bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combustion in a solid fuel scramjet with channel geometry variation due to burnout
Authors: Yakush S E , Rashkovskiy S A , Bryzgalov A I 
Published: July 2019

Abstract
Stability of combustion in solid fuel scramjets is contingent upon proper geometry of fuel grain and availability of a flame holder. Flame stabilization is achieved in the recirculation zone developing due to sudden expansion behind the inlet. Previous experimental and theoretical works suggest that there exists an optimum range of length-to-diameter ratios for the flame holder. However, due to fuel burnout the channel and flame holder geometry change in the process of scramjet operation, the regression rate being variable both in time and length. The purpose of this work is to develop a computational model of a solid-fuel scramjet taking into account the geometry variation, as well as to obtain typical flow patterns at the different stages of combustion. The numerical model is based on a system of fully compressible RANS equations with k-epsilon turbulence model. Turbulent combustion is described by the Eddy Dissipation Concept (EDC) model.Stability of combustion in solid fuel scramjets is contingent upon proper geometry of fuel grain and availability of a flame holder. Flame stabilization is achieved in the recirculation zone developing due to sudden expansion behind the inlet. Previous experimental and theoretical works suggest that there exists an optimum range of length-to-diameter ratios for the flame holder. However, due to fuel burnout the channel and flame holder geometry change in the process of scramjet operation, the regression rate being variable both in time and length. The purpose of this work is to develop a computational model of a solid-fuel scramjet taking into account the geometry variation, as well as to obtain typical flow patterns at the different stages of combustion. The numerical model is based on a system of fully compressible RANS equations with k-epsilon turbulence model. Turbulent combustion is described by the Eddy Dissipation Concept (EDC) model.
Seismic response analysis and damping method of spherical liquid storage tank
Authors: Chen Junqi , Xian Qingjun , Zhang Peng 
Published: July 2019

Abstract
Earthquake is a natural disaster with outburst and ruinous in the world. The damage of spherical liquid storage tank due to earthquake can result in serious deaths and economic loss. In this thesis, the analysis of seismic response of spherical tank, which considering interior pressure, gravity, liquid sloshing and earthquake, is carried out. Seismic response analysis shows that the spherical tank rotates horizontally while rotating a small amount around the horizontal axis, mainly around the vertical axis. Time-history analysis of the tank under passive control is performed. The spherical tank model with dissipative bracing system installed has a very good damping effect by comparing the seismic responses of controlled and uncontrolled structures.
Influence of dressing parameters on surface roughness of workpiece for grinding hardened 9XC tool steel
Authors: Xuan Tu Hoang , Thao Le Phuong , Thi Hong Tran , Thi Thanh Nga Nguyen , Trung Do Duc , Gong Jun , Pi Vu Ngoc 
Published: July 2019

Abstract
The quality of final machining surfaces in a grinding process, such as the surface roughness and the accuracy depends on the grinding and dressing parameters. In order to improve the surface smoothness and precise tolerances, many grinding and dressing parameters need to be optimized. However, several dressing parameters, i.e., the rough dressing, the final dressing, and the dressing without depth of cut affected on the surface roughness have not yet been mentioned in the grinding process. This paper presents an optimization of these parameters on the surface roughness for grinding the hardened 9XC steel using grinding wheel Cn80MV1 400x40x203. An experimental system was set up to evaluate those parameters. The optimal values of these parameters were determined by using Minitab® 16 for analyzing data from the experiment.
Methods for measuring residual contact pressure of hydraulic expansion joints in heat exchangers
Authors: Jiang Jingyu , Yang Lianfa , Wei Jun , Han Junjie , Huang Jinjie 
Published: July 2019

Abstract
The hydraulic expansion of the heat exchanger tube and tubesheet is an important method in the uniform expansion. Compared with other methods, the advantages of hydraulic expansion are high productivity, low labor intensity and reliable expansion performance. This paper describes several common methods for the determination of the residual contact pressure between the tube and tubesheet, and describes the principle, characteristics and the current status of the measurement at home and abroad. This paper also summarizes the development of future methods for measuring the residual contact pressure in the hydraulic expansion joint.
The state-of-art and prospect of contactless torque measurement methods
Authors: Liu Jun , Yang LianFa , Ma JianPing 
Published: July 2019

