Search results for: Zhao Hong
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 956

Search results for: Zhao Hong

716 Chemical Vapor Deposition (CVD) of Molybdenum Disulphide (MoS2) Monolayers

Authors: Omar Omar, Yuan Jun, Hong Jinghua, Jin Chuanhong

Abstract:

In this work molybdenum dioxide (MoO2) and sulphur powders are used to grow MoS2 mono layers at elevated temperatures T≥800 °C. Centimetre scale continues thin films with grain size up to 410 µm have been grown using chemical vapour deposition. To our best knowledge, these domains are the largest that have been grown so far. Advantage of our approach is not only because of the high quality films with large domain size one can produce, but also the procedure is potentially less hazardous than other methods tried. The thin films have been characterized using transmission electron microscopy (TEM), atomic force microscopy (AFM) and Raman spectroscopy.

Keywords: molybdenum disulphide (MoS2), monolayers, chemical vapour deposition (CVD), growth and characterization

Procedia PDF Downloads 299
715 Design of Reinforced Concrete (RC) Walls Considering Shear Amplification by Nonlinear Dynamic Behavior

Authors: Sunghyun Kim, Hong-Gun Park

Abstract:

In the performance-based design (PBD), by using the nonlinear dynamic analysis (NDA), the actual performance of the structure is evaluated. Unlike frame structures, in the wall structures, base shear force which is resulted from the NDA, is greatly amplified than that from the elastic analysis. This shear amplifying effect causes repeated designs which make designer difficult to apply the PBD. Therefore, in this paper, factors which affect shear amplification were studied. For the 20-story wall model, the NDA was performed. From the analysis results, the base shear amplification factor was proposed.

Keywords: performance based design, shear amplification factor, nonlinear dynamic analysis, RC shear wall

Procedia PDF Downloads 360
714 Effect of Aging Treatment on Tensile Properties of AZ91D Mg Alloy

Authors: Ju Hyun Won, Seok Hong Min, Tae Kwon Ha

Abstract:

Phase equilibria of AZ91D Mg alloys for nonflammable use, containing Ca and Y, were carried out by using FactSage® and FTLite database, which revealed that solid solution treatment, could be performed at temperatures from 400 to 450 °C. Solid solution treatment of AZ91D Mg alloy without Ca and Y was successfully conducted at 420 °C and supersaturated microstructure with all beta phase resolved into matrix was obtained. In the case of AZ91D Mg alloy with some Ca and Y, however, a little amount of intermetallic particles were observed after solid solution treatment. After solid solution treatment, each alloy was annealed at temperatures of 180 and 200 °C for time intervals from 1 min to 48 hrs and hardness of each condition was measured by micro-Vickers method. Peak aging conditions were deduced as at the temperature of 200 °C for 10 hrs.

Keywords: Mg alloy, AZ91D, nonflammable alloy, phase equilibrium, peak aging

Procedia PDF Downloads 401
713 Stability Analysis and Experimental Evaluation on Maxwell Model of Impedance Control

Authors: Le Fu, Rui Wu, Gang Feng Liu, Jie Zhao

Abstract:

Normally, impedance control methods are based on a model that connects a spring and damper in parallel. The series connection, namely the Maxwell model, has emerged as a counterpart and draw the attention of robotics researchers. In the theoretical analysis, it turns out that the two pattern are both equivalents to some extent, but notable differences of response characteristics exist, especially in the effect of damping viscosity. However, this novel impedance control design is lack of validation on realistic robot platforms. In this study, stability analysis and experimental evaluation are achieved using a 3-fingered Barrett® robotic hand BH8-282 endowed with tactile sensing, mounted on a torque-controlled lightweight and collaborative robot KUKA® LBR iiwa 14 R820. Object handover and incoming objects catching tasks are executed for validation and analysis. Experimental results show that the series connection pattern has much better performance in natural impact or shock absorption, which indicate promising applications in robots’ safe and physical interaction with humans and objects in various environments.

