bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Hydrodynamic Characteristics of Wave Energy Power Plant
Authors: Huang Yu 
Published: October 2020

Abstract
Ocean energy is a kind of high-quality renewable energy. Therefore, it will not be exhausted and has attracted wide attention. China’s coastline is 18,000 kilometers long, so China has abundant ocean energy. In order to realize the utilization of wave energy, the research on wave energy power generation technology has never stopped. Wave energy generation refers to the use of wave motion to generate electricity, first converting wave energy into intermediate energy through a conversion device, and then converting intermediate energy into electrical energy. Combining with China’s actual situation, China’s research on wave energy devices mainly has three types: oscillating water column, pendulum, sink and float. Due to the huge difference in sea conditions and the characteristics of China’s offshore waves with short periods and relatively low energy density, wave energy conversion devices must be independently developed, and hydrodynamic behavior research is the basic work. In this paper, through the theoretical analysis and numerical calculation research methods, the hydrodynamic behavior characteristics of the wave energy conversion device are studied, and the simulation analysis is performed using the hydrodynamic software AQWA.
Structural and elastic properties of WSe2: first-principles calculations
Authors: Li Jihong , Jia Liping , Zheng Xingrong , Peng Changning , Fu Xijing 
Published: October 2020

Abstract
By using the first principle’ density functional theory, we calculated the structural and elastic properties of WSe2 crystals under different pressures. The results show that the compressibility of WSe2 in the c-direction is much greater than that in the a-direction. The results of the elastic constants reveal that WSe2 is mechanically stable under pressure 0 GPa to 50 GPa. The calculation results of elasticity-relevant properties show that the WSe2 crystal is a brittle material and is solid with interatomic forces.
Numerical Study of Mechanical Properties of Composite Solid Propellant with Initial Defects
Authors: Wang Jiaxiang , Qiang Hongfu , Wang Zhejun , Li Shiqi 
Published: October 2020

Abstract
In order to study the effect of initial interface defects and initial void defects on the macro tensile mechanical properties of composite solid propellant, based on the Python script, the particle filling model of composite solid propellant with meso pores and interface defects was established in ABAQUS. Firstly, zero thickness cohesive elements were embedded at the adjacent elements of the matrix and the particle/matrix interface, and the traction separate law was used to simulate the fracture failure of composite solid propellant. Then, the influence of different shapes, porosity and interface defect ratio on the elastic modulus and tensile strength of composite solid propellant was studied. Accordingly, the relationship between the initial damage of the composite solid propellant and the porosity and interface defects was established. Morever, the initial damage surface of the composite solid propellant was depicted. Results showed that the initial damage of polygon filling model is larger than that of circular particle filling model under the same initial defect condition; The elastic modulus of composite solid propellant decreases linearly with the increase of porosity and interface defect ratio; The tensile strength of composite solid propellant decreases linearly with the increase of interface defect ratio, and decreases logarithmically with the increase of porosity.
Flow Force of Pressure Independent Control Valve with Different Valve Core Structural
Authors: Fan Y L , Lei Y , Zhang J W , Wang J , Li Z 
Published: October 2020

Abstract
Aiming at the problem of hydraulic and thermal imbalance in variable flow heating and cooling systems, based on the computational fluid dynamics method, the 3D model of pressure independent control valve under different control valve core structure is established. The kinetic equation of valve core were established by using the valve core movement. The influence of different control core structure on valve Properties under transient pressure was studied, the distribution of fluid force, and pressure on valve core are obtained. The results show that, under the same flow characteristics, there are certain unbalanced forces in different valve core structure under different pressure differences, the fluid force distribution of the valve core is different, with a maximum value difference of 140%. Reasonable selection of different valve core structures for different working conditions can effectively improve the properties of the valve.
Performance Research on Bi-directional Tilting Pad Thrust Bearing Considering the Verticality Error of Thrust Plate
Authors: Chen Runlin , Han Qin , Wang Xingzhao , Cui Yahui , Liu Kai 
Published: October 2020

