bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of multilevel ensemble-based data assimilation for reservoir history matching
Authors: Fossum Kristian , Mannseth Trond , Stordal Andreas S.
Published: December 2019

Multilevel ensemble-based data assimilation (DA) as an alternative to standard (single-level) ensemble-based DA for reservoir history matching problems is considered. Restricted computational resources currently limit the ensemble size to about 100 for field-scale cases, resulting in large sampling errors if no measures are taken to prevent it. With multilevel methods, the computational resources are spread over models with different accuracy and computational cost, enabling a substantially increased total ensemble size. Hence, reduced numerical accuracy is partially traded for increased statistical accuracy. A novel multilevel DA method, the multilevel hybrid ensemble Kalman filter (MLHEnKF) is proposed. Both the expected and the true efficiency of a previously published multilevel method, the multilevel ensemble Kalman filter (MLEnKF), and the MLHEnKF are assessed for a toy model and two reservoir models. A multilevel sequence of approximations is introduced for all models. This is achieved via spatial grid coarsening and simple upscaling for the reservoir models, and via a designed synthetic sequence for the toy model. For all models, the finest discretization level is assumed to correspond to the exact model. The results obtained show that, despite its good theoretical properties, MLEnKF does not perform well for the reservoir history matching problems considered. We also show that this is probably caused by the assumptions underlying its theoretical properties not being fulfilled for the multilevel reservoir models considered. The performance of MLHEnKF, which is designed to handle restricted computational resources well, is quite good. Furthermore, the toy model is utilized to set up a case where the assumptions underlying the theoretical properties of MLEnKF are fulfilled. On that case, MLEnKF performs very well and clearly better than MLHEnKF.
Prolonged diapause has sex-specific fertility and fitness costs
Authors: Margus Aigi , Lindström Leena
Published: December 2019

Diapause in seasonal environments allows insects to survive adverse seasons. However, individuals can sometimes enter a prolonged diapause for more than a year, and also skip favourable seasons, which can bring additional costs through e.g. loss of metabolic resources. At the same time, prolonged diapause can be beneficial if it allows individuals to have a risk-spreading strategy to skip potentially suboptimal breeding seasons. We studied if prolonged diapause (2-year diapause) negatively affects the fertility and fitness of female and male Colorado potato beetles (Leptinotarsa decemlineata) compared to control (1-year diapause) beetles. We also tested the parental effects on the subsequent chemical stress tolerance of their offspring. We found that prolonged diapause carried fertility costs only for females who were less fertile than the control females. However, no differences in fertility were observed in males. Furthermore, prolonged diapause in females resulted in offspring with lower larvae-to-adult survival even though these offspring had accelerated development times. In contrast, paternal diapause duration had no effects on their offspring larvae-to adult survival, but prolonged diapause males sired offspring with slower development times than control males. Perhaps to compensate the costs related to prolonged diapause both older parents produced or sired offspring with higher body mass than control parents. Despite the differences in emergence mass, parental diapause duration did not affect offspring insecticide stress tolerance. The difference between females and males most likely results from the observed differences in prolonged diapause females’ capacity to fight against cellular oxidative damage which was poorer compared to the control females. Even though prolonged diapause allows individuals to have a risk-spreading strategy it carries sex-specific fertility and fitness costs indicating that selection could favour this in males but not in females.
Discussing Atypical Sexual Harassment as a Controversial Issue in Bystander Programmes: One UK Campus Study
Authors: Bovill Helen , Waller Richard , McCartan Kieran
Published: December 2019

This research emanates from an anti-sexual violence bystander programme delivered at an English university. Fifteen students were identified through purposive and convenience sampling to take part in focus groups. Discussions emerged regarding atypical sexual harassment. There is a gap in the literature exploring sexual harassment outside of the male perpetrator and female victim narrative which this paper contributes to. This paper considers four conversational themes: ‘unwanted touching: women to men’, ‘sexual banter: women to men’, ‘sexual stereotypes: women and men’, and ‘developing stronger ethical subjectivity’. This paper recognises most sexual harassment occurs from men to women, and acknowledges criticism of focussing otherwise when resources are limited, noting this risks obscuring the enduring power differentials between the sexes. It contends that exploring a controversial issue, such as male experience of sexual harassment, might help bystander programmes by developing ethical subjectivity in undergraduate students. Exploring sexual behaviour as a spectrum may lead to counter hegemonic discourses to emerge.
Investigation and analysis of a fluidized bed dryer by process tomography sensor
Authors: Wang Hai-Gang , Lin Yong-Lei , Yang Wu-Qiang
Published: December 2019

In the pharmaceutical industry, fluidized beds are typically used for pellets drying, coating and granulation. The gas–solids flow characteristic in the process plays an important role to control the heat and mass transfer as well as the end-point product quality. Therefore, it is necessary to investigate the flow characteristics based on advanced measurement technologies. In this research, electrical capacitance tomography (ECT) sensor with eight electrodes was used to investigate the pharmaceutical fluidized bed drying process with different operation conditions. Key process parameters including solids concentration, particle moisture and capacitance signals in the process are given and analysed based on the ECT sensor. In addition, the fluidized bed process with Wurster tube is also investigated based on this ECT sensor. The effect of Wurster tube on the hydrodynamic behaviour and the dominant frequency spectrum distribution in the chamber were analysed based on fast Fourier transform. Test results reveal that process moisture change can be addressed from the raw capacitance of adjacent electrode pair combined with calibration model. Experimental result also indicates that ECT technology can provide useful information for process monitor in a fluidized bed dryer.
Forested Wetland Hydrology in a Large Mississippi River Tributary System
Authors: Berkowitz Jacob F. , Johnson David R. , Price Jaybus J.
Published: December 2019

