bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of a Low Cost Ceramic Filter for Recycling Sand Filter Backwash Water
Authors: Shafiquzzaman Md , Al-Mahmud Abdullah , AlSaleem Saleem , Haider Husnain
Published: February 2018

The aim of this study is to examine the application of a low cost ceramic filter for the treatment of sand filter backwash water (SFBW). The treatment process is comprised of pre-coagulation of SFBW with aluminum sulfate (Alum) followed by continuous filtration usinga low cost ceramic filter at different trans-membrane pressures (TMPs). Jar test results showed that 20 mg/L of alum is the optimum dose for maximum removal of turbidity, Fe, and Mn from SFBW. The filter can be operated at a TMP between 0.6 and 3 kPa as well as a corresponding flux of 480–2000 L/m2/d without any flux declination. Significant removal, up to 99%, was observed forturbidity, iron (Fe), and manganese (Mn). The flux started to decline at 4.5 kPa TMP (corresponding flux 3280 L/m2/d), thus indicated fouling of the filter. The complete pore blocking model was found as the most appropriate model to explain the insight mechanism of flux decline. The optimum operating pressure and the permeate flux were found to be 3 kPa and 2000 L/m2/d, respectively. Treated SFBW by a low cost ceramic filter was found to be suitable to recycle back to the water treatment plant. The ceramic filtration process would be a low cost and efficient option to recycle the SFBW.
Facile synthesis of ZnFe2O4 photocatalysts for decolourization of organic dyes under solar irradiation
Authors: Behera Arjun , Kandi Debasmita , Majhi Sanjit Manohar , Martha Satyabadi , Parida Kulamani
Published: February 2018

ZnFe2O4 was fabricated by a simple solution-combustion method. The structural, optical and electronic properties are investigated by XRD, TEM, FESEM, UV–vis DRS, PL, FTIR and photocurrent measurements. The photocatalytic activity of the prepared material is studied with regard to the degradation of rhodamine B (Rh B) and Congo red under solar irradiation. The kinetic study showed that the material exhibits zeroth and first order reaction kinetics for the degradation of Rh B and Congo red, respectively. The photocatalytic behaviour of ZnFe2O4 was systematically studied as a function of the activation temperature. ZnFe2O4 prepared at 500 °C showed the highest activity in degrading Rh B and Congo red. The highest activity of ZnFe2O4-500 °C correlates well with the lowest PL intensity, highest photocurrent and lowest particle size.
Two Transient X-Ray Quasi-periodic Oscillations Separated by an Intermediate State in 1H 0707-495
Authors: Zhang Peng-fei , Zhang Peng , Liao Neng-hui , Yan Jing-zhi , Fan Yi-zhong , Liu Qing-zhong
Published: February 2018

In the narrow-line Seyfert 1 galaxy 1H 0707-495, recently a transient quasi-periodic oscillation (QPO) signal with a frequency of

Hz has been detected at a high statistical significance. Here, we reanalyze the same set of XMM-Newton data observed on 2008 February 4 with the weighted-wavelet Z-transform method. In addition to confirming the previous findings, we also find another QPO signal with a frequency of 

Hz in a separated X-ray emission phase at the significance level of

. The signal is also found fitting an autoregressive model though at a lower significance. The frequency ratio between these two signals is

. The analysis of other XMM-Newton measurements of 1H 0707-495 also reveals the presence of the

Hz (

Hz) QPO signal on 2007 May 14 (2010 September 17) at the significance level of

(

). The QPO frequency found in this work follows the

relation reported in previous works spanning from stellar mass to supermassive black holes. This is the first observation of two separated transient X-ray QPO signals in active galactic nuclei, which sheds a new light on the physics of accreting supermassive black holes.
GPI Spectroscopy of the Mass, Age, and Metallicity Benchmark Brown Dwarf HD 4747 B
Authors: Crepp Justin R. , Principe David A. , Wolff Schuyler , Godfrey Paige A. Giorla , Rice Emily L. , Cieza Lucas , Pueyo Laurent , Bechter Eric B. , Gonzales Erica J.
Published: February 2018

The physical properties of brown dwarf companions found to orbit nearby, solar-type stars can be benchmarked against independent measures of their mass, age, chemical composition, and other parameters, offering insights into the evolution of substellar objects. The TRENDS high-contrast imaging survey has recently discovered a (mass/age/metallicity) benchmark brown dwarf orbiting the nearby (d = 18.69 ± 0.19 pc), G8V/K0V star HD 4747. We have acquired follow-up spectroscopic measurements of HD 4747 B using the Gemini Planet Imager to study its spectral type, effective temperature, surface gravity, and cloud properties. Observations obtained in the H-band and K
1-band recover the companion and reveal that it is near the L/T transition (T1 ± 2). Fitting atmospheric models to the companion spectrum, we find strong evidence for the presence of clouds. However, spectral models cannot satisfactorily fit the complete data set: while the shape of the spectrum can be well-matched in individual filters, a joint fit across the full passband results in discrepancies that are a consequence of the inherent color of the brown dwarf. We also find a 2σ tension in the companion mass, age, and surface gravity when comparing to evolutionary models. These results highlight the importance of using benchmark objects to study “secondary effects” such as metallicity, non-equilibrium chemistry, cloud parameters, electron conduction, non-adiabatic cooling, and other subtleties affecting emergent spectra. As a new L/T transition benchmark, HD 4747 B warrants further investigation into the modeling of cloud physics using higher resolution spectroscopy across a broader range of wavelengths, polarimetric observations, and continued Doppler radial velocity and astrometric monitoring.
Hubble Space Telescope Wide Field Camera 3 Observations of Escaping Lyman Continuum Radiation from Galaxies and Weak AGN at Redshifts z ∼ 2.3–4.1
Authors: Smith Brent M. , Windhorst Rogier A. , Jansen Rolf A. , Cohen Seth H. , Jiang Linhua , Dijkstra Mark , Koekemoer Anton M. , Bielby Richard , Inoue Akio K. , MacKenty John W. , O’Connell Robert W. , Silk Joseph I.
Published: February 2018

