bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-K multi-particle bands and pairing reduction in 254No *
Authors: He Xiao-Tao , Zhao Shu-Yong , Zhang Zhen-Hua , Ren Zhong-Zhou 
Published: March 2020

Abstract
The multi-particle states and rotational properties of the two-particle bands in

are investigated by the cranked shell model with pairing correlations treated by the particle number conserving method. The rotational bands on top of the two-particle

and

states and the pairing reduction are studied theoretically in

for the first time. The experimental excitation energies and moments of inertia of the multi-particle states are reproduced well by the calculations. Better agreement with the data is achieved by including the high-order deformation

, which leads to enlarged

and

deformed shell gaps. An increase of

in these two-particle bands compared with the ground state band is attributed to the pairing reduction due to the Pauli blocking effect.
The kinematical and space structures of IC 2391 open cluster and moving group with Gaia-DR2
Authors: Postnikova E. S. , Elsanhoury W. H. , Sariya Devesh P. , Chupina N. V. , Vereshchagin S. V. , Jiang Ing-Guey 
Published: March 2020

Abstract
The kinematical parameters, spatial shape and structure of the open cluster IC 2391 and the associated stellar stream are studied here using Gaia Data Release 2 (GDR2) astrometry data. The apex positions are determined for the open cluster IC 2391 (data taken from Cantat-Gaudin et al.) and for the kinematical stream’s stars mentioned in Montes et al. employing both convergent point and AD-diagram methods. The values of apex coordinates are: (A, D)CP = (

6
.
h

17
±

0
.
h

004
,
−

6
.
°

88
±

0
.
°

381

; for cluster) and (

6
.
h

07
±

0
.
h

007

,

−

5
.
°

00
±

0
.
°

447

; stream), and (A
0, D
0) = (

6
.
h

12
±

0
.
h

004

,

−

3
.
°

4
±

0
.
°

3

; cluster) and (

6
.
h

21
±

0
.
h

007

,

−

11

.
°

895
±

0
.
°

290

; stream). The results are in good agreement with the previously calculated values. The positions of the stars in the disk and the spatial dispersion velocities are determined. The paths of cluster and associated stream are traced in the disk by orbit calculation back in time to their places of formation. A possible genetic relationship between the cluster and stream has been detected. The approximation of the spatial and kinematical shape of the stream and the cluster is made. According to this study, even though currently the cluster and stream seem to have a spatial difference in their locations, they appear to have formed in the same region of the Galactic disk.
The physical properties of galaxies with unusually high gas-phase metallicity
Authors: Chen Yong-Yun , Gu Qiu-Sheng , Ge Xue 
Published: March 2020

Abstract
We use 1221 galaxies with unusually high gas-phase metallicity to study their physical properties. The scope of redshift is 0.02 < z < 0.25 for these galaxies with unusually high gas-phase metallicity. Our goal is to understand the physical origins of the high gas-phase metallicity. To address this study, we select a control sample matching similar redshift and stellar mass. Our main results are as follows. (i) Compared with the control sample, the high-metallicity sample shows lower ionization parameter, higher electron density and more dust content. (ii) We also find that the high-metallicity sample has older stellar age and higher [Mgb/<Fe>] ratio, which indicates that the high-metallicity sample has shorter timescale of star formation. (iii) According to the plane of HδA
vs. D
n
4000, we can see that the control sample has higher HδA
and lower D
n
4000 than the high-metallicity sample, which may imply that the control sample experiences recent star formation. (iv) There is a significant difference in gas distribution between the high-metallicity and control samples. The high-metallicity sample has lower gas fraction than control sample, which indicates that galaxies have high gas-phase metallicity probably due to their low HI gas fraction. (v) There is no significant difference between the high-metallicity and control samples in environment, which may suggest that the environment has no effect on gas-phase metallicity.
The mid-infrared variability of the SDSS optical quasars
Authors: Wang Hong-Tao , Shi Yong 
Published: March 2020

