bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying High-Speed Vision Sensing to an Industrial Robot for High-Performance Position Regulation under Uncertainties
Authors: Huang Shouren , Bergström Niklas , Yamakawa Yuji , Senoo Taku , Ishikawa Masatoshi
Published: July 2016

It is traditionally difficult to implement fast and accurate position regulation on an industrial robot in the presence of uncertainties. The uncertain factors can be attributed either to the industrial robot itself (e.g., a mismatch of dynamics, mechanical defects such as backlash, etc.) or to the external environment (e.g., calibration errors, misalignment or perturbations of a workpiece, etc.). This paper proposes a systematic approach to implement high-performance position regulation under uncertainties on a general industrial robot (referred to as the main robot) with minimal or no manual teaching. The method is based on a coarse-to-fine strategy that involves configuring an add-on module for the main robot’s end effector. The add-on module consists of a 1000 Hz vision sensor and a high-speed actuator to compensate for accumulated uncertainties. The main robot only focuses on fast and coarse motion, with its trajectories automatically planned by image information from a static low-cost camera. Fast and accurate peg-and-hole alignment in one dimension was implemented as an application scenario by using a commercial parallel-link robot and an add-on compensation module with one degree of freedom (DoF). Experimental results yielded an almost 100% success rate for fast peg-in-hole manipulation (with regulation accuracy at about 0.1 mm) when the workpiece was randomly placed.
A Novel Single-Excitation Capacitive Angular Position Sensor Design
Authors: Hou Bo , Zhou Bin , Song Mingliang , Lin Zhihui , Zhang Rong
Published: July 2016

This paper presents a high-precision capacitive angular position sensor (CAPS). The CAPS is designed to be excited by a single voltage to eliminate the matching errors of multi-excitations, and it is mainly composed of excitation electrodes, coupling electrodes, petal-form sensitive electrodes and a set of collection electrodes. A sinusoidal voltage is applied on the excitation electrodes, then the voltage couples to the coupling electrodes and sensitive electrodes without contact. The sensitive electrodes together with the set of collection electrodes encode the angular position to amplitude-modulated signals, and in order to increase the scale factor, the sensitive electrodes are patterned in the shape of petal-form sinusoidal circles. By utilizing a resolver demodulation method, the amplitude-modulated signals are digitally decoded to get the angular position. A prototype of the CAPS is fabricated and tested. The measurement results show that the accuracy of the sensor is 0.0036°, the resolution is 0.0009° and the nonlinearity over the full range is 0.008° (after compensation), indicating that the CAPS has great potential to be applied in high-precision applications with a low cost.
Integrating a DNA Strand Displacement Reaction with a Whispering Gallery Mode Sensor for Label-Free Mercury (II) Ion Detection
Authors: Wu Fengchi , Wu Yuqiang , Niu Zhongwei , Vollmer Frank
Published: July 2016

Mercury is an extremely toxic chemical pollutant of our environment. It has attracted the world’s attention due to its high mobility and the ease with which it accumulates in organisms. Sensitive devices and methods specific for detecting mercury ions are, hence, in great need. Here, we have integrated a DNA strand displacement reaction with a whispering gallery mode (WGM) sensor for demonstrating the detection of Hg2+ ions. Our approach relies on the displacement of a DNA hairpin structure, which forms after the binding of mercury ions to an aptamer DNA sequence. The strand displacement reaction of the DNA aptamer provides highly specific and quantitative means for determining the mercury ion concentration on a label-free WGM sensor platform. Our approach also shows the possibility for manipulating the kinetics of a strand displacement reaction with specific ionic species.
Development of a Distributed Crack Sensor Using Coaxial Cable
Authors: Zhou Zhi , Jiao Tong , Zhao Peng , Liu Jia , Xiao Hai
Published: July 2016

Cracks, the important factor of structure failure, reflect structural damage directly. Thus, it is significant to realize distributed, real-time crack monitoring. To overcome the shortages of traditional crack detectors, such as the inconvenience of installation, vulnerability, and low measurement range, etc., an improved topology-based cable sensor with a shallow helical groove on the outside surface of a coaxial cable is proposed in this paper. The sensing mechanism, fabrication method, and performances are investigated both numerically and experimentally. Crack monitoring experiments of the reinforced beams are also presented in this paper, illustrating the utility of this sensor in practical applications. These studies show that the sensor can identify a minimum crack width of 0.02 mm and can measure multiple cracks with a spatial resolution of 3 mm. In addition, it is also proved that the sensor performs well to detect the initiation and development of cracks until structure failure.
Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization
Authors: Mi Jian , Takahashi Yasutake
Published: July 2016

Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot.
Driftwood Biomass in Italy: Estimation and Characterization
Authors: Cotana Franco , Buratti Cinzia , Barbanera Marco , Cavalaglio Gianluca , Foschini Daniele , Nicolini Andrea , Pisello Anna
Published: July 2016

