bluuebunny/crossref_metadata_2025 huggingface dataset:
Congestion probabilities in OFDM wireless networks with compound Poisson arrivals
Authors: Panagoulias Panagiotis I. , Moscholios Ioannis D. , Sarigiannidis Panagiotis G. , Logothetis Michael D.
Published: December 2019

The authors study the downlink of an orthogonal frequency division multiplexing (OFDM) based cell that services calls from different service‐classes with various resource requirements. They assume that calls arrive in the cell as batches according to a compound Poisson process. They consider that the batch size is generally distributed while each call of a batch is treated separately from the other calls of the same batch, according to the complete sharing policy. To determine the most important performance metrics, i.e. congestion probabilities and resource utilisation in this OFDM‐based cell, they model it as a multirate loss model, show that the steady‐state probabilities can be determined via a product form solution (PFS) and propose recursive formulas which reduce the complexity of the calculations. In addition, they study the bandwidth reservation (BR) policy which can be used for the reservation of subcarriers in order to favour service‐classes whose calls have high subcarrier requirements. The existence of the BR policy destroys the PFS of the steady‐state probabilities. However, they show that there exist recursive formulas for the determination of the various performance measures. Simulation verifies the accuracy of the proposed formulas.
Performance comparison and stability analysis of ACM and ENLC controlled SEPIC PFC converter
Authors: Munuswamy Radha , Govindarajan Uma , Anbukumar Kavitha
Published: December 2019

In this study, a detailed comparison between two power factor correction (PFC) controls, viz., average current mode (ACM) control and enhanced non‐linear carrier (ENLC) control for single‐ended primary inductance converter (SEPIC) are made. In ACM control, a linear current reference, generated using the conventional method is compared with the inductor current. In ENLC control, a non‐linear carrier current reference, generated using passive components is compared with switch current. The proposed ENLC control uses reduced components and sensors compared to ACM and conventional non‐linear carrier control methods. The evolving of nonlinear phenomena during load variation is investigated along with the electromagnetic interference (EMI) study with power spectral density estimation. For stability enhancement and EMI mitigation, a detailed simulation study is performed using MATLAB/Simulink platform. Mathematical bifurcation analysis, by deriving critical phase angle is carried out to obtain a better insight of stability boundaries in order to access the system behaviour. Owing to the advantages of ENLC, an experimental setup of ENLC controlled SEPIC PFC converter was built to support the results.
Optimisation of power electronics for regulated transformer rectifier units
Authors: Mallik Ayan , Singh Akshay , Khaligh Alireza
Published: December 2019

This study presents a comprehensive approach for the design optimisation of passive components and heatsinks in power electronic converters. The design and selection of passive components are posed as a multi‐objective optimisation problem, which can be simplified to a single‐objective optimisation based on preferences and weights assigned by the designer. The mathematical equations describing the efficiency, volume, and reliability are laid out to describe the feasible space for optimisation in this study. In addition to the proposed optimisation, a substantial amount of passive component comparison data has been consolidated and presented in this study. The results from the optimisation are demonstrated on the target power electronic circuit of a regulated transformer rectifier unit for more‐electric aircrafts. The optimisation framework is developed in a generic manner that would lend itself to the optimisation of any choice of converter topology, circuit components, or objective functions.
Synthesis of SiC nanoparticles by central composite design response surface methodology directed mechanical milling
Authors: Erdemir F. , Varol T. , Çanakçı A.
Published: December 2019

In this work, synthesising of SiC nanoparticles by mechanical milling was studied. The influence of ball to powder ratios, milling speeds and milling times in three levels on the specific surface area of SiC particles using central composite design was investigated. The statistical significance of the independent variables and their dual interactions were analysed. The specific surface area and morphology of SiC particles were characterised using a laser particle size analyser and scanning electron microscope, respectively. It was found that milling speed is the most important parameter for the conversion of SiC particles from micro‐sized to nanosized powders. The morphology and specific surface area of SiC particles are almost unchanged at the milling speed of 100 rpm. The specific surface area substantially increased from 0.0643 to 3.59 m2/g with increasing the milling speed from 100 to 300 rpm.
Reversal of Warfarin-Associated Major Hemorrhage: Activated Prothrombin Complex Concentrate versus 4-Factor Prothrombin Complex Concentrate
Authors: Peksa Gary D. , Mokszycki Robert K. , Rech Megan A. , Maynard Brian , Panos Nicholas G. , Sweis Rolla T. , DeMott Joshua M.
Published: December 2019

Background Warfarin-associated major hemorrhage is frequently treated with prothrombin complex concentrates to correct international normalized ratio (INR).

Objective This article aims to investigate the efficacy of activated prothrombin complex concentrate (aPCC) versus 4-factor prothrombin complex concentrate (4PCC) for vitamin K antagonist reversal in patients with warfarin-associated major hemorrhage.

Materials and Methods This was a multicenter, retrospective cohort study. Patients included were age ≥ 18 years with pretreatment INR of > 1.5. Exclusion criteria were patients treated for urgent procedures without hemorrhage, treated but not taking warfarin, unavailable INR values, and pregnant patients. Patients were stratified into two groups: aPCC or 4PCC. The primary outcome was achievement of INR ≤ 1.5 at the posttreatment INR sampling. Secondary outcomes focused on thrombotic events and mortality.