We present observations of escaping Lyman Continuum (LyC) radiation from 34 massive star-forming galaxies (SFGs) and 12 weak AGN with reliably measured spectroscopic redshifts at

. We analyzed Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) mosaics of the Early Release Science (ERS) field in three UVIS filters to sample the rest-frame LyC over this redshift range. With our best current assessment of the WFC3 systematics, we provide

upper limits for the average LyC emission of galaxies at

= 2.35, 2.75, and 3.60 to ∼28.5, 28.1, and 30.7 mag in image stacks of 11–15 galaxies in the WFC3/UVIS F225W, F275W, and F336W, respectively. The LyC flux of weak AGN at

= 2.62 and 3.32 are detected at 28.3 and 27.4 mag with S/Ns of ∼2.7 and 2.5 in F275W and F336W for stacks of 7 and 3 AGN, respectively, while AGN at

= 2.37 are constrained to ≳27.9 mag at

in a stack of 2 AGN. The stacked AGN LyC light profiles are flatter than their corresponding non-ionizing UV continuum profiles out to radii of

, which may indicate a radial dependence of porosity in the ISM. With synthetic stellar SEDs fit to UV continuum measurements longward of

and IGM transmission models, we constrain the absolute LyC escape fractions to

% at

= 2.35 and ≲55% at

= 2.75 and 3.60, respectively. All available data for galaxies, including published work, suggests a more sudden increase of

with redshift at

. Dust accumulating in (massive) galaxies over cosmic time correlates with increased H i column density, which may lead to reducing

more suddenly at

. This may suggest that SFGs collectively contributed to maintaining cosmic reionization at redshifts

, while AGN likely dominated reionization at

.
Magnetic Flux Cancelation as the Trigger of Solar Coronal Jets in Coronal Holes
Authors: Panesar Navdeep K. , Sterling Alphonse C. , Moore Ronald L.
Published: February 2018

We investigate in detail the magnetic cause of minifilament eruptions that drive coronal-hole jets. We study 13 random on-disk coronal-hole jet eruptions, using high-resolution X-ray images from the Hinode/X-ray telescope(XRT), EUV images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), and magnetograms from the SDO/Helioseismic and Magnetic Imager (HMI). For all 13 events, we track the evolution of the jet-base region and find that a minifilament of cool (transition-region-temperature) plasma is present prior to each jet eruption. HMI magnetograms show that the minifilaments reside along a magnetic neutral line between majority-polarity and minority-polarity magnetic flux patches. These patches converge and cancel with each other, with an average cancelation rate of ∼0.6 × 1018 Mx hr−1 for all 13 jets. Persistent flux cancelation at the neutral line eventually destabilizes the minifilament field, which erupts outward and produces the jet spire. Thus, we find that all 13 coronal-hole-jet-driving minifilament eruptions are triggered by flux cancelation at the neutral line. These results are in agreement with our recent findings for quiet-region jets, where flux cancelation at the underlying neutral line triggers the minifilament eruption that drives each jet. Thus, from that study of quiet-Sun jets and this study of coronal-hole jets, we conclude that flux cancelation is the main candidate for triggering quiet-region and coronal-hole jets.
The Properties of Reconnection Current Sheets in GRMHD Simulations of Radiatively Inefficient Accretion Flows
Authors: Ball David , Özel Feryal , Psaltis Dimitrios , Chan Chi-Kwan , Sironi Lorenzo
Published: February 2018

Non-ideal magnetohydrodynamic (MHD) effects may play a significant role in determining the dynamics, thermal properties, and observational signatures of radiatively inefficient accretion flows onto black holes. In particular, particle acceleration during magnetic reconnection events may influence black hole spectra and flaring properties. We use representative general relativistic magnetohydrodynamic (GRMHD) simulations of black hole accretion flows to identify and explore the structures and properties of current sheets as potential sites of magnetic reconnection. In the case of standard and normal evolution (SANE) disks, we find that in the reconnection sites, the plasma beta ranges from 0.1 to 1000, the magnetization ranges from 10−4 to 1, and the guide fields are weak compared with the reconnecting fields. In magnetically arrested (MAD) disks, we find typical values for plasma beta from 10−2 to 103, magnetizations from 10−3 to 10, and typically stronger guide fields, with strengths comparable to or greater than the reconnecting fields. These are critical parameters that govern the electron energy distribution resulting from magnetic reconnection and can be used in the context of plasma simulations to provide microphysics inputs to global simulations. We also find that ample magnetic energy is available in the reconnection regions to power the fluence of bright X-ray flares observed from the black hole in the center of the Milky Way.
From Cool to Hot F-stars: The Influence of Two Ionization Regions in the Acoustic Oscillations
Authors: Brito Ana , Lopes Ilídio
Published: February 2018

