-Hermitian topological phases have exploited the unusual features in photonics systems. In particular, the coupling effect and parity–time (PT) symmetry have been found to jointly determine the transition of topological edge states, which have yet to be detected directly in coupled PT-symmetric waveguides. In this work, we use a finite waveguide array described by the Su–Schrieffer–Heeger model to explicitly reveal the relation between the topological states and PT symmetry and unveil the condition for the coexistence of topological edge states and PT phases. Microwave-near-field experiments have revealed non-trivial edge states in both exact- and broken-PT phases in ultrathin corrugated metallic coupled waveguide arrays. This work thus establishes an integrated microwave waveguide platform based on which more interesting physics and functional devices related to topological photonics and PT symmetry may be developed.
Spin–phonon coupling and dynamic zero-field splitting contributions to spin conversion processes in iron(II) complexes
Authors: Higdon Nicholas J. , Barth Alexandra T. , Kozlowski Patryk T. , Hadt Ryan G.
Published: May 2020

Magnetization dynamics of transition metal complexes manifest in properties and phenomena of fundamental and applied interest [e.g., slow magnetic relaxation in single molecule magnets, quantum coherence in quantum bits (qubits), and intersystem crossing (ISC) rates in photophysics]. While spin–phonon coupling is recognized as an important determinant of these dynamics, additional fundamental studies are required to unravel the nature of the coupling and, thus, leverage it in molecular engineering approaches. To this end, we describe here a combined ligand field theory and multireference ab initio model to define spin–phonon coupling terms in S = 2 transition metal complexes and demonstrate how couplings originate from both the static and dynamic properties of ground and excited states. By extending concepts to spin conversion processes, ligand field dynamics manifest in the evolution of the excited state origins of zero-field splitting (ZFS) along specific normal mode potential energy surfaces. Dynamic ZFSs provide a powerful means to independently evaluate contributions from spin-allowed and/or spin-forbidden excited states to spin–phonon coupling terms. Furthermore, ratios between various intramolecular coupling terms for a given mode drive spin conversion processes in transition metal complexes and can be used to analyze the mechanisms of ISC. Variations in geometric structure strongly influence the relative intramolecular linear spin–phonon coupling terms and will define the overall spin state dynamics. While the findings of this study are of general importance for understanding magnetization dynamics, they also link the phenomenon of spin–phonon coupling across fields of single molecule magnetism, quantum materials/qubits, and transition metal photophysics.
Time-resolved diagnostics of a bipolar HiPIMS discharge
Authors: Hippler Rainer , Cada Martin , Hubicka Zdenek
Published: May 2020

Bipolar high power impulse magnetron sputtering (HiPIMS) with a yttrium target is investigated with the help of time-resolved diagnostics. The bipolar HiPIMS discharge is operated with a negative pulse with a width of 100μs, which is immediately followed by a positive pulse (pulse voltage up to +60 V) with a duration of ∼310μs. The time-resolved floating potential first rises to a large positive voltage of ∼55V at the beginning of the positive pulse (+60 V) and after 30μs drops to ∼38V. It indicates the ignition of a reversed discharge. Further evidence of such a reversed discharge is confirmed by time-resolved mass spectrometry and time-resolved optical emission spectroscopy.
Hierarchical machine learning of potential energy surfaces
Authors: Dral Pavlo O. , Owens Alec , Dral Alexey , Csányi Gábor
Published: May 2020

We present hierarchical machine learning (hML) of highly accurate potential energy surfaces (PESs). Our scheme is based on adding predictions of multiple Δ-machine learning models trained on energies and energy corrections calculated with a hierarchy of quantum chemical methods. Our (semi-)automatic procedure determines the optimal training set size and composition of each constituent machine learning model, simultaneously minimizing the computational effort necessary to achieve the required accuracy of the hML PES. Machine learning models are built using kernel ridge regression, and training points are selected with structure-based sampling. As an illustrative example, hML is applied to a high-level ab initio CH3Cl PES and is shown to significantly reduce the computational cost of generating the PES by a factor of 100 while retaining similar levels of accuracy (errors of ∼1 cm−1).
On the thermal conductivity of single crystal AlN
Authors: Inyushkin A. V. , Taldenkov A. N. , Chernodubov D. A. , Mokhov E. N. , Nagalyuk S. S. , Ralchenko V. G. , Khomich A. A.
Published: May 2020