In Italy, the accumulation of driftwood along the shore is a significant issue, especially for the coastal municipalities of the Central and Northern regions. The purpose of this study was to evaluate the distribution and availability of the coastal driftwood in Italy and its impacts, as well as analyzing its chemical–physical properties to evaluate possible employment in combustion applications. On the basis of a data gathering campaign for the period 2010–2014, about 60,000 tons of driftwood are reported to accumulate along the Italian shores every year. The two regions hardest-hit were Liguria and Veneto, with about 15,000 tons and 12,000 tons, respectively. Three sites were selected for driftwood sampling. The main issue deriving from chemical characterization was the high chlorine content (up to 2% on dry basis) and metal oxides in the ashes. Driftwood samples were then subjected to a natural washing cycle for 1 month; results revealed a significant drop in chlorine and metal oxides contents (up to 80%) and a low decrease of the lower heating value (about 20%). Furthermore, the percolated water was analyzed in terms of chemical oxygen demand (COD), showing values (up to 1100 mg O2/L) above the Italian limits for discharges into surface waters.
Broken versus Non-Broken Time Reversal Symmetry: Irreversibility and Response
Authors: Dal Cengio Sara , Rondoni Lamberto
Published: July 2016

We review some approaches to macroscopic irreversibility from reversible microscopic dynamics, introducing the contribution of time dependent perturbations within the framework of recent developments in non-equilibrium statistical physics. We show that situations commonly assumed to violate the time reversal symmetry (presence of magnetic fields, rotating reference frames, and some time dependent perturbations) in reality do not violate this symmetry, and can be treated with standard theories and within standard experimental protocols.
Long-Term Comparison of Disinfection By-Product Formation Potential in a Full Scale Treatment Plant Utilizing a Multi-Coagulant Drinking Water Treatment Scheme
Authors: Skeriotis Andrew , Sanchez Nancy , Kennedy Marla , Johnstone David , Miller Christopher
Published: July 2016

A comparative study of two coagulants, aluminum sulfate (Alum) and aluminum chlorohydrate (ACH), used in parallel in a full scale water treatment plant (WTP) in Ohio from October 2009 to December 2012, was conducted to determine disinfection by-product (DBP) formation potential removal based on both dissolved organic matter (DOM) and fluorescence-derived metrics. Water quality parameters and fluorescence intensity of water samples collected before and after coagulation were measured three times per week and fluorescence matrices were analyzed using parallel factor (PARAFAC) analysis, while DBP formation potential was measured in a weekly basis in pre- and post-coagulation water samples. This study revealed that Alum consistently removed more trihalomethane (THM) formation potential per mg/L of dissolved organic carbon (DOC) than ACH. ACH treated waters averaged approximately 33% more THM formation potential when normalized to DOC. Similarly, haloacetic acid (HAA) formation potential averaged 10% higher in ACH treated waters. From the fluorescence analysis, PARAFAC components C1 and C2 (humic-like fluorophores groups) removal were 23% and 16% higher, respectively, with Alum when compared to ACH. Monte Carlo simulations, based on neural network models developed from the field data, were performed to compare DBP formation across a wide range of conditions. At similar pH, the model results showed that ACH coagulated water had 13% and 20% higher THM and HAA formation potential, respectively, when compared with Alum. The observations from this study reveal that a coagulant’s preferential removal of DBP precursors has an impact on DBP formation despite similar DOC removal.
Biomechanical evaluation of polymethyl methacrylate with the addition of various doses of cefazolin, vancomycin, gentamicin, and silver microparticles
Authors: Ficklin Michael , Suber Jonathan , Gerard Patrick , Kowaleski Michael , Kunkel Kevin
Published: July 2016

Objectives: Numerous studies have examined the biomechanics of polymethyl methacrylate (PMMA) with added antibiotics, but direct comparison between studies is difficult. Our purpose was to evaluate the effects of the addition of antibiotic drugs and silver on compressive and bending strength of PMMA. Our null hypothesis was that there would be no significant difference in the compressive strength or bending strength of PMMA with the addition of silver or varying amounts of antibiotic drugs.

Methods: Polymethyl methacrylate was mixed with cefazolin, gentamicin, vancomycin, or silver; the control was PMMA alone. Antibiotic groups contained 20 g PMMA and 0.5 g, 1 g, 2 g, or 3 g of antibiotic. Silver groups had 0.25 g silver powder alone added to 20 g PMMA or silver with PMMA and 0, 0.5 g or 1 g of antibiotic. Samples underwent four-point bending and compression testing in air at room temperature and prevailing humidity. Pairwise comparisons between groups and to the ASTM and ISO standards were performed.

Results: Compression: All antibiotic and silver groups were weaker than the control. Samples with cefazolin tended to be stronger than other antibiotic groups with equivalent doses of antibiotic. All groups were above the ASTM standard, except 3 g vancomycin. Four-point bending: The addition of antibiotics did not significantly affect bending strength in groups with lower doses of antibiotics. The silver + PMMA group was weaker than the control. No groups were significantly below the ISO standard except the 3 g vancomycin group.

Clinical significance: The addition of antibiotic or silver decreased the biomechanical strength in all samples, but not below the ASTM or ISO standard for most groups. The addition of cefazolin appears to affect strength the least, while high doses of vancomycin alter strength the most.
Bone morphogenetic protein 2 stimulates chondrogenesis of equine synovial membrane-derived progenitor cells
Authors: Chen Yuwen , Caporali Evelyn , Stewart Matthew
Published: July 2016

Objectives: Bone morphogenetic protein 2 (BMP-2) is critical for skeletal and cartilage development, homeostasis and repair. This study was conducted to clone and characterize equine BMP-2, develop expression constructs for equine BMP-2, and to determine whether BMP-2 can stimulate chondrogenesis of equine synovial membrane-derived progenitor cells (SMPC).