Abstract
In order to improve the axial stiffness and its controllability of the CNC machine tool spindle system, a bi-directional tilting pad thrust bearing is used instead of the hydrostatic thrust bearing to bear the axial load. Due to the processing and installing, there must be a certain verticality error between the thrust plate and rotor axis. The lubrication model of the thrust bearing considering the verticality error is established in this paper. The Reynolds equation is solved by FDM (finite difference method), and the key performance data of the bidirectional tilting pad thrust bearing under rated conditions are obtained, including eccentricity, minimum film thickness, maximum temperature rise and axial stiffness, etc. The variation of performance parameters such as film thickness, temperature rise and stiffness of thrust bearing with different working conditions are mainly studied. The maximum allowable verticality errors in the whole working condition range of load and speed are given. According to the requirements of film thickness and temperature rise, the thrust bearing clearance is optimized based on the comprehensive consideration of lubrication performance and dynamic performance, and the allowable ranges of clearance under different verticality errors is analyzed. This research provides theoretical guidance for the design and manufacture of tilting pad thrust bearings used for the CNC machine tool spindle system.
Optimization and Design of Regenerative Cooling Channel for Scramjet Engine
Authors: Gao Feng , Zhang Qian , Xiao Hongyu , Zhang Chengtao , Xia Xuefeng 
Published: October 2020

Abstract
In this paper, the optimization model and numerical calculation verification model of the regenerative cooling channel structure of the scramjet engine are established, and the structural parameters of the regenerative cooling channel of the scramjet engine are optimized and numerically verified. The results show that the established optimization model of the regenerative cooling channel structure of the scramjet engine can meet the design requirements; after the structure optimization, the wall temperature change trend is basically the same as the original design change trend, and the overall temperature is low; the central flow calculated by the optimized configuration calculation, but the pressure loss of kerosene in the cooling channel is small. The oil temperature and convection heat transfer coefficient are large; the inner wall and fins of the optimized configuration are thinner, the channel height is higher, and the width is narrower, which can effectively increase the convection heat transfer efficiency of the cooling channel, which can ensure that the material temperature is not Exceeding its maximum allowable temperature can make the pressure loss relatively low.
Researches on plateau flight trajectory characteristics of Non-controlled rotating projectile
Authors: Liu Yuwen , Duan Yanan , Jiang Ming , Cai Hongtu 
Published: October 2020

Abstract
The projectile dispersion in the plateau area has increased in various degree and decreased of the fire precision. The analysis shows that it has a considerably relations with altitude and the changes of trajectory characteristics associated with altitude. In order to reflect the change law of external ballistics trajectory characteristic in the plateau area clearly. Simulate compute the trajectory data and changes of projectile attitude in different altitude accord to trajectory model. These research findings will lay a foundation for further research on projectile precision in the plateau.
Topological Lightweight Optimization Simulation on EMU Luggage Rack Bracket
Authors: Sun Linfeng , Wang Bingsong 
Published: October 2020

Abstract
Basing on unite simulation method with INSPIRE and HYPERMESH, topological lightweight optimization on coach luggage rack bracket structure of China Standard EMU train had been executed. By comparing the simulation results with the test data, accuracy of the computational models had been verified. It was proved that the modified luggage rack bracket structure would have better mechanical performance and reach the goal of lightweight at the same time.
An optimization method of separation parameters for pico-satellite by minimizing external moment
Authors: Liu Yuchen , Teng Lai , Jin Zhonghe 
Published: October 2020

Abstract
In this article, a direct and key factor which affects separation parameters of satellite-rocket separation mechanism called optimization method of minimizing external moment is introduced. By changing the positions of elastic launch devices, popping process is effectively controlled. This optimization method is proved by ground test which can offset gravity, and it particularly adapts to the fixed and non-stable status elastic parameters, the distribution of all kinds of elastic devices and bias aircrafts which are hard to make the correction. The method has successfully applied to prediction and optimization for the separation of “Zhejiang University BJ Pico-satellite”. It is widely used now in practice with its easy operation.
Chaotic motion of time-delay fractional order financial dynamic system of single sliding mode control
Authors: Dong Jun , Xiao Yao , Ma Hu , Zhang Guangjun 
Published: October 2020

