bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling radio-frequency plasma cleaning of fusion optics
Authors: Shaw David , Wagenaars Erik 
Published: June 2019

Abstract
Metallic mirrors are to be used extensively within ITER for diagnostics and real time control. Erosion of the first wall within ITER will cause particles to be redeposited around the machine, including on these first mirrors, which will cause a reduction in reflectivity and a degradation in quality of signal received by the detectors. Powering these mirrors to form capacitively-coupled plasmas (CCPs) with an induced self bias, and using the ions within the plasmas to bombard and remove the deposits, has shown some experimental success in recovering mirror reflectivity. In this work the ion energy distribution functions (IEDFs) from an Ar CCP formed on a 5 cm radius metallic mirror are modelled and investigated using the hybrid plasma equipment model. Initially a geometry variation is done showing that a simple increase in reactor volume can significantly impact the spatial distribution of the ion flux to the mirror surface leading to non-uniform etch rates across the surface, even after the maximum bias has been achieved. The ion energies need to be sufficient to remove depositions (focussing on the first wall material of Be which forms a surface oxide BeO) but not subsequently damage the underlying mirror. In order to achieve this both the voltage (50–1000 V) and the frequency (13.56–60 MHz) have been varied within the model showing trends that may lead towards IEDF optimisation. The increase in voltage increases the self bias linearly and the plasma density super-linearly, whereas increasing the frequency barely effects the self bias while increasing the plasma density sub-linearly. Both increases cause an increase in ion flux for these reasons but both also decrease the homogeneity of the ion flux across the mirror surface which will be required should the energies be above the threshold for the mirror. These results are also unique to the geometry being investigated and thus the conclusion is that it would be prudent to model individual mirror geometries to find optimal parameters. This becomes especially clear with the introduction of a perpendicular magnetic field into the simulation that significantly reduces electron transport within the plasma.
Pattern recognition as tools for understanding night sky brightness variabilities
Authors: Rezky M , Priyatikanto R , Admiranto A G , Soegiartini E 
Published: June 2019

Abstract
Night sky brightness (NSB) research related to the artificial light pollution issues has been increasing all over the world, using various measurement techniques and tools. The research produces tens of thousands of data for each month such that proper handling, processing and analysing the data become challenging. In this article, we demonstrate an alternative method for processing the NSB data by utilising pattern recognition techniques: Canny edge detection and Hough transform. These techniques were applied to identify data and extract important parameter from the NSB density plot semi-automatically. Datasets collected from Bandung, Garut, Subang and Sumedang used as the test cases. Three time-segments (dusk, night and dawn) became the main focus of the analyses and our method successfully extracted following parameters: the rate of sky brightness change at dusk and dawn, the average NSB at night and the intersections which indicate transition time. This method, along with its many possible improvements, enables us to process data more effectively and encourage more observation campaigns to be conducted in the future.
Cosmic Evolution of Nearby Radio Active Galactic Nuclei
Authors: Andika Irham Taufik , Arifyanto Mochamad Ikbal , Istiqomah Ade Nur , Amalina Shinta Nur , Aprilia  , Hakim Muhamad Irfan 
Published: June 2019