Abstract
Based on the Seventh Data Release (DR7) quasar catalog from the Sloan Digital Sky Survey, we investigate the variability of optical quasars in W1, W2, W3 and W4 bands of the Wide-field Infrared Survey Explorer (WISE) and the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). Adopting the structure function (SF) method, we calculate the SF (δ t = 1 yr) which shows no obvious correlations with the bolometric luminosity, the black hole mass and the Eddington ratio. The ensemble SFs in W1 and W2 bands show that the SF slopes are steeper than those in previous studies which may be caused by different cadence and observational epoch number. We further investigate the relation of variability amplitude σm
between mid-infrared band and optical band, but no obvious correlation is found. No correlation is found between W1–W2 and g – r color. We think that the mid-infrared emission of quasars may be smoothed out by the extended dust distribution, thus leading to no obvious correlation. For the radio-loud quasar sub-sample, we further analyze the relation between the variability amplitude in the mid-infrared band and the radio luminosity at 6 cm, but no obvious correlations are found, which indicate the mid-infrared emission contributed from the synchrotron radiation of the relativistic jet is very weak.
Periodic variation and phase analysis of grouped solar flare with sunspot activity
Authors: Deng Hui , Mei Ying , Wang Feng 
Published: March 2020

Abstract
Studies on the periodic variation and the phase relationship between different solar activity indicators are useful for understanding the long-term evolution of solar activity cycles. Here we report the statistical analysis of grouped solar flare (GSF) and sunspot number (SN) during the time interval from January 1965 to March 2009. We find that, (1) the significant periodicities of both GSF and SN are related to the differential rotation periodicity, the quasi-biennial oscillation (QBO), and the eleven-year Schwabe cycle (ESC), but the specific values are not absolutely identical; (2) the ESC signal of GSF lags behind that of SN with an average of 7.8 months during the considered time interval, which implies that the systematic phase delays between GSF and SN originate from the inter-solar-cycle signal. Our results may provide evidence about the storage of magnetic energy in the corona.
Interplanetary consequences and geoeffectiveness of CME associated with major solar flare from NOAA AR 12673
Authors: Soni Shirsh Lata , Gupta Radhe Shyam , Verma Pyare Lala 
Published: March 2020

Abstract
In this reported work, we study a major X-class flare (X9.3) that arose from NOAA Active Region (AR) 12673 on 2017 September 6, from 11:53 UT to 12:10 UT in multi-wavelength views. This event also produced a fast coronal mass ejection (CME). NOAA AR 12673 emerged at S09W30 on 2017 September 6 and grew rapidly to a large AR. On 2017 September 9, the maximum area of this AR was 1060 millionth of the solar hemisphere. The group of sunspots disappeared over the west limb of the Sun (S09W83) on September 10. It was a fast emerging flux region. The group of sunspots showed magnetic configuration category alpha-beta-gamma. We identified their earliest signatures of eruption in AIA 94 Å images with initialization and successive rapid growth from low coronal heights of hot channeled structures. On the other hand, the CME associated with this flare event triggered the intense Dst at 1AU (−142nT). We have acquired observations and analyze the reported event from the Sun’s surface, corona (source AR), interplanetary space and in-situ measurement near Earth. In addition, here we analyze the complex processes of CME-CME interaction that have contributed a significant role to make the reported event so geoeffective.
The relationship between the radio core-dominance parameter and spectral index in different classes of extragalactic radio sources (III)
Authors: Pei Zhi-Yuan , Fan Jun-Hui , Bastieri Denis , Yang Jiang-He , Xiao Hu-Bing , Yang Wen-Xin 
Published: March 2020

Abstract
Active galactic nuclei (AGNs) can be divided into two major classes, namely radio-loud and radio-quiet AGNs. A small subset of the radio-loud AGNs is called blazars, which are believed to be unified with Fanaroff-Riley type I and type II (FRI&II) radio galaxies. Following our previous work, we present a latest sample of 966 sources with measured radio flux densities of the core and extended components. The sample includes 83 BL Lacs, 473 flat spectrum radio quasars, 101 Seyferts, 245 galaxies, 52 FRIs&IIs and 12 unidentified sources. We then calculate the radio core-dominance parameters and spectral indices and study their relationship. Our analysis shows that the core-dominance parameters and spectral indices are quite different for different types of sources. We also confirm that the correlation between core-dominance parameter and radio spectral index extends over all the sources in a large sample presented.
A quark nova in the wake of a core-collapse supernova: a unifying model for long duration gamma-ray bursts and fast radio bursts
Authors: Ouyed Rachid , Leahy Denis , Koning Nico 
Published: March 2020