Thermal conductivity κ(T) of single crystal aluminum nitride grown by physical vapor transport has been measured at temperatures T from 5 to 410 K. The samples exhibit high thermal conductivity with a value of up to 316 W m−1 K−1 at room temperature and about 2800 W m−1 K−1 at a peak of 66 K. At lowest temperatures, κ(T) approaches the conductivity limited by the diffuse phonon scattering from sample surfaces. The peculiarities in measured κ(T) suggest that the phonon scattering from point defects contributes essentially to the total phonon scattering in samples under investigation at low temperatures. The phonon interaction with electrons and holes bound to neutral donor and acceptor centers is suggested, adding substantially to thermal resistivity near and below the peak in κ(T).
Phase equilibrium of liquid water and hexagonal ice from enhanced sampling molecular dynamics simulations
Authors: Piaggi Pablo M. , Car Roberto
Published: May 2020

We study the phase equilibrium between liquid water and ice Ih modeled by the TIP4P/Ice interatomic potential using enhanced sampling molecular dynamics simulations. Our approach is based on the calculation of ice Ih-liquid free energy differences from simulations that visit reversibly both phases. The reversible interconversion is achieved by introducing a static bias potential as a function of an order parameter. The order parameter was tailored to crystallize the hexagonal diamond structure of oxygen in ice Ih. We analyze the effect of the system size on the ice Ih-liquid free energy differences, and we obtain a melting temperature of 270 K in the thermodynamic limit. This result is in agreement with estimates from thermodynamic integration (272 K) and coexistence simulations (270 K). Since the order parameter does not include information about the coordinates of the protons, the spontaneously formed solid configurations contain proton disorder as expected for ice Ih.
Disease X ver1.0: COVID-19
Authors: Young Paul R
Published: May 2020

The SARS-Cov2 has presented the world with a novel pandemic challenge requiring a rapid response. This article provides a May 2020 snapshot from Professor Paul Young, who is part of a group working with urgency on Australia’s leading COVID-19 candidate vaccine.
An aphid RNA transcript migrates systemically within plants and is a virulence factor
Authors: Chen Yazhou , Singh Archana , Kaithakottil Gemy G. , Mathers Thomas C. , Gravino Matteo , Mugford Sam T. , van Oosterhout Cock , Swarbreck David , Hogenhout Saskia A.
Published: May 2020

Aphids are sap-feeding insects that colonize a broad range of plant species and often cause feeding damage and transmit plant pathogens, including bacteria, viruses, and viroids. These insects feed from the plant vascular tissue, predominantly the phloem. However, it remains largely unknown how aphids, and other sap-feeding insects, establish intimate long-term interactions with plants. To identify aphid virulence factors, we took advantage of the ability of the green peach aphidMyzus persicaeto colonize divergent plant species. We found that aM. persicaeclone of near-identical females established stable colonies on nine plant species of five representative plant eudicot and monocot families that span the angiosperm phylogeny. Members of the novel aphid gene familyYaare differentially expressed in aphids on the nine plant species and are coregulated and organized as tandem repeats in aphid genomes. Aphids translocateYatranscripts into plants, and some transcripts migrate to distal leaves within several plant species. RNAi-mediated knockdown ofYagenes reducesM. persicaefecundity, andM. persicaeproduces more progeny on transgenic plants that heterologously produce one of the systemically migratingYatranscripts as a long noncoding (lnc) RNA. Taken together, our findings show that beyond a range of pathogens,M. persicaeaphids translocate their own transcripts into plants, including aYalncRNA that migrates to distal locations within plants, promotes aphid fecundity, and is a member of a previously undescribed host-responsive aphid gene family that operate as virulence factors.
Properties of spherical and deformed nuclei using regularized pseudopotentials in nuclear DFT
Authors: Bennaceur K , Dobaczewski J , Haverinen T , Kortelainen M
Published: May 2020

We developed new parameterizations of local regularized finite-range pseudopotentials up to next-to-next-to-next-to-leading order (N3LO), used as generators of nuclear density functionals. When supplemented with zero-range spin–orbit and density-dependent terms, they provide a correct single-reference description of binding energies and radii of spherical and deformed nuclei. We compared the obtained results to experimental data and discussed benchmarks against the standard well-established Gogny D1S functional.
Material assignment for proton range prediction in Monte Carlo patient simulations using stopping-power datasets
Authors: Permatasari Felicia Fibiani , Eulitz Jan , Richter Christian , Wohlfahrt Patrick , Lühr Armin
Published: May 2020