The high-precision data available from the Kepler satellite allows us to study the complex outer convective envelopes of solar-type stars. We use a seismic diagnostic, specialized for investigating the outer layers of solar-type stars, to infer the impact of the ionization processes on the oscillation spectrum, for a sample of Kepler stars. These stars, of spectral type F, cover all of the observational seismic domain of the acoustic oscillation spectrum in solar-type stars. They also cover the range between a cool F-dwarf (∼6000 K) and a hotter F-star (∼6400 K). Our study reveals the existence of two relevant ionization regions. One of these regions, which is located closer to the surface of the star, is commonly associated with the second ionization of helium, although other chemical species also contribute to ionization. The second region, located deeper in the envelope, is linked with the ionization of heavy elements. Specifically, in this study, we analyze the elements carbon, nitrogen, oxygen, neon, and iron. Both regions can be related to the K electronic shell. We show that, while for cooler stars like the Sun, the influence of this second region on the oscillation frequencies is small; in hotter stars, its influence becomes comparable to the influence of the region of the second ionization of helium. This can guide us in the study of the outer layers of F-stars, specifically with the understanding of phenomena related to rotation and magnetic activity in these stars.
An Empirical Correlation of Tmax–MWD of Dwarf Novae and the Average White Dwarf Mass in Cataclysmic Variables in the Galactic Bulge
Authors: Yu Zhuo-li , Xu Xiao-jie , Li Xiang-Dong , Bao Tong , Li Ying-xi , Xing Yu-chen , Shen Yu-fu
Published: February 2018

The mean white dwarf (WD) mass in the Galactic bulge cataclysmic variables (CVs) was measured by applying the shock temperature-WD mass correlation of magnetic cataclysmic variables (mCVs) to the Galactic bulge X-ray emission (GBXE) spectra. However, the resulting mean WD mass is lower than that of the local CVs. This discrepancy could be explained by the dominating sources in the GBXE, which are non-mCVs instead of mCVs. In this work, we conduct a thorough investigation of the X-ray spectra of local DNe from the Suzaku archives and derive semi-empirical correlations between the shock temperature T
max, the flux ratio of Fe xxvi–Lyα to Fe xxv–Heα lines, and WD mass for quiescent, nonmagnetic CVs. By applying these correlations to the GBXE, we derive the average WD mass of CVs in the Galactic bulge to be 0.81 ± 0.07M
⊙. This value is consistent with previous optical measurements of WD mass in local CVs.
PHIBSS: Unified Scaling Relations of Gas Depletion Time and Molecular Gas Fractions*
Authors: Tacconi L. J. , Genzel R. , Saintonge A. , Combes F. , García-Burillo S. , Neri R. , Bolatto A. , Contini T. , Schreiber N. M. Förster , Lilly S. , Lutz D. , Wuyts S. , Accurso G. , Boissier J. , Boone F. , Bouché N. , Bournaud F. , Burkert A. , Carollo M. , Cooper M. , Cox P. , Feruglio C. , Freundlich J. , Herrera-Camus R. , Juneau S. , Lippa M. , Naab T. , Renzini A. , Salome P. , Sternberg A. , Tadaki K. , Übler H. , Walter F. , Weiner B. , Weiss A.
Published: February 2018

This paper provides an update of our previous scaling relations between galaxy-integrated molecular gas masses, stellar masses, and star formation rates (SFRs), in the framework of the star formation main sequence (MS), with the main goal of testing for possible systematic effects. For this purpose our new study combines three independent methods of determining molecular gas masses from CO line fluxes, far-infrared dust spectral energy distributions, and ∼1 mm dust photometry, in a large sample of 1444 star-forming galaxies between z = 0 and 4. The sample covers the stellar mass range log(M
*/M
⊙) = 9.0–11.8, and SFRs relative to that on the MS, δMS = SFR/SFR(MS), from 10−1.3 to 102.2. Our most important finding is that all data sets, despite the different techniques and analysis methods used, follow the same scaling trends, once method-to-method zero-point offsets are minimized and uncertainties are properly taken into account. The molecular gas depletion time t
depl, defined as the ratio of molecular gas mass to SFR, scales as (1 + z)−0.6 × (δMS)−0.44 and is only weakly dependent on stellar mass. The ratio of molecular to stellar mass μ
gas depends on (

1
+
z

)

2.5

×

(
δ
MS
)

0.52

×

(

M

*

)

−
0.36

, which tracks the evolution of the specific SFR. The redshift dependence of μ
gas requires a curvature term, as may the mass dependences of t
depl and μ
gas. We find no or only weak correlations of t
depl and μ
gas with optical size R or surface density once one removes the above scalings, but we caution that optical sizes may not be appropriate for the high gas and dust columns at high z.
The Coronal Monsoon: Thermal Nonequilibrium Revealed by Periodic Coronal Rain
Authors: Auchère Frédéric , Froment Clara , Soubrié Elie , Antolin Patrick , Oliver Ramon , Pelouze Gabriel
Published: February 2018

