bluuebunny/crossref_metadata_2025_split huggingface dataset:
Step height standards based on self-assembly for 3D metrology of biological samples
Authors: Heikkinen V , Kassamakov I , Viitala T , Järvinen M , Vainikka T , Nolvi A , Bermúdez C , Artigas R , Martinez P , Korpelainen V , Lassila A , Hæggström E 
Published: April 2020

Abstract
Modern microscopes and profilometers such as the coherence scanning interferometer (CSI) approach sub-nm precision in height measurements. Transfer standards at all measured size scales are needed to guarantee traceability at any scale and utilize the full potential of these instruments, but transfer standards with similar characteristics upon reflection to those of the measured samples are preferred. This is currently not the case for samples featuring dimensions of less than 10 nm and for biosamples with different optical charasteristics to silicon, silica or metals. To address the need for 3D images of biosamples with traceable dimensions, we introduce a transfer standard with dimensions guaranteed by natural self-assembly and a material that is optically similar to that in typical biosamples. We test the functionality of these transfer standards by first calibrating them using an atomic force microscope (AFM) and then using them to calibrate a CSI. We investigate whether a good enough calibration accuracy can be reached to enable a useful calibration of the CSI system. The result is that the calibration uncertainty is only marginally increased due to the sample.
Penalized maximum-likelihood reconstruction for improving limited-angle artifacts in a dedicated head and neck PET system
Authors: Zhang Hengquan , Wang Yuli , Qi Jinyi , Abbaszadeh Shiva 
Published: April 2020

Abstract
Positron emission tomography (PET) suffers from limited spatial resolution in current head and neck cancer management. We are building a dual-panel high-resolution PET system to aid the detection of tumor involvement in small lymph nodes (

<

10 mm in diameter). The system is based on cadmium zinc telluride (CZT) detectors with cross-strip electrode readout (1 mm anode pitch and 5 mm cathode pitch). One challenge of the dual-panel system is that the limited angular coverage of the imaging volume leads to artifacts in reconstructed images, such as the elongation of lesions. In this work, we leverage a penalized maximum-likelihood (PML) reconstruction for the limited-angle PET system. The dissimilarity between the image to be reconstructed and a prior image from a low-resolution whole-body scanner is penalized. An image-based resolution model is incorporated into the regularization. Computer simulations were used to evaluate the performance of the method. Results demonstrate that the elongation of the 6-mm and 8-mm diameter hot spheres is eliminated with the regularization strength γ being 0.02 or larger. The PML reconstruction yields higher contrast recovery coefficient (CRC) of hot spheres compared to the maximum-likelihood reconstruction, as well as the low-resolution whole-body image, across all hot sphere sizes tested (3, 4, 6, and 8 mm). The method studied in this work provides a way to mitigate the limited-angle artifacts in the reconstruction from limited-angle PET data, making the high-resolution dual-panel dedicated head and neck PET system promising for head and neck cancer management.
Delineating rainbow reflection and trapping with applications for energy harvesting
Authors: Chaplain G J , Pajer Daniel , De Ponti Jacopo M , Craster R V 
Published: April 2020

Abstract
Important distinctions are made between two related wave control mechanisms that act to spatially separate frequency components; these so-called rainbow mechanisms either slow or reverse guided waves propagating along a graded line array. We demonstrate an important nuance distinguishing rainbow reflection from genuine rainbow trapping and show the implications of this distinction for energy harvesting designs, through inspection of the interaction time between slowed zero group velocity waves and the array. The difference between these related mechanisms is highlighted using a design methodology, applied to flexural waves on mass loaded thin Kirchhoff–Love elastic plates, and emphasised through simulations for energy harvesting in the setting of elasticity, by elastic metasurfaces of graded line arrays of resonant rods atop a beam. The delineation of these two effects, reflection and trapping, allows us to characterise the behaviour of forced line array systems and predict their capabilities for trapping, conversion and focussing of energy.
Hubble telescope 30 years in orbit: personal reflections
Authors: Williams Robert 
Published: April 2020