Motivation and objective. For each institute, the selection and calibration of the most suitable approach to assign material properties for Monte Carlo (MC) patient simulation in proton therapy is a major challenge. Current conventional approaches based on computed tomography (CT) depend on CT acquisition and reconstruction settings. This study proposes a material assignment approach, referred to as MATA (MATerial Assignment), which is independent of CT scanner properties and, therefore, universally applicable by any institute. Materials and methods. The MATA approach assigns material properties to the physical quantity stopping-power ratio (SPR) using a set of 40 material compositions specified for human tissues and linearly determined mass density. The application of clinically available CT-number-to-SPR conversion avoids the need for any further calibration. The MATA approach was validated with homogeneous and heterogeneous SPR datasets by assessing the SPR accuracy after material assignment obtained either based on dose scoring or determination of water-equivalent thickness. Finally, MATA was applied on patient datasets to evaluate dose differences induced by different approaches for material assignment and SPR prediction. Results. The deviation between the SPR after material assignment and the input SPR was close to zero in homogeneous datasets and below 0.002 (0.2% relative to water) in heterogeneous datasets, which was within the systematic uncertainty in SPR estimation. The comparison of different material assignment approaches revealed relevant differences in dose distribution and SPR. The comparison between two SPR prediction approaches, a standard look-up table and direct SPR determination from dual-energy CT, resulted in patient-specific mean proton range shifts between 1.3 mm and 4.8 mm. Conclusion. MATA eliminates the need for institution-specific adaptations of the material assignment. It allows for using any SPR dataset and thus facilitates the implementation of more accurate SPR prediction approaches. Hence, MATA provides a universal solution for patient modeling in MC-based proton treatment planning.
Trap analysis of composite 2D–3D channel in AlGaN/GaN/graded-AlGaN:Si/GaN:C multi-heterostructure at different temperatures*
Authors: Hu Sheng , Yang Ling , Mi Min-Han , Hou Bin , Liu Sheng , Zhang Meng , Wu Mei , Zhu Qing , Wu Sheng , Lu Yang , Zhu Jie-Jie , Zhou Xiao-Wei , Lv Ling , Ma Xiao-Hua , Hao Yue
Published: May 2020

The graded AlGaN:Si back barrier can form the majority of three-dimensional electron gases (3DEGs) at the GaN/graded AlGaN:Si heterostructure and create a composite two-dimensional (2D)–three-dimensional (3D) channel in AlGaN/GaN/graded-AlGaN:Si/GaN:C heterostructure (DH:Si/C). Frequency-dependent capacitances and conductance are measured to investigate the characteristics of the multi-temperature trap states of in DH:Si/C and AlGaN/GaN/GaN:C heterostructure (SH:C). There are fast, medium, and slow trap states in DH:Si/C, while only medium trap states exist in SH:C. The time constant/trap density for medium trap state in SH:C heterostructure are (11 μs–17.7 μs)/(1.1 × 1013 cm−2·eV−1–3.9× 1013 cm−2·eV−1) and (8.7 μs–14.1 μs)/(0.7× 1013 cm−2·eV−1–1.9× 1013 cm−2·eV−1) at 300 K and 500 K respectively. The time constant/trap density for fast, medium, and slow trap states in DH:Si/C heterostructure are (4.2 μs–7.7 μs)/(1.5× 1013 cm−2·eV−1–3.2× 1013 cm−2·eV−1), (6.8 μs–11.8 μs)/(0.8× 1013 cm−2 · eV−1–2.8× 1013 cm−2 · eV−1), (30.1 μs–151 μs)/(7.5× 1012 cm−2 · eV−1–7.8× 1012 cm−2 · eV−1) at 300 K and (3.5 μs–6.5 μs)/(0.9× 1013 cm−2 · eV−1–1.8× 1013 cm−2 · eV−1), (4.9 μs–9.4 μs)/(0.6× 1013 cm−2 · eV−1–1.7× 1013 cm−2 · eV−1), (20.6 μs–61.9 μs)/(3.2× 1012 cm−2 · eV−1–3.5× 1012 cm−2·eV−1) at 500 K, respectively. The DH:Si/C structure can effectively reduce the density of medium trap states compared with SH:C structure.
Manufacturing enterprise collaboration network: An empirical research and evolutionarymodel*
Authors: Hu Ji-Wei , Gao Song , Yan Jun-Wei , Lou Ping , Yin Yong
Published: May 2020