Keywords: impedance control, Maxwell model, force control, dexterous manipulation

Procedia PDF Downloads 479
712 Validation of the Career Motivation Scale among Chinese University and Vocational College Teachers

Authors: Wei Zhang, Lifen Zhao

Abstract:

The present study aims to translate and validate the Career Motivation Scale among Chinese university and vocational college teachers. Exploratory factor analysis supported a three-factor structure that was consistent with the original structure of career motivation: career insight, career identity, and career resilience. Confirmatory factor analysis showed that a second-order three-factor model with correlated measurement errors best fit the data. Configural, metric, and scalar invariance models were tested, demonstrating that the Chinese version of the Career Motivation Scale did not differ across groups of school type, educational level, and working years in current institutions. The concurrent validity of the Chinese Career Motivation Scale was confirmed by its significant correlations with work engagement, career adaptability, career satisfaction, job crafting, and intention to quit. The results of the study indicated that the Chinese Career Motivation Scale was a valid and reliable measure of career motivation among university and vocational college teachers in China.

Keywords: career motivation scale, Chinese University, vocational college teachers, measurement invariance, validation

Procedia PDF Downloads 96
711 Study of Drawing Characteristics due to Friction between the Materials by FEM

Authors: Won Jin Ryu, Mok Tan Ahn, Hyeok Choi, Joon Hong Park, Sung Min Kim, Jong Bae Park

Abstract:

Pipes for offshore plants require specifications that satisfy both high strength and high corrosion resistance. Therefore, currently, clad pipes are used in offshore plants. Clad pipes can be made using either overlay welding or clad plates. The present study was intended to figure out the effects of friction between two materials, which is a factor that affects two materials, were figured out using FEM to make clad pipes through heterogenous material drawing instead of the two methods mentioned above. Therefore, FEM has conducted while all other variables that the variable friction was fixed. The experimental results showed increases in pullout force along with increases in the friction in the boundary layer.

Keywords: clad pipe, FEM, friction, pullout force

Procedia PDF Downloads 464
710 The Pedagogical Functions of Arts and Cultural-Heritage Education with ICTs in Museums – A Case Study of FINNA and Google Art

Authors: Pei Zhao, Sara Sintonen, Heikki Kynäslahti

Abstract:

Digital museums and arts galleries have become popular in museum education and management. Museum and arts galleries website is one of the most effective and efficient ways. Google, a corporation specializing in Internet-related services and projects, not only puts high-resolution arts images online, but also uses augmented-reality in digital art gallery. The Google Art Project, Google’s production, provides users a platform in appreciating and learning arts. After Google Art Project, more and more countries released their own museum and arts gallery websites, like British Paining in BBC, and FINNA in Finland. Pedagogical function in these websites is one of the most important functions. In this paper, we use Google Art Project and FINNA as the case studies to investigate what kinds of pedagogical functions exist in these websites. Finally, this paper will give the recommendation to digital museums and websites development, especially the pedagogical functions development, in the future.

Keywords: arts education, cultural-heritage education, education with ICTs, pedagogical functions

Procedia PDF Downloads 521
709 Analysis of the CO2 Emissions of Public Passenger Transport in Tianjin City of China

Authors: Tao Zhao, Xianshuo Xu

Abstract:

Low-carbon public passenger transport is an important part of low carbon city. The CO2 emissions of public passenger transport in Tianjin from 1995 to 2010 are estimated with IPCC CO2 counting method, which shows that the total CO2 emissions of Tianjin public passenger transport have gradually become stable at 1,425.1 thousand tons. And then the CO2 emissions of the buses, taxies, and rail transits are calculated respectively. A CO2 emission of 829.9 thousand tons makes taxies become the largest CO2 emissions source among the public passenger transport in Tianjin. Combining with passenger volume, this paper analyzes the CO2 emissions proportion of the buses, taxies, and rail transits compare the passenger transport rate with the proportion of CO2 emissions, as well as the CO2 emissions change of per 10,000 people. The passenger volume proportion of bus among the three public means of transport is 72.62% which is much higher than its CO2 emissions proportion of 36.01%, with the minimum number of CO2 emissions per 10,000 people of 4.90 tons. The countermeasures to reduce CO2 emissions of public passenger transport in Tianjin are to develop rail transit, update vehicles and use alternative fuel vehicles.

