bluuebunny/crossref_metadata_2025 huggingface dataset:
A molecular dynamics study on glucose molecular recognition by a non-enzymatic selective sensor based on a conducting polymer
Authors: Zanuy David , Fabregat Georgina , Ferreira Carlos A. , Alemán Carlos
Published: March 2019

Atomistic molecular dynamics simulations have been used to ascertain the selective detection mechanism of glucose by poly(hydroxymethyl-3,4-ethylenedioxythiophene).
Classical harmonic model for the behavior of pure fluids at the critical point
Authors: Ploetz Elizabeth A. , Smith Paul E.
Published: March 2019

We present a simple model to explain the limiting behavior of many thermodynamic properties of pure classical fluids as one approaches the critical point.
DFT calculations of the synergistic effect of λ-MnO2/graphene composites for electrochemical adsorption of lithium ions
Authors: Zhang Huixin , Du Xiao , Ding Shengqi , Wang Qiang , Chang Lutong , Ma Xuli , Hao Xiaogang , Pen Changjun
Published: March 2019

Density functional theory (DFT) was used to calculate the geometric and electronic structure of λ-MnO2 and λ-MnO2/graphene composites.
Glucose transport via the pseudomonad porin OprB: implications for the design of Trojan Horse anti-infectives
Authors: Coines Joan , Acosta-Gutierrez Silvia , Bodrenko Igor , Rovira Carme , Ceccarelli Matteo
Published: March 2019

Knowing the structural and dynamical features of specific porins from poor-permeable Gram-negative bacteria helps to design anti-infectives with optimal permeation. Molecular dynamics simulations can characterize and quantify the transport of substrates through these specific porins.
Molecular QCA embedding in microporous materials
Authors: Pintus Alberto M. , Gabrieli Andrea , Pazzona Federico G. , Pireddu Giovanni , Demontis Pierfranco
Published: March 2019

We propose an environment for information encoding and transmission via a nanoconfined molecular Quantum Dot Cellular Automata (QCA) wire, composed of a single row of head-to-tail interacting 2-dots molecular switches.
Comprehensive study of the promotional mechanism of F on Ce–Mo/TiO2 catalysts for wide temperature NH3-SCR performance: the activation of surface Ti–F bonds
Authors: Zhang Guodong , Huang Xiaosheng , Yang Xing , Tang Zhicheng
Published: March 2019

The CeFMoTiOx catalyst was prepared via a solvothermal method. It confirmed that Oα was not only generated during the transformation between Ce4+ and Ce3+ but was also released from F− species of the surface Ti–F bonds.
Carbonyl complexes of copper(i) stabilized by bridging fluorinated pyrazolates and halide ions
Authors: Parasar Devaborniny , Jayaratna Naleen B. , Muñoz-Castro Alvaro , Conway Allison E. , Mykhailiuk Pavel K. , Dias H. V. Rasika
Published: March 2019

Halide ions provide a promising tool to stabilize – through bridging interactions – copper carbonyl clusters of fluorinated pyrazolates.
Controlled synthesis of bifunctional particle-like Mo/Mn-NixSy/NF electrocatalyst for highly efficient overall water splitting
Authors: Gong Yaqiong , Zhi Yang , Lin Yu , Zhou Tao , Li Jinhui , Jiao Feixiang , Wang Wenfei
Published: March 2019

Mo/Mn-NixSy/NF catalyst was successfully synthesized and exhibited excellent catalytic activities and long-term durability.
Emerging investigator series: primary emissions, ozone reactivity, and byproduct emissions from building insulation materials
Authors: Chin Kyle , Laguerre Aurelie , Ramasubramanian Pradeep , Pleshakov David , Stephens Brent , Gall Elliott T.
Published: March 2019

Insulation materials affect indoor air by (i) releasing primary volatile organic compounds (VOCs) from enclosure cavities to the interior space, (ii) mitigating exposure to outdoor pollutants through reactive deposition (of oxidants,e.g., ozone) or filtration in infiltration air, and (iii) generating secondary VOCs and gas-phase byproducts from chemical reactions.
Online supercritical fluid extraction mass spectrometry (SFE-LC-FTMS) for sensitive characterization of soil organic matter
Authors: Shen Yufeng , Zhao Rui , Tolić Nikola , Tfaily Malak M. , Robinson Errol W. , Boiteau Rene , Paša-Tolić Ljiljana , Hess Nancy J.
Published: March 2019

We report a novel technical approach for subcritical fluid extraction (SFE) for organic matter characterization in complex matrices such as soil.
Extraction techniques and potential health benefits of bioactive compounds from marine molluscs: a review
Authors: Odeleye Tinu , White William Lindsey , Lu Jun
Published: March 2019

Marine molluscs and their bioactive compounds are of particular relevance to the growing pool of nutraceutical resources under global investigation.
Solvent and catalyst free synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones by twin screw extrusion
Authors: Carvalho Reyniel Ben , Joshi Shreerang V.
Published: March 2019

Rapid, high yielding, and solvent and catalyst free synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones by twin screw extrusion.
Simultaneous detection of multiple NT-proBNP clinical samples utilizing an aptamer-based sandwich assay on an integrated microfluidic system
Authors: Sinha Anirban , Gopinathan Priya , Chung Yi-Da , Shiesh Shu-Chu , Lee Gwo-Bin
Published: March 2019

An integrated microfluidic platform was developed for the simultaneous detection of NT-proBNP, a widely studied biomarker for heart failure diagnosis, in up to six clinical samples within 25 min by using a novel aptamer-based sandwich assay.
AgoFISH: cost-effective in situ labelling of genomic loci based on DNA-guided dTtAgo protein
Authors: Chang Lei , Sheng Gang , Zhang Yiwen , Shao Shipeng , Wang Yanli , Sun Yujie
Published: March 2019