Results Of 342 patients, 237 patients received aPCC and 105 patients received 4PCC. After 1:1 propensity score matching, 86 patients remained in each group. In the matched cohort, the proportion of patients who achieved target INR ≤ 1.5 was greater with 4PCC (aPCC = 61 [70.9%] vs. 4PCC = 76 [88.4%]; 95% confidence interval [CI] –29.2% to –5.7%) and groups had comparable in-hospital thrombotic events and mortality. In the unmatched cohort, achievement of target INR ≤ 1.5 was greater with 4PCC (aPCC = 151 [63.7%] vs. 4PCC = 92 [87.6%]; 95% CI –32.7% to –15.1%).

Conclusion In the treatment of warfarin-associated major hemorrhage, 4PCC compared with aPCC was associated with greater achievement of INR ≤ 1.5 with comparable thrombotic events and mortality. Further controlled studies are needed to confirm these findings and determine the optimal dosing strategy that maximizes efficacy and safety.
Smallholder farmers and contract farming in developing countries
Authors: Meemken Eva-Marie , Bellemare Marc F.
Published: December 2019

Poverty is prevalent in the small-farm sector of many developing countries. A large literature suggests that contract farming—a preharvest agreement between farmers and buyers—can facilitate smallholder market participation, improve household welfare, and promote rural development. These findings have influenced the development policy debate, but the external validity of the extant evidence is limited. Available studies typically focus on a single contract scheme or on a small geographical area in one country. We generate evidence that is generalizable beyond a particular contract scheme, crop, or country, using nationally representative survey data from 6 countries. We focus on the implications of contract farming for household income and labor demand, finding that contract farmers obtain higher incomes than their counterparts without contracts only in some countries. Contract farmers in most countries exhibit increased demand for hired labor, which suggests that contract farming stimulates employment, yet we do not find evidence of spillover effects at the community level. Our results challenge the notion that contract farming unambiguously improves welfare. We discuss why our results may diverge from previous findings and propose research designs that yield greater internal and external validity. Implications for policy and research are relevant beyond contract farming.
New Meredithiella species from mycangia of Corthylus ambrosia beetles suggest genus-level coadaptation but not species-level coevolution
Authors: Mayers  , Bateman  , Harrington
Published: December 2019

Meredithiella norrisii (Microascales, Ceratocystidaceae) is an ambrosia fungus carried in mycangia of the North American ambrosia beetle, Corthylus punctatissimus. Reports on the identity of the fungal symbionts of other species of Corthylus have been inconsistent.
This study tested the hypothesis that Meredithiella spp. are the primary symbionts of Corthylus spp. Cultures and/or internal transcribed spacer (ITS) rDNA barcode sequences of Meredithiella spp. were obtained consistently from beetles and galleries of nine Corthylus
spp. The ITS sequences of three putative species of Meredithiella were associated with C. consimilis and C. flagellifer in Mexico and C. calamarius in Costa Rica. The symbiont of C. columbianus in the USA was identified as M. norrisii. Two new Meredithiella
spp. are described: M. fracta from C. papulans in Florida and Honduras, and M. guianensis associated with C. crassus and two unidentified Corthylus spp. in French Guyana. The Meredithiella spp. propagate in the mycangia of adult females by thallic-arthric
growth, and the ambrosia growth in larval cradles comprises bead-like hyphal swellings or conidiophores, with or without terminal aleurioconidia. Bayesian phylogenetic analysis of a combined 18S and 28S nuc rDNA and translation elongation factor 1-α (TEF1-α) data set demonstrated
that Meredithiella is a distinct monophyletic clade within the Ceratocystidaceae, but its phylogenetic placement with regard to the other ambrosial genera in the family remains ambiguous. The mycangia of C. punctatissimus and C. papulans are also compared using light microscopy
and micro-computed tomography (micro-CT) imaging, revealing that they differ in both size and shape, but these differences may not correlate with different lineages of Meredithiella.
Cadophora meredithiae and C. interclivum, new species from roots of sedge and spruce in a western Canada subalpine forest
Authors: Walsh  , Duan  , Mehdi  , Naphri  , Khiste  , Scalera  , Zhang
Published: December 2019

Two new species of Cadophora are described based on multigene phylogenetic analyses and phenotypic and ecological characters. The species delimitation was based on concordance of gene genealogies. The cultures of the Cadophora species were isolated from the roots of long-beaked
sedge and white spruce from a subalpine forest in western Canada; however, they probably have a broader distribution because their internal transcribed spacer (ITS) sequences have high similarity with a number of GenBank sequences from ecological studies of plant roots. The taxonomy of Cadophora
in Leotiomycetes is discussed based on the phylogeny generated in this study. Results from this work will facilitate ecological and evolutionary studies on root-associated fungi.
Intragenomic nuclear RNA variation in a cryptic Amanita taxon
Authors: Hughes  , Tulloss  , Petersen
Published: December 2019