Keywords: public passenger transport, carbon emissions, countermeasures, China

Procedia PDF Downloads 400
708 Experimental Study on the Floor Vibration Evaluation of Concrete Slab for Existing Buildings

Authors: Yong-Taeg Lee, Jun-Ho Na, Seung-Hun Kim, Seong-Uk Hong

Abstract:

Damages from noise and vibration are increasing every year, most of which are noises between floors in deteriorated building caused by floor impact sound. In this study, the concrete slab measured vibration impact sound for evaluation floor vibration of deteriorated buildings that fails to satisfy with the minimum thickness. In this experimental study, the vibration scale by impact sound was calibrated and compared with ISO and AIJ standard for vibration. The results show that vibration in slab with thickness used in existing building reach human perception levels.

Keywords: vibration, frequency, accelerometer, concrete slab

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707 Rapid Soil Classification Using Computer Vision, Electrical Resistivity and Soil Strength

Authors: Eugene Y. J. Aw, J. W. Koh, S. H. Chew, K. E. Chua, Lionel L. J. Ang, Algernon C. S. Hong, Danette S. E. Tan, Grace H. B. Foo, K. Q. Hong, L. M. Cheng, M. L. Leong

Abstract:

This paper presents a novel rapid soil classification technique that combines computer vision with four-probe soil electrical resistivity method and cone penetration test (CPT), to improve the accuracy and productivity of on-site classification of excavated soil. In Singapore, excavated soils from local construction projects are transported to Staging Grounds (SGs) to be reused as fill material for land reclamation. Excavated soils are mainly categorized into two groups (“Good Earth” and “Soft Clay”) based on particle size distribution (PSD) and water content (w) from soil investigation reports and on-site visual survey, such that proper treatment and usage can be exercised. However, this process is time-consuming and labour-intensive. Thus, a rapid classification method is needed at the SGs. Computer vision, four-probe soil electrical resistivity and CPT were combined into an innovative non-destructive and instantaneous classification method for this purpose. The computer vision technique comprises soil image acquisition using industrial grade camera; image processing and analysis via calculation of Grey Level Co-occurrence Matrix (GLCM) textural parameters; and decision-making using an Artificial Neural Network (ANN). Complementing the computer vision technique, the apparent electrical resistivity of soil (ρ) is measured using a set of four probes arranged in Wenner’s array. It was found from the previous study that the ANN model coupled with ρ can classify soils into “Good Earth” and “Soft Clay” in less than a minute, with an accuracy of 85% based on selected representative soil images. To further improve the technique, the soil strength is measured using a modified mini cone penetrometer, and w is measured using a set of time-domain reflectometry (TDR) probes. Laboratory proof-of-concept was conducted through a series of seven tests with three types of soils – “Good Earth”, “Soft Clay” and an even mix of the two. Validation was performed against the PSD and w of each soil type obtained from conventional laboratory tests. The results show that ρ, w and CPT measurements can be collectively analyzed to classify soils into “Good Earth” or “Soft Clay”. It is also found that these parameters can be integrated with the computer vision technique on-site to complete the rapid soil classification in less than three minutes.

