bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combining Floquet and Lyapunov techniques for time-dependent problems in optomechanics and electromechanics
Authors: Pietikäinen Iivari , Černotík Ondřej , Filip Radim 
Published: April 2020

Abstract
Cavity optomechanics and electromechanics form an established field of research investigating the interactions between electromagnetic fields and the motion of quantum mechanical resonators. In many applications, linearised form of the interaction is used, which allows for the system dynamics to be fully described using a Lyapunov equation for the covariance matrix of the Wigner function. This approach, however, is problematic in situations where the Hamiltonian becomes time dependent as is the case for systems driven at multiple frequencies simultaneously. This scenario is highly relevant as it leads to dissipative preparation of mechanical states or backaction-evading measurements of mechanical motion. The time-dependent dynamics can be solved with Floquet techniques whose application is, nevertheless, not straightforward. Here, we describe a general method for combining the Lyapunov approach with Floquet techniques that enables us to transform the initial time-dependent problem into a time-independent one, at the acceptable cost of enlarging the drift and diffusion matrix. We show how the lengthy process of applying the Floquet formalism to the original equations of motion and deriving a Lyapunov equation from their time-independent form can be simplified with the use of properly defined Fourier components of the drift matrix of the original time-dependent system. We then use our formalism to comprehensively analyse dissipative generation of mechanical squeezing beyond the rotating wave approximation. Our method is applicable to various problems with multitone driving schemes in cavity optomechanics, electromechanics, and related disciplines.
A recurrent plot based stochastic nonlinear ray propagation model for underwater signal propagation
Authors: Haiyang Yao , Haiyan Wang , Yong Xu , Kurths Juergen 
Published: April 2020

Abstract
A stochastic nonlinear ray propagation model is proposed to carry out an exploration of the nonlinear ray theory in underwater signal propagation. The recurrence plot method is proposed to quantify the ray chaos and stochastics to optimize the model. Based on this method, the distribution function of the control parameter δ is derived. Experiments and simulations indicate that this stochastic nonlinear ray propagation model provides a good explanation and description on the stochastic frequency shift in underwater signal propagation.
Spectro-polarimetric observations at the NVST: I. instrumental polarization calibration and primary measurements
Authors: Hou Jun-Feng , Xu Zhi , Yuan Shu , Chen Yu-Chao , Peng Jian-Guo , Wang Dong-Guang , Xu Jun , Deng Yuan-Yong , Jin Zhen-Yu , Ji Kai-Fan , Liu Zhong 
Published: April 2020

AbstractThis paper is devoted to the primary spectro-polarimetric observation performed at the New Vacuum Solar Telescope (NVST) of China since 2017, and our aim is to precisely evaluate the real polarimetric accuracy and sensitivity of this polarimetry by using full Stokes spectro-polarimetric observations of the photospheric line Fe I 532.4 nm. In the work, we briefly describe the salient characteristic of the NVST as a polarimeter in terms of technology and then characterize its instrumental polarization based on the operation in 2017 and 2019. It is verified that the calibration method utilizing the instrumental polarization calibration unit (ICU) is stable and credible. The calibration accuracy can reach up to 3 × 10−3. Based on the scientific observation of NOAA Active Region 12645 on 2017 April 5, we estimate that the residual cross-talk from StokesIto StokesQ,UandV, after the instrumental polarization calibration, is about 4 × 10−3on average, which is consistent with the calibration accuracy and close to the photon noise. The polarimetric sensitivity (i.e., the detection limit) for polarized light is of the order of 10−3with an integration time over 20 s. Slow modulation rate is indeed an issue for the present system. The present NVST polarimeter is expected to be integrated with a high-order adaptive optics system and a field scanner to realize 2D vector magnetic field measurements in the following instrumentation update.
A study of type I X-ray bursts from an NS accreting pure helium
Authors: Ma Yan-Cun , Liu He-Lei , Zhu Chun-Hua , Wang Zhao-Jun , Li Lin , Lü Guo-Liang 
Published: April 2020