Methods: Equine BMP-2 cDNA was amplified from chondrocyte RNA, and then transferred into an expression plasmid and adenoviral vector. Effective expression of equine BMP-2 was confirmed using a BMP reporter cell line. SMPC were isolated from synovium, expanded through two passages and transferred to chondrogenic cultures, with recombinant human (rh) transforming growth factor beta 1 (TGF-[uni03B2]1) or rhBMP-2. Chondro-genesis was assessed by up-regulation of collagen types II and X, and aggrecan mRNA, secretion of collagen type II protein and sulfated glycosaminoglycans (sGAG), and by alkaline phosphatase induction. Chondrogenic stimulation of SMPC by the equine BMP-2 adenovirus was assessed by sGAG secretion and histology.

Results: The mature equine BMP-2 peptide is identical to human and murine peptides. Recombinant human BMP-2 and TGF-[uni03B2]1 stimulated equivalent amounts of collagen type II protein in SMPC pellets, but sGAG secretion was doubled by BMP-2. Neither factor stimulated hypertrophic marker expression. The equine BMP-2 adenoviral vector induced chondrogenesis comparably to rhBMP-2 protein, with no indication of hypertrophy.

Clinical significance: Bone morphogenetic protein 2 is a potent inducer of SMPC nonhypertrophic chondrogenesis, supporting the use of this combination for articular cartilage repair applications.
Exploring the Positive Psychology Domains of Well-Being Activated Through Charity Sport Event Experiences
Authors: Filo Kevin , Coghlan Alexandra
Published: July 2016

Charity sport events provide charities with an opportunity to promote the organization's mission, while providing participants with the opportunity to support the cause through participation. This research applies positive psychology to investigate well-being dimensions present in the
event experience. Specifically, this study explores the five domains of well-being: positive emotions, engagement, relationships, meaning, and accomplishment (PERMA) among event participants. Five focus groups were conducted with participants from three different charity sport events. Directed
content analysis results indicate that all five domains of PERMA emerged to varying degrees. The results provide implications for event managers to enhance the event experience, and bolster appeals for external funding, as well as a basis for further investigation of well-being and charity
sport events in public health policies.
Voltammetric determination of polyphenolic content in pomegranate juice using a poly(gallic acid)/multiwalled carbon nanotube modified electrode
Authors: Abdel-Hamid Refat , Newair Emad F
Published: July 2016

A simple and sensitive poly(gallic acid)/multiwalled carbon nanotube modified glassy carbon electrode (PGA/MWCNT/GCE) electrochemical sensor was prepared for direct determination of the total phenolic content (TPC) as gallic acid equivalent. The GCE working electrode was electrochemically modified and characterized using scanning electron microscope (SEM), cyclic voltammetry (CV), chronoamperometry and chronocoulometry. It was found that gallic acid (GA) exhibits a superior electrochemical response on the PGA/MWCNT/GCE sensor in comparison with bare GCE. The results reveal that a PGA/MWCNT/GCE sensor can remarkably enhance the electro-oxidation signal of GA as well as shift the peak potentials towards less positive potential values. The dependence of peak current on accumulation potential, accumulation time and pH were investigated by square-wave voltammetry (SWV) to optimize the experimental conditions for the determination of GA. Using the optimized conditions, the sensor responded linearly to a GA concentration throughout the range of 4.97 × 10−6to 3.38 × 10−5M with a detection limit of 3.22 × 10−6M (S/N = 3). The fabricated sensor shows good selectivity, stability, repeatability and (101%) recovery. The sensor was successfully utilized for the determination of total phenolic content in fresh pomegranate juice without interference of ascorbic acid, fructose, potassium nitrate and barbituric acid. The obtained data were compared with the standard Folin–Ciocalteu spectrophotometric results.
CAN HELIUM ENVELOPES CHANGE THE OUTCOME OF DIRECT WHITE DWARF COLLISIONS?
Authors: Holcomb Cole , Kushnir Doron
Published: July 2016

A pivotal feature for the viability of white dwarf (WD) collisions as SN Ia progenitors is that a significant fraction of the mass is highly compressed to the densities required for efficient 56Ni production before the ignition of the detonation wave. Previous studies have employed model WDs composed of carbon–oxygen (CO), whereas WDs typically have a non-negligible helium envelope. Given that helium is more susceptible to explosive burning than CO under the conditions of WD collision, a legitimate concern is whether or not early time He detonation ignition can lead to early time CO detonation, drastically reducing 56Ni synthesis. We investigate the role of He in determining the fate of WD collisions by performing a series of two-dimensional hydrodynamics calculations. We find that a necessary condition for non-trivial reduction of the CO ignition time is that the He detonation birthed in the contact region successfully propagates into the unshocked shell. We determine the minimal He shell mass as a function of the total WD mass that upholds this condition. Although we utilize a simplified reaction network similar to those used in previous studies, our findings are in good agreement with detailed investigations concerning the impact of network size on He shell detonations. This allows us to extend our results to the case with more realistic burning physics. Based on the comparison of these findings against evolutionary calculations of WD compositions, we conclude that most, if not all, WD collisions will not be drastically impacted by their intrinsic He components.
DISENTANGLING AGN AND STAR FORMATION ACTIVITY AT HIGH REDSHIFT USING HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY
Authors: Bridge Joanna S. , Zeimann Gregory R. , Trump Jonathan R. , Gronwall Caryl , Ciardullo Robin , Fox Derek , Schneider Donald P.
Published: July 2016