Abstract
Torsional vibration is an important factor in the transmission process of mechanical shaft. The torque is also a part of the important parameters for working state of the mechanical shaft. In recent years, research on the measurement method of contactless torque of mechanical transmission shaft has been studied by many scholars. The contactless torque measurement methods have been continuously improved to achieve high precision and high reliability.The methods of contactless torque measurement is presented. The advantages of contactless torque measurement methods are introduced. The development of contactless torque measurement methods in the industry is discussed. Finally, the prospect of contactless torque measurement methods is prospected.
Simulation Analysis of Ground Infrared Background Based on Numerical Fitting Model
Authors: Chengcheng Wang , tao Sun , yan Wang 
Published: July 2019

Abstract
In view of the poor real-time and authenticity of the ground scene generation in the infrared scene simulation, a method of ground infrared background generation based on numerical fitting model is proposed. Combining with the main influencing factors of ground infrared scene, a numerical fitting model of surface temperature field of typical ground material is established. On the basis of the texture of the ground material area, the infrared texture of the ground is dynamically generated in the shader by combining the numerical fitting model of the temperature field and the texture mask generated by the multi-spectral image method. The simulation results show that the numerical fitting model of ground temperature field is in good agreement with the measured data, and the generated infrared texture is more realistic, which meets the real-time and authenticity requirements of infrared scene simulation system.
Simulation of finding the optimized gravel radius of the arrester bed on truck escape ramp
Authors: Qin Pin-Pin , Guang-Yi Qin , Ji-Qiang Mo , Da Wu 
Published: July 2019

Abstract
Propose a simulation method of finding the optimized gravel radius of the arrester bed on truck escape ramp in order to obtain the shortest stopping distance of runaway vehicle. A simulation model between gravel and tire is generated and calibrated by PFC2D (Particle Flow Code in two-dimensions) respectively. Utilize the model to simulate the relationship between radius and stopping distance at varied slopes and initial vehicle speeds. Simulation shows that whatever the slopes and the speeds are, the shortest stopping distance corresponds to gravel radius range is between 8.3mm and 15.7mm, that average radius is 12mm. The average radius is basically consistent with the ideal gravel radius 12.7mm, which indicates that the method is effective and could be a substitute for the full-scale test.
Numerical study of the stopping distance for runaway vehicle on truck escape ramp by using the improved equation of car driving
Authors: Qin Pinpin , Wang Jie , Qin Guangyi , Cheng Ming , Meng Qiang 
Published: July 2019

Abstract
The stopping distance of the runaway vehicle on the mountain road directly affects the length design of the arrester bed. Since the subsidence depth of runaway vehicle wheel on the arrester bed is neglected in the past researches, the stopping distance estimated by the vehicle driving equation is not accurate. The purpose of this paper is to supplement the influence of subsidence depth on rolling resistance and the influence of mountain highway altitude on air resistance, and improve the estimation accuracy through improved vehicle driving equation. Firstly, the formula for fitting the subsidence depth is established, and the formula for calculating the pushing resistance and compaction resistance is added. Considering the influence of the altitude of the mountain road on the air resistance, the formula for calculating the corrected air resistance and the air lift is added too and the improved vehicle driving equation is generated. Secondly, a simulink model is established based on the improved vehicle driving equation and determine the attester bed entering position and the initial entering speed of the runaway vehicle. Finally, the simulation model is run and analysed. The results show that the error rate of the simulation results is less than 8.0% compared with the full-scale test data. Compared with original equation, the shortening rate of the stopping distance is up to 85.59%.
A non-Hertzian contact analysis for the ball and raceway of a deep groove ball bearing
Authors: Xi Qiang , Pi Yangjun , Hu Yumei 
Published: July 2019