Abstract
In this paper, the equations of time-delay fractional order financial dynamic system are studied. Firstly, the dynamic characteristics of the time-delay fractional order financial system with are analyzed. Secondly, the attractor state change of the time-delay fractional order financial system induced by disturbance is studied. By adding specific uncertainties and disturbances to the specified state variables of the system, the attractor of the system is induced to change. Finally, the classical integral sliding mode control method is used to design a single controller to control the time-delay fractional order financial system from chaos to fixed point, and the feasibility and robustness of the control scheme have been proved theoretically and verified by the simulation.
Simulation research of the Pulsating Excitation and Vibration Response of Propeller in Wake Field
Authors: Peng W C , Tan Y H 
Published: October 2020

Abstract
The pulsating excitation and vibration response of a highly skewed propeller, running in wake field, was studied by the Fluid-Solid Interaction (FSI) simulation. Coupling calculation of elastic propeller was realized on ANSYS-CFX modules based on the CFD/FEM FSI method, and the rigid results were compared. The results show that, the pulsating thrust of the elastic propeller considering FSI effect has the same low frequency peak as the rigid except the low frequency elastic peak (the first-order natural frequency of propeller), and the low-frequency broadband force amplitude of the elastic propeller is an order of magnitude higher than the rigid. In addition to the correlation between blade frequency and shaft frequency, the propeller also has obvious vibration response at the lower natural frequency. The results are significant to the prediction and control of propeller vibration response.
AOCS General Architecture Design for SVOM Satellite
Authors: Liu Shuang , Li Jinsong , Qin Genjian , Li Dong , Fang Yuxin 
Published: October 2020

Abstract
SVOM mission is a Sino-French cooperation satellite which requires high attitude accuracy and platform stability. In order to guarantee the 100s’ observation time, the Relative Pointing Error is required to up to 0.8arcsec/100sec (3 sigma). The Attitude and Orbital Control System (AOCS) is a key element for SVOM mission because of this severe pointing performance requirement. This article describes the AOCS general architecture design for SVOM satellite. First, the main requirements are presented. Second, the key hardware is introduced, including a newly designed sensor, named Fine Guidance Sensor. At last, the AOCS modes design and transfer logic are given.
Fabrication and characterization of a thick, viable bi-layered stem cell-derived surrogate for future myocardial tissue regeneration
Authors: Pretorius Danielle , Kahn-Krell Asher M , LaBarge Wesley C , Lou Xi , Kannappan Ramaswamy , Pollard Andrew E , Fast Vladimir G , Berry Joel L , Eberhardt Alan W , Zhang Jianyi 
Published: October 2020

AbstractCardiac tissue surrogates show promise for restoring mechanical and electrical function in infarcted left ventricular (LV) myocardium. For these cardiac surrogates to be usefulin vivo, they are required to support synchronous and forceful contraction over the infarcted region. These design requirements necessitate a thickness sufficient to produce a useful contractile force, an area large enough to cover an infarcted region, and prevascularization to overcome diffusion limitations. Attempts to meet these requirements have been hampered by diffusion limits of oxygen and nutrients (100–200 µm) leading to necrotic regions. This study demonstrates a novel layer-by-layer (LbL) fabrication method used to produce tissue surrogates that meet these requirements and mimic normal myocardium in form and function. Thick (1.5–2 mm) LbL cardiac tissues created from human induced pluripotent stem cell-derived cardiomyocytes and endothelial cells were assessed,in vitro, over a 4-week period for viability (<5.6 ± 1.4% nectrotic cells), cell morphology, viscoelastic properties and functionality. Viscoelastic properties of the cardiac surrogates were determined via stress relaxation response modeling and compared to native murine LV tissue. Viscoelastic characterization showed that the generalized Maxwell model of order 4 described the samples well (0.7 <R2< 0.98). Functional performance assessment showed enhanced t-tubule network development, gap junction communication as well as conduction velocity (16.9 ± 2.3 cm s−1). These results demonstrate that LbL fabrication can be utilized successfully in creating complex, functional cardiac surrogates for potential therapeutic applications.
A new example of the effects of a singular background on the zeta function
*
Authors: Falomir Horacio , Liniado Joaquín , Pisani Pablo 
Published: October 2020