Abstract
Using the Modules for Experiments in Stellar Astrophysics (MESA) code, we investigate Type I X-ray bursts (XRBs) produced by neutron stars (NSs) accreting pure helium, which are called intermediate XRBs in observations. We simulate 21 models for intermediate XRBs with various mass-accretion rates (Ṁ) from 2.5 × 10−8 to 5 × 10−10
M
⊙ yr−1. Compared with normal XRBs, in which the NS accretes matter with solar metallicity, intermediate XRBs have higher luminosity and longer recurrence time, which are essentially consistent with observations. We find that the recurrence time of intermediate XRBs is proportional to Ṁ
−2.0.
The column density structure of Orion A depicted by N-PDF
Authors: Ma Yue-Hui , Wang Hong-Chi , Li Chong , Yang Ji 
Published: April 2020

Abstract
We have conducted a large-field simultaneous survey of 12CO, 13CO and C18O J = 1 – 0 emission toward the Orion A giant molecular cloud (GMC) with a sky coverage of ∼4.4 deg2 using the Purple Mountain Observatory (PMO)-13.7 m millimeter-wavelength telescope. We use the probability distribution function of the column density (N-PDF) to investigate the distribution of molecular hydrogen in the Orion A GMC. The H2 column density, derived from the 13CO emission, of the GMC is dominated by a log-normal distribution in the range from ∼ 4 × 1021 to ∼ 1.5 × 1023 cm−2 with excesses both at the low-density and high-density ends. The excess of the low-density end is possibly caused by an extended and low-temperature (∼10 K) component with velocities in the range of 5 – 8 km s−1. Compared with the northern sub-regions, the southern sub-regions of the Orion A GMC contain less gas with column density in N
H2
> 1.25 × 1022 cm−2. The dispersions of the N-PDFs of the sub-regions are found to correlate with the evolutionary stages of the clouds across the Orion A GMC. The structure hierarchy of Orion A GMC is explored with the DENDROGRAM algorithm, and it is found that the GMC is composed of two branches. All structures except one in the tree have virial parameters less than 2, indicating self-gravity is important on the spatial scales from ∼0.3 to ∼4 pc. Although power-laws and departures from lognormal distributions are found at the high-density end of N-PDFs for active star-forming regions, the N-PDFs of structures in the Orion A GMC are predominantly lognormal on scales from R∼0.4 to 4 pc.
Chinese sunspot drawings and their digitization – (II) accuracy analysis for digitized sunspot hand-drawing records of Yunnan Observatories
Authors: Peng Yang , Luo Xiao-Yu , Zeng Shu-Guang , Deng Lin-Hua , Zheng Sheng , Lin Gang-Hua , Cheng Yu-Lin , Tao Jin-Ping , Feng Yong-Li 
Published: April 2020

Abstract
Sunspots are the most striking and easily observed magnetic structures of the Sun, and statistical analysis of solar historical data could reveal a wealth of information on the long-term variation of solar activity cycle. The hand-drawn sunspot records of Yunnan Observatories, Chinese Academy of Sciences have been accumulating for more than 60 years, and nearly 16 000 images have been preserved. In the future, the observation mode of recording sunspots by hand-drawing will be replaced inevitably by digital images observed either at ground or in space. To connect the hand-drawn sunspot data and the purely digital sunspot data in future, it is necessary to analyze the systematic errors of the data which are observed by the two observation modes in the period of transition. In this paper, we choose 268 round sunspots (H-type in modified Zurich sunspot classification) from the drawing of Yunnan Observatories to compare their positions and areas with the CCD observations made by Helioseismic and Magnetic Imager (HMI) on board Solar Dynamic Observatory (SDO) and Global Oscillation Network Group (GONG). We find that the latitude and longitude accuracy of hand-drawn sunspot are within −0.127 and 2.29 degree respectively, and the area accuracy is about 16.36 sunspot unit (μHem). Systematic errors apparently decrease with large sunspot.
Burning fraction, radial transport, and steady state profiles of multi-species particles in CFETR burning plasmas
Authors: Lin W.S. , Wang X.G. , Xiao C.J. , Wang Z.H. , Kong D.F. , Lang Y. 
Published: April 2020

Abstract
The burning fraction of fuel particles is a crucial issue for future fusion reactors. In order to achieve the high tritium burning fraction required by China Fusion Engineering Test Reactor (CFETR) engineering design, fueling depths and quantities should be estimated by particle control analysis for different scenarios. Thus, in this paper, a multi-species fluid model of deuterium-tritium (D-T) fusion plasmas is applied to study radial transport and profile evolution with CFETR parameters under different fueling conditions. In the model, alpha particles are treated with a slowing down model and diffusion coefficients are introduced according to