Amanita cf. lavendula collections in eastern North America, Mexico, and Costa Rica were found to consist of four cryptic taxa, one of which exhibited consistently unreadable nuclear rDNA ITS1-5.8S-ITS2 (fungal barcode) sequences after ITS1 base 130. This taxon is designated
here as Amanita cf. lavendula taxon 1. ITS sequences from dikaryotic basidiomata were cloned, but sequences recovered from cloning did not segregate into distinct haplotypes. Rather, there was a mix of haplotypes that varied among themselves predominantly at 28 ITS positions.
Analysis of each of these 28 variable bases showed predominantly two alternate bases at each position. Based on these findings and additional sequence data from the nuclear rDNA 28S, RNA polymerase II subunit 2 (RPB2) and mitochondrial rDNA small subunit (SSU) and 23S genes, we speculate
that taxon 1 represents an initial hybridization event between two divergent taxa followed by failure of the ribosomal repeat to homogenize. Homogenization failure may be a result of repeated hybridization between divergent internal transcribed spacer (ITS) types with inadequate time for concerted
evolution of the ribosomal repeat or, alternately, a complete failure of the ribosomal homogenization process. To our knowledge, this finding represents the first report of a geographically widespread taxon (Canada, eastern USA, Costa Rica) with apparent homogenization failure across all collections.
Findings such as these have implications for fungal barcoding efforts and the application of fungal barcodes in identifying environmental sequences.
A closer look at Sporidiobolales: Ubiquitous microbial community members of plant and food biospheres
Authors: Urbina  , Aime
Published: December 2019

Carotenoid-containing yeasts in Sporidiobolales (Microbotryomycetes, Pucciniomycotina, Basidiomycota) have been reported from contrasting ecosystems, including marine, soil, phylloplane, polar ice, and many others. Here, we present several analyses drawing on 583 new isolates collected
from various substrates around the globe and publicly available sequences from numerous published environmental studies. We provide a multilocus phylogenetic reconstruction of the order, estimates for total species richness, a snapshot of global distribution patterns, and analysis of niche
preferences in Sporidiobolales, emphasizing their occurrence in commercial crops and food products. We evaluated loci commonly used in fungal phylogenetics, finding that RNA polymerase II subunits 1 and 2 (RPB1, RPB2) are of little utility in this group. We have reconfirmed the monophyly
of Sporidiobolales with three well-supported genera, which are, in descending order of number of species, Rhodotorula, Sporobolomyces, and Rhodosporidiobolus. From our data, we estimate ca. 260 species in Sporidiobolales, of which 42 are described, and ca. 52,000 species in Pucciniomycotina.
The majority of data regarding Sporidiobolales are from North America and Europe, highlighting severe knowledge gaps for most of South and Central America and Africa.
Harnessing the power of phylogenomics to disentangle the directionality and signatures of interkingdom host jumping in the parasitic fungal genus Tolypocladium
Authors: Quandt  , Patterson  , Spatafora
Published: December 2019

Host specialization is common among parasitic fungi; however, there are examples when transitions in host specificity between disparately related hosts have occurred. Here, we examine the interkingdom host jump from insect pathogenicity and mycoparasitism in Tolypocladium. Previous
phylogenetic inferences made using only a few genes and with poor support reconstructed an ancestral character state of insect pathogenesis, a transition to mycoparasitism, and reversions to insect pathogenesis. To further explore the directionality and genes underlying the transitions in
host, we sequenced two additional species of Tolypocladium (T. capitatum and T. paradoxum) and used phylogenomics to compare two insect pathogens and two mycoparasites. Our whole-genome-scale analysis suggests that the diversification of Tolypocladium species happened
relatively quickly and that the truffle parasites form a monophyletic, derived lineage within the genus that is the result of a single ecological transition or host jump from insects to fungi. A significant amount of gene tree/species tree discordance occurs within the data set, and we infer
this to be the product of both an historical hybridization event and incomplete lineage sorting that was likely because of the rapid diversification of the clade. Furthermore, comparative genomic analyses revealed a set of genes that are exclusive to the mycoparasitic species. These potentially
mycoparasitic gene clusters were characterized by a reduced proportion of secreted proteins when compared with entomopathogen-enriched genes and involved the reshaping of the fungal secretome in the ecological context of mycoparasitism.
Multilocus phylogeny of the Trichophyton mentagrophytes species complex and the application of matrix-assisted laser desorption/ionization–time-of-flight (MALDI-TOF) mass spectrometry for the rapid identification of dermatophytes
Authors: Suh  , Grosso  , Carrion
Published: December 2019