Abstract
To motivate our discussion, we consider a 1 + 1 dimensional scalar field interacting with a static Coulomb-type background, so that the spectrum of quantum fluctuations is given by a second-order differential operator on a single coordinate r with a singular coefficient proportional to 1/r. We find that the spectral functions of this operator present an interesting behavior: the ζ function has multiple poles in the complex plane; accordingly, logarithms of the proper time appear in the heat-trace expansion. As a consequence, the ζ function does not provide a finite regularization of the effective action. This work extends similar results previously derived in the context of conical singularities.
The Effect of Mechanochemical on The Formation of Calcium Titanate (CaTiO3) Prepared by High Energy Milling
Authors: Fauzi Fiqhi , Muhammad Habieb Alvin , Noviyanto Alfian , Kusumaningrum Retno , Sukmarani Galuh , Uswah Dien Muhammad Edela , Jovanka Widodo Valleta , Calista Amalia Diva , Aryanto Didik , Taufiqu Rochman Nurul 
Published: October 2020

Abstract
Single-phase calcium titanate (CaTiO3) was successfully synthesized by mechanical milling and the solid-state reaction of CaCO3 and TiO2. The speed of high energy ball milling was 700 rpm with the ball and jar were made from stainless steel. The milling time and ball to powder ratio was 10 h and 50 h, respectively. After milling for 10 h, the mixed powder of CaCO3 and TiO2 experienced heavy milling, which indicated by the average particle size before and after milling was > 1 µm and 85.56 ± 35.62 nm, respectively. Furthermore, the XRD pattern of milled powder revealed the disappearance of CaCO3 peaks and a considerable reduction of TiO2 peaks after milling for 10 h. Moreover, the presence of CaTiO3 peaks in the milled powder was noticeably detected in the XRD pattern, showing the mechanical alloying of CaCO3 and TiO2 was occurred. The milled powder was calcined at 800, 900 and 1000°C for 2 h. The results showed the formation of a single phase of CaTiO3 after calcination at any temperatures. However, the samples indicated the presence of Fe2O3, which from the milling media. The presence of impurities after milling is inevitable due to friction between ball and jar. Further study is needed to obtain the optimum condition of mechanical milling to minimize the contamination.
Distribution of Hardness, Surface Roughness and Wettability of AISI 316L Induced by Shot Peening with Different Duration and Shooting Distance
Authors: Tri Iswanto Priyo , Akhyar  , Faqihudin Arif , Muhammad Sadida Hizba 
Published: October 2020

Abstract
A research is conducted to analyze the effect of shot peening on distribution of hardness, surface roughness, and wettability of AISI 316 L. The shot peening process was performed on the surface of a 316L stainless steel sample with a shooting duration of 2, 4, 15, and 30 minutes, using a 0.4 mm diameter steel ball with a hardness of 40-50 HRC, the pressure of compressor held constant at 8 bar with nozzle diameter 5 mm, and the distance between the nozzle and the surface sample is 6 cm and 12 cm for each shooting duration. The results show that the shot peening can change the surface roughness. The closer the distance and the longer the duration of shot peening will reduce the surface roughness. Surface hardness increase with increasing of shooting duration and hardness distribution rate declines as the farther the distance from the surface of the shot peening.
Clean Water Programs In Oefafi Village, Kupang, Nusa Tenggara Barat
Authors: Yoga Santoso Prasetya , Erland Hamzah Radja , Pratiwi Erma 
Published: October 2020