Abstract
Aiming at the premature damage of deep groove ball bearings, considering axial load, elastic-plastic constitutive, coordinated contact and bearing clearance and so on, a non-Hertzian elasto-plastic contact analysis for the bearing ball and the raceway is performed by trans-scale three-dimensional finite element simulation. The results shown that the failure mechanism of the bearing is extremely similar to the L-P fatigue life theory. The effects of load magnitude and direction on contact state were further studied. It indicates that a certain angle of load is beneficial to reduce the maximum internal stress of the bearing, but the angle should not be too large. Besides, increasing the load magnitude results in an increase in the stress value and the depth of maximum stress, but when the load is too heavy, the area that touches the contact surface will be damaged firstly and quickly.
Application of Augmented Reality in Satellite Cable Network Assembly
Authors: Zhang Wei , Chen Changyu , Chen Huajun , Sun Gang , Zhao Shuping 
Published: July 2019

Abstract
This paper reviews the traditional cable installation in assembly and integration process of satellite. An effective and accurate cable network assembly information transmission method from designers to operators is not formed, in the process of laying complex cables, operators need to frequently confirm cable laying status back and forth between satellite and computer stations, this can easily lead to cable routing error or cable fixing point selection error. In order to improve efficiency and quality of satellite cable installation, a cable assembly system based on AR technology is designed. The successful application of this system provides a new solution for satellite cable laying and marks a new step in the digital assembly capacity.
New direction in research on extraction of Citrus aurantifolia (Lemon fruit) essential oil grown in Mekong Delta - Vietnam via microwave-assisted hydrodistillation
Authors: Hien Tran Thien , Tien Nguyen Van , Phat Dao Tan , Duc Lam Tri , Quoc Toan Tran , Duy Nguyen Trinh , Vo Dai-Viet N. , Anh Vy Tran , Bui Le Minh 
Published: July 2019

Abstract
A new research approach has been applied to the extraction of lemon essential oils to increase the extraction efficiency and improve the quality of isolated essential oils. In this study, the combination of microwave extraction method and response surface method is employed to investigate factors influencing lemon peel essential oil extraction process; including size of the raw material particles, raw material to water ratio, extraction time, and microwave power. The results showed that lemon peel of sizes 1 to 2 mm, material: solvent ratio 1:3 g/mL, extraction time of 60 min and microwave power of 450 W gave the highest yield of essential oil (2.4 %). The GC-MS results showed the domination of D-Limonene, the main ingredient of citrus essential oils, in higher concentrations than those reported by previous studies.
A Facile Synthesis and Properties of Bismuth Vanadate (BiVO4) Photocatalyst by Hydrothermal Method
Authors: Duy Trinh Nguyen , Hoang Ho Huy , Xuan Linh Nong , Huu Vinh Nguyen , Thi Vu Hien , Thanh Nguyen Hai , Vo Dai-Viet N. , Do Sy Trung , Tri Duc Lam 
Published: July 2019

Abstract
In this study, BiVO4 photocatalysts were synthesized by hydrothermal method using Bi(NO3)3·5H2O and NH4VO3 as raw materials followed by calcination at different temperatures in the range from 350 °C to 600 °C. The as-synthesized BiVO4 samples were characterized by a number of physicochemical techniques including X-ray diffraction (XRD), Raman analysis, Scanning Electron Microscopy (SEM), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The effect of temperatures calcination on structure, surface morphology, visible-light photocatalytic activity and light absorption performance of BiVO4 was discussed in details.
Visible Light Induced Enhanced Photocatalytic Degradation of Industrial Effluents (Rhodamine B) Using BiVO4 Nanoparticles
Authors: Duy Trinh Nguyen , Hoang Ho Huy , Xuan Linh Nong , Huu Vinh Nguyen , Thi Vu Hien , Thanh Nguyen Hai , Do Sy Trung , Viet N-Vo Dai 
Published: July 2019

Abstract
This study investigates the photodegradation of the organic dye Rhodamine B (RhB) under visible light irradiation by BiVO4 photocatalysts synthesized hydrothermal method. A RhB solution (100 mL, 15 ppm) was degraded in 20 min using the BiVO4 photocatalysts with visible light irradiation. The effect of temperatures calcination on visible-light photocatalytic activity and light absorption performance of BiVO4 was discussed in details. The results showed that BiVO4 sample calcined at 450 °C exhibited the highest photocatalytic performance on the degradation of a Rhodamine B solution. The RhB degradation by the BiVO4 catalyst is 62.38% after 200 min of simulated solar irradiation.
Photochemical Synthesis of Composite Noble Metal Nanoparticles for Fuel Cell Catalysts
Authors: Dong Yingnan , Li Shanshan , Zhu Mei , Tang Jian , Niu Wei , Bi Xiaoguo 
Published: July 2019