Despite intensive studies of the Trichophyton mentagrophytes species complex, its taxonomy still causes confusion. In this study, more than 70 dermatophytes were analyzed based on nuc rDNA ITS1-5.8S-ITS2 (ITS), D1–D2 domains of nuc 28S rDNA (D1D2), and β-tubulin gene
(TUBB) sequences to clarify phylogenetic relationships in the complex. This demonstrated that strains of the complex were divided into three major lineages with high statistical support: (i) T. benhamiae and related species; (ii) T. simii and two related species, T.
quinckeanum and T. schoenleinii; and (iii) T. mentagrophytes, T. interdigitale, and related species. The major lineages could be further divided into 18 phylogroups, representing either individual species or phylogenetically distinct groups within species. Among strains of
T. benhamiae, African isolates American Type Culture Collection (ATCC) 28064 and 28065 formed a phylogenetically distinct phylogroup from their type strain and were considered a distinct species. Strains of T. mentagrophytes were divided into at least four phylogroups based on
combined sequence analysis, but some phylogroups showed closer relationships to T. interdigitale, T. equinum, and T. tonsurans when compared by individual genes. This indicates that identifying those species with one gene could lead to incorrect results. For rapid identification
of those dermatophytes, each phylogroup was tested by matrix-assisted laser desorption/ionization–time-of-flight (MALDI-TOF) mass spectrometry using a database with customized reference spectra of each phylogroup. This system was able to identify all the tested strains to species level
with higher than 91% accuracy, except for strains of T. interdigitale. The three phylogroups of T. benhamiae were well distinguished from one another with high identification accuracy, whereas phylogroups of T. mentagrophytes were often cross-identified to one another
or to T. interdigitale. Further research should improve identification accuracy for some species, but the results suggested that MALDI-TOF MS could be a rapid and efficient identification tool for closely related dermatophytes in the T. mentagrophytes species complex.
New species and emendations of Orphella: taxonomic and phylogenetic reassessment of the genus to establish the Orphellales, for stonefly gut fungi with a twist
Authors: White  , Guàrdia Valle  , Lichtwardt  , Siri  , Strongman  , William  , Gause  , Tretter
Published: December 2019

We consolidate and present data for the sexual stages of five North American species of Orphella, fungal members of trichomycetes previously classified within Harpellales. Three species emendations accommodate the newly recognized characters, including not only the coiled zygospores
and accompanying cells but also other morphological traits not provided in the original descriptions for O. avalonensis, O. haysii, and O. hiemalis. We describe three new species, Orphella cataloochensis from both the Smoky Mountains in USA and two provinces in Canada
as well as O. pseudoavalonensis and O. pseudohiemalis, both from the Cascade Range, in Oregon, USA. Key morphological features for all known species are summarized and reviewed, with illustrations of some of the North American taxa to update and supplement the literature. The
entire suite of morphological characters is discussed, with emphasis on species relationships and hypotheses on possible vicariant origins. We also present a molecular phylogeny based on nuc rDNA 18S and 28S, which supports Orphella as a lineage distinct from Harpellales, and we establish
a new order, Orphellales, for it. With the combination of sexual features, now known for 12 of the 14 species of Orphella, and new molecular data, the group is now better characterized, facilitating and hopefully also promoting future studies toward a better understanding of their relationships,
origins, and evolutionary history as stonefly gut–dwelling fungi.
Three new species of Harpellales from Mount Tsukuba
Authors: Sato  , Degawa
Published: December 2019

Three new species of Harpellales, collected on Mt. Tsukuba, Kanto Plain on Honshu Island, are described. Stachylina philoricola, derived from midgut of Philorus sp. (Blephariceridae: Diptera), and Lancisporomyces tsukubaensis, derived from the hindgut of Amphinemura
sp. (Nemouridae: Plecoptera) nymphs, are described. Blephariceridae is newly added to the host insect families of Harpellales. A new genus, Zygopolaropsis, is proposed to accommodate the new species Z. sphaerica, derived from the hindgut of Baetis thermicus (Baetidae,
Ephemeroptera) nymphs.
Simulation of phase-ordering dynamics of 2d Ising model under influence of oscillatory shear
Authors: Sasom S , Hengpunya V
Published: December 2019

In this paper, we study phase-ordering dynamics of 2d Ising model under influence of oscillatory shear by computer simulation. We focus on the time evolution of the equal-time correlation functions to test the dynamical scaling hypothesis and to determine the governing growth laws. We find that at late times the system has two different behaviours which are a non-shear behaviour and a uniformly sheared behaviour. Initial phases and frequencies of oscillatory shear determine the behaviour of the system. On one hand, if the frequency is high, the system behaves as if it is not under shear. On the other hand, if the frequency is approached zero, the behaviour of the system will be determined by the initial phase of oscillatory shear. At the initial phase of 90 degree (or 270 degree), the system also behaves as if it is not under shear. Otherwise, the system behaves as if it is under uniform shear (Oscillatory shear is in the form of cosine function).
Establishment of Thailand’s national primary vacuum standard by a static expansion method
Authors: Phanakulwijit S , Pitakarnnop J
Published: December 2019

A novel primary standard system for a vacuum pressure calibration has been established at the National Institute of Metrology, Thailand (NIMT). The system, which cover the pressure range from 1.3 • 10-1 Pa up to 1.3 • 103 Pa is based on the static expansion method. By the series of re-expansion, the range could be extended to lower calibration pressures. The facility consists of two small and one large vessels, which provide an expansion ratio by a factor of approximately 102 to 103 for a single expansion and more for a multiple one. Six platinum resistance thermometers are attached to the vessel to ensure the correction of the non-isothermal effect during an expansion. The system could deliver the expanded (k = 2) relative uncertainties under 0.6% of reading at the lowest operating pressure. The measurement results of the system were verified by comparing with the calibration results of the capacitance diaphragm gauge (CDG) from Physikalisch-Technische Budensanstalt (PTB). The En
ratios represent an excellent agreement between NIMT and PTB calibration results.
Application of magnetic field for improvement of energy spread of an electron beam
Authors: Wongrach Kunaree , Photia Thanarwut , Chiangga Surasak , Pinchaipat Rattachai
Published: December 2019