Abstract
With an initial requirement to make observations a minimum of 5–10 years, Hubble Space Telescope (HST) has continued to operate well for 30 years. It has relied upon five servicing missions to repair and replace essential components. Since the final Space Shuttle mission 10 years ago, it has avoided major breaks in its operation, with the only serious effects of aging in space being a progressive deterioration in the performance of the gyroscopes and sensitivity of the instrument detectors. A number of factors were important in making HST a scientific landmark. Ground-breaking discoveries have been made with HST — the most important being the discovery of cosmic acceleration. When HST operation ceases, future observations in space should be assured with successful operation of major missions now planned by NASA, ESA, and the Chinese and Japanese Space Agencies.
HIKER: a halo-finding method based on kernel-shift algorithm
Authors: Sun Shuang-Peng , Liao Shi-Hong , Guo Qi , Wang Qiao , Gao Liang 
Published: April 2020

Abstract
We introduce a new halo/subhalo finder, HIKER (a Halo fInder based on KERnel-shift algorithm), which takes advantage of a machine learning method – the mean-shift algorithm combined with the Plummer kernel function, to effectively locate density peaks corresponding to halos/subhalos in density field. Based on these density peaks, dark matter halos are identified as spherical overdensity structures, and subhalos are bound substructures with boundaries at their tidal radius. By testing HIKER code with mock halos, we show that HIKER performs excellently in recovering input halo properties. In particular, HIKER has higher accuracy in locating halo/subhalo centres than most halo finders. With cosmological simulations, we further show that HIKER reproduces the abundance of dark matter halos and subhalos quite accurately, and the HIKER halo/subhalo mass functions and V
max functions are in good agreement with two widely used halo finders, SUBFIND and AHF.
New multi-color photometric investigations of solar-like contact binary V680 Per
Authors: Wang Jing-Jing , He Jia-Jia , Zhao Song-Qing 
Published: April 2020

Abstract
High-precision CCD photometric observations of the contact binary V680 Per were obtained in 2016. Its symmetric multi-color light curves were analyzed by using the Wilson–Devinney (2013) program. These photometric solutions suggest that V680 Per is an A-type W UMa contact binary with the mass ratio of q = 0.693 and a fill-out factor of f = 18.84% with a small temperature difference of 101 K. Based on all minimum times, the O − C curve was analyzed for the first time in this study. A cyclic oscillation (A
3 = 0.00093 d, T
3 = 4.92 yr) superimposed on a secular decrease (dP/dt = −8.16 × 10−8 d yr−1) was identified. The continuous decrease in period is possibly a result of mass transfer from the more massive component to the less massive one, or angular momentum loss due to a magnetic stellar wind. Because of this secular decrease, it is predicted that the degree of contact will become higher, and V680 Per will evolve into a deeper overcontact binary.
Exploring the spectral information content in the LAMOST medium-resolution survey (MRS)
Authors: Zhang Bo , Liu Chao , Li Chun-Qian , Deng Li-Cai , Yan Tai-Sheng , Shi Jian-Rong 
Published: April 2020

Abstract
Although high-resolution stellar spectra allow us to derive precise stellar labels (effective temperature, metallicity, surface gravity, elemental abundances, etc.) based on resolved atomic lines and molecular bands, low-resolution spectra have been proved to be competitive in determiningmany stellar labels at comparable precision. It is useful to consider the spectral information content when assessing the capability of a stellar spectrum in deriving precise stellar labels. In this work, we quantify the information content brought by the LAMOST-II medium-resolution spectroscopic survey (MRS) using the gradient spectra as well as the coefficients-of-dependence (CODs). In general, the wavelength coverage of the MRS well constrains the stellar labels but the sensitivities of different stellar labels vary with spectral types and metallicity of the stars of interest. Consequently, this affects the performance of the stellar label determination from the MRS spectra. By applying the SLAM method to the synthetic spectra which mimic the MRS data, we find that the precision of the fundamental stellar parameters T
eff, log g and [M/H] are better when combining both the blue and red bands of the MRS. This is especially important for warm stars because the Hα line located in the red part plays a more important role in determining the effective temperature for warm stars. With blue and red parts together, we are able to reach similar performance to the low-resolution spectra except for warm stars. However, at [M/H] ∼ −2.0 dex, the uncertainties of fundamental stellar labels estimated from MRS are substantially larger than that from low-resolution spectra. We also tested the uncertainties of T
eff, log g and [M/H] From MRS data induced from the radial velocity mismatch and find that a mismatch of about 1 km s−1, which is typical for LAMOST MRS data, would not significantly affect the stellar label estimates. Finally, reference precision limits are calculated using synthetic gradient spectra, according to which we expect abundances of at least 17 elements to be measured precisely from MRS spectra.
Investigation of near-contact semi-detached binary WUMi through observations and evolutionary models
Authors: Soydugan Faruk , Soydugan Esin , Aliçavuş Fahri 
Published: April 2020