Abstract
Direct methanol fuel cell is an ideal way for energy use because of its low noise, simple structure, rich fuel source, low price, easy storage and transportation. However, in the commercial application, it is necessary to overcome high catalyst cost and short life. The work used photochemical reduction and seed crystal growth to reduce PtII and PdII on the surface of Ag nanoparticles to form Ag@Pt-Pd core-shell composite nanoparticles with particle size of about 5∼10 nm. The results showed that the synthesized composite nanoparticles have good electrocatalytic activity, with good research and application in the electrode catalysts of fuel cells.
Comparison of Calibration Methods Used for Rietveld Quantitative Phase Analysis of Cement and Fly Ash
Authors: Wei Y Q , Yao W , Wang C Y 
Published: July 2019

Abstract
The overestimated contents of crystalline phases in polycrystalline powder samples containing amorphous phases must be calibrated when they are done by using Rietveld phase analysis (RPA) for quantitative X-ray diffraction patterns of samples. It has been indicated that there are two methods for this calibration are verified with nice accuracy involving internal standard method (ISM) and G-factor method (GFM) that have been applied to the RPA of both cement and fly ash that contain amorphous mine phases. However, the consistency between these two methods in quantitative determination of phase contents in silicate materials has not yet been discussed. Therefore, the accuracy and consistency between them in quantifying standard mixtures, cement and fly ash were evaluated experimentally. Results indicate that (1) both ISM and GFM gained the very nice accuracy and consistency for the ternary standard mixture, and also the good consistency for cement clinker and fly ash; (2) relatively, GFM is suitable for systems with any content of amorphous phases while ISM is preferably suitable for the system with much more amorphous phase contents, e.g. more than 50% in weight (denoted as wt.% henceforth), by adding the suggested 10wt.% of Al2O3 as internal standard;(3) ISM is not suggested to be used for quantifying the system containing less than 10w.t % of amorphous phases, and the wisely higher addition of internal standard, such as 20%, should be employed when it applied to quantifying the system with amorphous phases from 10wt.% to 50 wt.% in content.
Design of Automatic Billiard Sports Service Machine
Authors: Sichun Luo , Tanggen Wen , Xiang Lan , Jin Gong , Chunlai Tian 
Published: July 2019

Abstract
The billiard sports service machine which adapts to most of the billiards matches now is designed in this paper. It has strong environmental adaptability with the purposes of saving manpower, high efficiency and smooth transport of billiards. It has five main parts, such as billiards collection part, billiards sorting part, billiards push up part and billiards placement part. It is operated according with the working principles of billiard service machine. It uses the color sensor to identify the color of billiard balls. It applies the single chip microcomputer to control the mechanical actors. It makes use of the rubber sucker and the vacuum pump to grab the billiard balls. The waiting time for the new balls arrangement is shorten significantly to help players enjoy the game. The design with the feasibility plan is provided for the realization of the service for the automated billiard sports.
The Inhibitory effect of Natural materials Black Tea Theaflavins on MMPs-2 and MMPs-9 activities in Dentine
Authors: Li Hong , Wang Yina , Xu Jiongyuan 
Published: July 2019

Abstract
The aim of the present study is to investigate the inhibitory effect of black tea theaflavins(TF) on gelatinases (MMP-2, MMP-9) in human dentine. Protein extracts from demineralized human dentine powder were treated with TFs concentration range from 0.1-1.6 mg/mL; Samples treated with EDTA was used as a positive control while untreated sample as a negative control; Zymography was utilized to assess MMP-2 and MMP-9 activities in dentin. The results demonstrated that untreated demineralized dentine showed the strongest band of MMPs activity on zymography, while EDTA treatment completely inhibited MMPs activity; MMPs activity was inhibited by TFs in a concentration dependent manner. We conclude that theaflavins inhibited MMP-2 and MMP-9 activities, suggesting that natural product theaflavins could be a potential supplementary therapy both for prevention and treatment of dentine caries.
Effects of Package Size on Household Food Purchases
Authors: Çakır Metin , Balagtas Joseph V. , Okrent Abigail M. , Urbina‐Ramirez Mariana 
Published: July 2019

