Miracle-dz/UniFAR-FTUs huggingface dataset:
Microtearing modes at the top of the pedestal

Microtearing modes (MTMs) are unstable in the shallow gradient region just inside the top of the pedestal in the spherical tokamak experiment MAST, and may play an important role in the pedestal evolution. The linear properties of these instabilities are compared with MTMs deeper inside the core, and further detailed investigations in s–α geometry expose the basic drive mechanism, which is not well described by existing theories. In particular, the growth rate of the dominant edge MTM does not peak at a finite collision frequency, as frequently reported for MTMs further into the core. Our study suggests that the edge MTM is driven by a collisionless trapped particle mechanism that is sensitive to magnetic drifts. This drive is enhanced in the outer region of MAST at high magnetic shear and high trapped particle fraction. Observations of similar modes in conventional aspect ratio devices suggest this drive mechanism may be somewhat ubiquitous towards the edge of current day and future hot tokamaks.
Synthetic Hydrocerussite, 2PbCO3×Pb(OH)2, by X‐Ray Powder Diffraction.

Synthetic hydrocerussite [trilead dihydroxide dicarbonate, Pb3(CO3)2(OH)2] can be easily obtained, as a white powder, by the action of carbon dioxide and water on either lead or litharge at pH 4±5. This compound is also found in lead corrosion technological products as a ®ne-grained phase. Ab initio crystal structure determination was carried out on X-ray powder diffraction data. The heavy-atom method and the Patterson function helped determine the crystallographic model and the atom locations. The Rietveld ®tting procedure was used for the ®nal re®nement. The atomic arrangement is closely related to the structures of other lead hydroxide carbonates. The hydrocerussite structure can be viewed as a sequence of two types of layers stacked along [001]. Layer A is composed of Pb and CO3, and layer B is composed of Pb and OH. The stacking sequence is . BAABAA .
Replication Data for: Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and PARAFAC analysis

Southeast Asian peatlands supply ~10% of the global flux of dissolved organic carbon (DOC) from land to the 10 ocean, but the biogeochemical cycling of this peat-derived DOC in coastal environments is still poorly understood. Here, we use fluorescence spectroscopy and parallel factor (PARAFAC) analysis to distinguish different fractions of dissolved organic matter (DOM) in peat-draining rivers, estuaries, and coastal waters of Sarawak, Borneo. The terrigenous fractions showed high concentrations at freshwater stations within the rivers, and conservative mixing with seawater across the estuaries. The autochthonous DOM fraction, in contrast, showed low concentrations throughout our study area at all salinities. The DOM 15 pool was also characterized by a high degree of humification in all rivers and estuaries up to salinity 25. These results indicate a predominantly terrestrial origin of the riverine DOM pool. Only at salinities >25 did we observe an increase in the proportion of autochthonous relative to terrestrial DOM. Natural sunlight exposure experiments with river water and seawater showed high photolability of the terrigenous DOM fractions, suggesting that photodegradation may account for the observed changes in DOM composition in coastal waters. Nevertheless, we estimate based on our fluorescence data that at least 20%–25% of 20 the DOC at even our most marine stations (salinity >31) was terrestrial in origin, indicating that peatlands likely play an important role in the carbon biogeochemistry of Southeast Asian shelf seas.
Distributed optimization problem for second-order multi-agent networks with only position interaction

In this paper, distributed optimization problem is investigated under a second-order multi-agent network, in which each agent is described as the double integrator. The multi-agent network is introduced for solving a large scale optimization problem by the cooperation of coupled agents. Based on the interaction over the network, the optimal solution of the problem can be obtained. Since the existing distributed algorithms for second-order multi-agent network enforce each agent to transmit complete information (both state information and derivation information of the independent variable, i.e., corresponded position and velocity information of the agent), this paper is motivated to design the distributed algorithm with only using the position information of neighbors, which reduces the requirement on communication bandwidth. With the help of Lyapunov analysis and LaSallel's Invariance Principle, the optimal solution is derived and the optimization problem is solved via the second-order multi-agent network. Finally, a numerical example is presented to illustrate the theoretical result.
The Face Of Feedback: Exploring The Use Of Asynchronous Video To Deliver Instructor Feedback In Multidisciplinary Online Courses