A cost-effective and simple method for in situ labelling of genomic loci utilizing the DNA-guided DNA binding activity of the nuclease-deficient Argonaute protein in Thermus thermophilus (dTtAgo).
Direct observation of an electrically degenerate interface layer in a GaN/sapphire heterostructure
Authors: Kim Young-Min , Lee Sung Bo , Lee Jaekwang , Oh Sang Ho
Published: March 2019

An electrically degenerate layer deteriorates the optoelectric performance of a wide band gap semiconductor grown on an insulator substrate.
β-Hairpins as peptidomimetics of human phosphoprotein-binding domains
Authors: Batalha I. L. , Lychko I. , Branco R. J. F. , Iranzo O. , Roque A. C. A.
Published: March 2019

Highly selective affinity reagents based on beta-hairpin cyclic peptides were designed to mimic the natural interactions between phosphoprotein-binding domains and their cognate targets.
Correction: Radical alkylation of isocyanides with amino acid-/peptide-derived Katritzky salts via photoredox catalysis
Authors: Zhu Ze-Fan , Zhang Miao-Miao , Liu Feng
Published: March 2019

Correction for ‘Radical alkylation of isocyanides with amino acid-/peptide-derived Katritzky salts via photoredox catalysis’ by Ze-Fan Zhu, et al., Org. Biomol. Chem., 2019, 17, 1531–1534.
Self-catalysed folding of single chain nanoparticles (SCNPs) by NHC-mediated intramolecular benzoin condensation
Authors: Garmendia Sofiem , Dove Andrew P. , Taton Daniel , O'Reilly Rachel K.
Published: March 2019

A self-catalysed folding strategy to form single chain nanoparticles (SCNPs) was developed via an intramolecular N-heterocyclic carbene (NHC)-mediated benzoin condensation.
Graphene/graphene nanoribbon aerogels decorated with S-doped MoSe2 nanosheets as an efficient electrocatalyst for hydrogen evolution
Authors: Fan Wei , Wang Dong , Sun Zhen , Ling Xing Yi , Liu Tianxi
Published: March 2019

Graphene/graphene nanoribbon (GGNR) aerogels facilitate fast electron and ion transfer while S-doping improves the activity of catalytic sites for efficient hydrogen evolution.
An amphiphilic organosilicon framework (AOF): a new solid Pickering catalyst carrier
Authors: Yu Honghao , Zou Houbing , Dai Jinyu , Shi Zhiqiang , Wang Runwei , Zhang Zongtao , Qiu Shilun
Published: March 2019

The amphiphilicity of the AOF carrier originates from the amphiphilic pyridine groups in the frameworks of the nanoparticles.
Arranged redistribution of sulfur species and synergistic mediation of polysulfide conversion in lithium–sulfur batteries by a cactus structure MnO2/carbon nanofiber interlayer
Authors: Yu Zhihao , Gao Tianji , Le TrungHieu , Cheng Jie , Yang Ying
Published: March 2019

Cactus structure MnO2/N-rich carbon nanofiber composites were synthesized via an in situ redox reaction to be utilized as the interlayer in lithium–sulfur batteries.
Mixed-halide perovskite for ultrasensitive two-terminal artificial synaptic devices
Authors: Yu Haiyang , Gong Jiangdong , Wei Huanhuan , Huang Wei , Xu Wentao
Published: March 2019

Ultrasensitive two-terminal synaptic devices based on mixed-halide perovskites were fabricated, which could emulate the fundamental bio-synaptic functions.
Innate pharmacophore assisted selective C–H functionalization to therapeutically important nicotinamides
Authors: Song Zehua , Wang Guotong , Li Wei , Li Shengkun
Published: March 2019

Tunable and regioselective C–H functionalization of nicotinamides was accomplished assisted by the innate pharmacophore NHOxa.
Nitrogen and sulfur co-doped cobalt carbon catalysts for ethylbenzene oxidation with synergistically enhanced performance
Authors: Chen Sheng , Wu Yujie , Jie Shanshan , Au Chak Tong , Liu Zhigang
Published: March 2019

Co-N-S-C catalysts with rod-like structures were synthesized for the selective oxidation of ethylbenzene using O2 as an oxidant.
Cu@Co-MOFs as a novel catalyst of peroxymonosulfate for the efficient removal of methylene blue
Authors: Li Huanxuan , Xu Shaodan , Du Jia , Tang Junhong , Zhou Qingwei
Published: March 2019

In this study, for the first time, we describe the single step synthesis of a Cu particle-doped cobalt-based metal–organic framework (Cu@Co-MOF) using a hydrothermal method.
Exploring the generation and use of acylketenes with continuous flow processes
Authors: Galaverna Renan , McBride Tom , Pastre Julio C. , Browne Duncan L.
Published: March 2019

The generation and use of acyl ketenes under continuous flow reaction conditions is reported. Several reaction classes of these reactive intermediates have been studied. Under zero headspace conditions, a ketone exchange process is possible between volatile ketones. The process can be readily scaled to deliver gram quantities of product.
Effects of local rearrangement of magnetic particles on deformation in magneto-sensitive elastomers
Authors: Romeis Dirk , Toshchevikov Vladimir , Saphiannikova Marina
Published: March 2019

Based on the dipole–dipole approach for magnetic interactions we present a comprehensive analysis of spatial rearrangement of magnetic particles under a magnetic field and its effect on the magneto-induced deformation of magneto-sensitive elastomers.
In between molecules and self-assembled fibrillar networks: highly stable nanogel particles from a low molecular weight hydrogelator
Authors: Torres-Martínez Ana , Angulo-Pachón César A. , Galindo Francisco , Miravet Juan F.
Published: March 2019