Electron diffraction is not solely a powerful method to study fundamental physics but has also been applied to quantum sensors. A low-coherence electron source results in a drop of fringe contrast. One approach to enhance a visibility of the diffraction pattern is to improve a longitudinal coherence of an electron beam. When electrons pass through a magnetic field, they experience a force which bends them to circular paths. Electrons with different energies will travel along the different paths. By placing a slit behind the magnetic field, the width of the electron energy distribution will become narrower and hence an improvement of the beam coherence. However, this method reduces the intensity of the electron beam. The simulation was performed to optimize the slit width for electron diffraction experiments with respect to the energy spread of the beam and electron flux.
An investigation of poleward expansion of the Hadley circulation using cloud cover
Authors: Chanalert W , Janjai S , Buntoung S
Published: December 2019

Amongst the issues associated with global climate change, the expansion of the tropics has become increasingly important. This expansion is normally demonstrated in the form of changes in the Hadley circulation. In this study the changes of the Hadley circulation were investigated using high cloud cover from the ERA-Interim reanalysis data. Trends of zonal-mean cloud cover computed over the period 1979-2017 in both hemispheres show that poleward expansion of the Hadley circulation is about 1.6 and 1.2 degree of latitude per 39 years in northern hemisphere and southern hemisphere, respectively. In addition, the expansion for all four seasons was also analysed. The analysis results show that poleward expansion occurs mostly in all seasons and the expansion of the Hadley circulation results in a poleward expansion of the subtropical dry regions.
Elliptic flow of the proton in 197Au + 197Au collisions reaction at intermediate energy by using a quantum molecular dynamics model
Authors: Chaimongkon Phacharatouch , Thapang Tanachod , Boonprasert Tanaporn , Chumsri Apichaya , Sittiketkorn Panadda , Thongkum Patcharapan , Srisawad Pornrad
Published: December 2019

The elliptic flow (v2) of the proton in 197Au + 197Au collisions reaction at intermediate energy by using a quantum molecular dynamics model (QMD) is investigated. We analyse the elliptic flow of the proton in 197Au + 197Au collisions reaction at incident energy 0.09, 0.12, 0.15 and 0.25 A GeV with the impact parameter from 0.25 to 0.45 (0.25 < b
0 < 0.45) by including a nuclear equation of state (EoS). The theoretical calculated results are compared with the FOPI data. We observe that the EoS effects obviously to the elliptic flow as a function of the centrality transverse component t of the 4-velocity (u

t0). After taking into account a soft nuclear equation of state (Soft EoS), a theoretical is in a good agreement with the experimental data this indicates that the elliptic flow as a function of the u

t0 is one of sensitive probes to extract information on the EoS properties at high density.
Azimuthal emission patterns of proton in 58Ni + 58Ni collision at intermediate energy by using a quantum molecular dynamics model
Authors: Chaimongkon Phacharatouch , Kunkaew Pitchayapak , Rerkwattanaampai Panwaris , Sittiketkorn Panadda , Thongkum Patcharapan , Srisawad Pornrad
Published: December 2019

The direct flow of a proton in the 58Ni + 58Ni collisions at incident energy 1.93 A GeV was computed by using a quantum molecular dynamics model (QMD). The mean transverse momentum projected on the reaction plane as a function normalized rapidity for the proton (〈px
/mp
〉 (Y(0))) from 58Ni + 58Ni collisions with impact parameter (b) < 4 fm was studied. Furthermore, the direct flow of the proton as a function of th transverse momentum (v
1(pt
)) at the incident energy 1.93 A GeV with b < 2.5 fm was investigated by taking into account the nuclear equation of state (hard and soft EoS). The theoretical results were compared with KaoS experiment and BUU model. The calculated results show that the theoretical calculations of the 〈px
/mp
〉 (Y0), a soft EoS is consistent with experimental data. In addition, the v
1(pt
) is confirmed by the soft EoS that is good agreement with the experimental data at the pt
< 0.6. Consequently, this work indicates that 〈px
/mp
〉 (Y(0)) and v
1(pt
) are sensitive observable to probe the nuclear equation of state in dense nuclear matter.
The effect of K+ potential on the nuclear equation of state for the K+ production in heavy ion collisions by using a quantum molecular dynamics model
Authors: Chaimongkon Phacharatouch , Jeerakad Jenitsata , Doo-saard Tidarut , Douykhumklaw Chanadan , Prajit Sakda , Sittiketkorn Panadda , Thongkum Patcharapan , Srisawad Pornrad
Published: December 2019