Wetlands in the Mississippi River Valley provide numerous functions supported by prolonged periods of soil saturation or inundation. However, few studies document forested wetland hydropatterns, especially in altered systems. In this study, we evaluated hydrologic drivers of forested wetlands in the Yazoo Basin, a large Mississippi River tributary system exhibiting regional hydrologic alteration. Results from 56 water table monitoring locations indicate that precipitation induced the majority (76%) of wetland saturation events, defined as soil inundation or water tables within ≤30 cm of the surface for ≥14 consecutive days. Flooding triggered 19% of saturation events, and 5% of events occurred in response to precipitation induced high water tables followed by flood inundation. Data suggest that most wetlands examined (87%) would persist in the absence of flooding, and that duration and inundation patterns differed with dominant water source. A multi-year hydropattern analysis highlights the influence of precipitation derived saturation during low evapotranspiration winter periods, spring flood water contributions in some wetlands, and decreasing water tables throughout summer and fall. A discussion of rainfall normality and stream discharge places the dataset in a larger context. Results reflect changes in historic hydropatterns, informing efforts to maximize wetland functions during forested wetland management and restoration.
Mathematical modeling and regionality-based optimal policy to reduce empty houses, Akiya, in Japan
Authors: Seirin-Lee Sungrim , Nomata Masaaki , Mukunoki Miyoko
Published: December 2019

Empty houses, Akiya, are of substantial concern to the ageing society of Japan; the ratio of Akiya is projected to worsen to 30.5% in 2033. Such a high ratio of Akiya will influence the social system and the Japanese economy overall in the near future. Nonetheless, Akiya continues to increase unabated because there are no specific government measures to address the problem. In this study, we develop a simple mathematical model based on Markovian transition whereby we anticipate the future tendency of empty houses based on real data. Using the model, we demonstrate three tax policies and estimate the effectiveness of the policies considering the extent of Akiya and local government financing. We also consider the spatial distribution of Akiya and suggest both a spatially and quantitaviely effective policy that could reduce Akiya. Our study suggests that to solve the Akiya problem, tax policies and spatial policies should be initiated together, and the policies should be conducted strategically based on the regional characteristics of cities such as economic scale and the population age distribution.
Single‐Station Lightning Location Using Azimuth and Time of Arrival of Sferics
Authors: Koochak Zahra , Fraser‐Smith Antony
Published: December 2019

Lightning strikes produce electromagnetic waves, now referred to as sferics, in the very low frequency (3 kHz–30 kHz) and the extremely low frequency (3 Hz–3 kHz) bands. Within these frequency bands, the Earth and ionosphere form a waveguide in which sferics propagate long distances with low attenuation. The structure of the received sferic waveform is mainly a function of propagation distance and the waveguide's parameters. This suggests that each observed sferic waveform contains information about the distance that this sferic has propagated which can be used to geolocate lightning. There are various approaches for analyzing received sferics, which mostly rely on measurements from multiple stations. However, in these methods, each station imposes an additional cost for building, maintenance, and synchronization. Here we present a novel method to estimate both the emission time and location of lightning, which works by measuring sferics recorded at a single station. We first process the sferic waveforms to obtain the arrival times of the very low frequency and extremely low frequency radiation components which propagate with different speeds. Once these two separate arrival times are determined, we use them to approximate the distance the sferic propagated in the Earth‐ionosphere waveguide. We have used this novel method in combination with a method to find sferic direction to geolocate a significant number of lightning strikes for 4 July 2013. Using this proposed method, the distance of propagation estimates are accurate to within 6.7% of the National Lightning Detection Network‐determined propagation distance, and the direction of propagation estimates are accurate to within
1.3% of the National Lightning Detection Network‐determined direction.
Drift‐Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations
Authors: Zhu Yi‐Fan , Gu Shu‐Jie , Zhou Xu‐Zhi , Zong Qiu‐Gang , Ren Jie , Sun Xin‐Ran , Liu Ying , Zhang Shuai , Shi Quanqi , Rankin Robert
Published: December 2019