A low molecular weight gelator forms reproducibly nanogel particles with good temporal and thermal stability and they present accessible hydrophobic domains.
Ternary blend organic solar cells with improved morphological stability
Authors: Nam Minwoo , Yoo Jaehong , Park Yunjae , Noh Hye Yeon , Park Yongkook , Cho Junhee , Kim Jung-A. , Kim Jehan , Lee Hyun Hwi , Chang Rakwoo , Ko Doo-Hyun
Published: March 2019

We demonstrate the improved morphological stability and lifetime of ternary organic solar cells incorporating nonfullerene small molecules in polymer:fullerene blends.
Improved photovoltaic performance of a nonfullerene acceptor based on a benzo[b]thiophene fused end group with extended π-conjugation
Authors: Yang Kun , Liao Qiaogan , Koh Chang Woo , Chen Jianhua , Su Mengyao , Zhou Xin , Tang Yumin , Wang Yang , Zhang Youming , Woo Han Young , Guo Xugang
Published: March 2019

By utilizing a conjugation extended benzo[b]thiophene-fused end group, a nonfullerene acceptor was developed with simultaneously improved photovoltaic parameters.
An extensive comparative analysis of two MOF databases: high-throughput screening of computation-ready MOFs for CH4 and H2 adsorption
Authors: Altintas Cigdem , Avci Gokay , Daglar Hilal , Nemati Vesali Azar Ayda , Erucar Ilknur , Velioglu Sadiye , Keskin Seda
Published: March 2019

An extensive comparative analysis of two computation-ready MOF databases was provided to study adsorption and separation of CH4 and H2.
A non-peptide NIR fluorescent probe for detection of chymotrypsin and its imaging application
Authors: Mu Shuai , Xu Yixuan , Zhang Yintang , Guo Xiumei , Li Jian , Wang Yali , Liu Xiaoyan , Zhang Haixia
Published: March 2019

A novel non-peptide NIR fluorescent probe for the detection of chymotrypsin and its imaging application.
Novel heparin-loaded mesoporous tubular micromotors formed via template-assisted electrochemical deposition
Authors: Wang Qi , Wang Yan , Guo Baoyan , Shao Shuibin , Yu Yueqi , Zhu Xiaotan , Wan Mimi , Zhao Bo , Bo Chi , Mao Chun
Published: March 2019

A novel kind of mesoporous tubular micromotor used to load heparin (Hep) and formed via template-assisted electrochemical deposition is presented.
Polysiloxane–poly(vinyl alcohol) composite dielectrics for high-efficiency low voltage organic thin film transistors
Authors: Cao Jupeng , Wei Xiaoyun , Che Yuxuan , Li Aiyuan , He Yaowu , He Chao , Zhu Yanan , Chen Xiaolong , Li Tingting , Murtaza Imran , Yan Lijia , Perepichka Dmitrii F. , Meng Hong
Published: March 2019

The strategy of composite polymer dielectrics for low consumption-high efficiency organic thin film transistors via the solution method.
Calcium–calmodulin gating of a pH-insensitive isoform of connexin43 gap junctions
Authors: Wei Siyu , Cassara Christian , Lin Xianming , Veenstra Richard D.
Published: March 2019

Intracellular protons and calcium ions are two major chemical factors that regulate connexin43 (Cx43) gap junction communication and the synergism or antagonism between pH and Ca2+ has been questioned for decades. To assess the ability of Ca2+ ions to modulate Cx43 junctional conductance (gj) in the absence of pH-sensitivity, patch clamp experiments were performed on Neuroblastoma-2a (N2a) cells or neonatal mouse ventricular myocytes (NMVMs) expressing either full-length Cx43 or the Cx43-M257 (Cx43K258stop) mutant protein, a carboxyl-terminus (CT) truncated version of Cx43 lacking pH-sensitivity. The addition of 1 μM ionomycin to normal calcium saline reduced Cx43 or Cx43-M257 gj to zero within 15 min of perfusion. This response was prevented by Ca2+-free saline or addition of 100 nM calmodulin (CaM) inhibitory peptide to the internal pipette solution. Internal addition of a connexin50 cytoplasmic loop calmodulin-binding domain (CaMBD) mimetic peptide (200 nM) prevented the Ca2+/ionomycin-induced decrease in Cx43 gj, while 100 μM Gap19 peptide had minimal effect. The investigation of the transjunctional voltage (Vj) gating properties of NMVM Cx43-M257 gap junctions confirmed the loss of the fast inactivation of Cx43-M257 gj, but also noted the abolishment of the previously reported facilitated recovery of gj from inactivating potentials. We conclude that the distal CT domain of Cx43 contributes to the Vj-dependent fast inactivation and facilitated recovery of Cx43 gap junctions, but the Ca2+/CaM-dependent gating mechanism remains intact in its absence. Sequence-specific connexin CaMBD mimetic peptides act by binding Ca2+/CaM non-specifically and the Cx43 mimetic Gap19 peptide has negligible effect on this chemical gating mechanism.
Reversing resistance to counter antimicrobial resistance in the World Health Organisation’s critical priority of most dangerous pathogens
Authors: Venter Henrietta
Published: March 2019