τ

E
_
9
8

. Then, in such a self-consistent burning plasma simulation, the results show that the fusion reaction and fueling parameters effect remarkably changes the shape of D/T profiles, while to alphas and helium ash however, the effect of the fueling parameters is much weaker. It is also seen that the burning fraction is increased substantially with the fueling depth, and significantly affected by particle confinement. Furthermore, by substantially raising the D:T ratio to the regime of above unity, the burning fraction can be increased notably, but with a cost of a certain level of fusion power reduction.
Development of an in situ injectable hydrogel containing hyaluronic acid for neural regeneration
Authors: Nguyen Linh T B , Hsu Chia-Chen , Ye Hua , Cui Zhanfeng 
Published: April 2020

Abstract
In this work, a novel enzymatically crosslinked injectable hydrogel comprising hyaluronic acid (HyA), dopamine (DA), and 3-(4-hydroxyphenyl) propionic acid (HPA) conjugates was successfully developed. To the best of our knowledge, it is the first time that HPA is conjugated to a HyA-based backbone. In situ hydrogelation of HyA-DA-HPA occurred in the presence of hydrogen peroxide (H2O2) as an oxidant and horseradish peroxidase (HRP) as a catalyst. Proton nuclear magnetic resonance and Fourier transform infrared spectroscopy were used to characterize the chemical reactions between HyA, DA, and HPA. Gel formation completed between 3 s to 5 min depending on the concentrations of polymer, HRP, and H2O2. Crosslinked HyA-DA-HPA gels acquired storage moduli ranging from ∼100 Pa to ∼20 000 Pa (at f = 2000 rad s−1). Biocompatibility of the hydrogels was examined with human mesenchymal stem cells (hMSCs) and human induced pluripotent stem cell-derived neural stem cells. The hydrogels made of 2.0 w/v% HyA-DA-HPA hydrogels, 0.24 U ml−1 HRP and ≤ 0.5 µmol ml−1 H2O2 were found biocompatible with hMSCs cultured on and encapsulated within the hydrogels. Since HyA serves as a backbone of the extracellular matrix in the central nervous system (CNS) and DA acquires the ability to restore dopaminergic neurons, use of this injectable HyA-DA-HPA hydrogel for stem cell transplantation is a potential treatment strategy for CNS repair and regeneration.
The effect of surge on riverine flood hazard and impact in deltas globally
Authors: Eilander Dirk , Couasnon Anaïs , Ikeuchi Hiroaki , Muis Sanne , Yamazaki Dai , Winsemius Hessel C , Ward Philip J 
Published: April 2020

Abstract
Current global riverine flood risk studies assume a constant mean sea level boundary. In reality high sea levels can propagate up a river, impede high river discharge, thus leading to elevated water levels. Riverine flood risk in deltas may therefore be underestimated. This paper presents the first global scale assessment of the joint influence of riverine and coastal drivers of flooding in deltas. We show that if storm surge is ignored, flood depths are significantly underestimated for 9.3% of the expected annual population exposed to riverine flooding. The assessment is based on extreme water levels at 3433 river mouth locations as modeled by a state-of-the-art global river routing model, forced with a multi-model runoff ensemble and bounded by dynamic sea level conditions derived from a global tide and surge reanalysis. We first classified the drivers of riverine flooding at each location into four classes: surge-dominant, discharge-dominant, compound-dominant or insignificant. We then developed a model experiment to quantify the effect of surge on flood hazard and impacts. Drivers of riverine flooding are compound-dominant at 19.7% of the locations analyzed, discharge-dominant at 69.2%, and surge-dominant at 7.8%. Compared to locations with either surge- or discharge-dominant flood drivers, locations with compound-dominant flood drivers generally have larger surge extremes and are located in basins with faster discharge response and/or flat topography. Globally, surge exacerbates 1-in-10 years flood levels at 64.0% of the locations analyzed, with a mean increase of 11 cm. While this increase is generally larger at locations with compound- or surge-dominant flood drivers, flood levels also increase at locations with discharge-dominant flood drivers. This study underlines the importance of including dynamic downstream sea level boundaries in (global) riverine flood risk studies.
Control of transient climate response and associated sea level rise by deep-ocean mixing
Authors: Watanabe Michio , Tatebe Hiroaki , Suzuki Tatsuo , Tachiiri Kaoru 
Published: April 2020