Differentiating between active galactic nucleus (AGN) activity and star formation in z ∼ 2 galaxies is difficult because traditional methods, such as line-ratio diagnostics, change with redshift, while multi-wavelength methods (X-ray, radio, IR) are sensitive to only the brightest AGNs. We have developed a new method for spatially resolving emission lines using the Hubble Space Telescope/Wide Field Camera 3 G141 grism spectra and quantifying AGN activity through the spatial gradient of the [O iii]/Hβ line ratio. Through detailed simulations, we show that our novel line-ratio gradient approach identifies ∼40% more low-mass and obscured AGNs than obtained by classical methods. Based on our simulations, we developed a relationship that maps the stellar mass, star formation rate, and measured [O iii]/Hβ gradient to the AGN Eddington ratio. We apply our technique to previously studied stacked samples of galaxies at z ∼ 2 and find that our results are consistent with these studies. This gradient method will also be able to inform other areas of galaxy evolution science, such as inside-out quenching and metallicity gradients, and will be widely applicable to future spatially resolved James Webb Space Telescope data.
THE FORMATION AND EARLY EVOLUTION OF A CORONAL MASS EJECTION AND ITS ASSOCIATED SHOCK WAVE ON 2014 JANUARY 8
Authors: Wan (万霖丰) Linfeng , Cheng Xin , Shi Tong , Su Wei , Ding M. D.
Published: July 2016

In this paper, we study the formation and early evolution of a limb coronal mass ejection (CME) and its associated shock wave that occurred on 2014 January 8. The extreme ultraviolet (EUV) images provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory disclose that the CME first appears as a bubble-like structure. Subsequently, its expansion forms the CME and causes a quasi-circular EUV wave. Interestingly, both the CME and the wave front are clearly visible at all of the AIA EUV passbands. Through a detailed kinematical analysis, it is found that the expansion of the CME undergoes two phases: a first phase with a strong but transient lateral over-expansion followed by a second phase with a self-similar expansion. The temporal evolution of the expansion velocity coincides very well with the variation of the 25–50 keV hard X-ray flux of the associated flare, which indicates that magnetic reconnection most likely plays an important role in driving the expansion. Moreover, we find that, when the velocity of the CME reaches ∼600 km s−1, the EUV wave starts to evolve into a shock wave, which is evidenced by the appearance of a type II radio burst. The shock’s formation height is estimated to be ∼0.2 R
sun, which is much lower than the height derived previously. Finally, we also study the thermal properties of the CME and the EUV wave. We find that the plasma in the CME leading front and the wave front has a temperature of ∼2 MK, while that in the CME core region and the flare region has a much higher temperature of ≥8 MK.
THE IONIZED GAS IN NEARBY GALAXIES AS TRACED BY THE
122 AND 205 μm TRANSITIONS
Authors: Herrera-Camus R. , Bolatto A. , Smith J. D. , Draine B. , Pellegrini E. , Wolfire M. , Croxall K. , Looze I. de , Calzetti D. , Kennicutt R. , Crocker A. , Armus L. , van der Werf P. , Sandstrom K. , Galametz M. , Brandl B. , Groves B. , Rigopoulou D. , Walter F. , Leroy A. , Boquien M. , Tabatabaei F. S. , Beirao P.
Published: July 2016

The [N ii] 122 and 205 μm transitions are powerful tracers of the ionized gas in the interstellar medium. By combining data from 21 galaxies selected from the Herschel KINGFISH and Beyond the Peak surveys, we have compiled 141 spatially resolved regions with a typical size of ∼1 kpc, with observations of both [N ii] far-infrared lines. We measure [N ii] 122/205 line ratios in the ∼0.6–6 range, which corresponds to electron gas densities of n
e ∼ 1–300 cm−3, with a median value of n
e = 30 cm−3. Variations in the electron density within individual galaxies can be as high as a factor of ∼50, frequently with strong radial gradients. We find that n
e increases as a function of infrared color, dust-weighted mean starlight intensity, and star-formation rate (SFR) surface density (ΣSFR). As the intensity of the [N ii] transitions is related to the ionizing photon flux, we investigate their reliability as tracers of the SFR. We derive relations between the [N ii] emission and SFR in the low-density limit and in the case of a log-normal distribution of densities. The scatter in the correlation between [N ii] surface brightness and ΣSFR can be understood as a property of the n
e distribution. For regions with n
e close to or higher than the [N ii] line critical densities, the low-density limit [N ii]-based SFR calibration systematically underestimates the SFR because the [N ii] emission is collisionally quenched. Finally, we investigate the relation between [N ii] emission, SFR, and n
e by comparing our observations to predictions from the MAPPINGS-III code.
THE BEAMING STRUCTURES OF JUPITER’S DECAMETRIC COMMON S-BURSTS OBSERVED FROM THE LWA1, NDA, AND URAN2 RADIO TELESCOPES
Authors: Imai Masafumi , Lecacheux Alain , Clarke Tracy E. , Higgins Charles A. , Panchenko Mykhaylo , Dowell Jayce , Imai Kazumasa , Brazhenko Anatolii I. , Frantsuzenko Anatolii V. , Konovalenko Alexandr A.
Published: July 2016