Abstract
The exact formation mechanism of massive galaxy in the universe still become an open question in modern astrophysics. Radio emission from active galactic nucleus (AGN) is known to be suppressing stellar growth in the most massive galaxies, thus becoming significant ingredient in modeling galaxy formation process. Radio luminosity function across cosmic redshifts (z) is an important tool to constrain the co-evolutionary models of radio AGN and its host galaxy. Therefore, we aim to calculate radio luminosity function at 1.4 GHz frequency for radio AGN in the range of 0.1 ≤ z ≤ 1.3 in this work. The radio data was taken from deep VLA observation of Stripe 82 field at angular resolution of 1.8” and 52 μJy sensitivity. On the other hand, the optical/near-infrared data was taken from Dark Energy Survey DR1 observation in g, r, i, z, Y bands with co-added catalog limiting magnitude of i = 23.44.
We estimated the photometric redshift (photo-z) of each sources by using combined two machine learning algorithms: neural networks and boosted regression trees. We successfully performed accurate photo-z measurement with average bias 〈δ〉 = −3.5 × 10−3, scatter 〈σ〉 = 0.15 and outlier fraction 〈f(3σ)〉 = 0.06. By using 1/V
max method, we calculated the luminosity function, then constrained their evolution with pure density evolution (PDE) or pure luminosity evolution (PLE) model. At median z = {0.31, 0.59, 0.88, 1.10}, we found the power-law index of PDE is αD
= {1.29, 1.43, 1.73, 0.94} while for PLE is αL
= {2.28, 2.59, 3.19, 1.63}. Our result is consistent with previous studies and gives better constraint to radio AGN luminosity and density evolution power-law indexes due to larger number of sources (6900) and wider covered sky fraction (92 deg2).
Diffuse Interstellar Bands in the High-Resolution GAOES Data
Authors: Puspitarini L , Malasan H L , Hashimoto O 
Published: June 2019

Abstract
Diffuse interstellar bands (DIBs) are an enigmatic set of interstellar absorption features, observed at optical and near infrared wavelengths in the spectra of reddened stars in our Galaxy also in other galaxies. Identifying the carriers of DIBs has been a longstanding challenge and is still very much a work in progress. In recent years, surveys of DIBs have been conducted, but mostly focus on strong bands. In this work, we extracted and measured DIBs recorded in the high-resolution stellar spectra of ε Auriga (ε Aur) and IQ Per observed by using Gunma Astronomical Observatory Echelle Spectrograph (GAOES) (spectral resolution R∼65000). Observations were aimed at obtaining high resolution spectra of double-lined detached eclipsing binaries. For each selected DIB, we performed spectral fitting of a combination of a smooth stellar continuum (polynomial function), an empirical DIB model, and a synthetic telluric transmission. The high-quality data allow us to measure not only strong and well-known DIBs, but also weaker DIBs.
Introducing the Zwicky Transient Facility and the Be star variability program: a progress report at the National Central University
Authors: Ngeow C-C , Lee C-D , Yu P-C , Masci F , Laher R , Kupfer T , Golkhou V Z 
Published: June 2019

Abstract
The Zwicky Transient Facility (ZTF) is a modern-day wide-field optical survey to systematically explore the transient and variable sky. The ZTF utilizes the 48-inch Samuel Oschin Schmidt Telescope located at the Palomar Observatory. This telescope is equipped with a mosaic CCD camera that provides a field of view of 47 squared degrees. The allocated observing time of ZTF can be divided into partnership time (40%), public time (40%) and Caltech time (20%). The public time contains two surveys: a 3-day cadence for the Northern Sky Survey and a 1-day cadence for the Galactic Plane Survey. Astronomical communities in South East Asian countries are encouraged to explore the public ZTF data once it is released in March 2019. Taiwan’s National Central University (NCU) is one of the partnered institutions, and a major ZTF-related project carried out at NCU is the ZTF Be stars variability (ZTF-BeV) program. The main goal of our program is to study the variability of Be stars in the range of ∼13.5 to ∼20.5 magnitudes.
Identification warp and flare milky way’s disk in the third galactic quadrant
Authors: Hidayat W , Arifyanto M I , Aprilia  , Hakim M I 
Published: June 2019

Abstract
Milky Way’s disk has a feature called warp and flare. Warp is a bending phenomenon of the galactic disk. This feature is noticeable in the first and third galactic quadrant. Meanwhile, flare define as the increment of galactic disk scale high depends on galactocentric distance. Galactic disk tracers (dust, gaseous, and stars) can be used to explain the presence of both structures. The reddening of 10 young open clusters (OC) and 2985 early-type (OB) stars chosen in this work. Both components predicted to represent the galactic disk component where the warp and flare occurred. The Milky Way Star Cluster (MWSC) catalogue used to select the open clusters initial parameters. Then, we used proper motion data from GAIA DR2 combined with photometric data from Two Micron All Sky Survey (2MASS) catalogue to determine the open cluster membership and reddening. The open cluster memberships are selected using scatter algorithm. Then, the JHKs photometric data used to build the Two Colour Diagram (TCD) and Colour-Magnitude Diagram (CMD). We selected the reddening of OB stars data from Tycho 2 catalogue. The result is an increment of colour excess depends on galactocentric distance. This distribution could indicate the presence of warp and flare of the Milky Way’s disk.
Relationship among Self-Motivation, Self-Efficacy and Achievement of High School Student in Biology
Authors: Nurwendah Wenty , Suyanto Slamet 
Published: June 2019