Ultralow frequency (ULF) waves have long been known to resonate with magnetospheric charged particles through their drift and bounce motions. Most research interest has focused on the resonance with drift motion, which can accelerate charged particles at very high energies. The role of the bounce motion, especially for particles with lower energies, has attracted less attention so far. Here we start from the general theory of wave‐particle interactions to predict the characteristic, observable signatures of drift‐bounce resonance. Such signatures can be described in the particle pitch angle spectrum as a series of inclined stripes, with the inclination angle depending on the latitude of the observing spacecraft. Each stripe is also twisted at two conjugated pitch angles, suggesting significant phase shifts across resonant pitch angles. These predicted signatures are found consistent with observations from the THEMIS (Time History of Events and Macroscale Interactions during Substorms) spacecraft, and therefore provide an identification of drift‐bounce resonance together with a validated picture over the importance of particle's bounce motion in the ULF wave‐particle interactions.
Statistics of Reconnecting Current Sheets in the Transition Region of Earth's Bow Shock
Authors: Gingell I. , Schwartz S. J. , Eastwood J. P. , Stawarz J. E. , Burch J. L. , Ergun R. E. , Fuselier S. A. , Gershman D. J. , Giles B. L. , Khotyaintsev Y. V. , Lavraud B. , Lindqvist P.‐A. , Paterson W. R. , Phan T. D. , Russell C. T. , Strangeway R. J. , Torbert R. B. , Wilder F.
Published: December 2019

We have conducted a comprehensive survey of burst mode observations of Earth's bow shock by the Magnetospheric Multiscale mission to identify and characterize current sheets associated with collisionless shocks, with a focus on those containing fast electron outflows, a likely signature of magnetic reconnection. The survey demonstrates that these thin current sheets are observed within the transition region of approximately 40% of shocks within the burst mode data set of Magnetospheric Multiscale. With only small apparent bias toward quasi‐parallel shock orientations and high Alfvén Mach numbers, the results suggest that reconnection at shocks is a universal process, occurring across all shock orientations and Mach numbers. On examining the distributions of current sheet properties, we find no correlation between distance from the shock, sheet width, or electron jet speed, though the relationship between electron and ion jet speed supports expectations of electron‐only reconnection in the region. Furthermore, we find that robust heating statistics are not separable from background fluctuations, and thus, the primary consequence of reconnection at shocks is in relaxing the topology of the disordered magnetic field in the transition region.
Comparison of Multiple and Logistic Regression Analyses of Relativistic Electron Flux Enhancement at Geosynchronous Orbit Following Storms
Authors: Capman N.S.S. , Simms L.E. , Engebretson M.J. , Clilverd M.A. , Rodger C.J. , Reeves G.D. , Lessard M.R. , Gjerloev J.
Published: December 2019

Many factors influence relativistic outer radiation belt electron fluxes, such as waves in the ultralow frequency (ULF) Pc5, very low frequency (VLF), and electromagnetic ion cyclotron (EMIC) frequency bands, seed electron flux, Dst disturbance levels, substorm occurrence, and solar wind inputs. In this work we compared relativistic electron flux poststorm versus prestorm using three methods of analysis: (1) multiple regression to predict flux values following storms, (2) multiple regression to predict the size and direction of the change in electron flux, and (3) multiple logistic regression to predict only the probability of the flux rising or falling. We determined which is the most predictive model and which factors are most influential. We found that a linear regression predicting the difference in prestorm and poststorm flux (Model 2) results in the highest validation correlations. The logistic regression used in Model 3 had slightly weaker predictive abilities than the other two models but had the most value in providing a prediction of the probability of the electron flux increasing after a storm. Of the variables used (ULF Pc5 and VLF, seed electrons, substorm activity, and EMIC waves), the most influential in the final model were ULF Pc5 waves and the seed electrons. IMF Bz, Dst, and solar wind number density, velocity, and pressure did not improve any of the models, and were deemed unnecessary for effective predictions.
Radiometric Temperature Measurements in Nongray Ferropericlase With Pressure‐ Spin‐ and Temperature‐Dependent Optical Properties
Authors: Lobanov Sergey S. , Speziale Sergio
Published: December 2019

Accurate temperature determination is central to measurements of physical and chemical properties in laser‐heated (LH) diamond anvil cells (DACs). Because the optical properties of samples at high pressure‐temperature (P‐T) conditions are generally unknown, virtually all LH DAC studies employ the graybody assumption (i.e., wavelength‐independent emissivity and absorptivity). Here we test the adequacy of this assumption for ferropericlase (13 mol.% Fe), the second most abundant mineral in the Earth's lower mantle. We model the wavelength‐dependent emission and absorption of thermal radiation in samples of variable geometry and with absorption coefficients experimentally constrained at lower mantle P and P‐T. The graybody assumption in LH DAC experiments on nongray ferropericlase contributes moderate systematic errors within ±200 K at 40, 75, and 135 GPa and T < 2300 K for all plausible sample geometries. However, at core‐mantle boundary P‐T conditions (135 GPa, 4000 K) the graybody assumption may underestimate the peak temperature in the DAC by up to 600 K in self‐insulated samples due to selective light attenuation in highly opaque ferropericlase. Our results allow insights into the apparent discrepancy between available ferropericlase melting studies and offer practical guidance for accurate measurements of its solidus in LH DACs. More generally, the results of this work demonstrate that reliable temperature measurements in LH DACs require that the optical and geometrical properties of the samples are established.
Carbon Partitioning Between the Earth's Inner and Outer Core
Authors: Li Yunguo , Vočadlo Lidunka , Alfè Dario , Brodholt John
Published: December 2019