We report on the discovery of periodic coronal rain in an off-limb sequence of Solar Dynamics Observatory/Atmospheric Imaging Assembly images. The showers are co-spatial and in phase with periodic (6.6 hr) intensity pulsations of coronal loops of the sort described by Auchère et al. and Froment et al. These new observations make possible a unified description of both phenomena. Coronal rain and periodic intensity pulsations of loops are two manifestations of the same physical process: evaporation/condensation cycles resulting from a state of thermal nonequilibrium. The fluctuations around coronal temperatures produce the intensity pulsations of loops, and rain falls along their legs if thermal runaway cools the periodic condensations down and below transition-region temperatures. This scenario is in line with the predictions of numerical models of quasi-steadily and footpoint heated loops. The presence of coronal rain—albeit non-periodic—in several other structures within the studied field of view implies that this type of heating is at play on a large scale.
Numerical Simulations of Multiphase Winds and Fountains from Star-forming Galactic Disks. I. Solar Neighborhood TIGRESS Model
Authors: Kim Chang-Goo , Ostriker Eve C.
Published: February 2018

Gas blown away from galactic disks by supernova (SN) feedback plays a key role in galaxy evolution. We investigate outflows utilizing the solar neighborhood model of our high-resolution, local galactic disk simulation suite, TIGRESS. In our numerical implementation, star formation and SN feedback are self-consistently treated and well resolved in the multiphase, turbulent, magnetized interstellar medium. Bursts of star formation produce spatially and temporally correlated SNe that drive strong outflows, consisting of hot (

) winds and warm (

) fountains. The hot gas at distance

from the midplane has mass and energy fluxes nearly constant with d. The hot flow escapes our local Cartesian box barely affected by gravity, and is expected to accelerate up to terminal velocity of

. The mean mass and energy loading factors of the hot wind are 0.1 and 0.02, respectively. For warm gas, the mean outward mass flux through

is comparable to the mean star formation rate, but only a small fraction of this gas is at velocity

. Thus, the warm outflows eventually fall back as inflows. The warm fountain flows are created by expanding hot superbubbles at

at larger d neither ram pressure acceleration nor cooling transfers significant momentum or energy flux from the hot wind to the warm outflow. The velocity distribution at launching near

is a better representation of warm outflows than a single mass loading factor, potentially enabling development of subgrid models for warm galactic winds in arbitrary large-scale galactic potentials.
Distributed Star Formation throughout the Galactic Center Cloud Sgr B2
Authors: Ginsburg Adam , Bally John , Barnes Ashley , Bastian Nate , Battersby Cara , Beuther Henrik , Brogan Crystal , Contreras Yanett , Corby Joanna , Darling Jeremy , De Pree Chris , Galván-Madrid Roberto , Garay Guido , Henshaw Jonathan , Hunter Todd , Kruijssen J. M. Diederik , Longmore Steven , Lu Xing , Meng Fanyi , Mills Elisabeth A. C. , Ott Juergen , Pineda Jaime E. , Sánchez-Monge Álvaro , Schilke Peter , Schmiedeke Anika , Walker Daniel , Wilner David
Published: February 2018

We report ALMA observations with resolution ≈0.″5 at 3 mm of the extended Sgr B2 cloud in the Central Molecular Zone (CMZ). We detect 271 compact sources, most of which are smaller than 5000 au. By ruling out alternative possibilities, we conclude that these sources consist of a mix of hypercompact H ii regions and young stellar objects (YSOs). Most of the newly detected sources are YSOs with gas envelopes that, based on their luminosities, must contain objects with stellar masses

M

*

≳
8

M

⊙

. Their spatial distribution spread over a ∼12 × 3 pc region demonstrates that Sgr B2 is experiencing an extended star formation event, not just an isolated “starburst” within the protocluster regions. Using this new sample, we examine star formation thresholds and surface density relations in Sgr B2. While all of the YSOs reside in regions of high column density (

N
(

H

2

)
≳
2
×

10

23

cm

−
2

), not all regions of high column density contain YSOs. The observed column density threshold for star formation is substantially higher than that in solar vicinity clouds, implying either that high-mass star formation requires a higher column density or that any star formation threshold in the CMZ must be higher than in nearby clouds. The relation between the surface density of gas and stars is incompatible with extrapolations from local clouds, and instead stellar densities in Sgr B2 follow a linear

Σ

*

–

Σ

gas

relation, shallower than that observed in local clouds. Together, these points suggest that a higher volume density threshold is required to explain star formation in CMZ clouds.
Discovery of Strong Balmer Line Absorption in Two Luminous LoBAL Quasars at z ∼ 1.5
Authors: Schulze Andreas , Misawa Toru , Zuo Wenwen , Wu Xue-Bing
Published: February 2018

We present the discovery of strong Balmer line absorption in Hα to Hγ in two luminous low-ionization broad absorption line quasars at

, with black hole masses around

from near-IR spectroscopy. There are only two previously known quasars at

showing Balmer line absorption. SDSS J1019+0225 shows blueshifted absorption by ∼1400 km s−1 with an Hα rest-frame equivalent width of 13 Å. In SDSS J0859+4239, we find redshifted absorption by ∼500 km s−1 with an Hα rest-frame equivalent width of 7 Å. The redshifted absorption could indicate an inflow of high-density gas onto the black hole, though we cannot rule out alternative interpretations. The Balmer line absorption in both objects appears to be saturated, indicating partial coverage of the background source by the absorber. We estimate the covering fractions and optical depth of the absorber and derive neutral hydrogen column densities, N
H i
∼ 1.3 × 1018 cm−2 for SDSS J1019+0225 and N
H i
∼ 9 × 1017 cm−2 for SDSS J0859+4239. In addition, the optical spectra reveal also absorption troughs in He i*

and

in both objects.
A Green Bank Telescope Survey of Large Galactic H ii Regions
Authors: Anderson L. D. , Armentrout W. P. , Luisi Matteo , Bania T. M. , Balser Dana S. , Wenger Trey V.
Published: February 2018