The speed at which bacteria develop antimicrobial resistance far outpace drug discovery and development efforts resulting in untreatable infections. The World Health Organisation recently released a list of pathogens in urgent need for the development of new antimicrobials. The organisms that are listed as the most critical priority are all Gram-negative bacteria resistant to the carbapenem class of antibiotics. Carbapenem resistance in these organisms is typified by intrinsic resistance due to the expression of antibiotic efflux pumps and the permeability barrier presented by the outer membrane, as well as by acquired resistance due to the acquisition of enzymes able to degrade β-lactam antibiotics. In this perspective article we argue the case for reversing resistance by targeting these resistance mechanisms – to increase our arsenal of available antibiotics and drastically reduce antibiotic discovery times – as the most effective way to combat antimicrobial resistance in these high priority pathogens.
Using Propensity Score Matching to Address Clinical Questions: The Impact of Remote Microphone Systems on Language Outcomes in Children Who Are Hard of Hearing
Authors: Curran Maura , Walker Elizabeth A. , Roush Patricia , Spratford Meredith
Published: March 2019

Purpose

Children who are hard of hearing (CHH) have restricted access to acoustic and linguistic information. Increased audibility provided by hearing aids influences language outcomes, but the benefits of hearing aids are often limited by acoustic factors and distance. Remote microphone (RM) systems further increase auditory access by reducing the negative consequences of these factors. The purpose of this article was to identify factors that influence likelihood of RM system receipt and to investigate the effects of RM systems in home settings on later language outcomes. We used propensity score matching to compare language outcomes between children with and without access to personal RM systems in home settings. This article provides a description of how and why to perform propensity score–matching analyses with clinical populations.

Method

Participants were 132 CHH. Through parent report, we identified children who received RM systems for home use by 4 years of age. Logistic regression was used to determine factors that predict likelihood of RM system receipt in home settings. Propensity score matching was conducted on a subgroup of 104 participants. Performance on language measures at age 5 years was compared across propensity-matched children who did and did not receive RMs for personal use.

Results

Likelihood of RM receipt was associated with degree of hearing loss, maternal education, and location (recruitment site). Comparisons between matched pairs of children with and without RM systems in early childhood indicated significantly better discourse skills for children whose families owned RM systems, but no significant differences for vocabulary or morphosyntax.

Conclusion

Results provide preliminary evidence that the provision of personal RM systems for preschool-age CHH enhances higher-level language skills. The propensity score–matching technique enabled us to use an observational, longitudinal data set to examine a question of clinical interest.
Linear Mixed-Model Analysis to Examine Longitudinal Trajectories in Vocabulary Depth and Breadth in Children Who Are Hard of Hearing
Authors: Walker Elizabeth A. , Redfern Alexandra , Oleson Jacob J.
Published: March 2019

Purpose

Children who are hard of hearing (CHH) tend to have reduced vocabularies compared to children with normal hearing (CNH). Prior research on vocabulary skills in children with hearing loss has focused primarily on their breadth of knowledge (how many words are known). Depth of vocabulary knowledge (how well words are known) is not well documented for CHH. The current study used linear mixed models (LMMs) to investigate growth trajectories of vocabulary depth and breadth in CHH relative to age-matched CNH.

Method

Participants for this study included 155 children (93 CHH, 62 CNH) enrolled in a longitudinal study. Examiners administered a standardized measure of vocabulary knowledge at ages 7, 8, and 9 years. We constructed multiple LMMs with fixed effects for group and age. The models included various combinations of random intercepts for subject and item and random slope for age.

Results

For depth, CHH showed significant and stable deficits compared to CNH over time. For breadth, CNH showed greater vocabulary breadth, but the group differences diminished with age. For CHH, higher aided audibility, age, and maternal educational level were associated with greater vocabulary breadth and depth. Age at hearing aid fitting was not.

Conclusions

A major advantage of using LMM is that it allowed us to cope with missing data points while still accounting for variability within and across participants. Assessment of both vocabulary breadth and depth may be useful in identifying school-age CHH who are at risk of delays in language outcomes.
Essential Statistical Concepts for Research in Speech, Language, and Hearing Sciences
Authors: Oleson Jacob J. , Brown Grant D. , McCreery Ryan
Published: March 2019

Purpose

Clinicians depend on the accuracy of research in the speech, language, and hearing sciences to improve assessment and treatment of patients with communication disorders. Although this work has contributed to great advances in clinical care, common statistical misconceptions remain, which deserve closer inspection in the field. Challenges in applying and interpreting traditional statistical methods with behavioral data from humans have led to difficulties with replication and reproducibility in other allied scientific fields, including psychology and medicine. The importance of research in our fields of study for advancing science and clinical care for our patients means that the choices of statistical methods can have far-reaching, real-world implications.

Method

The goal of this article is to provide an overview of fundamental statistical concepts and methods that are used in the speech, language, and hearing sciences.

Results

We reintroduce basic statistical terms such as thepvalue and effect size, as well as recommended procedures for model selection and multiple comparisons.

Conclusions

Research in the speech, language, and hearing sciences can have a profound positive impact on the lives of individuals with communication disorders, but the validity of scientific findings in our fields is enhanced when data are analyzed using sound statistical methods. Misunderstanding or misinterpretation of basic statistical principles may erode public trust in research findings. Recommendations for practices that can help minimize the likelihood of errors in statistical inference are provided.

Supplemental Material

https://doi.org/10.23641/asha.7849223
Core and stellar mass functions in massive collapsing filaments
Authors: Ntormousi Evangelia , Hennebelle Patrick
Published: March 2019

Context. The connection between the prestellar core mass function (CMF) and the stellar initial mass function (IMF) lies at the heart of all star formation theories, but it is inherently observationally unreachable.

Aims. In this paper we aim to elucidate the earliest phases of star formation with a series of high-resolution numerical simulations that include the formation of sinks from high-density clumps. In particular, we focus on the transition from cores to sink particles within a massive molecular filament, and work towards identifying the factors that determine the shape of the CMF and the IMF.