Knowledge of the abundance and distribution of light elements in the core is fundamental to the understanding of the Earth and other planetary systems. Recent studies (Li et al., 2018; Mashino et al., 2019) suggest the particular importance of carbon for explaining core properties, yet knowledge of carbon partitioning between the outer and inner core is unknown. By using the quasiharmonic approximation, ab initio molecular dynamics, and thermodynamic integration techniques, we have computed the chemical potential of carbon in liquid Fe and solid hcp‐Fe at core conditions. We find that substitutional carbon is more stable than interstitial carbon and other carbon defect cluster structures in solid Fe. Lattice strain and overcoordination effects lead to a high chemical potential of C in solid Fe compared to the liquid, and consequently carbon partitions almost completely into the liquid. We find that carbon can account for most of the density jump at the inner‐core boundary. This provides an alternative mechanism to the necessity of an oxygen‐rich outer core and may have significant implications for the composition and structure of the deep Earth.
An asymptotically compatible approach for Neumann-type boundary condition on nonlocal problems
Authors: You Huaiqian , Lu XinYang , Task Nathaniel , Yu Yue
Published: December 2019

In this paper we consider 2D nonlocal diffusion models with a finite nonlocal horizon parameterδcharacterizing the range of nonlocal interactions, and consider the treatment of Neumann-like boundary conditions that have proven challenging for discretizations of nonlocal models. We propose a new generalization of classical local Neumann conditions by converting the local flux to a correction term in the nonlocal model, which provides an estimate for the nonlocal interactions of each point with points outside the domain. While existing 2D nonlocal flux boundary conditions have been shown to exhibit at most first order convergence to the local counter part asδ → 0, the proposed Neumann-type boundary formulation recovers the local case asO(δ2) in theL∞(Ω) norm, which is optimal considering theO(δ2) convergence of the nonlocal equation to its local limit away from the boundary. We analyze the application of this new boundary treatment to the nonlocal diffusion problem, and present conditions under which the solution of the nonlocal boundary value problem converges to the solution of the corresponding local Neumann problem as the horizon is reduced. To demonstrate the applicability of this nonlocal flux boundary condition to more complicated scenarios, we extend the approach to less regular domains, numerically verifying that we preserve second-order convergence for non-convex domains with corners. Based on the new formulation for nonlocal boundary condition, we develop an asymptotically compatible meshfree discretization, obtaining a solution to the nonlocal diffusion equation with mixed boundary conditions that converges withO(δ2) convergence.
Hyphal tip growth and cytoplasmic characters of Conidiobolus coronatus (Zoopagomycota, Entomophthoromycotina)
Authors: Fisher  , Romberger  , Lowry  , Shange  , Roberson
Published: December 2019

Characteristics of hyphal structure and growth can provide insights into the mechanisms of polarized growth and support investigations of fungal phylogeny. To assist with the resolution of evolutionary relationships of the zygomycetes, the authors used comparative bioimaging methods
(light [LM] and transmission electron [TEM] microscopy) to describe selected subcellular characters of hyphal tips of Conidiobolus coronatus. Growing hyphae of C. coronatus contain Spitzenkörper (Spk). Spk are most commonly present in hyphae of Dikarya (Ascomycota and Basidiomycota)
and are rarely reported in zygomycete hyphae, which possess an apical vesicle crescent (AVC). Such findings raise questions regarding the evolution of the Spk and its relationship with the AVC. Descriptions of additional subcellular characters (e.g., mitotic-phase spindle pole bodies, cytoplasmic
behavior, organelle structure) are also presented.
Lost and found: the Bermudan Donadinia seaveri found in North America, with comments on its juniper associates
Authors: Pfister  , LoBuglio
Published: December 2019

Collections of a species referred to Sarcosomataceae (Pezizomycetes) from eastern North America were studied both morphologically and using nuc rDNA internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2 = ITS) and approximately 800 bp from the 5′ region of the nuc 28S rDNA
(28S) to construct a phylogeny. The analyses indicate that these collections are Donadinia seaveri, a species previously known only from Bermuda. Because the associated tree, Juniperus bermudiana, has declined as a result of insect attack, it was thought that D. seaveri
might be extinct. This work indicates that it is not extinct but is present in eastern North America. The species is described, new distributional records are given, and its association with the genus Juniperus is discussed.
Herpomyces ectoparasitic fungi (Ascomycota, Laboulbeniales) are globally distributed by their invasive cockroach hosts and through the pet trade industry
Authors: Pfliegler  , Báthori  , Wang  , Tartally  , Haelewaters
Published: December 2019