Keywords: Computer vision technique, cone penetration test, electrical resistivity, rapid and non-destructive, soil classification

Procedia PDF Downloads 179
706 Dynamics of Adiabatic Rapid Passage in an Open Rabi Dimer Model

Authors: Justin Zhengjie Tan, Yang Zhao

Abstract:

Adiabatic Rapid Passage, a popular method of achieving population inversion, is studied in a Rabi dimer model in the presence of noise which acts as a dissipative environment. The integration of the multi-Davydov D2 Ansatz into the time-dependent variational framework enables us to model the intricate quantum system accurately. By influencing the system with a driving field strength resonant with the energy spacing, the probability of adiabatic rapid passage, which is modelled after the Landau Zener model, can be derived along with several other observables, such as the photon population. The effects of a dissipative environment can be reproduced by coupling the system to a common phonon mode. By manipulating the strength and frequency of the driving field, along with the coupling strength of the phonon mode to the qubits, we are able to control the qubits and photon dynamics and subsequently increase the probability of Adiabatic Rapid Passage happening.

Keywords: quantum electrodynamics, adiabatic rapid passage, Landau-Zener transitions, dissipative environment

Procedia PDF Downloads 55
705 A Simple Approach for the Analysis of First Vibration Mode of Layered Soil Profiles

Authors: Haizhong Zhang, Yan-Gang Zhao

Abstract:

Fundamental period, mode shape, and participation factor are important basic information for the understanding of earthquake response of ground. In this study, a simple approach is presented to calculate these basic information of layered soil profiles. To develop this method, closed form equations are derived for analysis of free vibration of layered soil profiles firstly, based on equilibrium between inertia and elastic forces. Then, by further associating with the Madera procedure developed for estimation of fundamental period, a simple method that can directly determine the fundamental period, mode shape and participation factor is proposed. The proposed approach can be conveniently implemented in simple spreadsheets and easily used by practicing engineers. In addition, the accuracy of the proposed approach is investigated by analyzing first vibration mode of 67 representative layered soil profiles, it is found that results by the proposed method agree very well with accurate results.

Keywords: layered soil profile, natural vibration, fundamental period, fundamental mode shape

Procedia PDF Downloads 293
704 Resistivity Tomography Optimization Based on Parallel Electrode Linear Back Projection Algorithm

Authors: Yiwei Huang, Chunyu Zhao, Jingjing Ding

Abstract:

Electrical Resistivity Tomography has been widely used in the medicine and the geology, such as the imaging of the lung impedance and the analysis of the soil impedance, etc. Linear Back Projection is the core algorithm of Electrical Resistivity Tomography, but the traditional Linear Back Projection can not make full use of the information of the electric field. In this paper, an imaging method of Parallel Electrode Linear Back Projection for Electrical Resistivity Tomography is proposed, which generates the electric field distribution that is not linearly related to the traditional Linear Back Projection, captures the new information and improves the imaging accuracy without increasing the number of electrodes by changing the connection mode of the electrodes. The simulation results show that the accuracy of the image obtained by the inverse operation obtained by the Parallel Electrode Linear Back Projection can be improved by about 20%.

Keywords: electrical resistivity tomography, finite element simulation, image optimization, parallel electrode linear back projection

Procedia PDF Downloads 122
703 A Low-Area Fully-Reconfigurable Hardware Design of Fast Fourier Transform System for 3GPP-LTE Standard

Authors: Xin-Yu Shih, Yue-Qu Liu, Hong-Ru Chou

Abstract:

This paper presents a low-area and fully-reconfigurable Fast Fourier Transform (FFT) hardware design for 3GPP-LTE communication standard. It can fully support 32 different FFT sizes, up to 2048 FFT points. Besides, a special processing element is developed for making reconfigurable computing characteristics possible, while first-in first-out (FIFO) scheduling scheme design technique is proposed for hardware-friendly FIFO resource arranging. In a synthesis chip realization via TSMC 40 nm CMOS technology, the hardware circuit only occupies core area of 0.2325 mm2 and dissipates 233.5 mW at maximal operating frequency of 250 MHz.