Abstract
To evaluate uncertainty in the transient climate response (TCR) associated with microscale deep-ocean mixing processes induced by internal tidal wave breaking, a set of idealized climate model experiments with two different implementations of deep-ocean mixing is conducted under increasing atmospheric CO2 concentration 1% per year. The difference in TCR between the two experiments is 0.16 °C, which is about half as large as the multimodel spread of TCR in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The TCR difference can be attributed to the difference in the preindustrial climatological state. In the case where deep-ocean mixing works to enhance ocean stratification in the Pacific intermediate-to-deep layers, because the Pacific water mass is transported to the Southern Ocean by the Pacific meridional overturning circulation, the subsurface stratification in the Southern Ocean is also enhanced and deep wintertime convection there is suppressed. Our study shows that in this case during CO2 increase, ocean heat uptake from the atmosphere to deeper layers is suppressed and TCR is estimated to be higher than the other case. Diminished accumulation of oceanic heat in the deep layer also leads to the sea level depression of ∼0.4 m in the Southern Ocean when atmospheric CO2 concentration has quadrupled. Together with convective and cloud-radiative processes in the atmosphere and oceanic mesoscale processes, microscale deep-ocean mixing can be one of the major candidates in explaining uncertainty in future climate projections.
Study the Effect of Combination of Shoe Height and Slot Opening width to Reduce Cogging Torque in Permanent Magnet Generator
Authors: Siregar Marsul , Joe Liza E. , Nur Tajuddin 
Published: April 2020

AbstractCogging torque is one important problem in a permanent magnet generator. With a good understanding of the phenomenon, the cogging torque can be minimized by using the multi-objective technique. This paper presents a combination technique for cogging torque reduction by an appropriate small stator slot opening width, stator shoe height with fractional technique in Permanent Magnet Generator. Cogging torque waveforms, along with other relevant characteristics are investigated in this research and by analysis using the finite element method, the combination width shoe height and magnet edge slotting effect to decline the cogging torque peak value. A significant value of cogging torque, when slot opening width of 1.55 mm and shoe height of 2.3 mm, provide the peak value of cogging torque in the structure is 0.00062 N-m for positive value and about -0.00064 N-m for the negative value. It can be concluded that this type of slot opening width of 1.55 mm and shoe height of 2.3 mm is the best structure of the fractional 8 slot, because it has any significant low of cogging torque and least of unbalance magnetic pull
Design of Low Speed Generator 1 Phase Using Permanent Magnetic Type Neodymium
Authors: Syafriyudin  , Mujiman  , Buyung Irawadi 
Published: April 2020

Abstract
The need for electricity in Indonesia and throughout the world is increasing, while most of the energy sources for electricity generation are still using fossil fuels such as oil, natural gas and coal. Fossil energy has a high level of pollution which is the cause of global warming, it is necessary to replace fossil energy that is environmentally friendly, namely renewable energy. The construction of power plants such as micro hydro power plants (PLTMh) which are located in irrigation canals or rivers with relatively small water discharge will result in low wheel rotation. The waterwheel rotation in this PLTMh system has a low rotating speed of around 200 rpm, and has a low torque or no cogging torque effect. Based on the needs in the field, a permanent Neodymium Type (NdFeB) Permanent Magnet Axial Flux Generator is built, which is specifically designed for low speeds of 200 rpm and has no cogging torque or low rotational torque effects. And it is hoped that the design of this generator can be used according to the needs of PLTMH. The results obtained in this study are, the generator can produce a voltage at a rotational speed of 200 Rpm and a frequency of 50 Hz is 100 VAC.
Application of Greenhouse Gas Monitoring System Using General Packet Radio Service on GSM Network
Authors: Iswahyudi C , Novianta M A , Muchlis  , Suseno H P 
Published: April 2020