The introduction of non-native animals occasionally results in the co-introduction of their microbial symbionts or parasites. The trade of exotic pets and zoo animals has inadvertently introduced several parasitic species to countries where they are non-native. Both the presence of
suitable native hosts and opportunity for dispersal determine whether these non-native species become naturalized. During our studies dealing with species of Herpomyces (Ascomycota, Laboulbeniomycetes), fungi that are exclusively ectoparasitic on cockroaches (Hexapoda, Blattodea), we
make use of artificial colonies. Most of our specimens originate from pet stores and laboratory populations. Although they were originally intended for transmission studies, we discovered that some cockroaches from artificial colonies carried fruiting bodies of Herpomyces. We screened
a total 292 cockroaches from 11 populations that we maintained after purchase. Sources were different pet stores, a toxicological laboratory, and a biological supply company. In eight populations, we found at least some Herpomyces-infected cockroaches. Parasite prevalence varied between
8.77% and 86.33%. Host associations were Blatta orientalis with Herpomyces stylopygae, Blattella germanica with H. ectobiae, Periplaneta americana with H. periplanetae, Phoetalia pallida with H. leurolestis, and Shelfordella lateralis with an undescribed
species of Herpomyces. Apart from the new reports, host associations, and consequences for taxonomy (a new species based on morphological and molecular characters), we started to think about the geographic distributions of these fungi and how we, humans, shape them through spreading
hosts and through international pet trade. We reviewed the currently known records of Herpomyces-associated cockroaches and host-parasite relationships. Based on the available data, on a global scale, at least half of the currently known species of Herpomyces are spread by globally
invasive host species and through international pet trade. This indicates that the distribution and host range of these obscure and often unnoticed fungi are affected by human activities.
Notes on Syncephalis (Zoopgales, Zoopagomycota) from the Farlow Herbarium, with the description of a new species, Syncephalis aethiopica
Authors: Benny  , Smith
Published: December 2019

The Harvard mycologist Roland Thaxter collected and studied a wide variety of fungi. Although he described >1000 fungal species, he was unable to describe all the specimens he collected before his death in 1932. His collections and microscope slides remain an important resource for
studying fungal diversity at the Farlow Herbarium at Harvard University. Thaxter described three species in the obligate mycoparasite genus Syncephalis: S. pycnosperma, S. tenuis, and S. wynneae. He retained slide mounts of several other species, including a new species from
his collection that was not described. Here, we describe that new species as S. aethiopica based on morphological analysis of his preserved slides. We also discuss the morphology of S. reflexa, a species apparently only known from slides preserved at the Farlow Herbarium.
Two new endophytic Atractiellomycetes, Atractidochium hillariae and Proceropycnis hameedii
Authors: Aime  , Urbina  , Liber  , Bonito  , Oono
Published: December 2019

Sterile fungal isolates are often recovered in leaf and root endophytic studies, although these seldom play a significant role in downstream analyses. The authors sought to identify and characterize two such endophytes—one representing the most commonly recovered fungal isolate
in recent studies of needle endophytes of Pinus taeda and the other representing a rarely isolated root endophyte of Populus trichocarpa. Both are shown by DNA sequencing to be undescribed species of Atractiellomycetes (Pucciniomycotina, Basidiomycota), a poorly characterized
class of mostly plant-associated and presumably saprobic microfungi. The authors describe the new genus and species Atractidochium hillariae (Phleogenaceae) and the new species Proceropycnis hameedii (Hoehnelomycetaceae), both in the Atractiellales, to accommodate these unusual
isolates. Following incubations of 1–2 mo, A. hillariae produces minute white sporodochia, similar to those produced by several other members of Atractiellales, whereas Pr. hameedii forms conidia singly or in chains in a manner similar to its sister species Pr. pinicola.
Additionally, we provide a taxonomic revision of Atractiellomycetes based on multilocus analyses and propose the new genera Neogloea (Helicogloeaceae) and Bourdotigloea (Phleogenaceae) to accommodate ex-Helicogloea species that are not congeneric with the type H. lagerheimii.
Atractiellomycetes consists of a single order, Atractiellales, and three families, Hoehnelomycetaceae, Phleogenaceae, and Helicogloeaceae. Accumulated evidence suggests that Atractiellomycetes species are common but infrequently isolated members of plant foliar and root endobiomes.
A Festschrift in Honor of Meredith Blackwell
Authors: Spatafora  , Aime  , Zhang  , Seifert
Published: December 2019

The end of the 20th century and the beginning of the 21st will be remembered as the golden age of molecular systematics of Fungi. The development of the Polymerase Chain Reaction (PCR), automated sequencing, and explicit algorithms for inferring phylogenetic trees
transformed fungal systematics into a hypothesis-testing discipline that would go on to serve as the foundation for comparative and evolutionary genomics. Many mycologists participated in this modernization of mycology and perhaps none more than Meredith Blackwell. She has played – and
continues to play – a leadership role in transforming mycology into a modern science based on a robust understanding of organismal biology, development, testing and refinement of biologically meaningful hypotheses, and incorporation of emerging technologies to data collection and analysis.
In this volume we recognize Meredith and her contributions to mycology with the publication of the first Festschrift issue in the 110 year history of Mycologia.
The role of inertia on a locally favoured structure in equimolar binary mass Hard Spheres
Authors: Pinchaipat Rattachai , Wongrach Kunaree
Published: December 2019

Molecular dynamics simulations have been carried out to investigate the effect of inertia on both dynamics and locally favoured structures (LFS) of a supercooled liquid toward glass transition. In this work, the equimolar supercooled liquid binary mixtures of Hard Spheres with the same diameter but different masses were studied. The mass ratio of the binary system was 2:1. The simulation was performed and sampled by using the microcanonical ensemble. Both dynamics and structure changing were analysed. A cluster structure analysis was detected by topological cluster classification (TCC) based on the results of local free energy minimisation. The slowing down dynamics were found to be related to cluster structure changing in both the binary mass Hard Sphere (BMHS) and Hard Sphere (HS). The inertia affected an increasing dynamical heterogeneity and had some effects on favouring some local structures before they get crystallisation.
Tarnish resistance of silver by gold microplates coating
Authors: Rattanapoltee P , Thongnopkun P
Published: December 2019