Keywords: reconfigurable, fast Fourier transform (FFT), single-path delay feedback (SDF), 3GPP-LTE

Procedia PDF Downloads 250
702 A Study on the Non-Destructive Test Characterization of Carbon Fiber Reinforced Plastics Using Thermo-Graphic Camera

Authors: Hee Jae Shin, In Pyo Cha, Min Sang Lee, Hyun Kyung Yoon, Tae Ho Kim, Yoon Sun Lee, Lee Ku Kwac, Hong Gun Kim

Abstract:

Non-destructive testing and evaluation techniques for assessing the integrity of composite structures are essential to both reduce manufacturing costs and out of service time of transport means due to maintenance. In this study, Analyze into non-destructive test characterization of carbon fiber reinforced plastics(CFRP) internal and external defects using thermo-graphic camera and transient thermography method. non-destructive testing were characterized by defect size(∅8,∅10,∅12,∅14) and depth(1.2mm,2.4mm).

Keywords: Non-Destructive Test (NDT), thermal characteristic, thermographic camera, Carbon Fiber Reinforced Plastics(CFRP).

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701 Analysis on Thermococcus achaeans with Frequent Pattern Mining

Authors: Jeongyeob Hong, Myeonghoon Park, Taeson Yoon

Abstract:

After the advent of Achaeans which utilize different metabolism pathway and contain conspicuously different cellular structure, they have been recognized as possible materials for developing quality of human beings. Among diverse Achaeans, in this paper, we compared 16s RNA Sequences of four different species of Thermococcus: Achaeans genus specialized in sulfur-dealing metabolism. Four Species, Barophilus, Kodakarensis, Hydrothermalis, and Onnurineus, live near the hydrothermal vent that emits extreme amount of sulfur and heat. By comparing ribosomal sequences of aforementioned four species, we found similarities in their sequences and expressed protein, enabling us to expect that certain ribosomal sequence or proteins are vital for their survival. Apriori algorithms and Decision Tree were used. for comparison.

Keywords: Achaeans, Thermococcus, apriori algorithm, decision tree

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700 CO2 Emissions Quantification of the Modular Bridge Superstructure

Authors: Chanhyuck Jeon, Jongho Park, Jinwoong Choi, Sungnam Hong, Sun-Kyu Park

Abstract:

Many industries put emphasis on environmentally-friendliness as environmental problems are on the rise all over the world. Among themselves, the Modular Bridge research is going on. Also performing cross-section optimization and duration reducing, this research aims at developing the modular bridge with Environment-Friendliness and economic feasibility. However, the difficulty lies in verifying environmental effectiveness because there are no field applications of the modular bridge until now. Therefore, this thesis is categorized according to the form of the modular bridge superstructure and assessed CO₂ emission quantification per work types and materials according to each form to verify the environmental effectiveness of the modular bridge.

Keywords: modular bridge, CO2 emission, environmentally friendly, quantification, carbon emission factor, LCA (Life Cycle Assessment)

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699 Species Diversity of Some Remarkable New Records of Lichens from Chwarta District, Kurdistan Region of Iraq

Authors: Salah Abdulla Salih, Muhamad Sohrabi

Abstract:

This paper aims to study the species, morphology, habitats and geographical distribution of new records of lichens from the Chwarta districts Kurdistan Region of Iraq from September 2022 to June 2023. As a result of the survey in the different locations belonging to the district, found that there are eleven species of lichens are reported from Iraq for the first time. Of these, the taxa of Lecanora thallophila H. Magn is the first species of parasitic lichen reported from Iraq, including the newly recorded genus of lichen Acarospora A.Massal. The lichenized fungi are Acarospora bullata Anzi., Acarospora laqueata Stizenb., Acarospora umbilicata Bagl., Acrocordia gemmata (Ach.) A. Massal., Squamulea subsoluta (Nyl.) Arup, Søchting & Frödén., Coppinsiella ulcerosa (Coppins & P.James) S.Y.Kondr. & L.Lőkös., Myriolecis flowersiana (H. Magn.) Śliwa, Zhao Xin & Lumbsch., Megaspora rimisorediata Valadbeigi & A. Nordin sp. nov., Physcia subtilis Degel., Polycauliona polycarpa (Hoffm.) Frödén, Arup, & Søchting.