Abstract
By appealing to a quark nova (QN; the explosive transition of a neutron star to a quark star) in the wake of a core-collapse supernova (CCSN) explosion of a massive star, we develop a unified model for long duration gamma-ray bursts (LGRBs) and fast radio bursts (FRBs). The time delay (years to decades) between the SN and the QN, and the fragmented nature (i.e., millions of chunks) of the relativistic QN ejecta are key to yielding a robust LGRB engine. In our model, an LGRB light curve exhibits the interaction of the fragmented QN ejecta with turbulent (i.e., filamentary and magnetically saturated) SN ejecta which is shaped by its interaction with an underlying pulsar wind nebula (PWN). The afterglow is due to the interaction of the QN chunks, exiting the SN ejecta, with the surrounding medium. Our model can fit BAT/XRT prompt and afterglow light curves simultaneously with their spectra, thus yielding the observed properties of LGRBs (e.g., the Band function and the X-ray flares). We find that the peak luminositypeak photon energy relationship (i.e., the Yonetoku law), and the isotropic energy-peak photon energy relationship (i.e., the Amati law) are not fundamental but phenomenological. FRB-like emission in our model results from coherent synchrotron emission (CSE) when the QN chunks interact with non-turbulent weakly magnetized PWN-SN ejecta, where conditions are prone to the Weibel instability. Magnetic field amplification induced by the Weibel instability in the shocked chunk frame sets the bunching length for electrons and pairs to radiate coherently. The resulting emission frequency, luminosity and duration in our model are consistent with FRB data. We find a natural unification of high-energy burst phenomena from FRBs (i.e., those connected to CCSNe) to LGRBs including X-ray flashes (XRFs) and X-ray rich GRBs (XRR-GRBs) as well as superluminous SNe (SLSNe). We find a possible connection between ultra-high energy cosmic rays and FRBs and propose that a QN following a binary neutron star merger can yield a short duration GRB (SGRB) with fits to BAT/XRT light curves.
Quantifying the role of internal variability in the temperature we expect to observe in the coming decades
Authors: Maher Nicola , Lehner Flavio , Marotzke Jochem 
Published: March 2020

Abstract
On short (15-year) to mid-term (30-year) time-scales how the Earth’s surface temperature evolves can be dominated by internal variability as demonstrated by the global-warming pause or ‘hiatus’. In this study, we use six single model initial-condition large ensembles (SMILEs) and the Coupled Model Intercomparison Project 5 (CMIP5) to visualise the role of internal variability in controlling possible observable surface temperature trends in the short-term and mid-term projections from 2019 onwards. We confirm that in the short-term, surface temperature trend projections are dominated by internal variability, with little influence of structural model differences or warming pathway. Additionally we demonstrate that this result is independent of the model-dependent estimate of the magnitude of internal variability. Indeed, and perhaps counter intuitively, in all models a lack of warming, or even a cooling trend could be observed at all individual points on the globe, even under the largest greenhouse gas emissions. The near-equivalence of all six SMILEs and CMIP5 demonstrates the robustness of this result to the choice of models used. On the mid-term time-scale, we confirm that structural model differences and scenario uncertainties play a larger role in controlling surface temperature trend projections than they did on the shorter time-scale. In addition we show that whether internal variability still dominates, or whether model uncertainties and internal variability are a similar magnitude, depends on the estimate of internal variability, which differs between the SMILEs. Finally we show that even out to thirty years large parts of the globe (or most of the globe in MPI-GE and CMIP5) could still experience no-warming due to internal variability.
Escalating global exposure to compound heat-humidity extremes with warming
Authors: Li Dawei , Yuan Jiacan , Kopp Robert E 
Published: March 2020

Abstract
Heat stress harms human health, agriculture, the economy, and the environment more broadly. Exposure to heat stress is increasing with rising global temperatures. While most studies assessing future heat stress have focused on surface air temperature, compound extremes of heat and humidity are key drivers of heat stress. Here, we use atmospheric reanalysis data and a large initial-condition ensemble of global climate model simulations to evaluate future changes in daily compound heat-humidity extremes as a function of increasing global-mean surface air temperature (GSAT). The changing frequency of heat-humidity extremes, measured using wet bulb globe temperature (WBGT), is strongly related to GSAT and, conditional upon GSAT, nearly independent of forcing pathway. The historical ∼1°C of GSAT increase above preindustrial levels has already increased the population annually exposed to at least one day with WBGT exceeding 33°C (the reference safety value for humans at rest per the ISO-7243 standard) from 97 million to 275 million. Maintaining the current population distribution, this exposure is projected to increase to 508 million with 1.5°C of warming, 789 million with 2.0°C of warming, and 1.22 billion with 3.0°C of warming (similar to late-century warming projected based on current mitigation policies).
Extreme dry and wet spells face changes in their duration and timing
Authors: Breinl Korbinian , Di Baldassarre Giuliano , Mazzoleni Maurizio , Lun David , Vico Giulia 
Published: March 2020