THE FACE OF FEEDBACK: EXPLORING THE USE OF ASYNCHRONOUS VIDEO TO DELIVER INSTRUCTOR FEEDBACK IN MULTIDISCIPLINARY ONLINE COURSES by NAIMAH NOELLE WADE May 2016 Advisor: Dr. Monica Tracey Major: Instructional Technology Degree: Doctor of Philosophy The purpose of this qualitative, design-based research study was to design, implement, and explore the use of an asynchronous video feedback protocol in higher education online courses. Bannan’s (2013) Integrative Learning Design Framework guided the design and implementation strategy for this study by dictating its three core phases; 1) Informed Exploration, 2) Enactment, and 3) Local Impact Evaluation. The video feedback intervention designed for this study cycled through two practical iterations to understand the experiences of the participants and interpret the corresponding implications for instructional designers, teaching and learning practitioners and student success administrators in higher education. The study gathered data using multiple methods including, a designer reflection journal, a practitioners pre-launch assessments, weekly reflections questionnaires, postintervention debrief interviews and student reflections. To expand upon the existing body of research on technology-enhanced feedback provision in online courses, this study
Shedding light onto topological insulator beads: perspectives for optical tweezing application

The interaction of electromagnetic radiation with a spheric-type three-dimensional topological insulator (TI) bead is described within classical optics framework. By virtue of the topological magnetoelectric effect (TMEE) experienced by reflected and transmitted rays at the TI surface, there appears a net constant force on the spherical bead which is proportional to the fine structure constant times the incident radiation power. Such an uniform dynamics (constant acceleration) may be particularly useful for optical tweeezing techniques, for instance, to investigate a DNA strip or a membrane piece under stretching as well as to displace a tiny object by means of purely optical control.
The Application of Google Classroom as a Tool for Teaching and Learning

Learning activities in the computer lab is one of the challenging in higher education. Subject that is most practical activities such as Data Mining are by nature illustrative or demonstrative in the computer lab that emphasize the acquisition of observational skills; and allow students to see the concept dealt in action and relate theory more closely to reality. However, the students’ reaction to practical work is often negative as a result they are not effective in laboratory work and this may reflect a student perception that there is lack of clear purpose for the lab hands on task. The main objective of this study is to explore the effectiveness of Google Classroom’s active learning activities for data mining subject under the Decision Sciences program. A set of questionnaire has been distributed to a sample of 100 students who enrolled data mining subject were used in this study. The analysis of the data was carried out using Technology Acceptance Model (TAM) to examine the relationship between the identified factors and the effectiveness of the learning activities. The results prove that majority of the students satisfy with the Google Classroom’s tool that were introduced in the class where all ratios are above averages. In particular, comparative performance is good in the areas of ease of access, perceived usefulness, communication and interaction, instruction delivery and students’ satisfaction towards the Google Classroom’s learning activities.
Making Sense of Custom Contrast Analysis: Seven Takeaways and a New Approach

Even though custom contrast weight testing is a common method used to test for the presence of ordinal interactions, the most appropriate methods of specifying, conducting, interpreting, and exhibiting these tests are not always clear. Drawing from our own experiences, we identify seven quandaries that researchers may encounter when working with custom contrasts, concluding our discussion of each with key takeaways. In these quandaries, we explore the role of residual between-cells variance testing, the use of zero weights in contrast coding schemes, custom contrast robustness testing using sensitivity analyses, how correlations between contrast coding weightings can impact inference, the role of effect size metrics in contrast analysis, and other topics. We then propose a new approach to custom contrast weight testing and offer a software application to ease in its implementation. We hope that by discussing these common, yet complex, scenarios and by using the takeaways from these discussions to suggest a multidimensional testing approach, we can provide a resource for authors and their readers to reference as they evaluate custom contrast hypotheses.
Pre-Service STEM Majors Understanding of Slope According to Common Core Mathematics Standards: An Exploratory Study