Methods. We have compared the CMF and IMF between magnetized and unmagnetized simulations, and between different resolutions. In order to study the effect of core stability, we applied different selection criteria according to the virial parameter and the mass-to-flux ratio of the cores.

Results. We find that, in all models, selecting cores based on their kinematic virial parameter tends to exclude collapsing objects, because they host high velocity dispersions. Selecting only the thermally unstable magnetized cores, we observe that their mass-to-flux ratio spans almost two orders of magnitude for a given mass. We also see that, when magnetic fields are included, the CMF peaks at higher core mass values with respect to a pure hydrodynamical simulation. Nonetheless, all models produce sink mass functions with a high-mass slope consistent with Salpeter. Finally, we examined the effects of resolution and find that, in these isothermal simulations, even models with very high dynamical range fail to converge in the mass function.

Conclusions. Our main conclusion is that, although the resulting CMFs and IMFs have similar slopes in all simulations, the cores have slightly different sizes and kinematical properties when a magnetic field is included, and this affects their gravitational stability. Nonetheless, a core selection based on the mass-to-flux ratio is not enough to alter the shape of the CMF, if we do not take thermal stability into account. Finally, we conclude that extreme care should be given to resolution issues when studying sink formation with an isothermal equation of state, since with each increase in resolution, fragmentation continues to smaller scales in a self-similar way.
Interstellar dust in the solar system: model versus in situ spacecraft data
Authors: Krüger Harald , Strub Peter , Altobelli Nicolas , Sterken Veerle J. , Srama Ralf , Grün Eberhard
Published: March 2019

Context. In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in situ dust detector on board the Ulysses spacecraft. Later on, interstellar dust was also identified in the data sets measured with dust instruments on board Galileo, Cassini, and Helios. Ulysses monitored the interstellar dust stream at high ecliptic latitudes for about 16 yr. The three other spacecraft data sets were obtained in the ecliptic plane and cover much shorter time intervals.

Aims. To test the reliability of the model predictions, we compare previously published in situ interstellar dust measurements, obtained with these four spacecraft, with predictions of an advanced model for the dynamics of interstellar dust in the inner solar system (Interplanetary Meteoroid environment for EXploration; IMEX).

Methods. Micrometer and sub-micrometer-sized dust particles are subject to solar gravity, radiation pressure and the Lorentz force on a charged dust particle moving through the interplanetary magnetic field. These forces lead to a complex size-dependent flow pattern of interstellar dust in the planetary system. The IMEX model was calibrated with the Ulysses interstellar dust measurements and includes these relevant forces. We study the time-resolved flux and mass distribution of interstellar dust in the solar system.

Results. The IMEX model agrees with the spacecraft measurements within a factor of 2–3, including time intervals and spatial regions not covered by the original model calibration with the Ulysses data set. The model usually underestimates the dust fluxes measured by the space missions which were not used for the model calibration, i.e. Galileo, Cassini, and Helios.

Conclusions. A unique time-dependent model, IMEX is designed to predict the interstellar dust fluxes and mass distributions for the inner and outer solar system. The model is suited to study dust detection conditions for past and future space missions.
Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc
Authors: Lallement R. , Babusiaux C. , Vergely J. L. , Katz D. , Arenou F. , Valette B. , Hottier C. , Capitanio L.
Published: March 2019

Gaiastellar measurements are currently revolutionizing our knowledge of the evolutionary history of the Milky Way. 3D maps of the interstellar dust provide complementary information and are a tool for a wide range of uses. We built 3D maps of the dust in the Local arm and surrounding regions. To do so,GaiaDR2 photometric data were combined with 2MASS measurements to derive extinction toward stars that possess accurate photometry and relative uncertainties on DR2 parallaxes smaller than 20%. We applied a new hierarchical inversion algorithm to the individual extinctions that is adapted to large datasets and to an inhomogeneous target distribution. Each step associates regularized Bayesian inversions in all radial directions and a subsequent inversion in 3D of all their results. Each inverted distribution serves as a prior for the subsequent step, and the spatial resolution is progressively increased. We present the resulting 3D distribution of the dust in a 6 × 6 × 0.8 kpc3volume around the Sun. Its main features are found to be elongated along different directions that vary from below to above the mid-plane. The outer part of Carina-Sagittarius, mainly located above the mid-plane, the Local arm/Cygnus Rift around and above the mid-plane, and the fragmented Perseus arm are oriented close to the direction of circular motion. The spur of more than 2 kpc length (nicknamed thesplit) that extends between the Local Arm and Carina-Sagittarius, the compact near side of Carina-Sagittarius, and the Cygnus Rift below the Plane are oriented along l ~40 to 55°. Dust density images in vertical planes reveal a wavy pattern in some regions and show that the solar neighborhood within ~500 pc remains atypical by its extent above and below the Plane. We show several comparisons with the locations of molecular clouds, HII regions, O stars, and masers. The link between the dust concentration and these tracers is markedly different from one region to the other.
Characterization and history of the Helmi streams with Gaia DR2
Authors: Koppelman Helmer H. , Helmi Amina , Massari Davide , Roelenga Sebastian , Bastian Ulrich
Published: March 2019

Context. The halo of the Milky Way has long been hypothesized to harbour significant amounts of merger debris. For more than a decade this view has been supported by wide-field photometric surveys which have revealed the outer halo to be lumpy.

Aims. The recent release of Gaia DR2 is allowing us to establish that mergers also have been important and possibly built up the majority of the inner halo. In this work we focus on the Helmi streams, a group of streams crossing the solar vicinity and known for almost two decades. We characterize their properties and relevance for the build-up of the Milky Way’s halo.