AbstractDry spells are sequences of days without precipitation. They can have negative implications for societies, including water security and agriculture. For example, changes in their duration and within-year timing can pose a threat to food production and wildfire risk. Conversely, wet spells are sequences of days with precipitation above a certain threshold, and changes in their duration and within-year timing can impact agriculture, flooding or the prevalence of water-related vector-borne diseases. Here we assess changes in the duration and within-year timing of extreme dry and wet spells over 60 years (1958–2017) using a consistent global land surface precipitation dataset of 5093 rain gauge locations. The dataset allowed for detailed spatial analyses of the United States, Europe and Australia. While many locations exhibit statistically significant changes in the duration of extreme dry and wet spells, the changes in the within-year timing are less often significant. Our results show consistencies with observations and projections from state-of-the-art climate and water resources research. In addition, we provide new insights regarding trends in the timing of extreme dry and wet spells, an aspect being equally important for possible future implications of extremes in a changing climate, which has not yet received the same level of attention and is characterized by larger uncertainty.
Enlargement of oil droplets by using asymmetric structure of polyvinylidene fluoride membranes
Authors: Chiam C K , Azierah R , Rosalam S 
Published: March 2020

Abstract
This paper presents a study for enlarging the oil droplets by using the polyvinylidene fluoride (PVDF) membranes in a cross-flow membrane filtration system at the transmembrane pressures range between 0 and 4 bars. The PVDF membranes are fabricated by using phase inversion technique with different concentrations of coagulant ethanol (0 – 30 v/v%). Alkaline-surfactant-polymer (ASP) produced water is synthesised and tested as the feed solution with the oil droplets sized between 0.1 and 0.2 μm. Results show that the effect of the membrane formulations on the oil droplet coalescence is lesser as compared to the effect of the transmembrane pressures. More than 65% of the coalesced oil droplets in permeate having the diameters exceeding 1.0 μm although at least 50% of the membrane pores are larger than the oil droplets in the feed solutions. It is suggested that the tortuous structure of the membranes coalesced the oil droplets significantly.
PI/NCC- based carbon molecular sieve membranes for Hydrogen purification: Effect of aging times
Authors: Sazali N , Salleh W N W , Siregar J P , Othman M H D , Jaafar J , Gunawan T. 
Published: March 2020

Abstract
In this study, the effect of stabilization temperature on the performance of tubular carbon Upgrade the gas separation performance of the resultant carbon molecular sieve (CMS) membrane, a synthesized nanocrystalline cellulose (NCC) utilizing tissue paper as an added substance was included into the simpleton arrangement at pyrolysis temperatures of 800°C. This paper shows the inference of CMSs from BTDA-TDI/MDI polyimide (PI) arranged by means of a dip-coating strategy on an inorganic cylindrical help surface, trailed by a heat treatment (adjustment and carbonization) under Ar gas stream. Extraordinary consideration was given to the physicochemical attributes of the subsequent PI/NCC-based CMS and its comparing gas permeation properties. Pure gas permeation tests were performed utilizing H2, and N2 at room temperature. The gas permeation information showed that the CMS displayed an amazing performance contrasted with the polymeric membrane. Upgrade in the two gas permeance and selectivity were watched arranged with fresh CMS membrane, with H2N2 selectivity of 434.68±1.39, regarding the neat CMS. By controlling different aging times (fresh, 1 day, multi week, and 3 months), CMSs with various structures and properties were gotten.
CO2 utilization for combined gasification and sorption enhanced water-gas shift for syngas production of biochar
Authors: Chimpae Supanida , Wongsakulphasatch Suwimol , Vivanpatarakij Supawat , Glinrun Thongchai , Wiwatwongwana Fasai , Assabumrungrat Suttichai 
Published: March 2020