Abstract
W UMi is a near contact, semi-detached, double-lined eclipsing binary star with an orbital period of 1.7 d. Simultaneous analysis of new BV R multi-color light curves and radial velocity data yields the main astrophysical parameters of the binary and its component stars. We determined mass and radius to be M
1 = 3.22 ± 0.08 M
⊙, R
1 = 3.63 ± 0.04 R
⊙ for the primary star and M
2 = 1.44 ± 0.05 M
⊙, R
2 = 3.09 ± 0.03 R
⊙ for the secondary star. Based on analysis of mid-eclipse times, variation in the orbital period is represented by a cyclic term and a downward parabola. Mass loss from the system is suggested for a secular decrease (−0.02 s yr−1) in the period. Both the mechanisms of a hypothetical tertiary star orbiting around W UMi and the surface magnetic activity of the less massive cooler companion were used to interpret periodic changes. Observational parameters were found to be consistent with binary stellar evolution models produced in the non-conservative approach of MESA at a higher metallicity than the Sun and an age of about 400 Myr for the system. Evidence that the system is rich in metal was obtained from spectral and kinematic analysis as well as evolution models. W UMi, a high mass ratio system compared to classical semi-detached binaries, is an important example since it is estimated from binary evolutionary models that the system may reach its contact phase in a short time interval.
Simultaneous photometric and spectral analysis of a new outburst of V1686 Cyg
Authors: Andreasyan Hasmik , Magakian Tigran , Movsessian Tigran 
Published: April 2020

Abstract
We present an analysis of the optical observations of Herbig Ae/Be (HAeBe) star V1686 Cyg, which is associated with a small isolated star-forming region around HAeBe star BD+40°4124. We observed this star as a part of our project investigating young eruptive stars. Observations were conducted on the 2.6-m telescope of Byurakan Observatory from 2015 to 2017. In this period, we obtained direct images of V1686 Cyg and 14 medium- and low-resolution spectra. In the course of observations, we noticed that this star underwent an atypical brightness outburst. After data reduction, we found that the full rise and decline in the brightness of V1686 Cyg had an amplitude of almost 3 magnitudes and lasted about 3 months. We were also able to track changes in the stellar spectrum during the outburst, which are correlated with the photometric variations.
Cosmological constraints on ultra-light axion fields
Authors: Kang Jian-Gang , Gong Yan , Cheng Gong , Chen Xuelei 
Published: April 2020

Abstract
Ultra-light axions (ULAs) with mass less than 10−20 eV have interesting behaviors that may contribute to either dark energy or dark matter at different epochs of the Universe. Their properties can be explored by cosmological observations, such as expansion history of the Universe, cosmic large-scale structure, cosmic microwave background, etc. In this work, we study the ULAs with mass around 10−33 eV, which means that the ULA field still rolls slowly at present with the equation of state w = −1 as dark energy. To investigate the mass and other properties of this kind of ULA field, we adopt the measurements of Type Ia supernova (SN Ia), baryon acoustic oscillation (BAO), and Hubble parameter H(z). The Markov Chain Monte Carlo (MCMC) technique is employed to perform the constraints on the parameters. Finally, by exploring four cases of the model, we find that the mass of this ULA field is about 3 × 10−33 eV if assuming the initial axion field ϕ
i = M
pl. We also investigate a general case by assuming ϕ
i ≤ M
pl, and find that the fitting results of ϕ
i/M
pl are consistent with or close to 1 for the datasets that we use.
Study on the pointing model of a slant-axis terahertz antenna
Authors: Wang Yu , Lou Zheng , Zuo Ying-Xi , Kang Hao-Ran , Zhang Ming-Zhu 
Published: April 2020