As part of our ongoing H ii Region Discovery Survey (HRDS), we report the Green Bank Telescope detection of 148 new angularly large Galactic H ii regions in radio recombination line (RRL) emission. Our targets are located at a declination of

, which corresponds to

at

. All sources were selected from the Wide-field Infrared Survey Explorer Catalog of Galactic H ii Regions, and have infrared angular diameters

. The Galactic distribution of these “large” H ii regions is similar to that of the previously known sample of Galactic H ii regions. The large H ii region RRL line width and peak line intensity distributions are skewed toward lower values, compared with that of previous HRDS surveys. We discover seven sources with extremely narrow RRLs

. If half the line width is due to turbulence, these seven sources have thermal plasma temperatures

. These temperatures are lower than any measured for Galactic H ii regions, and the narrow-line components may arise instead from partially ionized zones in the H ii region photodissociation regions. We discover G039.515+00.511, one of the most luminous H ii regions in the Galaxy. We also detect the RRL emission from three H ii regions with diameters

, making them some of the physically largest known H ii regions in the Galaxy. This survey completes the HRDS H ii region census in the Northern sky, where we have discovered 887 H ii regions and more than doubled the size of the previously known census of Galactic H ii regions.
Carbon Stars Identified from LAMOST DR4 Using Machine Learning
Authors: Li Yin-Bi , Luo A-Li , Du Chang-De , Zuo Fang , Wang Meng-Xin , Zhao Gang , Jiang Bi-Wei , Zhang Hua-Wei , Liu Chao , Qin Li , Wang Rui , Du Bing , Guo Yan-Xin , Wang Bo , Han Zhan-Wen , Xiang Mao-Sheng , Huang Yang , Chen Bing-Qiu , Chen Jian-Jun , Kong Xiao , Hou Wen , Song Yi-Han , Wang You-Fen , Wu Ke-Fei , Zhang Jian-Nan , Zhang Yong , Wang Yue-Fei , Cao Zi-Huang , Hou Yong-Hui , Zhao Yong-Heng
Published: February 2018

In this work, we present a catalog of 2651 carbon stars from the fourth Data Release (DR4) of the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST). Using an efficient machine-learning algorithm, we find these stars from more than 7 million spectra. As a by-product, 17 carbon-enhanced metal-poor turnoff star candidates are also reported in this paper, and they are preliminarily identified by their atmospheric parameters. Except for 176 stars that could not be given spectral types, we classify the other 2475 carbon stars into five subtypes: 864 C-H, 226 C-R, 400 C-J, 266 C-N, and 719 barium stars based on a series of spectral features. Furthermore, we divide the C-J stars into three subtypes, C-J(H), C-J(R), and C-J(N), and about 90% of them are cool N-type stars as expected from previous literature. Besides spectroscopic classification, we also match these carbon stars to multiple broadband photometries. Using ultraviolet photometry data, we find that 25 carbon stars have FUV detections and that they are likely to be in binary systems with compact white dwarf companions.
Eleven remarkable Diptera species, emerged from fallen aspens in Kivach Nature Reserve, Russian Karelia
Authors: Polevoi Alexei , Ruokolainen Anna , Shorohova Ekaterina
Published: February 2018

In 2016, saproxylic Diptera associated with aspen (Populus tremula L.) logs were studied in the Kivach Nature Reserve, Russian Karelia, using trunk emergence traps.

Eleven rare species of Diptera (families Limoniidae, Scatopsidae, Axymyiidae, Mycetophilidae, Sciaridae, Platypezidae, Syrphidae and Clusiidae) with poorly known distribution and ecology were recorded. For each species, basic diagnostic characteristics were provided along with the information on microhabitats. An attempt was also undertaken to outline possible associations with wood-decaying macrofungi using nonparametric correlation.
The Language Centre: A dynamic space to foster the development of multiple interactions?
Authors: Rivens Mompean Annick , Macré Nicola
Published: February 2018

The present context within French Universities, with language policies under construction, the evolution of technology and their effects on language learning, brings us to question the Language Centre's (LC) role in this process today. How is it being used? What activities are implemented and how does the LC support language learning?While a certain number of universities are equipping themselves with "new learning areas" including "active rooms" and "friendly spaces", why maintain these areas when students can work from home? What kind of help or guidance can be provided?We ask whether the current interactions at the LC correspond to students' needs, and do in fact provide the necessary social, psychological, or linguistic support required. To do so, an analysis of students' usage of the LC was carried out. We will underline the fact that the question is not so much to oppose a physical to a virtual LC but rather, referring to a systemic approach, to underline the type of support the LC can offer, developing interactions with resources whether they be material and digital or human, by offering tutoring and guidance.
Fight against discrimination or promotion of diversity in employment? A public policy in the Brussels-Capital Region (1997-2012)
Authors: Tandé Alexandre
Published: February 2018