Abstract
Searching for alternative renewable energy to serve high demand of energy consumption has been of interest for decades. However, the production of energy comes with an emission of large amount of CO2, the main cause of global warming problem. As a consequence, improvement of energy production process in terms of increasing high efficiency and reducing CO2 emission are required [1]. This research verified the combined systems: biochar gasification and sorption-enhanced water gas shift reaction for the production of synthesis gas. The effect of calcium precursor on CaO-based sorbents, type of metal on multifunctional materials, and amount of co-feed CO2 as gasifying agent on process performances were focused on this work. Fixed-bed reactors were used for both gasification and sorption-enhanced water-gas shift experiments. Performances of the system were analyzed in terms of %biochar conversion, H2/CO ratio, and CO2 emission. The temperature used in the gasification process was fixed at 900°C and sorption-enhanced water-gas shift was 600°C at 1 atm. The results showed the sorbent CaO/Caj2Alj4O33 derived from calcium nitrate displayed the best performance for CO2 capture, whose CO2 capture capacity is 0.34 gCO2/g sorbent at 30%CO2v/v at 600°C. For the combined gasification and sorption-enhanced water-gas shift reaction, 98% biochar conversion can be obtained. Ni/CaO-Caj2Ali4O33 offered higher H2/CO ratio and CO2 emission when compared to Cu/CaO-Ca12Al14O33 at fixed feed molar ratio of H2O:CO2:O2:C = 0.5:0.5:0.125:1. The utilization of CO2 as gasifying agent at feed molar ratio of H2O:CO2:O2:C = 0.5:0.1:0.125:1 demonstrated the reduction of CO2 emission with the production of H2/CO ratio = 0.23.
PI/NCC Carbon Membrane: Effect of Heating Rates Towards Oxygen Separation Performance
Authors: Sazali N , Mamat R , Salleh W N W , Ismail A F , Aziz F , Mahyon N I 
Published: March 2020

Abstract
Separation of oxygen and nitrogen gas was considered by utilizing tubular carbon membrane (TCMs) arranged from polymeric precursors. A coating methodology called dip coating strategy was utilized to manufacture the TCMs utilizing P84 co-polyimide and Nanocrystalline cellulose (NCC) as the primary precursor and added additives individually. Past examination has demonstrated that properties of PI/NCC can be adjusted by changing the carbonization parameter i.e. time, temperature and condition. The statement of PI/NCC on the tubular supported help was utilized to deliver an assortment of TCMs for gas separation by basic carbonization process. In this examination, the heating rates was controlled to watch the impact of TCMs on gas permeation by setting the heat rates at 1, 3, 5, and 7 °C/min. It was demonstrating that the gas separation performance was profoundly influenced by the carbonization heating rates amid the manufacture of PI/NCC-based carbon membrane. Likewise, heat rates at (3 °C/min) demonstrates an enhancement in the membrane selectivity and separation performance.
Organic acid pretreatment of oil palm trunk biomass for fermentable xylose production
Authors: Bukhari N A , Jahim J M , Loh S K , Harun S , Nasrin A B 
Published: March 2020

AbstractGreen alternatives to chemical pretreatment in hydrolysing hemicellulose for efficient biorefineries are very much sought-after. In this study, we aimed to determine the effectiveness of several organic acids in hydrolysing hemicellulose of oil palm trunk biomass (OPTB) to form fermentable xylose. Various organic acids (citric acid, formic acid and oxalic acid) of different concentration (0.5-5.0%) were assessed to find a suitable catalyst in hydrolysing OPTB for reaction time (15-120 min) at a fixed temperature (120°C), aiming for high xylose selectivity. Of these, oxalic acid was shown the most effective in solubilizing hemicellulose from OPTB, producing a maximum xylose yield of ∼70% at the optimum catalyst concentration of 5.0% (w/v) for 120 min. The main components in the hemicellulosic hydrolysate were xylose, 16.26±0.30 g/L; glucose, 2.11±0.04 g/L; arabinose, 0.19±0.05 g/L; acetic acid, 5.59±0.07 g/L and trace amount of furfural and hydroxylmethylfurfural (HMF). The resulting xylose recovery was comparable to the conventional pretreatment using dilute sulphuric acid, thus provides an alternative approach of biomass pretreatment for process improvement. The fermentability of xylose from the hemicellulosic hydrolysate was further evaluated for succinic acid production.