Abstract
This research aims to reveal: (1) the relationship among self-motivation and self-efficacy of high school student in biology (2) the relationship among self-efficacy and achievement of high school student in biology (3) the relationship among self-motivation and self-efficacy of high school student in biology, and (4) the relationship among self-motivation and self-efficacy and achievement of highs school student in biology. This research was a quantitative descriptive research, using a survey method. The instrument used a questionnaire for collecting the data. The population was all of grade XI students of natural science class of high schools in Yogyakarta City. The sample was by using the quota sampling technique. The data were analyzed by using the linear regression, Pearson correlation coefficient, and multiple regression analysis. The criteria for determination was at the significance level of 0.05.
A Meta Analysis on Biology Worksheet’ Students Forms
Authors: Windari Tri , Gusti Suryadharma I 
Published: June 2019

Abstract
This study was aimed to analyze LKPD (students’ worksheet) in Biology subjects. The LKPD (students’ worksheet) is a collection of sheets containing the activities of students that allow students to carry out real activities with objects and problems learned. The LKPD (students’ worksheet) is used by teachers in facilitating students and must be oriented to the scientific process to find or prove the concept. This research method is a meta-analysis. Data collection techniques were by searching for electronic journals on Google and Google scholars. The population of this study is the level of secondary education, especially high school. The sample is LKPD (students’ worksheet) of Biology subjects. Based on the meta-analysis, the results of this study are the LKPD (students’ worksheet) in Biology subjects can be grouped according to their form, namely LKPD which helps students find concepts, LKPD which helps students apply and integrate concepts, LKPD as a learning guide, LKPD as reinforcement, LKPD as practical guide. The LKPD (students’ worksheet) classification including conventional LKPD (students’ worksheet), approach based LKPD (students’ worksheet), learning model based LKPD (students’ worksheet), character education based LKPD (students’ worksheet), thinking skills based LKPD (students’ worksheet), problem based LKPD (students’ worksheet), and technology based LKPD (students’ worksheet). The form of LKPD (students’ worksheet) finding the highest concept of 39% and the highest frequency is conventional LKPD (students’ worksheet) of 12.
Exploring Guided Discovery Learning: The Effect on Students’ Integrated Ability and Self-Regulated in Chemistry
Authors: Permatasari Dea , Laksono E. W. 
Published: June 2019

Abstract
The purpose of this study was to investigate the effect of a guided discovery learning (GDL) toward students’ integrated ability and self-regulated. The study was post-test only control group research design and the participants consisted of students in senior high school (N = 65). The topic of buffer solution was selected both the experimental class and control class, whereas the experiment class used GDL approach and control class used expository learning (EL). The ‘Integrated Assessment’ and ‘Self-Regulated Questionnaire Form’ were used as data collection tools in the research. Results of the descriptive analysis of post-test showed that the frequency of answers was the higher category for the experimental class than the control class students. In addition, results of the MANOVA test indicated that post-test scores were students in GDL class had significantly higher total integrated ability and self-regulated scores over their traditional counterparts. In this research, it was concluded that the GDL used in relation to the topic of buffer solution had significant effect toward students’ integrated ability.
Development of Android Comic Media for the Chapter of Newton’s Gravity to Map Learning Motivation of Students
Authors: Nikmah Syafridatun , Haroky Faruq , Jumadi  , Wilujeng Insih , Kuswanto Heru 
Published: June 2019