Silver is a promising precious metal for the jewelry industry. The silver jewelry findings exposed to air would be tarnished because it comes into contact with sulfur particles in atmospheres. Therefore, surface treatments and coating methods were developed to prevent the tarnishing of silver. However, the methods still have several limitations and disadvantages. The objective of this research was to develop gold microplates for surface coating and tarnish resistance of silver. In this study, the gold microplates were synthesized by chemical reduction methods. Multilayer gold coating was performed by a simple dip coating method to produce the gold film using a gold microplate solution, which disperses gold particles in ethylene glycol. The anti-tarnish properties of the coated silvers were investigated using the sodium sulphide solution. To specify the color change after multilayer coatings of gold particles and tarnishing test, the color measurement was determined according to the Commission Internationale d’ Eclairage (CIELAB) standard by UV-visible spectrometer. The result pointed out that the gold microplates layers coating on silver are invisible and efficiently prevents tarnishing.
Crustal body–wave velocities beneath Thailand from teleseismic analysis
Authors: Yongsiriwith P , Khoonphunnarai P , Daoh M
Published: December 2019

We estimated the crustal seismic body-wave velocities beneath Thailand and Malay Peninsula by using teleseismic waveform analysis from 7 earthquakes in Prachuap Khiri Khan, Thailand. The seismic waveform studies on phase arrivals of P–wave and S-wave data retrieve from 2 broadband seismic stations, 1 CHTO station (Chiang Mai–Thailand) and 2 BTDF station (Singapore), are analysed in this paper. Obviously, the crustal seismic velocities from each stations were difference, with Vp (7.683–7.892 km/s) and Vs (4.275–4.403 km/s) propagations in the southern path (Malay Peninsula) are greater than Vp (7.556–7.827 km/s) and Vs (4.220–4.376 km/s) propagates in the northern path. The results show that to the corresponding with differ in earth’s crust density, the continental crust is less dense than the oceanic crust, and these data available for crustal seismic velocity for these region.
An array of coupled nonlinear oscillators as a model for amplitude variations in intermodulation distortions from the auditory system
Authors: Prawanta E , Kitana N , Leelasiriwong W , Roongthumskul Y
Published: December 2019

The response of a nonlinear oscillator driven by two or more forces displays several frequency components corresponding to the linear combinations of the driving frequencies, known as intermodulation distortions (IMDs). The auditory system of all classes of vertebrates produces strong IMDs in the presence of sounds of two tones. This phenomenon is attributed to the nonlinearity of the biological acoustic sensors within the inner ear. In this work, we developed a numerical model to investigate the total IMDs generated by a chain of coupled nonlinear oscillators. Total nonlinear distortions exhibited variations in amplitudes with respect to the stimulus frequency. The variation profile was sensitive to the magnitude of the driving forces and the difference in the two driving frequencies. We found that the arrangement of the oscillators’ characteristic frequencies was necessary for the variations in total IMD level. Results from the numerical model agreed with measurements of IMDs from Chinese edible frog (Hoplobatrachus Rugulosus), whose inner ear is constituted by arrays of acoustic receptors with progressively increasing natural frequencies. In response to sounds of two tones, IMDs produced by the inner ear of Chinese edible frog exhibited variations in amplitudes with respect to the driving frequencies. The third-order distortion level displayed several peaks at high stimulating sound pressure level, and at large differences between the stimulus frequencies. Our findings suggest that an array of coupled nonlinear oscillator can serve as a simple model for the generation of nonlinear distortions by the inner ear.
Photon signal from non-interacting scalar dark matter annihilation
Authors: Sukrakarn Supalert , Robkob Udom
Published: December 2019

One proposal to search for Dark Matter is to look for photon signals which originates from DM annihilation. This is usually referred to as indirect detection experiment. In the case of Non-Interacting Scalar Dark Matter, there are no electromagnetic, strong, and weak interactions. Thus, the DM only interacts gravitationally. In our model, we determine the NISDM annihilation into a virtual graviton which subsequently creates a pair of Higgs bosons. The Higgs boson then suddenly decays into two photons. The line of sight integral is considered as a signifcant efect of the DM halos density profle. The total cross-section, thermally averaged cross-section and photon signal are fnally calculated and illustrated.
Concentration measurement of chromium passivation solutions by an optical method
Authors: Sibsiri K , Suwanchaituch T , Meechan W , Luengviriya C
Published: December 2019