Common Core Mathematics Standards (CCMS) is a major effort at revamping the U.S. K-12 mathematics education in order to improve American studentsâ€™ mathematical performance and international competitiveness. To ensure the successful implementation of CCMS, there have been calls for both recruiting from those with the strongest quantitative backgrounds (e.g., STEM majors) and offering rigorous mathematics training in teacher preparation. Missing from the literature are questions of whether STEM majors who arguably represent the strongest candidates for the teaching force have the depth of content understanding in order to teach mathematical topics at the rigorous level that CCMS expects, and whether future mathematics teachers need the opportunities to learn rigorously the K-12 mathematical topics they are expected to teach down the road. Our paper addresses the knowledge gap in these two areas through investigating the understanding of the concept of slope among a group STEM majors who were enrolled in an undergraduate experimental teacher preparation program. We found that even among these students, there are holes in their conceptual understanding of slope and of the connection between linear equation and its graph. These weaknesses could pose challenges for their preparedness to teach the slope concept consistent with the rigor that CCMS calls for. Taking courses that specifically address the K-12 math topics is helpful. We discuss implications of these findings for the content preparation of mathematics teachers.
RADIAL PROFILE OF THE 3.5 keV LINE OUT TO R200 IN THE PERSEUS CLUSTER

The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.
Galactic double neutron star total masses and Gaussian mixture model selection

Huang et al. [arXiv:1804.03101] have analysed the population of 15 known galactic Double Neutron Stars (DNSs) regarding the total masses of these systems. They suggest the existence of two sub-populations, and report likelihood-based preference for a two-component Gaussian mixture model over a single Gaussian distribution. This note offers a cautionary perspective on model selection for this data set: Especially for such a small sample size, a pure likelihood ratio test can encourage overfitting. This can be avoided by penalising models with a higher number of free parameters. Re-examining the DNS total mass data set within the class of Gaussian mixture models, this can be achieved through several simple and well-established statistical tests, including information criteria (AICc, BIC), cross-validation, Bayesian evidence ratios and a penalised EM-test. While this re-analysis confirms the basic finding that a two-component mixture is consistent with the data, the model selection criteria consistently indicate that there is no robust preference for it over a single-component fit. Additional DNS discoveries will be needed to settle the question of sub-populations.
Analysis of the displacement error of the WRF–ARW model in predicting tropical cyclone tracks over the Philippines

The direct positional errors (DPEs) in tropical cyclone (TC) track predictions over the Philippine domain of the Weather Research Forecasting (WRF) model's Advance Research WRF (ARW) was studied. The 3 year dataset (i.e. 2012–2014) was categorized (i.e. tropical storm (TS), severe tropical storm (STS), typhoon (TY)) and the marginal distributions of the DPEs over the short‐range (i.e. 84 h) prognosis of the model were analysed.
Faraday Rotation in the Jet of M87 inside the Bondi Radius: Indication of Winds from Hot Accretion Flows Confining the Relativistic Jet