On 2015 February 21, simultaneous observations of Jupiter's decametric radio emission between 10 and 33 MHz were carried out using three powerful low-frequency radio telescopes: the Long Wavelength Array Station One in the USA, the Nançay Decameter Array in France, and the URAN2 telescope in Ukraine. We measured the lag times of short-bursts (S-bursts) for 105 minutes of data over effective baselines of up to 8460 km by using cross-correlation analysis of the spectrograms from each instrument. Of particular interest is the measurement of the beaming thickness of S-bursts, testing if either flashlight- or beacon-like beaming is emanating from Jupiter. We find that the lag times for all pairs drift slightly as time elapses, in agreement with expectations from the flashlight-like beaming model. This leads to a new constraint of the minimum beaming thickness of 2.″66. Also, we find that most of the analyzed data abound with S-bursts, whose occurrence probability peaks at 17–18 MHz.
ASYMPTOTIC STEADY-STATE SOLUTION TO A BOW SHOCK WITH AN INFINITE MACH NUMBER
Authors: Yalinewich Almog , Sari Re’em
Published: July 2016

The problem of a cold gas flowing past a stationary obstacle is considered. We study the bow shock that forms around the obstacle and show that at large distances from the obstacle the shock front forms a parabolic solid of revolution. The profiles of the hydrodynamic variables in the interior of the shock are obtained by solution of the hydrodynamic equations in parabolic coordinates. The results are verified with a hydrodynamic simulation. The drag force on the obstacle is also calculated. Finally, we use these results to model the bow shock around an isolated neutron star.
EXPLAINING THE MOST ENERGETIC SUPERNOVAE WITH AN INEFFICIENT JET-FEEDBACK MECHANISM
Authors: Gilkis Avishai , Soker Noam , Papish Oded
Published: July 2016

We suggest that the energetic radiation from core-collapse super-energetic supernovae (SESNe) is due to a long-lasting accretion process onto the newly born neutron star (NS), resulting from an inefficient operation of the jet-feedback mechanism (JFM). The jets that are launched by the accreting NS or black hole maintain their axis due to a rapidly rotating pre-collapse core and do not manage to eject core material from near the equatorial plane. The jets are able to eject material from the core along the polar directions and reduce the gravity near the equatorial plane. The equatorial gas expands, and part of it falls back over a timescale of minutes to days to prolong the jet-launching episode. According to the model for SESNe proposed in the present paper, the principal parameter that distinguishes between the different cases of core-collapse supernova (CCSN) explosions, such as between normal CCSNe and SESNe, is the efficiency of the JFM. This efficiency, in turn, depends on the pre-collapse core mass, envelope mass, core convection, and, most of all, the angular momentum profile in the core. One prediction of the inefficient JFM for SESNe is the formation of a slow equatorial outflow in the explosion. The typical velocity and mass of this outflow are estimated to be v
eq ≈ 1000 km s−1 and M
eq ≳ 1 M
⊙, respectively, though quantitative values will have to be checked in future hydrodynamic simulations.
THREE-DIMENSIONAL SIMULATIONS OF LONG DURATION GAMMA-RAY BURST JETS: TIMESCALES FROM VARIABLE ENGINES
Authors: López-Cámara D. , Lazzati Davide , Morsony Brian J.
Published: July 2016

Gamma-ray burst (GRB) light curves are characterized by marked variability, each showing unique properties. The origin of this variability, at least for a fraction of long GRBs, may be the result of an unsteady central engine. It is thus important to study the effects that an episodic central engine has on the jet propagation and, eventually, on the prompt emission within the collapsar scenario. Thus, in this study we follow the interaction of pulsed outflows with their progenitor stars with hydrodynamic numerical simulations in both two and three dimensions. We show that the propagation of unsteady jets is affected by the interaction with the progenitor material well after the break-out time, especially for jets with long quiescent times comparable to or larger than a second. We also show that this interaction can lead to an asymmetric behavior in which pulse durations and quiescent periods are systematically different. After the pulsed jets drill through the progenitor and the interstellar medium, we find that, on average, the quiescent epochs last longer than the pulses (even in simulations with symmetrical active and quiescent engine times). This could explain the asymmetry detected in the light curves of long quiescent time GRBs.
RADIO PULSATION SEARCH AND IMAGING STUDY OF SGR J1935+2154
Authors: Surnis Mayuresh. P. , Joshi Bhal Chandra , Maan Yogesh , Krishnakumar M. A. , Manoharan P. K. , Naidu Arun
Published: July 2016

We present the results obtained from imaging observations and a search for radio pulsations toward the magnetar SGR J1935+2154 made using the Giant Metrewave Radio Telescope and the Ooty Radio Telescope. We present the high-resolution radio image of the supernova remnant (SNR) G57.2+0.8, which is positionally associated with SGR J1935+2154. We did not detect significant periodic radio pulsations from the magnetar, with 8σ upper limits on its flux density of 0.4 and 0.2 mJy at 326.5 and 610 MHz, respectively, for an assumed duty cycle of 10%. The corresponding 6σ upper limits at the two frequencies for any burst emission with an assumed width of 10 ms are 0.5 Jy and 63 mJy, respectively. No continuum radio point source was detected at the position of SGR J1935+2154 with a 3σ upper limit of 1.2 mJy. We also did not detect significant diffuse radio emission in a radius of 70 arc s coinciding with the recently reported diffuse X-ray emission, with a 3σ upper limit of 4.5 mJy. Using the archival HI spectra, we estimate the distance of SNR G57.2+0.8 to be 11.7 ± 2.8 kpc. Based on the measured HI column density (N