Abstract
Emissions of carbon dioxide (CO2) is the greatest influence on the air quality for the largest contribution to global warming is about 50%. These gases absorb and reflect radiation emitted waves of the earth, so that the heat will be stored on the surface of the earth. The absorption capacity on mangrove plants is one of the efforts to reduce CO2 emissions. In this work, a gas monitoring system was developed to monitor greenhouse gas utilizing GSM network using GPRS service. Based on experiment result, this system can monitor the absorption of CO2 emissions and the formation of O2 gas in mangrove plants as one of the efforts to reduce the impact of global warming. The information can be transmitted using SMS service on GSM network in less packet size and data transmission time, and also can be accessed through web-based application. As conclusion, the use of small and portable gas-sensing air pollution monitoring technologies can obtain more spatially and temporally representative air pollution data.
Improvement of Teacher’s Ability to Make IT-Based Teaching and Evaluation Materials Using Scribe, Camtasia and Quiz Creator (Case Study in SMK Negeri 1 Tembarak, Temanggung, Central Java, Indonesia)
Authors: Nurnawati E K , Sutanta E , Bekti R D 
Published: April 2020

Abstract
Teachers are an important element in the formal education system, both in primary, secondary, and high education. The ability of teachers to prepare teaching materials is very influential on student learning outcomes. Learning materials that are easy to understand and look interesting will be preferred and easily understood by students. Evaluation is one of the benchmarks for knowing the results achieved by students. Success in delivering subject matter certainly influences the results achieved in student evaluation. This study aims to measure the extent to which training in making teaching materials and exam questions based on information and communication technology (ICT) affects improving the ability of teachers in the learning process and evaluation of students. The method used in this study is a method of collecting data with experimental methods for teachers before and after training. The software used in this training was Scribe 1.0.4 and Camtasia 8.0 video for making IT-based learning material and Quiz Creator 4.5.1 used for making student evaluation materials. Survey data collection was conducted on forty teachers who attended training and sixty students at SMK N 1 Tembarak Temanggung. Wilcoxon Test is used to analyse survey data. The results of this study are that there is a significant correlation with the ability of teachers to develop teaching materials before and after training. The results of a survey of students found that 80% of students preferred teachers to use ICT-based teaching materials and 75% of students preferred to work on ICT-based questions rather than conventional exam questions, 87% teachers found to benefit from the training. The Wilcoxon test proves that the teacher’s ability to make teaching materials and exam materials increases after training.
Low Cycle Fatigue Properties of Aluminizing Coating on Cold-Drawn AISI 1018 Steel
Authors: Badaruddin M , Kurniawan R D , Sugiyanto  , Pambudi A 
Published: April 2020

Abstract
The mechanical and the low cycle fatigue (LCF) properties of cold-drawn AISI 1018 steel (CDS 1018) with and without hot-dip aluminizing (HDA) coating had been experimentally investigated at room temperature. The tensile properties and the LCF properties were determined from tensile test results and cyclic strain-fatigue test results, respectively. The aluminide coating on the CDS 1018 significantly decreases the mechanical properties and the strain-fatigue life of the steel. With increasing in strain amplitude levels, CDS 1018 experienced continuously cyclic softening behaviour after cyclic loading in few cycles. By contrast, the cyclic softening of HDA steel was observed in few cycles and HDA steel continuously exhibits the stably cyclic hardening behaviour until failure. CDS 1018 with aluminide coating results the longer transition fatigue cycles (Nt) than those of CDS 1018 without aluminide coating by a factor of ∼3.0. CDS 1018 with HDA coating can be used for material components which the components are safely designed under cyclic loading below the yield strength of the material.
Analysis of Availability and Water Demand: A Case Study in Sumberejo Village Tanggamus Regency
Authors: Anwar  , Novilyanza Elza , Abdul Fatah Kemas Muhammat 
Published: April 2020

Abstract
Clean water is a basic need for humans so that it is normal if clean water gets priority in handling and fulfilling it. The spring in Sumberejo Village, Sumberejo Subdistrict, Tanggamus District Is needed to facilitate. The purpose of this study is to identify the potential sources of raw water (clean water) in Sumberejo Village. The EPANET 2.0 program was implemented by calculative the number of people to be served as well as the need for clean water, reservoir capacity, and planning for distribution network. The methods used in water availability include measurement of discharge, topographic data, and water quality and for water requirements are projections of population, total water requirements and pipeline network pressure. The results of the analysis and projections of the number of villagers up to 2030 with a total of 2443 people, total water needs of 2842 liters/second, the availability debit in Sumberejo water eyes was 2,979 liters/second, the discharge was still sufficient for water needs until 2030. Hydraulic analysis using EPANET 2.0 obtained pressure at the highest location is 24.75 meters and the lowest is 2.95 meters. The study indicates that availability and water demand is sufficient until 2030