Abstract
Oefafi is one of the driest places in Indonesia and community experiences water shortages. They need to walk up to 1-2 km to get a water source due to the unavailability of water. There are many aid programs in the Oefafi but it is unsuccessful. They were not used maximally by the community and the level of community involvement was low. Jaka Perkasa Citra Cemerlang Foundation (JPCC) is a non-profit organization. This foundation empowers the community through the clean water programs in Oefafi. The research objective is to find out how JPCC foundation’s communication strategy in empowering the local community through the clean water program. It also focuses on the supporting factors as well as the inhibiting factors in implementing community empowerment communication strategies. This research uses a qualitative approach with a case study method. The results of the study showed the success case of community empowerment in Oefafi. Empowerment by JPCC Foundation already showed an active participation. The communication strategy carried out successfully to trust in the community so that the community has the awareness and willingness to change. Although there are some communities who refuse to be empowered due to the character of people.
The Effects of Rice Husk Ashes Filled Recycled Polyethylene Composites towards Physical, Mechanical Properties and Its Degradation Characteristics
Authors: Nurhayati Chasri , Susanto Tri 
Published: October 2020

Abstract
Plastic waste is dominated by 46% Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE). The plastics waste are persistent pollutants that is not biodegradable waste. Recycled polyethylene (RP) from the plastic waste would potentially be used as polymer composites for pavement or road construction application. In order to improve physical, mechanical and water absorption properties, some fillers need to be added. The agro-industrial waste of rice husk ashes (RHA) containing highly silica SiO2 may be utilized as filler in this composites. The objective of this research is to observe the effect of RHA addition in to the recycled plastic composites towards its physical, mechanical properties and degradation characteristics. The RHA loading was designed weight/weight of RP as follows 0%; 5%; 10%; 15%; 20%, while degradation duration was 0, 30 and 60 days. The recycled ethylene was smelted and mixed with the RHA at temperature 120 o C; and then pressed using 200 kg.cm2 hydraulic press as pavement block (20x10x6 cm dimension). The results showed that the addition of RHA leads to increase the water absorption capacity, whereas it reduces the compressive strength. The RHA filler addition into composites has less significantly effects on thickness and surface-physical appearance (cracking profile). The 60 days degradation at ambient temperature with the sun lighting in a burial soil has a slight effect on the decreasing of compressive strength, thickness, and physical appearance (small crack on the surface) due to the thermal oxidative degradation. In addition, the burial soil exacerbate the bio-degradation mechanism due to the presence of high water absorbed within the RP-RHA composites. To sum up, the RHA may be potentially used as filler to improve water absorption capacity. Anti-oxidant and plasticizer types need to be researched to improve its physical mechanical properties.
Magnetization of Biodiesel (Cooking Oil Waste) to Temperature and Pressure Combustion in Diesel Engine
Authors: Nufus T H , Lestari S , Ulfiana A , Manawan M 
Published: October 2020

Abstract
Research related to the provision of magnetic field strength in the flow of fuel that can cause more complete combustion has been reported by many researchers and most of these observations were carried out by measuring machine performance using a dynamometer. Given the dynamometer prices are very expensive then another way to prove the occurrence of complete combustion is through the combustion chamber indicator. The hypothesis is the greater magnetic field passed by fuel, the more perfect the combustion is. In addition, the combustion chamber temperature also increases and thermal efficiency increases. The fuel used is biodiesel derived from cooking oil waste, biodiesel 100% (denoted as B0), a blend of biodiesel (20%)-diesel (80%) (denoted as B20), a blend of biodiesel (40%)-diesel (60%) (denoted as B40), a blend of biodiesel (30%)-diesel (30%) (denoted as B70), and diesel 100% (denoted as B100). The magnetic field used is 500 Gauss, 900 Gauss and 1500 Gauss. Measurement of combustion temperature is using R type temperature sensor, which is connected to the NI USB interface to computer and LabVIEW for data acquisition. 13 HP capacity of diesel engine was used. The results obtained is 13 % temperature increase in the combustion chamber of the engine and 7 - 12% thermal efficiency increase equipped with a magnet compared to a non-magnetic engine.