Abstract
This paper describes the establishment and verification of an accurate pointing model for a 1.2 m aperture slant-axis terahertz antenna. A new analytical pointing model for the slant-axis antenna is presented based on an analogy to that of the alt-azimuth antennas. Furthermore, extra error terms are added to the pointing model based on the structure and mechanical analysis of the slant-axis antenna. To verify the pointing model experimentally, a pointing error measurement method based on photogrammetric techniques is proposed. Using this method, pointing behaviors of the antenna are accurately measured without the aid of astronomical observations, and major sources of the pointing errors are measured individually by photogrammetry and their respective coefficients are compared with those in the analytical pointing model. The results show that an extended pointing model consisting 21 error terms can significantly reduce the residual systematic errors compared with the traditional model, more details are given in the following sections.
Photometric light curve solutions of three ultra-short period eclipsing binaries
Authors: Acerbi Francesco , Michel Raul , Barani Carlo , Martignoni Massimiliano , Fox-Machado Lexter 
Published: April 2020

Abstract
We present the results of our study of the eclipsing binary systems CSS J112237.1+395219, LINEAR 1286561 and LINEAR 2602707 based on new CCD B, V, Rc
and Ic
complete light curves. The ultra-short period nature of these stars, as reported by Drake et al., is confirmed and the system’s periods are revised. The light curves were modeled using the 2003 version of the Wilson-Devinney code. When necessary, cool spots on the surface of the primary component were introduced to account for asymmetries in the light curves. As a result, we found that CSS J112237.1+395219 is a W UMa type contact binary system belonging to W subclass with a mass ratio of q = 1.61 and a shallow degree of contact of 14.8% where the primary component is hotter than the secondary one by 500 K. LINEAR 1286561 and LINEAR 2602707 are detached binary systems with mass ratios q = 3.467 and q = 0.987 respectively. These detached systems are low-mass M-type eclipsing binaries with similar temperatures. The marginal contact, fill-out factor and temperature difference between components of CSS J112237.1+395219 suggest that this system may be at a key evolutionary state predicted by thermal relaxation oscillation (TRO) theory. From the estimated absolute parameters, we conclude that our systems share common properties with other ultra-short period binaries.
Preliminary Study of Melting Basalt Rock As A Raw of Advanced Material
Authors: Isnugroho Kusno , Birawidha David C , Hendronursito Yusup , Amin Muhammad , Muttaqii Muhammad Al , Efriyo Hadi R Agung , Fazma Muhammad Fadil 
Published: April 2020

Abstract
The aim of this research is to conduct initial research on the process of melting basalt rocks using an upright shaft furnace. The preliminary process of melting basalt rock has been carried out as a raw of advanced material. The raw material of basalt was obtained from East Lampung, Lampung Province, Indonesia. Coke is used as fuel for the smelting process. Laboratory scale of shaft furnace which is designed and made by Research Unit for Mineral Technology is used for the smelting process. The basalt smelting process lasts for 4 hours, starting from the charging materials to the tapping process, with a process temperature of 1500-1600 °C. The yield of this process can reach 68,7%, while the rest was trap inside the bottom of the furnace due to lack of pressure at the end of the smelting process and the other was lost during the process. The product was basalt cast with the following dominant composition is MgO 5.244%, Al2O3 21.295%, SiO2 48.750, CaO 10.138%, Fe2O3 11.019%, TiO2 1.361% and Na2O 2.132%. However, the products obtained are still brittle. Therefore, further research related to the crystallization process needs to be done to obtain products that are not brittle.
Optimization of Fuel Savers Preheater Water System (PWS) for Diesel Fuel
Authors: Pranoto A , Purwanto A 
Published: April 2020