Methods. We identify new members of the Helmi streams in an unprecedented dataset with full phase-space information combining Gaia DR2, and the APOGEE DR2, RAVE DR5, and LAMOST DR4 spectroscopic surveys. Based on the orbital properties of the stars, we find new stream members up to a distance of 5 kpc from the Sun, which we characterized using photometry and metallicity information. We also perform N-body experiments to constrain the time of accretion and properties of the progenitor of the streams.

Results. We find nearly 600 new members of the Helmi streams. Their HR diagram reveals a broad age range, from ≈11 to 13 Gyr, while their metallicity distribution goes from −2.3 to −1.0, and peaks at [Fe/H] ∼ −1.5. These findings confirm that the streams originate in a dwarf galaxy. Furthermore, we find seven globular clusters to be likely associated, and which follow a well-defined age-metallicity sequence whose properties suggest a relatively massive progenitor object. Our N-body simulations favour a system with a stellar mass of ∼108 M⊙ accreted 5 − 8 Gyr ago.

Conclusions. The debris from the Helmi streams is an important donor to the Milky Way halo, contributing ≈15% of its mass in field stars and 10% of its globular clusters.
Using deep neural networks to compute the mass of forming planets
Authors: Alibert Y. , Venturini J.
Published: March 2019

Context. Computing the mass of planetary envelopes and the critical mass beyond which planets accrete gas in a runaway fashion is important for studying planet formation, in particular, for planets up to the Neptune-mass range. This computation in principle requires solving a set of differential equations, the internal structure equations, for some boundary conditions (pressure, temperature in the protoplanetary disc where a planet forms, core mass, and the rate of accretion of solids by the planet). Solving these equations in turn proves to be time-consuming and sometimes numerically unstable.

Aims. The aim is to provide a way to approximate the result of integrating the internal structure equations for a variety of boundary conditions.

Methods. We computed a set of internal planetary structures for a very large number (millions) of boundary conditions, considering two opacities: that of the interstellar medium, and a reduced opacity. This database was then used to train deep neural networks (DNN) in order to predict the critical core mass and the mass of planetary envelopes as a function of the boundary conditions.

Results. We show that our neural networks provide a very good approximation (at the percent level) of the result obtained by solving interior structure equations, but the required computer time is much shorter. The difference with the real solution is much smaller than the difference that is obtained with some analytical formulas that are available in the literature, which only provide the correct order of magnitude at best. We compare the results of the DNN with other popular machine-learning methods (random forest, gradient boost, support vector regression) and show that the DNN outperforms these methods by a factor of at least two.

Conclusions. We show that some analytical formulas that can be found in various papers can severely overestimate the mass of planets and therefore predict the formation of planets in the Jupiter-mass regime instead of the Neptune-mass regime. The python tools that we provide allow computing the critical mass and the mass of planetary envelopes in a variety of cases, without the requirement of solving the internal structure equations. These tools can easily replace previous analytical formulas and provide far more accurate results.
The deteriorating effect of plasma density ﬂuctuations on microwave beam quality
Authors: Köhn Alf , Austin Max E. , Brookman Michael W. , Gentle Kenneth W. , Guidi Lorenzo , Holzhauer Eberhard , La Haye Rob J. , Leddy Jarrod B. , Maj Omar , Petty Craig C. , Poli Emanuele , Snicker Antti , Thomas Matthew B. , Vann Roddy G. L. , Weber Hannes
Published: March 2019

Turbulent plasma edge density ﬂuctuations can broaden a traversing microwave beam degrading its quality. This can be a problem for scenarios relying on a high spatial localization of the deposition of injected microwave power, like controlling MHD instabilities. Here we present numerical estimations of the scattering of a microwave beam by density ﬂuctuations over a large parameter range, including extrapolations to ITER. Two codes are used, the full-wave code IPF-FDMC and the wave kinetic equation solver WKBeam. A successful comparison between beam broadening obtained from DIII-D experiments and corresponding full-wave simulations is shown.
Reduced ﬁeld Scenario with X3 heating in W7-X
Authors: Marushchenko Nikolai B. , Aleynikov Pavel , Beidler Craig D. , Dinklage Andreas , Geiger Joachim , Helander Per , Laqua Heinrich P. , Maassberg Henning , Turkin Yuri ,   W7-X Team
Published: March 2019

In the present work, an ECRH scenario with reduced magnetic ﬁeld 1.75 T is considered. For 140 GHz, this ﬁeld corresponds to X3 heating. The high mirror-ratio magnetic conﬁguration, B01/B00 ≃ 0.24, was considered as one from most attractive for long-pulse operation with low bootstrap current. Since X3 wave mode can be eﬀectively absorbed only in suﬃciently hot plasmas, a preheating stage is necessary, and the requirements for target plasmas suitable for starting X3 have been studied. Diﬀerent ways to establish target plasmas are also discussed, in particular, augmenting X3 heating with X2 beams at 105 GHz.
EC absorption efficiency in ITER at one-third nominal magnetic field strength
Authors: Micheletti Daniele , Farina Daniela , Figini Lorenzo
Published: March 2019