AbstractThis article analyzes household food purchase behavior in response to changes in product package size. In particular, we exploit food manufacturer package downsizing strategy and design a difference‐in‐difference analysis to track shifts in household purchase volume in affected and comparison product groups before and after package size changes. We use UPC‐level purchase data from a panel of households over a seven‐year period for analysis. Our empirical approach overcomes two important limitations of the extant literature: it (i) accounts for determinants of purchase behavior and (ii) produces results that elucidate the long‐term effects of package size changes. The main finding is that, on average, smaller package size significantly reduces household purchase volume, which indicates a positive correlation between package size and food‐at‐home consumption. The results also show that downsizing does not have a significant effect on the purchase volume of non‐downsized products and on the number of packages purchased. The implications of the results for policy and potential interventions are discussed.
The Colonial/Imperial History of Insect Food Avoidance in the United States
Authors: Lesnik Julie J 
Published: July 2019

AbstractInterest in edible insects has increased greatly since the 2013 report by the United Nations Food and Agriculture Organization demonstrated that insects offer an appealing option for a more sustainable livestock alternative. However, overcoming the cultural bias against insect consumption is necessary in order to see widespread adoption. In order to overcome the bias, it is important to first understand it. There is not a simple answer as to why westerners do not eat insects, but using the United States as an example, this paper works to untangle the history that western culture has with insects as food; a history that is stained by the colonial exploitation of native peoples. Notions that insects are a ‘primitive’ food source and the strong disgust response they trigger can be traced back to the 15th century and Age of Exploration. These ideas have persisted because of the perpetuation of European imperial attitudes and the unconscious transfer of the disgust emotion from parents to offspring for many generations. Fortunately, continued outreach events that normalize insects as food, especially those open to families, will be helpful in reprogramming mindsets that have been deeply rooted in our culture for centuries.
Dose–Response Characteristics of the Alcohol Biomarker Phosphatidylethanol (PEth)—A Study of Outpatients in Treatment for Reduced Drinking
Authors: Helander Anders , Hermansson Ulric , Beck Olof 
Published: July 2019

AbstractAimMeasurement of whole-blood phosphatidylethanol (PEth) offers high sensitivity and specificity as alcohol biomarker. A remaining issue of importance for the routine application is to better establish the relationship between PEth concentration and amount and duration of drinking.MethodsThe study included 36 subjects (32–83 years) voluntarily attending outpatient treatment for reduced drinking. At ~ 3- to 4-week intervals, they provided a diary on their daily alcohol intake and gave blood samples for measurement of PEth and carbohydrate-deficient transferrin (CDT). Whole-blood PEth 16:0/18:1 was measured by liquid chromatography-tandem mass spectrometry and serum CDT (%disialotransferrin) by high-performance liquid chromatography.ResultsAt start, the self-reported past 2-week alcohol intake ranged 0–1260 (median 330) g ethanol, the PEth 16:0/18:1 concentration ranged 0.05–1.20 (median 0.23) μmol/L, and the CDT value ranged 0.7–13.0% (median 1.5%). At the final sampling after 5–20 (median 12) weeks, neither reported alcohol intake nor PEth and CDT levels differed significantly from the starting values. The PEth concentration showed best association with past 2-week drinking, followed by for intake in the next last week. The changes in PEth concentration vs past 2-week alcohol intake between two successive tests revealed that an increased ethanol intake by ~ 20 g/day elevated the PEth concentration by on average ~ 0.10 μmol/L, and vice versa for decreased drinking.ConclusionsThe PEth concentration correlated well with past weeks alcohol intake, albeit with a large inter-individual scatter. This indicates that it is possible to make only approximate estimates of drinking based on a single PEth value, implying risk for misclassification between moderate and heavy drinking.