Abstract
This research was designed to map students’s learning motivation by developing comic physics media. This study used the ADDIE development model. The subjects tried in this study were students in one senior high school in Yogyakarta at the grade of 10th science. Data collection instruments were in the form of students’ motivation observation sheets and students’ learning motivation questionnaire. The data obtained were analyzed quantitatively. The results showed that (1) Android-based physics comic media on the Newton’s Gravity chapter was an innovation in the world of education that utilized TPACK (Technological Pedagogical Content Knowledge). (2) Comic media can be and are suitable for use in physics learning for senior high school, and (3) comic media can be used to map the learning motivation of high school students.
Experimental and Numerical Study of Co-firing Peat with Syngas in a Vortex Burner
Authors: Evdokimov O A , Mikhailov A S , Guryanov A I , Piralishvili Sh A , Veretennikov S V 
Published: June 2019

Abstract
Experimental and numerical study of co-firing peat with different gaseous fuels in the vortex burner are carried out. At the “lean” operational regimes co-firing peat with syngas is more effective and allows to organize reliable ignition and stable combustion at the values of excess air coefficient up to αΣ = 2.7. In addition, co-firing with syngas requires less initial methane to produce it applying catalytic reforming than direct co-firing with methane. Also, syngas supply into vortex burner allows to reduce combustion temperature and emission of NOx.
Mathematical modeling of burn-out of the coal particle coke residue
Authors: Salomatov Vl , Salomatov Vas 
Published: June 2019

Abstract
Combustion of solid fuels in general includes a number of stages: heating, drying, devolatilization, ignition, and burn-out of coke. The stage of coke residue burn-out is the leading one. In this paper, analytical solutions for the burn-out of the coke part of an anthracite particle were developed using the asymptotic procedures, and combustion of anthracite particles with the size of 100 µm and less (presented size for the flare process) and 12 mm or more (characteristic size for burning in a fluidized bed) was calculated. In the first case, combustion occurs in the kinetic regime, and in the second, it occurs in the diffusion regime. The models of the “hard” ash frame, as well as the model “with segregating” ash, have been implemented.
Subsurface analysis of 6082-T6 Aluminium alloy’s mechanical properties subjected to small particles erosion
Authors: Erdoğan A A , Țarcă I C , Rus A , Țarcă R C 
Published: June 2019

Abstract
6082-T6 aluminium alloy is a ductile metal. When subjected to small particles erosion, sub-surface deformations are expected due to the particle impact. Plasticity is one of the properties which might reveal the rate of the deformations. As a result of plastic deformation, mechanical properties of the samples are expected to change with distance from the surface. Typically, the depth of the plastically deformed region could be between 5 and 200 μm. In order to understand the plasticity of the materials, nanoindentation researches were conducted. Aluminium alloy samples were previously subjected to hard material particles jets (Al2O3) under different values of incident angle, between 15 and 90 degrees. After a 3D scan of the resulted surfaces, the samples were cut in such a manner that the middle section remained visible and prepared for nanoindentation analysis. The paper presents the experiments conducted as well as some of the achieved results.
Additivation of vegetal oils for improving tribological characteristics
Authors: Georgescu C , Solea L C , Deleanu L 
Published: June 2019

Abstract
This paper presents a review on issues on additivating vegetal oils with friction and anti-wear modifiers. A SWOT analysis on vegetal oils reveals the shortcomings of these oils and the trend in their modification by the help of additives. Based on research reports available from literature and their experimental work, the authors formulated a synthesis on how the friction and wear modifiers act in lubricants and especially in vegetal oils. They discussed the influence of some friction and anti-wear modifiers added in vegetal oils, especially in soybean oil and rapeseed oil. The conclusion is that additivation of vegetal oils is still at the beginning as the reported results are not so efficient as compared to aditivation of classical alternative -mineral oils and even less as compared to synthetic oils. But research must be continued as these vegetal oils become an actual resource for lubricants base-stock.
Geometry influence on silent chain – sprocket friction
Authors: Jurj L , Velicu R , Lates M T 
Published: June 2019