H
) along this line of sight, we argue that the magnetar could be physically associated with SNR G57.2+0.8. Based on the present data, we cannot rule out either a pulsar wind nebula or a dust-scattering halo origin for the diffuse X-ray emission seen around the magnetar.
EXTRAGALACTIC PLUS GALACTIC MODEL FOR ICECUBE NEUTRINO EVENTS
Authors: Palladino Andrea , Vissani Francesco
Published: July 2016

The hypothesis that high-energy cosmic neutrinos are power law distributed is critically analyzed. We propose a model with two components that better explains the observations. The extragalactic component of the high-energy neutrino flux has a canonical

spectrum while the galactic component has a

spectrum; both of them are significant. This model has several implications, which can be tested by IceCube and ANTARES over the next several years. Moreover, the existence of a diffuse component, close to the Galactic plane and that yields (20–30)% of IceCube’s events, is interesting for the future km3 neutrino telescopes located in the Northern Hemisphere and for gamma-ray telescopes aiming to measure events up to a few 100 TeV from the southern sky.
TOWARD AN UNDERSTANDING OF CHANGING-LOOK QUASARS: AN ARCHIVAL SPECTROSCOPIC SEARCH IN SDSS
Authors: Ruan John J. , Anderson Scott F. , Cales Sabrina L. , Eracleous Michael , Green Paul J. , Morganson Eric , Runnoe Jessie C. , Shen Yue , Wilkinson Tessa D. , Blanton Michael R. , Dwelly Tom , Georgakakis Antonis , Greene Jenny E. , LaMassa Stephanie M. , Merloni Andrea , Schneider Donald P.
Published: July 2016

The uncertain origin of the recently discovered “changing-look” quasar phenomenon—in which a luminous quasar dims significantly to a quiescent state in repeat spectroscopy over ∼10-year timescales—may present unexpected challenges to our understanding of quasar accretion. To better understand this phenomenon, we take a first step toward building a sample of changing-look quasars with a systematic but simple archival search for these objects in the Sloan Digital Sky Survey Data Release 12. By leveraging the >10-year baselines for objects with repeat spectroscopy, we uncover two new changing-look quasars and a third discovered previously. Decomposition of the multiepoch spectra and analysis of the broad emission lines suggest that the quasar accretion disk emission dims because of rapidly decreasing accretion rates (by factors of ≳2.5), while disfavoring changes in intrinsic dust extinction for the two objects where these analyses are possible. Broad emission line energetics also support intrinsic dimming of quasar emission as the origin for this phenomenon rather than transient tidal disruption events or supernovae. Although our search criteria included quasars at all redshifts and transitions from either quasar-like to galaxy-like states or the reverse, all of the clear cases of changing-look quasars discovered were at relatively low redshift (

) and only exhibit quasar-like to galaxy-like transitions.
THE GAMMA-RAY-EMITTING QUASAR 0202+149: A CSS REVISITED
Authors: An T. , Cui Y.-Z. , Baan W. A. , Wang W.-H. , Mohan P.
Published: July 2016

PKS 0202+149 is a low-power radio source with blazar-like, γ-ray active galactic nucleus (AGN) characteristics. We investigate its properties and classification in relation to its γ-ray characteristics. This source shows a hint of low-frequency turnover at about 200 MHz. Radio imaging data of 0202+149 at different frequencies show differing morphologies on both kiloparsec (kpc) and parsec (pc) scales. The overall source shows a triple structure of a core and double lobes with a total projected size of ∼1.3 kpc. The compact source structure of 0202+149 is reminiscent of a compact steep spectrum (CSS) source. At pc scales, a core-jet structure extends ∼25 pc (in projection) at a position angle perpendicular to the kpc-scale structure. The curved pc-scale structure with a jet and inner lobe suggests that the CSS nuclear activity has recently re-started, although its power has been decreasing, while the kpc-scale lobes are relics of earlier activity. A maximum apparent superluminal motion of

is detected in the jet components, indicating a highly relativistic jet flow. The brightness temperature of the core is lower than the average value found for highly beamed, γ-ray AGNs, indicating a lower radio power and a relatively lower Doppler boosting factor. The CSS radio classification indicates that blazar-like γ-ray properties can also be manifested in low-power CSS radio sources with the appropriate jet and beaming properties.
THE INTRINSIC ABUNDANCE RATIO AND X-FACTOR OF CO ISOTOPOLOGUES IN L 1551 SHIELDED FROM FUV PHOTODISSOCIATION
Authors: Lin 林聖鈞 Sheng-Jun , Shimajiri Yoshito , Hara Chihomi , Lai 賴詩萍 Shih-Ping , Nakamura Fumitaka , Sugitani Koji , Kawabe Ryohei , Kitamura Yoshimi , Yoshida Atsushi , Tatei Hidefumi , Akashi Toshiya , Higuchi Aya E. , Tsukagoshi Takashi
Published: July 2016

We investigate the intrinsic abundance ratio of 13CO to C18O and the X-factor in L 1551 using the Nobeyama Radio Observatory (NRO) 45 m telescope. L 1551 is chosen because it is relatively isolated in the Taurus molecular cloud shielded from FUV photons, providing an ideal environment for studying the target properties. Our observations cover

with a resolution of

which make up maps with the highest spatial dynamical range to date. We derive the

value on the sub-parsec scales in the range of ∼3–27 with a mean value of 8.0 ± 2.8. Comparing to the visual extinction map derived from the Herschel observations, we found that the abundance ratio reaches its maximum at low