Keywords: apothecia, lichen species, new records, Kurdistan region

Procedia PDF Downloads 34
698 Study on Shape Coefficient of Large Statue Building Based on CFD

Authors: Wang Guangda, Ma Jun, Zhao Caiqi, Pan Rui

Abstract:

Wind load is the main control load of large statue structures. Due to the irregular plane and elevation and uneven outer contour, statues’ shape coefficient can not pick up from the current code. Currently a common practice is based on wind tunnel test. But this method is time-consuming and high cost. In this paper, based on the fundamental theory of CFD, using fluid dynamics software of Fluent 15.0, a few large statue structure of 40 to 70m high, which are located in china , including large fairy statues and large Buddha statues, are analyzed by numerical wind tunnel. The results are contrasted with the recommended values in load code and the wind tunnel test results respectively. Results show that the shape coefficient has a good reliability by the numerical wind tunnel method of this kind of building. This will has a certain reference value of wind load values for large statues’ structure.

Keywords: large statue structure, shape coefficient, irregular structure, wind tunnel test, numerical wind tunnel simulation

Procedia PDF Downloads 344
697 Numerical and Experimental Investigation of Pulse Combustion for Fabric Drying

Authors: Dan Zhao, Y. W. Sheng

Abstract:

The present work considers a convection-driven T-shaped pulse combustion system. Both experimental and numerical investigations are conducted to study the mechanism of pulse combustion and its potential application in fabric drying. To gain insight on flame-acoustic dynamic interaction and pulsating flow characteristics, 3D numerical simulation of the pulse combustion process of a premixed turbulent flame in a Rijke-type combustor is performed. Two parameters are examined: (1) fuel-air ratio, (2) inlet flow velocity. Their effects on triggering pulsating flow and Nusselt number are studied. As each of the parameters is varied, Nusselt number characterizing the heat transfer rate and the heat-driven pulsating flow signature is found to change. The main nonlinearity is identified in the heat fluxes. To validate our numerical findings, a cylindrical T-shaped Rijke-type combustor made of quartz-glass with a Bunsen burner is designed and tested.

Keywords: pulse combustion, fabric drying, heat transfer, combustion oscillations, pressure oscillations

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696 The Study on Life of Valves Evaluation Based on Tests Data

Authors: Binjuan Xu, Qian Zhao, Ping Jiang, Bo Guo, Zhijun Cheng, Xiaoyue Wu

Abstract:

Astronautical valves are key units in engine systems of astronautical products; their reliability will influence results of rocket or missile launching, even lead to damage to staff and devices on the ground. Besides failure in engine system may influence the hitting accuracy and flight shot of missiles. Therefore high reliability is quite essential to astronautical products. There are quite a few literature doing research based on few failure test data to estimate valves’ reliability, thus this paper proposed a new method to estimate valves’ reliability, according to the corresponding tests of different failure modes, this paper takes advantage of tests data which acquired from temperature, vibration, and action tests to estimate reliability in every failure modes, then this paper has regarded these three kinds of tests as three stages in products’ process to integrate these results to acquire valves’ reliability. Through the comparison of results achieving from tests data and simulated data, the results have illustrated how to obtain valves’ reliability based on the few failure data with failure modes and prove that the results are effective and rational.