With the increasingly fierce market competition, manufacturing enterprises have to continuously improve their competitiveness through their collaboration and labor division with each other, i.e. forming manufacturing enterprise collaborative network (MECN) through their collaboration and labor division is an effective guarantee for obtaining competitive advantages. To explore the topology and evolutionary process of MECN, in this paper we investigate an empirical MECN from the viewpoint of complex network theory, and construct an evolutionary model to reproduce the topological properties found in the empirical network. Firstly, large-size empirical data related to the automotive industry are collected to construct an MECN. Topological analysis indicates that the MECN is not a scale-free network, but a small-world network with disassortativity. Small-world property indicates that the enterprises can respond quickly to the market, but disassortativity shows the risk spreading is fast and the coordinated operation is difficult. Then, an evolutionary model based on fitness preferential attachment and entropy-TOPSIS is proposed to capture the features of MECN. Besides, the evolutionary model is compared with a degree-based model in which only node degree is taken into consideration. The simulation results show the proposed evolutionary model can reproduce a number of critical topological properties of empirical MECN, while the degree-based model does not, which validates the effectiveness of the proposed evolutionary model.
Early retirement of power plants in climate mitigation scenarios
Authors: Fofrich Robert , Tong Dan , Calvin Katherine , De Boer Harmen Sytze , Emmerling Johannes , Fricko Oliver , Fujimori Shinichiro , Luderer Gunnar , Rogelj Joeri , Davis Steven J
Published: May 2020

International efforts to avoid dangerous climate change aim for large and rapid reductions of fossil fuel CO2 emissions worldwide, including nearly complete decarbonization of the electric power sector. However, achieving such rapid reductions may depend on early retirement of coal- and natural gas-fired power plants. Here, we analyze future fossil fuel electricity demand in 171 energy-emissions scenarios from Integrated Assessment Models (IAMs), evaluating the implicit retirements and/or reduced operation of generating infrastructure. Although IAMs calculate retirements endogenously, the structure and methods of each model differ; we use a standard approach to infer retirements in outputs from all six major IAMs and—unlike the IAMs themselves—we begin with the age distribution and region-specific operating capacities of the existing power fleet. We find that coal-fired power plants in scenarios consistent with international climate targets (i.e. keeping global warming well-below 2 °C or 1.5 °C) retire one to three decades earlier than historically has been the case. If plants are built to meet projected fossil electricity demand and instead allowed to operate at the level and over the lifetimes they have historically, the roughly 200 Gt CO2 of additional emissions this century would be incompatible with keeping global warming well-below 2 °C. Thus, ambitious climate mitigation scenarios entail drastic, and perhaps un-appreciated, changes in the operating and/or retirement schedules of power infrastructure.
The perception of local cocoa farmers to the swisscontact program: economics, environment and social dimension
Authors: Karim I , Fatmawaty D , Anas  , Wulandari E
Published: May 2020

Swisscontact as a partner of local cocoa farmers in West Sulawesi plays an important role in improving the sustainability of cocoa farming, not only in the economy but also in the environment and social dimension. In addition, cocoa as a product has a strategic role in high impact for the regional and national economyof Indonesia. This research focused on measuring the satisfaction level of local farmers from the economic, environmental and social dimensions to extent the success of the program implemented both by Swisscontact as an International NGOs from Swiss and local cocoa farmers. This research was conducted in West Sulawesi, one of the largest cocoa producers nationally. The data were collected through interview to the 269 local cocoa farmers in Polewali, Mandar as one of the Swisscontact Partner by the Sustainable Cocoa Production Program (SSCP). The results showed that the economic dimension had a good performance as well as the environmental dimension. Meanwhile, social dimension showed a bad performance. Three of the dimensions are important for the local farmers to support in improving their income and also in producing high-quality cocoa product which is environmental and social friendly.
Product flow pattern at cayyene pepper supply chain
Authors: Indriani R , Darma R , Musa Y , Tenriawaru A N , Imran S
Published: May 2020