We study Faraday rotation in the jet of M87 inside the Bondi radius using eight Very Long Baseline Array data sets, one at 8 GHz, four at 5 GHz, and three at 2 GHz. We obtain Faraday rotation measures (RMs) measured across the bandwidth of each data set. We find that the magnitude of RM systematically decreases with increasing distance from 5000 to 200,000 Schwarzschild radii. The data, showing predominantly negative RM signs without significant difference of the RMs on the northern and southern jet edges, suggest that the spatial extent of the Faraday screen is much larger than the jet. We apply models of hot accretion flows, thought to be prevalent in active galactic nuclei with a relatively low luminosity such as M87, and find that the decrease of RM is described well by a gas density profile . This behavior matches the theoretically expected signature of substantial winds, nonrelativistic un-collimated gas outflows from hot accretion flows, which is consistent with the results of various numerical simulations. The pressure profile inferred from the density profile is flat enough to collimate the jet, which can result in gradual acceleration of the jet in a magneto-hydrodynamical process. This picture is in good agreement with the observed gradual collimation and acceleration of the M87 jet inside the Bondi radius. The dominance of negative RMs suggests that the jet and wind axis are misaligned such that the jet emission exposes only one side of the toroidal magnetic fields permeating the winds.
Classification of flat bands according to the band-crossing singularity of Bloch wave functions

We show that flat bands can be categorized into two distinct classes, that is, singular and non-singular flat bands, by exploiting the singular behavior of their Bloch wave functions in momentum space. In the case of a singular flat band, its Bloch wave function possesses irremovable discontinuities generated by the band crossing with other bands. Once the degeneracy at the band crossing point is lifted, the flat band becomes dispersive and may acquire a finite Chern number in general. On the other hand, the Bloch wave function of a non-singular flat band has no singularity, and thus it can be completely isolated from other bands while preserving the perfect flatness. All one dimensional flat bands belong to the non-singular class. We show that a singular flat band displays a novel bulk-boundary correspondence such that the presence of the robust boundary mode is guaranteed by the singularity of the Bloch wave function. Moreover, we develop a general scheme to construct a flat band model Hamiltonian in which one can freely design its singular or non-singular nature. Finally, we propose a general formula for the compact localized state spanning the flat band, which can be easily implemented in numerics and offer a basis set useful in analyzing correlation effects in flat bands.
The Mouse Pulsar Wind Nebula

The young energetic pulsar J1747–2958 (τ = 26 kyr, erg s−1) powers the Mouse pulsar wind nebula (PWN), famous for its spectacular tail spanning 45″ in X-rays and 12′ in radio (d ∼ 5 kpc). We present the results of Chandra observations of the PWN and the analysis of archival lower-frequency data. The Chandra HRC image reveals a point-like source at the pulsar position, ≈1′ behind the bow shock apex of the PWN. The flattened appearance of the compact nebula is consistent with an equatorial outflow deformed by the ram pressure, implying that the angle between the pulsar’s spin axis and line of sight is ∼70° (in agreement with the radio and γ-ray pulse profiles). The spatially resolved spectroscopy with Chandra ACIS shows that the power-law (PL) spectrum steepens from Γ = 1.65 ± 0.02 to 3.0 ± 0.1 over the 45′ extent of the X-ray tail. However, the tail’s X-ray spectrum integrated over its 45″ length fits a single absorbed PL with Γ = 2.09 ± 0.03. We also found the Mouse PWN in 150 MHz GMRT data and a possible counterpart in 24 μm Spitzer data. The multiwavelength data suggest that, at low frequencies, the spectrum of the X-ray-emitting tail region can be described by a broken PL with at least one turnover between radio and X-rays. This is consistent with synchrotron cooling of electrons injected at the termination shock (with a spectral energy distribution slope of 2.2) with an equipartition magnetic field B ∼ 200 μG and a bulk flow speed v ∼ 4000 km s−1.
Clusters of galaxies identified from all sky surveys of 2MASS, WISE and SuperCOSMOS

We identify 47,600 clusters of galaxies from photometric data of Two Micron All Sky Survey (2MASS), Wide-field Infrared Survey Explorer (WISE) and SuperCOSMOS, among which 26,125 clusters are recognized for the first time and mostly in the sky outside the Sloan Digital Sky Survey (SDSS) area. About 90% of massive clusters of M_{500}>3*10^{14} M_{\odot} in the redshift range of 0.025<z<0.3 have been detected from such survey data, and the detection rate drops down to 50% for clusters with a mass of M_{500}~1*10^{14} M_{\odot}. Monte Carlo simulations show that the false detection rate for the whole cluster sample is less than 5%. By cross-matching with ROSAT and XMM-Newton sources, we get 779 new X-ray cluster candidates which have X-ray counterparts within a projected offset of 0.2 Mpc.
Comparative study of polyoxometalates and semiconductor metal oxides as catalysts. Photochemical oxidative degradation of thioethers