Keywords: censored data, temperature tests, valves, vibration tests

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695 Applying Massively Parallel Sequencing to Forensic Soil Bacterial Profiling

Authors: Hui Li, Xueying Zhao, Ke Ma, Yu Cao, Fan Yang, Qingwen Xu, Wenbin Liu

Abstract:

Soil can often link a person or item to a crime scene, which makes it a valuable evidence in forensic casework. Several techniques have been utilized in forensic soil discrimination in previous studies. Because soil contains a vast number of microbiomes, the analyse of soil microbiomes is expected to be a potential way to characterise soil evidence. In this study, we applied massively parallel sequencing (MPS) to soil bacterial profiling on the Ion Torrent Personal Genome Machine (PGM). Soils from different regions were collected repeatedly. V-region 3 and 4 of Bacterial 16S rRNA gene were detected by MPS. Operational taxonomic units (OTU, 97%) were used to analyse soil bacteria. Several bioinformatics methods (PCoA, NMDS, Metastats, LEfse, and Heatmap) were applied in bacterial profiles. Our results demonstrate that MPS can provide a more detailed picture of the soil microbiomes and the composition of soil bacterial components from different region was individualistic. In conclusion, the utility of soil bacterial profiling via MPS of the 16S rRNA gene has potential value in characterising soil evidences and associating them with their place of origin, which can play an important role in forensic science in the future.

Keywords: bacterial profiling, forensic, massively parallel sequencing, soil evidence

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694 Design of Torque Actuator in Hybrid Multi-DOF System with Taking into Account Magnetic Saturation

Authors: Hyun-Seok Hong, Tae-Chul Jeong, Huai-Cong Liu, Ju Lee

Abstract:

In this paper, proposes to replace the three-phase SPM for tilting by a single-phase torque actuator of the hybrid multi-DOF system. If a three-phase motor for tilting SPM as acting as instantaneous, low electricity use efficiency, controllability is bad disadvantages. It uses a single-phase torque actuator has a high electrical efficiency compared, good controllability. Thus this will have a great influence on the development and practical use of the system. This study designed a single phase torque actuator in consideration of the magnetic saturation. And compared the SPM and FEM analysis and validation through testing of the production model.

Keywords: hybrid multi-DOF system, SPM, torque actuator, UAV, drone

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693 Optimization of Surface Coating on Magnetic Nanoparticles for Biomedical Applications

Authors: Xiao-Li Liu, Ling-Yun Zhao, Xing-Jie Liang, Hai-Ming Fan

Abstract:

Owing to their unique properties, magnetic nanoparticles have been used as diagnostic and therapeutic agents for biomedical applications. Highly monodispersed magnetic nanoparticles with controlled particle size and surface coating have been successfully synthesized as a model system to investigate the effect of surface coating on the T2 relaxivity and specific absorption rate (SAR) under an alternating magnetic field, respectively. Amongst, by using mPEG-g-PEI to solubilize oleic-acid capped 6 nm magnetic nanoparticles, the T2 relaxivity could be significantly increased by up to 4-fold as compared to PEG coated nanoparticles. Moreover, it largely enhances the cell uptake with a T2 relaxivity of 92.6 mM-1s-1 for in vitro cell MRI. As for hyperthermia agent, SAR value increase with the decreased thickness of PEG surface coating. By elaborate optimization of surface coating and particle size, a significant increase of SAR (up to 74%) could be achieved with a minimal variation on the saturation magnetization (<5%). The 19 nm magnetic nanoparticles with 2000 Da PEG exhibited the highest SAR of 930 W•g-1 among the samples, which can be maintained in various simulated physiological conditions. This systematic work provides a general strategy for the optimization of surface coating of magnetic core for high performance MRI contrast agent and hyperthermia agent.

Keywords: magnetic nanoparticles, magnetic hyperthermia, magnetic resonance imaging, surface modification

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692 Phase Equilibria in Zn-Al-Sn Alloy for Lead-free Solder Application

Authors: Ji Chan Kim, Seok Hong Min, Tae Kwon Ha

Abstract:

The effect of Yttrium addition on the microstructure and mechanical properties of Sn-Zn eutectic alloy, which has been attracting intensive focus as a Pb-free solder material, was investigated in this study. Phase equilibrium has been calculated by using FactSage® to evaluate the composition and fraction of equilibrium intermetallic compounds and construct a phase diagram. In the case of Sn-8.8 Zn eutectic alloy, the as-cast microstructure was typical lamellar. With addition of 0.25 wt. %Y, a large amount of pro-eutectic phases have been observed and various YZnx intermetallic compounds were expected to successively form during cooling. Hardness of Sn-8.8 Zn alloy was not affected by Y-addition and both alloys could be rolled by 90% at room temperature.