Abstract
The present work aims to design and investigate the performance of diesel fuel heating system called Preheater Water System (PWS). The PWS is made of stainless-steel container, copper spiral pipe and electric heater. The container has a diameter of 140 mm and height of 170 mm. The tube has a diameter of 8.5 mm. This system heats the diesel fuel before entering the fuel injector pump. The system utilizes heat from the heat from radiator cooling water and also uses additional electrical heating. The system is equipped with temperature sensor to measure the diesel fuel entering the fuel injector pump. The results show that at engine speed of 800 rpm (idle condition), temperature of the fuel increases 55°C, fuel consumption is 26% more efficient. At medium speed of 1200 rpm, the temperature increases up to 55°C and fuel consumption is 15% less. Meanwhile at the engine speed of 2200 rpm, the temperature rises to 60°C and fuel consumption increases up to 15%. In can be conclude that the PWS works well and the optimum temperature of the diesel fuel is 50°C.
Optimization of information technology utilization based on geography information system as a marketing media for micro, small, and medium enterprises to improve competitiveness in Bantul Regency, Indonesia
Authors: Hardiyanto Denny , Sholeh Muhammad , Rachmawati Rr Yuliana 
Published: April 2020

AbstractMicro, small and medium enterprises (MSMEs) are the largest group of economic actors in the Indonesian economy. The growth of the micro industry grew by 8% every year, especially in Bantul Regency, Special Region of Yogyakarta. Various factors that led to the growth of the small micro industry in Bantul were caused by the increasing stretch of business in the creative economy sector, the majority of which were engaged in the craft sector. As support, the Government of Bantul provides policies that protect or secure raw materials for handicraft or industrial production properly and facilitate physical promotion by participating in various exhibition events through online media. In the era of information technology development, the support of online information system become one of the promotional media that can reach a large area. The research objectives are to build a website for MSME in Bantul Regency and to provide a media for MSME actors to advertise their goods and services. In this study, the MSME information system that was built was equipped with facilities for maps, images and videos of MSME products. This map facility makes it easy for users to go to business locations. The system was developed by utilizing the Application Programming Interface (API) of google map and database used to store all MSME data using MySQL with the PHP: Hypertext Pre-processor Programming language. The result is development of marketplace website (https://wartacara.com/ukm) that have many features to explore and advertise MSME actor in Bantul Regency.
The Effect of Orientation Fibres on Flexural and Tensile Properties of Arenga Pinnata Fibres Reinforced Polyester Composites
Authors: Widodo R D , Robi W , Rusiyanto  , Nugroho A , Al-Janan D H 
Published: April 2020

AbstractThis paper presents flexural and tensile properties of sugar palm (Arenga pinnata) fibres-reinforced polyester composites study. The fibres were treated by alkaline solution with 5% NaOH solution for 2 hours of soaking time. The composites were prepared with different orientations of fibres (i.e. 0° + 45°, 0° + 90°, 45° + 90°, and 45° + (-45°)), while the ratio between Arenga pinnata fibres and polyester is 30 percent volume. Hand lay-up method was employed to produce the specimens. ASTM D-790 03 and ASTM D-3039 standard were employed to characterize the specimens in good sequent. As the result, the specimen with 45°+90° orientation generated maximum important values both in flexural strength (24.03 MPa) and modulus (4.01 GPa), tensile strength (23.84 MPa) and modulus elasticity (0.97 GPa). This is due to palm fibres as reinforcement that forms an angle of 90 ° or increasingly upright to the load crossing field (load of bending) and tensile load giving the effect of maximum reinforcement compared to other fibres orientations.
Identification of the delaying factors on construction work completion in Jambi city according to the contractor perception
Authors: Handayani Elvira , Amalia Kiki Rizky , Yamali Fakrul Rozi 
Published: April 2020

Abstract
One of the successes in the Implementation of Construction Works is marked by the implementation of timely work. However, in the process of implementing the construction work often encountered various problems, one of which is work delays. the number of factors is the cause of delays that are often faced by parties involved, especially contractors who act as executors. This study aims to determine the main factors of the delay in the Construction Work. The questionnaire was distributed to 63 Middle-class contractors with the value of the company’s assets qualified into the M1-M2 based on the Business Entity Registration List (DRBU) of the Jambi City Construction Services Development Agency (LPJK). The factors of delay in construction work are grouped into 7 factors, each of which consists of several sub-factors. The results showed that the most dominant factor in the construction work in Jambi City was environmental factors with sub-factors Heavy rain / waterlogged work location with a percentage of 15.73%, while the Time Factors namely Sub-factors Too late shop drawing agreement is the 7th most influential factor in work delay has the smallest percentage value of 13.41%.