Chromium passivation solutions are widely used in the last step of plating process for improving metal surfaces. The appearance as well as corrosion resistance of the threated surface depend on the thickness of chrome layer which is controlled by many factors including the concentration of the solution. In this research, we study the relation of the light absorption and the concentrations of a chromium passivation solution. We prepare the solutions with five different concentrations and measure their absorbance by using an ultraviolet-visible spectrometer. The absorption spectrum non-monotonously changes with the wavelength of the incident light. However, the absorbance always linearly increases with the concentration at all wavelengths. We construct several calibration equations at different wavelengths and test them by using solution samples with other concentrations. The results show that the concentration of chromium passivation solution should be measured at wavelengths in the range of 420-700 nm because the errors are less than 5%.
A sky survey of neutral Hydrogen at 21 cm using NARIT 4.5m small radio telescope
Authors: Tisawech K , Tummuangpak P , Asanok K , Jaroenjittichai P
Published: December 2019

We surveyed the neutral hydrogen (HI) at 21 cm by using the 4.5m Thai Small Radio Telescope (SRT) of the National Research Institute of Thailand (NARIT) during January–March 2019. The main aim of this project is for doing the distribution maps of HI in our Galaxy which will be shown in terms of the radial velocities and the HI positions in the galactic coordinate. The selected positions are mainly along the galactic plane (above or under the plane) within 21 degrees. The galactic longitudes are during 0 to 258 degrees. According to studies, the spectrum mode of NARIT-SRT receiver is recorded and divided into 400 channels with the velocity resolution ∼1.05 kms-1. Full width at half maximum (FWHM) of the NARIT - SRT is about 3-4 degrees. Its system temperature is 147.5 ± 5.1 K. The distribution map of HI clouds at 21 cm with the NARIT-SRT is presented in term of the radial velocity (vr
) in the range of [0: +220] kms-1 and the column density of HI down to the level 1019 per cm-2. Our results are in good agreement with theoretical values and international database.
Photoluminescence of ZnO nanorods prepared by hydrothermal method
Authors: Thongpool V , Phunpueok A , Jaiyen S
Published: December 2019

In this research, the effects of calcination temperature and reaction time on the photoluminescent properties of ZnO nanorods prepared by hydrothermal processes were studied. Morphology, crystalline structure and photoluminescent properties of the prepared samples were analyzed by scanning electron microscope (SEM), X-ray diffractrometer (XRD) and fluorescent spectrophotometer. The study found that a reaction time of 5 hours on a glass slide and calcination at 500°C was the best preparation condition. The prepared ZnO nanorods were aligned without direction and distributed throughout the substrate. The average diameter of the prepared ZnO nanorods was 91.96 ± 21.16 nm. The prepared ZnO nanorods comprised a hexagonal crystalline structure with an emission peak in the UV range.
Classifying Maser features with Fortran and shell script for proper motion study of Water masers in W49N
Authors: Phetra M , Asanok K , Hirota T , Kramer B H , Sugiyama K , Nuntiyakul W
Published: December 2019

The 22-GHz Water masers in the W49N star-forming region are one of the richest and most luminous sources in our Galaxy, at the distance of 11.11 kpc. Very Long Baseline Interferometric (VLBI) observations allow us to study both physics of these masers and the star formation process. However, observational results often show numerous (up to several thousand) maser spots, making manual data analysis time-consuming. Therefore, we have developed a new software with simple computer codes to classify maser features in this source observed with KaVA by Asanok et al. (in preparation). Fortran computer language and bash shell script are developed and tested by applying to 3 epochs of data sets. The peak flux and relative position of maser spots are measured using AIPS software. The analysis procedures are as follows: (1) the data are extracted to the package in table format (peak flux and x-y relative positions), (2) maser spots are counted under specified rules, (3) the maser feature is calculated by using flux-weighted mean method, and (4) the output results are compared with those obtained from the conventional method. Preliminary results show that these newly developed codes are able to automatically identify up to 30% of those maser features found by the conventional method in a consistent manner. Therefore, further improvement and development are needed for future application.
Physical properties distribution of galaxy population in Abell 2142 cluster
Authors: Poopakun Kledsai , Kriwattanawong Wichean
Published: December 2019

In this work, we investigate the physical properties of galaxies in Abell 2142 using photometric and spectroscopic data from the Sloan Digital Sky Survey (SDSS). The sample was selected by two criteria: redshift of 0.0781 ⩽ z ⩽ 0.1038 and the location within a radius of 100 arcminutes from the cluster centre. We found that the sample distributes into 2 groups, a foreground filament galaxies with z ⩽ 0.085 and the cluster members with z > 0.085. The relation between apparent magnitude in g filter band and u – z colour suggests that we can use the u – z equals 3.2 as a criterion to separate galaxies into blue (u – z ⩽ 3.2) and red (u – z > 3.2) sequence galaxies. Moreover, blue sequence galaxies have higher value of equivalent width of hydrogen alpha corresponding to higher star forming activity than red sequence galaxies. The nearby filament contains higher fraction of star forming galaxies (65%) than the cluster Abell 2142 galaxy members (46%). This could be due to difference of the environmental effect.
Effect of formamidinium cation on electronic structure of formamidinium lead iodide
Authors: Sukmas Wiwittawin , Nedkun Piyanooch , Pinsook Udomsilp , Tsuppayakorn-aek Prutthipong , Bovornratanaraks Thiti
Published: December 2019