At the end of the 1990s, the Brussels-Capital Region launched actions to fight against employment discrimination with respect to people of foreign origin. In a social and historical perspective, using oral and documentary sources, this article presents the context in which this public policy emerged, the experimental actions in the first years, and its transformation in the mid 2000s. At the same time that it was consolidated (inclusion of new measures in the regional law, establishment of a Brussels unit of consultants in the area of diversity), this policy was also given a new objective: the promotion of diversity. While the fight against discrimination and the promotion of diversity are often presented as the "two sides of the same coin", these two objectives may also diverge or oppose each other. A review of the history of this Brussels policy, its evolution and impact, therefore allows the current responses to two major challenges for the urban area to be questioned: the inequality of access to employment and the recognition of sociocultural diversity.
Use of Ant Colony Optimization (ACO) for Post-Deployment Replanning of UMTS Networks
Authors: Sadhukhan Samir K , Bose Chayanika , Saha Debashis
Published: February 2018

Inherent dynamism in user movement demands for post-deployment tuning of UMTS networks to minimize the total cost of ownership (TCO). Conventionally, UMTS operators so far have considered many-to-one mapping of RNCs to MSCs. However, such single-homed networks do not remain cost-effective over the passage of time, typically when subscribers later on begin to show specific mobility patterns such as diurnal movement. This necessitates topological extension of the network in terms of dual-homing of some selected RNCs to two MSCs simultaneously via direct fibre links, resulting in a many-to-two mapping in parts of the network. The aim of such selective dual-homing is to reduce handoff cost maximally at the expense of minimal increase in link cost, thereby reducing the TCO optimally. In this article, the authors have formulated the scenario as an integer linear programming problem, converted it into a state space search and then solved it using Ant Colony Optimization (ACO) technique. Compared to Simulated Annealing (SA) and Tabu Search (TS), ACO exhibits 10% to 15% improvement in solution quality.
Plant-Derived Compounds and Their Potential Role in Drug Development
Authors: Kaloudas Dimitrios , Penchovsky Robert
Published: February 2018

This article describes how with the development of biotechnology, plants have gained again a prominent place as a relatively inexpensive source for the creation of recombinant pharmaceuticals. Plant-derived compounds have started playing a major role in the pharmaceutical industry with many plant-based products to have found their way in drugs and chemicals used for the treatment of different diseases and their symptoms. Plant-derived compounds have been tested for the treatment of several types of cancer, Central Nervous System disorders, as enhancers during chemotherapy and as vessels for targeted drug delivery. Genetically modified plant cells have been recruited for the production of therapeutic agencies as well as in the creation of expression systems for virus-like particles that could be used as vaccines. Moreover, microRNAs mimicking the plant ones have the ability to inhibit tumors in mammalian cells. This review describes plant-derived compounds and their properties as potential therapeutic agents and precursors for the development of novel drugs in the pharmaceutical industry.
Computing Competences and Digital Competences
Authors: De Vito Leila
Published: February 2018

This article discusses the results of the authors' introductory study on the comparison of computing competences and digital competences. The start of this article describes from the presentation of the discipline structure of Computer Science as proposed by Computing organizations and reports the experience one of the authors made, while working in the international committee of the Beaver competition, for the questionnaires on the assessment of computing competences. Soon after the structure of the DIGCOMP 2.0 is reported as a framework for digital competence analysis and the experience the same author made while working at developing a questionnaire for digital competence assessment. Finally, the structure of study is reported, the instrument for the carrying out of the survey the authors decided to use is presented and the analysis of the collected data.
Incubator of Projectuality
Authors: Giovannella Carlo
Published: February 2018

This article describes the recent introduction of a massive alternance scheme in the Italian schools by means of the so called “Buona scuola” (good school) law. In this article, the authors report on a) the outcomes of a survey carried out on a large sample of high school students attending schools located in the South-East area of Rome; b) a comparison of such outcomes with those contained in a recent report released by Unindustria, the entrepreneurs' union of Lazio Region. The comparison highlights the cultural and organizational limits that affect both the school and the productive systems that have not been able to fully dampen the impact produced by the new alternance scheme. As a consequence, politicians and scholars are called to imagine alternative models and solutions that, at the same time could mitigate the skills gap, increase the students' capacity to read entrepreneurial organizations and, ultimately, contribute concretely to the economic development of the territory. In response to this pressing need, the authors propose, as ASLERD, an approach that has been designed to mitigate the criticalities emerged from their survey and Unindustria's report. The core of the strategy is based on the in-situ simulation of innovation processes and in the development of an open badge system to certificate competences/skills and roles.
Newspaper Framing of Climate Change and Sustainability Issues in India
Authors: Nirmala T , Aram I. Arul
Published: February 2018

This article describes how climate change influences nature and human life and it is the basis for social and economic development. News reporting on climate change must address the challenges in the deeper social and economic dimensions of sustainable development. The news coverage of climate change and sustainability issues helps people to better understand the concepts and perspectives of environment. This article aims to examine how dominant newspapers in Tamil Nadu have framed climate change and sustainability issues. This is done by analyzing climate change articles (N = 120) in two mainstream newspapers – The Hindu in English and the Daily Thanthi in Tamil. Climate change communication in regional newspapers and local news stories may increase the public's interest and knowledge level regarding climate change and sustainability issues.
The Awareness and Impact of Carbon Capture and Storage (CCS) on Climate Change in Malaysia
Authors: Ghazali Zulkipli , Zahid Muhammad
Published: February 2018