This work investigates and focuses on the effect of K+ potential on the nuclear equation of state (soft and hard EoS) for K+ production in heavy ion-collision by using the quantum molecular dynamics model (QMD). Production of a cross-section of K+ mesons in 197Au +197 Au collision at incident energy 1.1 (polar angle 56°) and 1.46 (polar angle 40° and 56°) A GeV respectively, as well as studying impact parameter between 4.14 and 12.41 fm. The production cross-section as a function of the laboratory momentum (plab) is computed and compared with KaoS experiments. The calculations performed with and without Brown-Rho parameters (K+N) as well as the soft and hard equation of state. The results displayed the theoretical calculations with the soft EoS are similar to the hard EoS. The theoretical calculations with soft and hard EoS while including K+N potential tend to be consistent with the KaoS experiments, this indicates that the production of the cross section for K+ mesons as a function of the laboratory momentum is one of sensitive probes to extract information on the K+N potential at high densities.
Development and validation of portable X-ray fluorescence spectrometry for elemental routine measurement in geological samples
Authors: Nuchdang S , Sukhummek B , Rattanaphra D
Published: December 2019

A pressed pellet technique was developed for quantitative analysis of elements in geological samples by portable X-ray fluorescence spectrometry (pXRF). Validation of analytical method was done using eight geological reference materials (BCR-2: basalt, COQ-1: carbonatite, GSP-2: granodiorite, JA-1: andesite, JB-2: basalt, JG-1a: granodiorite, JG-2: granite and JSy-1: Syenite). Minimum concentrations of Al, Ca, Cu, Fe, K, Mn, Pb, Rb, Si, Sr, Ti, Y, Zn and Zr in geological reference materials for pXRF detection were 6.60%, 0.50%, 19 mg/kg, 0.06%, 0.35%, 120 mg/kg, 5.36 mg/kg, 7.37 mg/kg, 1.62%, 17.92 mg/kg, 0.09%, 24.90 mg/kg, 13.60 mg/kg and 51.20 mg/kg, respectively. The accuracy of the developed method was acceptable with the mean error below 18%. The geological samples received from the Department of Mineral Resources (DMR) were also tested using this method. The results showed that the concentration values obtained by the studied method were in good agreement with those obtained by the DMR for K, Mn, Pb, Rb, Si, Sr, Ti, Y and Zn with concentrations ranging of 3.70-4.20%, 90-400 mg/kg, 64-89 mg/kg, 296-404 mg/kg, 24.44-32.17%, 50-180 mg/kg, 0.22-0.28%, 34-47 mg/kg and 30-41 mg/kg, respectively. This method is suitable for elemental routine measurement in geological samples.
Examination of Thai freshmen’s understanding on vectors using a model analysis technique
Authors: Kusindrastuti B , Reyes M G , Rakkapao S , Prasitpong S
Published: December 2019

This study focused on an investigation of Thai students’ comprehension of vectors using the model analysis technique, which is based on the matrix representation of quantum physics. This technique displays students’ knowledge states and the probability of applying each mental model to solve a given vector concept. A well-known vector concept test in physics education research named the Test of Understanding of Vectors (TUV) was translated into Thai language and validated by a group of physics lecturers. It was administered to 651 first-year engineering students at Prince of Songkla University via the online system at the beginning of the first semester. The three common mental states of vectors were identified as correct, popular incorrect, and other models. Model estimation of the model analysis revealed that although 54% of the students correctly answered vector addition, they still had difficulty with vector subtraction. Theoretically, both topics are considered as identical concepts. The students had inconsistent ideas on vector subtraction as reported by eigenvalues < 0.65. Moreover, they demonstrated equal distribution in using the three mental models to solve the dot product of vectors. The most common incorrect idea was that a dot product resultant was a vector quantity. The initial knowledge states of the cross product were in an incorrect model region involving confusion between calculating magnitudes of the cross product and the dot product, and incorrectly applying the right-hand rule to locate a direction of the cross product. Overall, the findings will guide instructors which common vector ideas should be revised and how. The vector concept plays an important role in physics learning since it is embedded in several physics topics as a learning mechanism.
An experimental study: mixing rate of granular materials under vertical vibration
Authors: Chaiworn P , Kiengmana K
Published: December 2019

This research aims to the master development result of learning in mixing ratio and quickly rate of mixing granular material for elementary study apply and development of mixing ratio industry and agriculture. The researcher separate 2 parts of mixing ratio put low dense material on the top and high dense material on the top with frequencies from 6, 7 and 8 Hz, Recording 60 s. of picture frame. Counting the mixing granular material in different high in container. Calculating the percentage of mixing in each different high, mixing rate 0 – 1 different of each experiment. Material used ceramics (1.61 g/cm3), plastic (0.98 g/cm3) and wood (0.72 g/cm3). It was found that more frequency better mixing, the high dense granular material on the top is mixing rate better than the low dense granular material on the top. In the time at 40 – 60 s. were the best of mixing rate, mixing granular material with different time in each frequency. The movement of granular material able to occurs in many form, disperse, clumping and spin and roll. Furthermore, the low dense granular much more quickly movement. Conclude that density, position, frequency and time effect to mixing. Frequency very with quickly but inverse with density of material and the materials were mixed at its best in each period of time different.
Wavelet spectrum analysis of PM10 data in Bangkok, Thailand
Authors: Anusasananan P
Published: December 2019