During the first phase of the ITER Pre-Fusion Power Operations (PFPO-1), the Electron Cyclotron Radio Frequency system will be the main heating and current drive source [1]. Evaluations of the L-H power threshold [2] have shown that H-mode is unlikely to be achieved in PFPO-1 scenarios at half-field (B0=2.65T). For this reason, the use of one-third field scenarios in an early phase might help to access H-mode. This means that the EC Heating (ECH) system, with gyrotrons operating at 170 GHz, would then rely on n=3 harmonic resonance. Using a lower frequency, namely 104 GHz, could allow the exploitation of n=2 harmonic resonance, improving heating efficiency and facilitating EC-assisted breakdown which has not been demonstrated yet for n=3 harmonic. This work presents a preliminary evaluation of the performances of an EC system using the two frequencies in a B0=1.8T scenario (obtained by adequately rescaling a reference half-field scenario [3]) via a parametric scan of density/temperature profiles, to cover the range of possible values expected to occur during the operations and provide an estimation of the parameter space region where the use of each frequency allows a good absorption efficiency.
Optimization of HF- injection at the 2nd harmonic of ECRH on T-10 tokamak in order to obtain high energy content in plasma
Authors: Borschegovskiy A. , Neudatchin S. , Pimenov I. , Trukhin V. , Dremin M. , Kislov A. , Pavlov Yu.
Published: March 2019

Non-traditional scheme of HF-injection has been used in T-10 tokamak for ECRH at the 2nd harmonic of ECR in X-mode. Two HF-launcher systems, with focusing beams, injected power in opposite directions under toroidal angles +/-20˚. Input power from each launcher was about the same (Phf =0.8 ÷ 0.85MWt). Absorbed energy was deposed in central area of plasma column.

The new phenomenon has been found in some shots with W-limiter and Li-coating in the regime mentioned above. The spontaneous rise of the electron density nearly in the all plasma column occurs simultaneously with the rise of Te in the wide region (0<r/a<0.8) at the steady-state of ECRH. The value of the energy confinement time abruptly rises by ~15%. The absolute value of the electron heat and density fluxes reduces abruptly in the whole plasma column similarly to that of at non-local (or global) L-H transitions found earlier in JET and JT-60U. The accumulation of tungsten and light impurities is absent.

In a series of shots, without L-H transitions, measurements of X-ray spectra (PHA data) showed a significant difference in comparison with the ECCD co-injection by two gyrotrons.
Protection of the DIII-D Vessel, Diagnostics and Windows from Microwaves Injected by the ECH/ECCD System
Authors: Cengher Mirela , Lohr John , Gorelov Yuri , Torrezan Antonio , Ponce Dan , Chen Xi
Published: March 2019

The ECH/ECCD system on DIII-D benefits from protective measures set in place in order to reduce the likelihood of refracted rf power potentially reaching sensitive areas of the vacuum vessel or diagnostics. In addition to installation of shutters and valves, a density interlock prevents the rf injection into overdense plasma. Visible light cameras, light detectors, Langmuir probes and reflected power sniffers complete the array of diagnostics used for EC protection. Besides the 110 GHz gyrotron, a new higher frequency gyrotron at 117.5 GHz was added to the system during the 2018 experimental campaign. The new frequency allows for operation at higher plasma density and with better current drive efficiency at higher magnetic field than for 110 GHz. Injection in O-mode was used in some of the high density plasmas where the X-mode is refracted.
Tests of advanced RF off-axis current drive techniques on DIII-D
Authors: Pinsker R.I. , Chen X. , Lohr J.M. , Moeller C.P. , Porkolab M. , Brookman M.W. , Petty C.C. , Wukitch S.J. , Wallace G.M. , Buttery R.J.
Published: March 2019

The establishment of reactor-relevant radiofrequency heating and current drive techniques is a focus of work on DIII-D in the next five-year period. This paper gives an overview of the planned experimental work in the areas of (1) nearly vertically launched ECCD, (2) ‘helicon’ (whistlers or fast waves in the lower hybrid range of frequencies) current drive, and (3) high-field-side-launch (HFS) lower hybrid (slow wave) current drive. Each of these techniques addresses the need for efficient off-axis current drive for a steady-state tokamak reactor to supplement the bootstrap current and to provide current profile control, and each will be experimentally assessed at a coupled power level of ~1 MW on DIII-D in the next few years.
Mode analysis limitations of ECE-I & ECE measurements at the plasma edge
Authors: Vanovac B. , Denk S.S. , Wolfrum E. , Willensdorfer M. , Suttrop W. , Fischer R. , Luhmann N.C. ,   ASDEX Upgrade Team
Published: March 2019

Interpretation of the Electron Cyclotron Emission (ECE) and ECE Imaging (ECE-I) measurements concerning the measurement position and the radiation temperature (Trad) at the plasma edge is associated with signiﬁcant uncertainty. Various limitations such as low and high-density limits, relativistic and Doppler shift-broadening, mode overlap were identiﬁed in the past. Here, we analyse the inﬂuence of density proﬁle variation onto the radiation temperature in H-mode plasmas at ASDEX Upgrade tokamak. We show that, in the region of steep gradients, the variation of the density proﬁle leads to an outward-shift of the measurement position, towards lower Trad. The analysis is extended towards the study of the contribution of the ordinary mode (O-mode) emission to the measured Trad at the plasma edge. With this analysis, we show the qualitative agreement between experimental observations and modeling when taking into account the O-mode contribution to the ECE measurements. All of these eﬀects are assessed via the Electron Cyclotron Radiation transport forward model that is now routinely used to model the response of the ECE-I and ECE systems in diﬀerent plasma scenarios.
Research activities and progress on the long pulse ECRH launcher for EAST
Authors: Wang Xiaojie , Liu Fukun , Wei Wei , Tang Yunying , Li Bo , Zhang Liyuan , Xu Handong , Wu Dajun , Shan Jiafang , Hu Huaichuan , Wang Jian , Wu Zege , Ma Wendong , Zhang Jian , Li Miaohui , Zhang Yang , Liu Yong , Liu Yong , Liu Yong , Liu Yong ,   EAST team
Published: March 2019