This article aims to investigate the level of public awareness and perception regarding carbon capture and storage (CCS) and climate change in Malaysia. The article also aims to identify those social, economic and environmental issues which affect CCS and combating climate change in the country. The findings revealed that more than 79 percent of the respondents were willing to have government initiatives to implement CCS projects. However, about 21 percent were against these initiatives due to their different perceptions and opinions regarding CCS. By using partial least squares (PLS) model through SmartPLS 2.0, it is found that social and economic issues of CCS have significant positive while environmental issues have no significant impact on combating climate change. The findings offer significant implications for regulators, policy makers, and practitioners regarding social, economic and environmental issues of CCS and climate change in Malaysia.
A Conceptual Model for Biomass Supply Chain Sustainability
Authors: Petridis Konstantinos , Grigoroudis Evangelos , Arabatzis Garyfallos
Published: February 2018

One of the key elements of future energy generation is the switch to non-depletable resources, widely known as renewable energy sources (RES). There are many types of RES, however, but the focus of this article is on biomass products, which mainly consists of forest production (wood) and energy crops. One of the main problems of using biomass products for renewable energy production is the fact that several constraints should be imposed for both the management of forests and land. There are different aspects of optimal management of biomass products that guarantees the sustainability of the ecological systems. In this article, an analysis of the management for forest and agricultural products from energy crops is presented, demonstrating latest trends in biomass products as primal resource for renewable energy. Finally, a conceptual model for a biomass supply chain is proposed and discussed.
Analyzing the Risks in Supply Chain Information System Implementations
Authors: Ganguly Kunal , Padhy R. K.
Published: February 2018

Organizations make considerable efforts when implementing Supply Chain Information systems (SCIS) to increase their competitiveness. This chapter attempts to identify the Risk Factors (RFs) in SCIS implementation and evaluate them. Sixteen risk factors were identified based on an extensive literature survey. A comprehensive framework is presented with three major phases to select an adequate SCIS. The risk assessment for SCIS implementation is then empirically investigated. The RFs are formulated as hierarchy structures and Fuzzy AHPs as a Multi Attribute Decision Making (MADM) tool applied to judge the viable candidates. Based on a fuzzy AHP approach, a revised risk matrix with a continuous scale is proposed to assess the RFs' classes. The result classifies the risk factors in different categories (Extreme, High, Medium and Low). The revised risk matrix with continuous scale for risk assessment in SCIS implementation is a novel approach.
A Study of User Continuance Behavioral Intentions Toward Privacy-Protection Practices
Authors: Han Ye , Ellis T. Selwyn
Published: February 2018

Prior research on privacy protective behaviors has found that online users irrationally trade protection for convenience, and so act against their own privacy preferences. The present article uses expectancy-confirmation theory (ECT) models to explain the continuance behavioral intentions of online users toward privacy-protection practices. It redefines convenience to highlight human behaviors involved in various stages of implementing privacy practices processes. The results show that earlier privacy practice experiences impact the present as well as the future protective behaviors of users, and that convenience-orientation is an important aspect of human nature that should not be inhibited by complex privacy practices. Therefore, to serve online users better, both researchers and practitioners should consider the personal perceptions of convenience of online users when constructing their privacy practices.
An annulus and a half-helicoid maximize Laplace eigenvalues
Authors: Ariturk Sinan
Published: February 2018

The Dirichlet eigenvalues of the Laplace–Beltrami operator are larger on an annulus than on any other surface of revolution in

\mathbb{R}^3

with the same boundary. This is established by defining a sequence of shrinking cylinders about the axis of symmetry and proving that flattening a surface outside of each cylinder successively increases the eigenvalues. A similar argument shows that the Dirichlet eigenvalues of the Laplace–Beltrami operator are larger on a half-helicoid than on any other screw surface in

\mathbb{R}^2 \times \mathbb{S}^1

with the same boundary.
Vrednotenje izobraževalnega potenciala geodiverzitete na primeru Cerkniškega polja
Authors: Stepišnik Uroš , Ilc Klun Mojca , Repe Blaž
Published: February 2018

Koncept geodiverzitete obstaja že več kot 20 let. Večina metod vrednotenja geodiverzitete se uporablja za ugotavljanje geokonzervatorskega ali geoturističnega potenciala. Metode, s katerimi bi lahko vrednotili izobraževalni potencial geodiverzitete, so zelo redke. Glavni cilj našega članka je podati novo metodo vrednotenja geodiverzitete za določanje izobraževalnega potenciala proučevanega območja. Metoda je uporabna za učne namene, ko učitelji načrtujejo organizacijo strokovnih ekskurzij ali terenskega dela.
Izobraževalne potrebe ponudnikov zasebnih turističnih nastanitev v Sloveniji
Authors: Balažič Gregor
Published: February 2018