PM10 is one of the key factors which influences the air quality in metropolitan areas throughout the world. In this research we investigate the variation period of PM10 concentration and its temporal patterns from 2009 to 2017 in Bangkok, Thailand using wavelet spectrum analysis. We also utilize the cross wavelet transform to study the potential relation between PM10 and the temperature. From the wavelet power spectrum of PM10, we can distinguish two dominant bands, one in the period between 8-16 months and the other between 1-8 months. The first oscillation is obviously related to natural annual periodicities that the high power occurs from December 2011to February 2015. The PM10 concentrations are high in winter and low in the rainy season. The second band between 1-8 months is the transient pattern with very high concentration of PM10 occurs only in the year 2013. Wavelet spectrum of the temperature is similar in pattern for it shows the strong annual signal and the lowest temperature band between 4-8 months. The cross wavelet transform (XWT) power spectra between PM10 and the temperature show significant common power, in the 8-16 month band from November 2009 to June 2016, and in the 1-8 month band around November 2012 to February 2014. The wavelet transform coherence (WTC) spectra show that PM10 and the temperature co-varied out of phase during all observed time intervals. This indicates the high seasonal dependence between PM10 and the temperature. Knowledge of the variation period of PM10 concentration and its evolution feature in Bangkok area will help the authorities to better prepare for public health and environmental hazard from the next PM10 pollution.
Measurement of radon concentrations and effective dose assessment in groundwater from Kamphaeng-Saen district, Nakhon Pathom province and Ban-Pong district, Ratchaburi province
Authors: Raksawong S , Sola P , Tampraserd P , Macha K , Khonman S , Somingmee C
Published: December 2019

Radon monitoring has been increasingly conducted worldwide because it is considered as the hazardous effects on the human healthy, probably making an increased cancer risk when people received radon by inhalation of air and ingestion of water containing high concentrations over extended periods of time. Radon is natural occurring radionuclides found in the rock, soil and water, and can therefore enter in the water supplies used for drinking water. The objective in this study was to determine the radon level in groundwater in order to set up a policy on water management. The groundwater radon concentrations were measured by RAD7 device with RAD H2O technique following a protocol proposed by the manufacturer from 26 groundwater samples randomized in Kamphaeng-Saen District, Nakhon Pathom Province and Ban-Pong District, Ratchaburi Province where the groundwater has been frequently used for public tap water. The results show that the radon concentrations range between 0.05 and 2.51 BqL–1 with an average value of 0.95 BqL–1. All measured radon concentrations are well below the allowed maximum contamination level (MCL) of radon concentration in water of 11 BqL-1, proposed by US Environmental Protection Agency (USEPA). The annual effective doses of adults calculated for inhalation and ingestion are below 12.74 µSvy–1, and also well lower than the safe limit (100 µSvy–1) recommended by World Health Organization and EU Council. Thus radon in groundwater of this study do not pose any significant health risk to the public.
Effects of surface diffusion length on steady-state persistence probabilities
Authors: Chanphana R , Chatraphorn P
Published: December 2019

The dependence of the steady-state persistence probabilities (Ps) and exponents (θs) on surface diffusion length (l) for four discrete growth models is investigated. The persistence exponents which describe the decay of the persistence probabilities, the probabilities of the average of all initial height (h
0), are increased as l is increased for all models. The results of one-dimensional Family ((1+1)-Family) and Das Sarma-Tamborenea ((1+1)-DT) models with kinetically rough film surface show the decrease of the growth exponent (β) with l. The l>1 results preserve the relation

β
=
max
[
1
−

θ
+
S

,
1
−

θ
−
S

]

. In contrast, β is observed to increase with l for the two-dimensional larger curvature ((2+1)-LC) and Wolf-Villain ((2+1)-WV) models with mounded morphology. Our results show that the

β
=
max
[
1
−

θ
+
S

,
1
−

θ
−
S

]

relation is not valid in l>1 cases in models with mounded surfaces. The persistence probabilities of a specific value of initial height (Ps
(h
0)) for l>1 are found to behave differently between mounded and kinetically rough models.
Efficiency of solar tree based on golden ratio
Authors: Srisai S , Harnsoongnoen S
Published: December 2019

The efficiency of a solar tree based on golden ratio was investigated and analyzed. The lengths and angles of the trunks, main branches and sub-branches are designed using the golden ratio principle. A trunk is divided into five ranges based on the Fibonacci sequence, consisting of four main branches and four sub-branches. The angle between the trunk and main branches, main branches and the next main branches, main branches and sub-branches, subbranches and the next sub-branches is equal to 137.5° (golden angle). The solar cells are installed at the ends of all branches along the direction of each branch. The power efficiency of the proposed structure and the land-based fixed angle are compared. The measurement system consists of (a) solar cell electricity measurements (voltage and current) and (b) environment measurements (temperature, humidity, and light intensity). The data are recorded through DAQ cards (PCI 628, Elvis board and USB 6008) which are connected to the LabVIEW program for analyzes and monitors. The experimental results show that the power efficiency of the solar tree based on the golden ratio was more than the land-based fixed angle by 1.295 percent and solar cells positioned at the end of branches (T1) of the trunk can generate most power.
Non-contact active microwave sensor for glucose concentration measurement
Authors: Suwanna K , Harnsoongnoen S
Published: December 2019