The photochemical degradation of thioether substrates catalyzed by representative semiconductor metal oxides and sulfides (anatase TiO{sub 2}, SnO{sub 2}, cubic WO{sub 3}, and CdS) and photoredox-active early-transition-metal polyometalates (W{sub 10}O{sub 32}{sup 4{minus}}, PMo{sub 12}O{sub 40}{sup 3{minus}}, PW{sub 12}O{sub 40}{sup 3{minus}}, SiMo{sub 12}O{sub 40}{sup 4{minus}}, PV{sub 2}Mo{sub 10}O{sub 10}{sup 5{minus}}, and P{sub 2}W{sub 18}O{sub 62}{sup 6{minus}}) have been examined under both anaerobic and aerobic conditions. Under anaerobic conditions, all the semiconductors are completely ineffective at photochemically oxidizing or degrading the exemplary thioether substrate tetrahydrothiophene (THT) in the oxidatively resistant solvent acetonitrile. In contrast, all the homogeneous polyoxometalate systems under the same reaction condition, except the neutral tetra-n-butylammonium (Q) salt of PW{sub 12}O{sub 40}{sup 3{minus}}, are quite effective. The latter systems generate products derived from the carbon-based radical {alpha} to the sulfur atom and not sulfoxide or sulfone, the usual products of thioether oxidation by oxometal species. The rate for the most active anaerobic system, that involving the photochemical degradation of THT by Q{sub 4}W{sub 10}O{sub 32}, under optically dilute conditions, is first order in W{sub 10}O{sub 32} {sup 4{minus}} and light intensity and variable order in THT substrate. A rate law consistent with these data is given. Upon addition of O{submore » 2}, TiO{sub 2} (with or without Pt(O)) becomes highly active, SnO{sub 2} becomes active, but WO{sub 3} and CdS remain inactive. Reactivity in thioether oxidation is dominated by the interactions of the semiconductors with O{sub 2} and O{sub 2}-derived intermediates; there is no correlation between reactivity and semiconductor band gap. Upon addition of O{sub 2}, all the polyoxometalate systems become more active. 29 refs., 4 figs., 3 tabs. « less
X-RAY ABSORPTION ANALYSIS OF NGC 3516: APPEARANCE OF FAST COMPONENTS WITH INCREASED SOURCE FLUX

By analyzing the X-ray spectra of NGC 3516 from 2001 and 2006 obtained with the HETGS spectrometer on board the Chandra X-ray Observatory, we find that the kinematic structure of the outflow can be well represented by four outflow components intrinsic to NGC 3516: −350 ± 100 km s−1, −1500 ± 150 km s−1, −2600 ± 200 km s−1, and −4000 ± 400 km s−1. A local component at z = 0 could be confused in the spectrum with intrinsic component 3. Components 1 and 2 have a broad range of ionization manifested by absorption from 23 different charge states of Fe. Components 3 and 4 are more highly ionized and show absorption from only nine different charge states of Fe. However, we were able to reconstruct the absorption measure distribution for all four. The total column density of each component is NH = (1.8 ± 0.5) × 1022 cm−2, (2.5 ± 0.3) × 1022 cm−2, (6.9 ± 4.3) × 1022 cm−2, and (5.4 ± 1.2) × 1022 cm−2, respectively. The fast components 3 and 4 appear only in the high state of 2006 and not in 2001, while the slower components persist during both epochs. On the other hand, there is no significant absorption variability within days during 2001 or 2006. We find that the covering factor plays a minor role for the line absorption.