V okviru projekta ROOMS to VET je bila opravljena raziskava med zasebnimi ponudniki turističnih nastanitev v Sloveniji. Z izvedenskimi intervjuji smo identificirali splošne probleme in potrebe na področju njihovega izobraževanja. Rezultati kažejo, da je najbolj problematično poznavanje zapletene zakonodaje. Ponudniki se zavedajo pomembnosti izobraževanja in izpostavljajo pomanjkanje organiziranih izobraževanj, nepovezanost turističnih ponudnikov in pomanjkljiva znanja na področju obvladovanja različnih spletnih orodij.
Oganihu Ndiigbo: through the social-existential forces of Ikeoha and Ikeotuonye
Authors: Okpalike Chika J.B.G.
Published: February 2018

‘Oganihu Ndiigbo’ is an ontological drive in being Igbo. The survival and sustenance of the race have been the pre-occupation of every Igbo generation from time immemorial. In ancient times, this drive is expressed in its microcosmic form in the various interclan clashes and boundary disputes aimed at preserving the parochial city-states which had little or no socio-political connection with each other. With the colonial arrangements, this microcosmic consciousness bloomed into a pan-Igbo drive for the social welfare of Ndiigbo. The post-war Igbo experience brought forth yet another dimension of this existential character of the Igbo which could be seen in what Eteng (2002) referred to as “selfhelp”. Many Igbo communities lived and provided social amenities and good governance for their people like there was no government. This article traces two moments of the social forces of Ikeoha and Ikeotuonye in the Igbo trajectory towards Oganihu Ndiigbo and proffers ways of harnessing them.
Are writers still “righting?”: a moral perspective to Adichie’s Americanah
Authors: Otunne Justice Ndubuisi
Published: February 2018

While some scholars in the past believed that art should be a vehicle for moral control, some writers and critics in recent times appear to be saying that literary works should only entertain. This shift is reflected in the publication of literary works with controversial moral contents and a seeming lack of moral critique of them. This study, therefore, makes a case for a moral criticism in African fictional studies through an insightful moral critique of Chimamanda Adichie’s Americanah. The critical offerings of scholars such as T.S Eliot and especially Plato were referred to and the tenets of the moral concept namely: restraint, discipline and order were extracted from them, with emphasis placed on restraint. Through a moral critique of the selected text, it is established that the novelist does not apply restraint in describing sex scenes and seems not to have adequately punished sexually immoral characters in the novel. While this could be a trend in the post-modern period, this study holds the opinion that the novel Americanah could be a negative influence on some readers.
El smartphone como barómetro en experimentos de Física
Authors: Salilnas Isabel , Giménez Marcos H. , Monsoriu Juan A. , Castro Palacio Juan Carlos
Published: February 2018

En este trabajo se presentan dos experimentos que sacan partido del sensor de presión de los teléfonos inteligentes, utilizándolo para determinar su valor en el seno de agua en equilibrio en una probeta. En un primer experimento, destinado a estudiantes de Secundaria y niveles superiores, las medidas de la presión obtenidos a diferentes profundidades permiten realizar un ajuste lineal, comprobando así la validez de la Ley de Stevin.  Además, a partir de dicha ley y de los parámetros del ajuste se puede determinar la densidad del agua. Los valores obtenidos indirectamente por este procedimiento difieren entre un 2% y un 4% del resultado de dividir entre sí la masa y el volumen de una muestra. En un segundo experimento, más enfocado a estudiantes de primeros cursos universitarios de asignaturas de Física, el teléfono móvil sumergido oscila suspendido de un muelle. Las medidas del sensor de presión permiten, mediante la Ley de Stevin, obtener la serie temporal de la presión en la correspondiente oscilación amortiguada, cuyos parámetros se determinan mediante un ajuste no lineal. La comparación de la pulsación libre obtenida a partir de estos valores difiere en un1,5% respecto del obtenido a partir de la medición directa del periodo fuera del agua.  En ambos casos, los resultados obtenidos indican la efectividad del método utilizado en contextos docentes.
Initiation of secondary ice production in clouds
Authors: Sullivan Sylvia C. , Hoose Corinna , Kiselev Alexei , Leisner Thomas , Nenes Athanasios
Published: February 2018

Abstract. Disparities between the measured concentrations of ice-nucleating particles (INPs) and in-cloud ice crystal number
concentrations (ICNCs) have led to the hypothesis that mechanisms other than primary nucleation form ice in the
atmosphere. Here, we model three of these secondary production mechanisms – rime splintering, frozen droplet shattering,
and ice–ice collisional breakup – with a six-hydrometeor-class parcel model. We perform three sets of simulations to
understand temporal evolution of ice hydrometeor number (Nice), thermodynamic limitations, and the impact of
parametric uncertainty when secondary production is active. Output is assessed in terms of the number of primarily
nucleated ice crystals that must exist before secondary production initiates (NINP(lim)) as well as
the ICNC enhancement from secondary production and the timing of a 100-fold enhancement. Nice evolution can be
understood in terms of collision-based nonlinearity and the “phasedness” of the process, i.e., whether it involves ice
hydrometeors, liquid ones, or both. Ice–ice collisional breakup is the only process for which a meaningful
NINP(lim) exists (0.002 up to 0.15 L−1). For droplet shattering and rime splintering,
a warm enough cloud base temperature and modest updraft are the more important criteria for initiation. The low values of
NINP(lim) here suggest that, under appropriate thermodynamic conditions for secondary ice
production, perturbations in cloud concentration nuclei concentrations are more influential in mixed-phase partitioning than those in INP
concentrations.