A non-contract microwave sensor with a common emitter amplifier circuit for glucose concentration sensing is developed and investigated in this article. The geometries and materials of the designed sensor are optimized and analyzed by the full-wave electromagnetic simulation. The microwave prototype was created using a printed circuit board based on dry film techniques. The microwave sensor was connected to a vector network analyzer (VNA) and the electromagnetic interaction between the samples and sensor was analyzed. The proposed sensor was tested for its electromagnetic response to glucose at various concentrations ranging from 0 to 16 % (W/V) with steps of 4 % (W/V) in the frequency range from 2.0 to 4.0 GHz through the measurement of the transmission coefficient (S21) and quality factors (Q-factor) based on non-contact detection. The experimental results confirmed that the magnitude of S21 and Q-factor were changed when the concentration of glucose was changed. The magnitude of S21 and Q-factor were reduced when the glucose concentration is increased. Based on the results of the study, the proposed microwave sensor will be further developed to measure the concentration of soluble glucose and can be used as a sensor for chemical solution measurement and biometrics without damaging the structure of the substance.
Optical morphology of the ejected Shell of V339 Del using SHAPE
Authors: Sutham S , Sobbong J , Surina F , Awipan S
Published: December 2019

The morphology of the ejected shell of V339 Del (Nova Del 2013) outburst was preliminary studied. The optical spectra from the Liverpool telescope around 80 days after discovery were examined. Synthetic line profile spectra were compared to emission lines of Hβ in order to find the best-fit morphology of the ejected shell using the programme SHAPE. When adopted an inclination i = 65° and suggested shape of the shell from literature, a simplest preliminary morphology was found to be a bipolar at squeeze parameter around 0.8 - 1 with a torus.
Real-time and versatile laser-power stabilization with arbitrary amplitude modulation
Authors: Phrompao J , Pongvuthithum R , Sucharitakul T , Srakaew K , Anukool W
Published: December 2019

We have demonstrated a technique to stabilize laser power at any point in an optical circuit. By employing a self-made Arduino-controlled stabilizer for real-time monitoring and generating feedback signal, the power fuctuation after an acousto-optic modulator (AOM) can be suppressed to 0.16% at an average power of 33.34µW. Our arrangement also allows simultaneous amplitude modulation using an arbitrary waveform. The system design and principle of operation are described.
Synthesis and characterization of Fe-doped TiO2 hollow nanospheres prepared by carbon sphere as hard template
Authors: Kanjana N , Laokul P
Published: December 2019

Fe-doped TiO2 hollow nanospheres (THs-Fe) with various Fe-dopant concentrations (0.25, 0.50, 0.75 and 1.00 mol%) were prepared using carbon spheres as templates. After calcination, the obtained hollow structure TiO2 were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDS) and ultraviolet-visible spectroscopy (UV-Vis). The analysis results revealed that the crystallite size and crystallinity of the samples decreased with increasing Fe content. Morphology and particle size were investigated by electron microscopic techniques and the results showed that dopant concentrations had a significant influence on average particle size. The average diameter of hollow spheres decreased from 146.92 to 61.57 nm when Fe-content increased from 0.25 to 1.00 mol%. The UV-Vis absorption spectra exhibited that the absorption edge of THs-Fe was shifted toward the visible light region with increased Fe content. The energy gap (Eg) was decreased from 2.85 to 1.84 eV when the dopant content increased from 0.25 to 1.00 mol%.
GADGET-2 simulation for active galactic nuclei feedback in galaxy NGC 5252
Authors: Boonmalai M , Sawangwit U , Wannawichian S
Published: December 2019

We present a numerical simulation of active galactic nuclei (AGN) feedback in galaxy NGC 5252, while galaxy has gas, halo, disk, and bulge particles. We set up one bulge particle’s mass to represent the black hole mass. According to the result from numerical simulation of active galactic nuclei feedback, we interpret that the gas provides some gas feedback at large distant approximately around 10 kpc. We generate initial condition, as known as IC fle of the galaxy, including a stellar disk and gas particles following an exponential density profle. A dark matter halo and a stellar bulge follow a Dehnen density profle. GADGET-2 was used to calculate the distribution of particles in galaxy simulation, which is based on smoothed particle hydrodynamics method. Ultimately, we study the gas feedback of active galactic nuclei in the form of outfow gas with numerical simulations. From preliminary result show that the gas particles seem to evolve with time and concentrate on the later time near 5 to 10 kpc.
A simple technique for measuring the spatial correlation of photon pairs for complete interference in the Michelson interferometer
Authors: Boonkham K , Limsuwan P
Published: December 2019

In this research, a simple technique for measuring the spatial correlation or angular correlation of photon pairs was developed. The system consisted of two aluminium rails which had the same pivot at the position of a nonlinear crystal. The rails were manually moved to find the position of the correlated photon pairs. At this position, the photon pairs were collected by the collimators attached at the end of the rails. The pairs were produced by type I spontaneous parametric down-conversion process using a 405 nm diode laser and a BBO crystal. The crystal was specifically cut for emitting the photon pairs at an angle of 3° with respect to the direction of the pump laser. These pairing photons were correlated and interfered in the Michelson interferometer, then, the correlated photons were demonstrated. It was found that the visibilities in the case of perfect alignment, near perfect alignment and misalignment were V = 1.0000 ± 0.0004, 0.869 ± 0.002, 0.591 ± 0.002 and 0.168 ± 0.002, respectively.