(i.e.,

∼ 1–4 mag), and decreases to the typical solar system value of 5.5 inside L 1551 MC. The high

value at the boundary of the cloud is most likely due to the selective FUV photodissociation of C18O. This is in contrast with Orion-A where internal OB stars keep the abundance ratio at a high level, greater than ∼10. In addition, we explore the variation of the X-factor, because it is an uncertain, but widely used, quantity in extragalactic studies. We found that the X-factor

, which is consistent with previous simulations. Excluding the high density region, the average X-factor is similar to the Milky Way average value.
THE IBEX RIBBON AND THE PICKUP ION RING STABILITY IN THE OUTER HELIOSHEATH. I. THEORY AND HYBRID SIMULATIONS
Authors: Florinski V. , Heerikhuisen J. , Niemiec J. , Ernst A.
Published: July 2016

The nearly circular band of energetic neutral atom emission dominating the field of view of the Interplanetary Boundary Explorer (IBEX ) satellite, is most commonly attributed to the effect of charge exchange of secondary pickup ions (PUIs) gyrating about the magnetic field in the outer heliosheath and the interstellar space beyond. Several models for the PUI dynamics of this mechanism have been proposed, each requiring either strong or weak scattering of the initial pitch angle. Conventional wisdom states that ring distributions tend to generate waves and scatter onto a shell on timescales too short for charge exchange to occur. We performed a careful study of ring and thin shell proton distribution stability using theoretical tools and hybrid plasma simulations. We show that the kinetic behavior of a freshly injected proton ring is a far more complicated process than previously thought. In the presence of a warm Maxwellian core, narrower rings could be more stable than broader toroidal distributions. The scattered rings possess a fine structure that can only be revealed using very large numbers of macroparticles in a simulation. It is demonstrated that a “stability gap” in ring temperature exists where the protons could retain large gyrating anisotropies for years, and the wave activity could remain below the level of the ambient magnetic fluctuations in interstellar space. In the directions away from the ribbon, however, a partial shell distribution is more likely to be unstable, leading to significant scattering into one hemisphere in velocity space. The process is accompanied by turbulence production, which is puzzling given the very low level of magnetic fluctuations measured in the outer heliosheath by Voyager 1.
DDO 68: A FLEA WITH SMALLER FLEAS THAT ON HIM PREY
Authors: Annibali Francesca , Nipoti Carlo , Ciotti Luca , Tosi Monica , Aloisi Alessandra , Bellazzini Michele , Cignoni Michele , Cusano Felice , Paris Diego , Sacchi Elena
Published: July 2016

We present new photometry of the dwarf irregular galaxy DDO 68, one of the most metal-poor and least massive dwarfs, located in the Lynx-Cancer Void. The images were acquired with the Large Binocular Telescope in the g and r passbands and show unequivocally that DDO 68 has previously unknown stellar streams related to the accretion of at least two smaller companions: a flea with smaller fleas biting it, to put it in Jonathan Swift’s words (from Jonathan Swift’s On Poetry: a Rhapsody: So, naturalists observe, a flea/has smaller fleas that on him prey/and these have smaller still to bite em/and so proceed ad infinitum). Our data provide direct observational evidence of multiple galaxy merging occurring at very low galactic mass scales. We present the results of an N-body simulation of the interaction of three dwarf galaxies that reproduce well the main morphological features of DDO 68.
A DECAM SEARCH FOR AN OPTICAL COUNTERPART TO THE LIGO GRAVITATIONAL-WAVE EVENT GW151226
Authors: Cowperthwaite P. S. , Berger E. , Soares-Santos M. , Annis J. , Brout D. , Brown D. A. , Buckley-Geer E. , Cenko S. B. , Chen H. Y. , Chornock R. , Diehl H. T. , Doctor Z. , Drlica-Wagner A. , Drout M. R. , Farr B. , Finley D. A. , Foley R. J. , Fong W. , Fox D. B. , Frieman J. , Garcia-Bellido J. , Gill M. S. S. , Gruendl R. A. , Herner K. , Holz D. E. , Kasen D. , Kessler R. , Lin H. , Margutti R. , Marriner J. , Matheson T. , Metzger B. D. , Neilsen Jr. E. H. , Quataert E. , Rest A. , Sako M. , Scolnic D. , Smith N. , Sobreira F. , Strampelli G. M. , Villar V. A. , Walker A. R. , Wester W. , Williams P. K. G. , Yanny B. , Abbott T. M. C. , Abdalla F. B. , Allam S. , Armstrong R. , Bechtol K. , Benoit-Lévy A. , Bertin E. , Brooks D. , Burke D. L. , Rosell A. Carnero , Kind M. Carrasco , Carretero J. , Castander F. J. , Cunha C. E. , D’Andrea C. B. , Costa L. N. da , Desai S. , Dietrich J. P. , Evrard A. E. , Neto A. Fausti , Fosalba P. , Gerdes D. W. , Giannantonio T. , Goldstein D. A. , Gruen D. , Gutierrez G. , Honscheid K. , James D. J. , Johnson M. W. G. , Johnson M. D. , Krause E. , Kuehn K. , Kuropatkin N. , Lima M. , Maia M. A. G. , Marshall J. L. , Menanteau F. , Miquel R. , Mohr J. J. , Nichol R. C. , Nord B. , Ogando R. , Plazas A. A. , Reil K. , Romer A. K. , Sanchez E. , Scarpine V. , Sevilla-Noarbe I. , Smith R. C. , Suchyta E. , Tarle G. , Thomas D. , Thomas R. C. , Tucker D. L. , Weller J. ,   (The DES Collaboration)
Published: July 2016