Cayenne pepper as an agricultural commodity has distinctive characteristics that are not available every time are difficult to store for a long time and prices tend to fluctuate. The implication is that chilies require a treatment such as supply chain management well and post-harvest treatment such as dried or mixed material for processing industries. This study aims to describe the pattern of product flow in the cayenne supply chain in Gorontalo. The study used the survey method and sampling using a purposive sampling technique to farmers and traders. Data analysis used descriptive analysis and Hayami added-value analysis. The results of the research show that the product flow pattern in the cayenne supply chain is a product distribution in the form of fresh cayenne pepper and dried cayenne pepper. Farmers sell fresh cayenne through collector traders, wholesalers, market traders and directly to retailers. While processing and distributing dried cayenne by retailers. The added value created by every kg of fresh cayenne pepper is Rp 1,126,688 or 90.27% of the production value. Hayami’s additional analysis shows that the added value in every one kg of dried chili is Rp. 7,400 or 59.20% of the value of the product. The rate of profit is 58.1% of the value of production, meaning that every 100 kg of production value will be obtained as much as 58.1 kg of profit.
Analysis of the contribution of income in fulfilling household livelihoods of coastal communities
Authors: Diansari P , Rukmana D , Nadja R A , Rahmadanih  , Fahmid I M , Syahrullah
Published: May 2020

The uncertainty of economic conditions which limited the employment opportunities has caused stability in family income. This condition has encouraged many coastal communities to diversify their work to increase income. Job diversification can provide a substantial contribution to meet household needs during the dry season. This study aims to determine the contribution of income made by coastal communities to support their household needs. This research was conducted in Punaga Village, Mangarabombang District, Takalar Regency. The results of this study indicated that the type of work carried out by coastal communities is rice cultivation and seaweed, which have so far significantly contributed to household life although the harvest is obtained in the rainy season and seaweed is harvested every 45 days after planting. Other sectors such as non-rice and non-agriculture contributed significantly to increase household income such as raising livestock, civil servants, employees, and others. Expenditures are mostly spent on farming costs and daily expenses such as consumption. The coastal community has 100% implemented a dual livelihood pattern to meet their needs, which contributes significantly to meet their needs and to build a more decent life.
Bird diversity on small islands in Maluku
Authors: Latumahina F S , Mardiatmoko G , Sahusilawane J
Published: May 2020

The bird species diversity is an indicator of the ecosystem stability. The high diversity index of birds is an indicator of healthy and stable ecosystem condition so that it can become a supporter of birdlife. The study aimed to determine the level of bird diversity on a small island in Maluku, namely the Saparua Island Protected Forest. The study was conducted in June - July 2019 using the Line Transect method on 100 m transect with 100 m transect distance, and 50 m band transect width left and right transect on a plot area of 50,000 m2 (5 ha). Observations were carried out in the morning at 07.30 - 10.00 Eastern Indonesian Time and afternoon at 16.00 - 18.30 Eastern Indonesian Time. The parameters used are the species distribution, species diversity, species abundance, and bird species evenness. The results found that the number of bird encounters in 5 transects varied. There were 16 species in transect one, 12 bird species in transect two, 9 bird species in transect three, 7 bird species in transect four and 12 bird species in transect five. The ten bird species that have conserved value and protected value were found. There were also three endemic species - each endemic was Ambon Bueno Ceram namely Myzomela seram, and the other two species are Maluku Endemic species, namely Sikatan Kelabu and Cabai Kelabu. The three types were species of birds with very limited distribution, while seven other species were animals that were protected by the state. Richness index of bird species ranges from low - medium, which was classified as medium category, transects 1, 2 and 5, with a value of the Richness Index in the range of 2.697707 - 3.413397 (2.5  4), while transects 3 and 4, low categories of 1.820478 - 1.987404 (R1 <2.5). The diversity index of bird species was classified as medium at 1.556579 - 2.155639 (1  3) which shows that transects 4 and 4 are in a low category and transects 1, 2 and 5 are in the high category. The abundance class of birds with conserved value and protected value were divided into three kinds. The four types were classified as rare abundance class, namely Elang bondol, Nuri bayan, Nuri pipi-merah dan Raja-udang suci. Then, the three types were classified as uncommon abundance class, namely Pergam mata-putih, Sikatan kelabu dan Myzomela seram. Furthermore, the three types were included in the frequent abundance class, namely Cabai kelabu, madu hitam dan madu sriganti.