The emergence of hybrid organic-inorganic perovskites (HOIPs) have attracted considerable attention due to their electronic and optical properties leading to potential applications, especially photovoltaics technology. The effects of the Formamidinium cation (HC(CH2)2
+) or FA cation on cubic/α-Formamidinium lead iodide (HC(CH2)2PbI3) or α-FAPI were thoroughly and systematically investigated. We calculated the electronic band structures and the density of states of FAPI and FAPI without the FA cation including spin-orbit coupling interactions based on the state-of-the-art density functional theory (DFT). The results suggest that, according to the band structures, the FA cation exhibits a couple of nearly non-dispersive bands, whereas it is revealed that the organic cation weakly interacts with the inorganic framework of PbI3 octahedral cage.
Effect of quantum well width on the electron and hole states in different single quantum well structures
Authors: Rueangnetr N , Sivalertporn K
Published: December 2019

In this study the electron and hole states in Al0.33Ga0.67As/GaAs single quantum well structures including squared QW, step QW and tilted QW, have been theoretically studied by solving the Schrodinger equation in real space. The energies and wave functions of electron and hole are calculated for different well widths. It is found that energy level of electron and hole decreases with increasing the well width. Adding step or tilted layers gives rise to the decrease of electron and hole energy levels. The ground state energy level in a tilted single quantum well structure is lower than that in a step single quantum well structure. It is also found that the energy of electron and hole ground states do not change as the width of step layer increase. This is because the ground state occupies in a lower well only. The wave functions are symmetric (ground state) and antisymmetric (the first excited state). The maximum of ground state wave function is at the central of the well and the probability of finding electron and hole in excited states are different in each region. The hole levels are lower than the electron levels due to the lower well depth and higher mass of hole compared to electron.
A free solution to the Dirac equation in R-spacetime
Authors: Angsachon T , Dhanawittayapol R , Kritsarunont K , Manida S N
Published: December 2019

In this work, the Dirac equation and its solution for a free fermion in R-spacetime is presented. In the solution obtained, the oscillation frequency increases as t → 0+. The time singularity and the necessity of restricting the time domain in R-spacetime is discussed. Limiting the time domain implies the possibility of quantization of the solution, though this is a subject for further work.
Radiological hazard assessment and excess lifetime cancer risk evaluation in surface soil samples collected from Ban Chang and Nikhom Phatthana districts in Rayong province, Thailand
Authors: Kessaratikoon P , Jewawongsakul J , Boonkrongcheep R , Pholthum S
Published: December 2019

Specific activity of natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides have been measured and analyzed in 27 surface soil samples in Rayong province in the eastern region of Thailand where is the home of the Southeast Asia industrial estate and one of the largest petrochemical plants in the world. Such high activity concentrations might be associated with the increase in cancerous patients who live in the studied area. All surface soil samples were collected from Ban Chang (12 samples) and Nikhom Phatthana (15 samples) districts in Rayong province. The average specific activities were analyzed and estimated by employing hyper-pure germanium (HPGe) detector and gamma-ray spectrometry analysis system. It was found that the frequency distribution of specific activities of 40K, 226Ra, 232Th and 137Cs for the investigated area were asymmetrical distribution with the skewness of 1.09, 1.54, 0.39 and 0.42, respectively. The median values of specific activities of 40K, 226Ra, 232Th and 137Cs in Bq/kg were 423.75 ± 11.30, 96.65 ± 2.16, 36.73 ± 1.06 and 1.32 ± 0.24 Bq/kg, respectively. In addition, four radiological hazard indices which are gamma-absorbed dose rate (D), radium equivalent activity (Raeq), external hazard index (Hex) and annual external effective dose rate (AEDout) were also studied and assessed by using the measured (median) values of specific activities. Furthermore, the excess lifetime cancer risk (ELCR(outdoor)) could be evaluated by using the AEDout value. The results were also compared with the Office of Atoms for Peace (OAP) annual report data, Thailand and global radioactivity measurement and calculations. Moreover, the radioactive contour maps of the investigated area were also created and presented in this paper. From this study, value for D was higher than the worldwide average value (84.98 ± 2.12 nGy/h). The AEDout and ELCR(outdoor) values were equal to 0.10 ± 0.003 mSv/y and (0.39 ± 0.01)×10-3, respectively and lower than the worldwide average. Further studies and evaluations need to assess the real risks and effects to people health.
Low dose gamma radiation effects on seed germination and seedling growth of cucumber and okra
Authors: Jaipo N , Kosiwikul M , Panpuang N , Prakrajang K
Published: December 2019

Cucumber and okra seeds were radiated by Co-60 gamma radiator for 50, 100, 150 and 200 Gy. Germination percentage and seedling growth were observed every day for 10 days. After 10 days of seedling growth, weight of fresh and dry seedling were measured. The result showed that the highest germination percentage of cucumber was 100% on the third day of 50 Gy gamma-radiated seeds. The highest germination percentage of okra was 100% on the fifth day of 50 Gy gamma-radiated seeds. The highest seedling lengths of cucumber and okra were 13.7 cm. and 9.4 cm. with 50 Gy and 200 Gy of gamma dose, respectively. Weight of fresh and dry seedings showed no trend corresponding to the seedling growth. This study shows that the low dose gamma radiation may enhance the germination rate and the seedling growth during the early seedling state of some vegetable seeds.