We report the results of a Dark Energy Camera optical follow-up of the gravitational-wave (GW) event GW151226, discovered by the Advanced Laser Interferometer Gravitational-wave Observatory detectors. Our observations cover 28.8 deg2 of the localization region in the i and z bands (containing 3% of the BAYESTAR localization probability), starting 10 hr after the event was announced and spanning four epochs at 2–24 days after the GW detection. We achieve

5
σ

point-source limiting magnitudes of

i
≈
21.7

and

z
≈
21.5

, with a scatter of 0.4 mag, in our difference images. Given the two-day delay, we search this area for a rapidly declining optical counterpart with

≳
3
σ

significance steady decline between the first and final observations. We recover four sources that pass our selection criteria, of which three are cataloged active galactic nuclei. The fourth source is offset by 5.8 arcsec from the center of a galaxy at a distance of 187 Mpc, exhibits a rapid decline by 0.5 mag over 4 days, and has a red color of

i
−
z
≈
0.3

mag. These properties could satisfy a set of cuts designed to identify kilonovae. However, this source was detected several times, starting 94 days prior to GW151226, in the Pan-STARRS Survey for Transients (dubbed as PS15cdi) and is therefore unrelated to the GW event. Given its long-term behavior, PS15cdi is likely a Type IIP supernova that transitioned out of its plateau phase during our observations, mimicking a kilonova-like behavior. We comment on the implications of this detection for contamination in future optical follow-up observations.
STATISTICAL MEASUREMENT OF THE GAMMA-RAY SOURCE-COUNT DISTRIBUTION AS A FUNCTION OF ENERGY
Authors: Zechlin Hannes-S. , Cuoco Alessandro , Donato Fiorenza , Fornengo Nicolao , Regis Marco
Published: July 2016

Statistical properties of photon count maps have recently been proven as a new tool to study the composition of the gamma-ray sky with high precision. We employ the 1-point probability distribution function of six years of Fermi-LAT data to measure the source-count distribution dN/dS and the diffuse components of the high-latitude gamma-ray sky as a function of energy. To that aim, we analyze the gamma-ray emission in five adjacent energy bands between 1 and 171 GeV. It is demonstrated that the source-count distribution as a function of flux is compatible with a broken power law up to energies of ∼50 GeV. The index below the break is between 1.95 and 2.0. For higher energies, a simple power-law fits the data, with an index of

2.2

−
0.3

+
0.7

in the energy band between 50 and 171 GeV. Upper limits on further possible breaks as well as the angular power of unresolved sources are derived. We find that point-source populations probed by this method can explain

83

−
13

+
7

% (

81

−
19

+
52

%) of the extragalactic gamma-ray background between 1.04 and 1.99 GeV (50 and 171 GeV). The method has excellent capabilities for constraining the gamma-ray luminosity function and the spectra of unresolved blazars.
Deployment of a Web-based Control Laboratory Using HTML5
Authors: Lei Zhongcheng , Hu Wenshan , Zhou Hong
Published: July 2016

With the recent achievements in Internet and communication technology and its utilization in online laboratory, remote learning and online laboratory are made possible in the last few decades. This not only provides learning opportunities for people living in rural areas of developing countries, but also offers simple alternatives for those who are already able to access educational resources. The evolution of Web technologies makes it relatively easy to facilitate laboratory deployments, thus, more and more different online laboratory platforms emerge. However, the use of Hyper Text Mark-up Language (HTML5) and related standards such as WebGL and CSS3 in experimental platform, which is future trends and provides full-featured environment, is rare so far. This paper introduces a new HTML5 version of Networked Control System Laboratory (NCSLab), which has been developing for over 10 years since 2006. The 3D version of NCSLab has been developing for almost 5 years in Wuhan University (WHU), whose rendering solution is changed from Flash 3D engine to HTML5 recently. Therefore, Flash player plug-in is eliminated to provide better user experience for users since most of the mainstream web browsers are compatible with HTML5.
EOTS: An Energy-consumption Optimization-oriented Task Scheduling Algorithm for Wireless Sensor Networks
Authors: Sun Zeyu , Li Yuanbo , Li Chuanfeng , Nie Yalin
Published: July 2016

The mismatch of task scheduling results in rapid network energy consumption during data transmission in wireless sensor networks. To address this issue, the paper proposed an Energy-consumption Optimization-oriented Task Scheduling Algorithm (EOTS algorithm) which formally described the overall power dissipation in the network system. On this basis, a network model was built up such that both the idle energy consumption in sensor nodes and energy consumption during the execution of tasks were taken into account, with which the whole task was effectively decomposed into sub-task sequences. They underwent simulated annealing and iterative refinement, with the intention of improving sensor nodes’ utilization rate, reducing local idle energy cost, as well as cutting down the overall energy consumption accordingly. The experiment result shows that under the environment of multi-task operation, from the perspective of energy cost optimization, the proposed scheduling strategy recorded an increase of 21.24% compared with the FIFO algorithm, and an increase of 16.77% in comparison to the EMRSA algorithm; while in light of network lifetimes, the EOTS algorithm surpassed the ECTA algorithm by a gain of 19.21%. Therefore, the effectiveness of the proposed EOTS algorithm is verified.