A long pulse Electron Cyclotron Resonance Heating (ECRH) system is developed on EAST tokamak for plasma heating and current profile tailoring. The ECRH system is designed to operate at 140GHz and to inject 4MW CW power. With respect to the physical objectives of the newly built ECRH system, a quasi-optical launcher is designed to inject 4MW continuous wave into plasma through an equatorial port. Gaussian beams delivered from evacuated corrugation waveguides will be focused and reflected by high thermal conductive metal mirrors, and then steered by using push-rod steering mechanism with entire scanning range of ±25° toroidally and over 30° poloidally in plasma cross section. The mirrors are carefully designed with mega watts power handling capability and optimum optical characteristics. The performance of steering mechanism has been tested before installation, an open-loop control system for ECRH launcher has been implemented for required mirror movement and proper polarization between plasma discharges. This paper will present the overall design and progress of the launcher, along with the performance in EAST campaigns. Considerations and possible upgrade of the design features relevant to long pulse operation are discussed.
Investigation of Optically Grey Electron Cyclotron Harmonics in Wendelstein 7-X
Authors: Chaudhary Neha , Oosterbeek Johan W. , Hirsch Matthias , Höfel Udo , Wolf Robert C. ,   W7-X Team
Published: March 2019

For a magnetic field of 2.5T, the electron cyclotron harmonics are spectrally well separated in W7-X as it has a large aspect ratio. Because of this advantage from the geometry of W7-X stellarator, it is easier to scan these higher harmonics (70,140,210…..GHz) compared to tokamaks with small aspect ratio. For confinement reasons, W7-X is planned to work at high plasma densities applying O2 electron cyclotron resonance heating (ECRH). For such plasmas, which already have been demonstrated in experimental campaign OP1.2a of W7-X, electron cyclotron emission (ECE) from second harmonic extraordinary mode (X2) is in cutoff. In that case, optically grey higher harmonics provide the only access to ECE signal and hence electron temperature profiles. A Michelson interferometer will be used in the next operational campaign of W7-X for broadband (50-500 GHz) ECE scan and that will be compared to modeling of ECE emission at different plasma parameters from radiation transport calculations (TRAVIS). The strong stray radiation from non-absorbed ECRH is a major concern in scanning these higher harmonics using an interferometer because this stray radiation will dominate the spectra thus masking the ECE signal. For this purpose, a multimode notch filter design based on a multilayer dielectric structure is constructed to attenuate the stray radiation at 140GHz by 50dB.
Studies towards an upgraded 1.5 MW gyrotron for W7-X
Authors: Avramidis Konstantinos A. , Ruess Tobias , Mentgen Felix , Jin Jianbo , Wagner Dietmar , Gantenbein Gerd , Illy Stefan , Ioannidis C. , Laqua Heinrich P. , Pagonakis Ioannis Gr. , Rzesnicki Tomasz , Thumm Manfred , Wolf Robert C. , Jelonnek John
Published: March 2019

Studies towards a 1.5 MW, 140 GHz CW gyrotron, with the capability of MW-class operation also at 175 GHz, are ongoing at Karlsruhe Institute of Technology in view of a possible future upgrade of the ECRH system of the stellarator W7-X. The upgrade of the existing 1.0 MW, 140 GHz European gyrotron for W7-X has been chosen as a development path. Detailed designs of the cavity, the non-linear uptaper, and the quasi-optical launcher for the upgraded gyrotron have been obtained and have been validated numerically. In parallel, a mode generator, intended for low-power tests of the quasi-optical mode converter system of the upgraded gyrotron, has been designed, manufactured, and successfully tested.
Recent Status and Future Prospects of Coaxial-Cavity Gyrotron Development at KIT
Authors: Illy Stefan , Avramidis Konstantinos A. , Gantenbein Gerd , Ioannidis Zisis , Jin Jianbo , Kalaria Parth C. , Pagonakis Ioannis Gr. , Ruess Sebastian , Ruess Tobias , Rzesnicki Tomasz , Thumm Manfred , Jelonnek John
Published: March 2019

Coaxial-cavity gyrotrons are microwave sources that can extend the possible power levels of hollow cavity gyrotrons significantly and make them attractive for future fusion experiments and power plants. KIT already demonstrated operation of a modular short-pulse 170 GHz coaxial-cavity gyrotron with an output power of 2.2 MW, operating in the TE34,19mode. Today’s focus of KIT is the verification of this technology at longer pulses, which will prove the long-pulse capabilities also. At the moment, the current KIT prototype has been extended with cooling capabilities for all critical, highly loaded components of the tube and two new, different electron guns are available for operation. This paper will give an overview about the recent status and the future prospects connected to the coaxial-cavity gyrotron development at KIT, including both experimental and theoretical activities.
Simulation of Polarising and Reflector Gratings for High Power mm Waves
Authors: Lechte Carsten , Kasparek Walter , Plaum Burkhard , Leuterer Fritz , Schubert Martin , Stober Jörg , Wagner Dietmar
Published: March 2019

High power mm waves for fusion plasma heating need to be elliptically polarised to ensure good absorption in the plasma. In some scenarios, electron cyclotron resonance heating (ECRH) at higher harmonics (X3 and O2) is used, but this has significant shine-through because of low single pass absorption. Grating reflectors at the inboard strike point form a holographic mirror that reflects the beam back into the plasma. This paper investigates the optical properties and ohmic losses of both the polariser and the reflectors with the 3D fullwave code IPF-FD3D. The reflection properties of a reflector for ASDEX Upgrade and the improved ohmic losses of a waveguide polariser were confirmed.