Abstract
The silent chains in theory should not present friction at the level of the plate entering in contact with the sprocket, based on the literature. Experimental results have shown that there is a certain amount of friction, which can be inspected even visually. This scientific paper presents a geometric simulation using the exact geometry of the plate and the sprocket, to calculate the amount of mechanical work lost by friction at the entering of the plate in contact with the sprocket teeth. This modelling considers the different deviations of the pitch of the chain, resulted from nominal tolerances, elastic elongation and wear.
Virtual keyboard based on a brain-computer interface
Authors: Rusanu O A , Cristea L , Luculescu M C , Cotfas P A , Cotfas D T 
Published: June 2019

Abstract
This paper proposes a novel LabVIEW based algorithm regarding the implementation of an eye-blinks strength controlled virtual keyboard aimed to help people with neuromotor disabilities. The application can be considered a brain-computer interface which is useful for the assistance of patients suffering from Locked-In syndrome or amyotrophic lateral sclerosis. A precise, repeatable and easily detectable control signal could be the eye-blink strength. The LabVIEW based virtual keyboard provides the following features: detection and counting the voluntary eye-blinks, switch command, select command, highlight action running in parallel with the previously mentioned processes, enabling cancel, delete and space commands. The working principle underlying the implementation of the proposed virtual keyboard is Divide and Conquer paradigm. Thus, it is possible the switching task across the rows, half rows and keys (characters) in order to select a row, half row, respectively key associated to the character that should be introduced in the text box.
Classification of industrial robots according to the number of degrees of mobility-structural synthesis and useful configurations
Authors: Staretu I 
Published: June 2019

Abstract
Industrial serial robots can be classified according to several criteria, the most important being: the number of mobility degrees or independent movements, the number of independent kinematic axes, the shape of the workspace, the value of the useful load, the precision of touching a predetermined point, etc. Among these criteria, the number of degrees of mobility directly determines the structure of the kinematic chain corresponding to the robot and implicitly its construction, functionality and utility. In this paper, we define the three classes of industrial serial robots according to the degree of mobility: the class of industrial serial robots of minimum configuration, the class of redundant industrial serial robots and the class of hyper-redundant industrial serial robots. For each class of industrial serial robots the structural synthesis method is presented and representative examples of structures are given.
A survey on gear meshing quality based on tooth contact analysis
Authors: Radu M C , Andrei L , Andrei G 
Published: June 2019

Abstract
Gears are common mechanical elements in power transmission systems. In order to avoid failure of transmission systems, it is necessary to inspect the gear meshing condition with respect to kinematic and dynamic parameters. Tooth contact analysis (TCA) method represents a useful tool for designing and analysing gear performance. It represents an important method to examine gear tooth contact points, contact ratios and kinematic errors. The primary objective of TCA is to establish the contact trail on gear tooth surfaces, and also to determine the transmission error functions generated by gear misalignments. TCA has several branches such as the loaded tooth contact analysis, unloaded tooth contact analysis and tooth contact analysis with errors. The determination of the initial contact point is necessary in order to achieve an accurate solution. The present survey allows a new insight into the improvement of the gear meshing quality, based on tooth contact analysis and transmission error.
The effect of urban buildings on the implementation of small wind turbines
Authors: Ciobanu D , Gheorghe M , Saulescu R , Midoi B , Jaliu C 
Published: June 2019

Abstract
The paper presents the main factors that can influence the location of a wind turbine (building shape, construction height, direction and wind speed) aiming to increase its performance. Thus, three types of buildings with various shapes and heights, which can be found in the urban environment (houses, offices and hotels) are presented in a case study, numerical simulations being carried out using the ANSYS software. The aerodynamic tunnel is customized for each building while maintaining a proportion of the building and the space needed to analyse it. All buildings are rotated to the wind direction and not to the theoretical North. The objective of this paper is to identify the area of the building in which an increase of the airflow is obtained, which allows to increase the performances of the wind turbine. The results allow formulating recommendations for the implementation location and types of units that should be installed.