Keywords: lead-free solder, zn-al-sn alloy, phase equilibrium, rolling, microstructure, hardness

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691 Coronavirus Academic Paper Sorting Application

Authors: Christina A. van Hal, Xiaoqian Jiang, Luyao Chen, Yan Chu, Robert D. Jolly, Yaobin Lin, Jitian Zhao, Kang Lin Hsieh

Abstract:

The COVID-19 Literature Summary App was created for the primary purpose of enabling academicians and clinicians to quickly sort through the vast array of recent coronavirus publications by topics of interest. Multiple methods of summarizing and sorting the manuscripts were created. A summary page introduces the application function and capabilities, while an interactive map provides daily updates on infection, death, and recovery rates. A page with a pivot table allows publication sorting by topic, with an interactive data table that allows sorting topics by columns, as wells as the capability to view abstracts. Additionally, publications may be sorted by the medical topics they cover. We used the CORD-19 database to compile lists of publications. The data table can sort binary variables, allowing the user to pick desired publication topics, such as papers that describe COVID-19 symptoms. The application is primarily designed for use by researchers but can be used by anybody who wants a faster and more efficient means of locating papers of interest.

Keywords: COVID-19, literature summary, information retrieval, Snorkel

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690 The Impact of Corporate Social Responsibility Information Disclosure on the Accuracy of Analysts' Earnings Forecasts

Authors: Xin-Hua Zhao

Abstract:

In recent years, the growth rate of social responsibility reports disclosed by Chinese corporations has grown rapidly. The economic effects of the growing corporate social responsibility reports have become a hot topic. The article takes the chemical listed engineering corporations that disclose social responsibility reports in China as a sample, and based on the information asymmetry theory, examines the economic effect generated by corporate social responsibility disclosure with the method of ordinary least squares. The research is conducted from the perspective of analysts’ earnings forecasts and studies the impact of corporate social responsibility information disclosure on improving the accuracy of analysts' earnings forecasts. The results show that there is a statistically significant negative correlation between corporate social responsibility disclosure index and analysts’ earnings forecast error. The conclusions confirm that enterprises can reduce the asymmetry of social and environmental information by disclosing social responsibility reports, and thus improve the accuracy of analysts’ earnings forecasts. It can promote the effective allocation of resources in the market.

Keywords: analysts' earnings forecasts, corporate social responsibility disclosure, economic effect, information asymmetry

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689 From Ritual City to Modern City: The City Space Transformation of Xi’an in the Early 20th Century

Authors: Zhang Bian, Zhao Jijun

Abstract:

The urban layout of Xi’an city (the capital Chang’an in the Tang dynasty) was shaped by feudal etiquette, but this dominant factor was replaced by modern city planning during the period of the Republic of China. This makes Xi’an a representative case to explore the transformation process of Chinese cities in the early 20th century. By analyzing the contrast and connection between the historical texts of city planning and the realistic construction activities recorded by the maps and images, this paper reviews the transformation process of the urban space of Xi’an in the early 20th century and divides it into four phases according to important events that significantly impacted planning and construction activities. Based on this, the entire transformation of Xi’an’s city planning and practices can be characterized by three aspects: 1) the dominant force of the city plan and construction changed with the establishment of modern city administrations; 2) the layout of the city was continuously broadened to meet the demand of modern economy and city life; and, 3) the ritual space was transformed into practical space for commercial and recreational activities.

Keywords: city space, the early 20th century, transformation, Xi’an city

Procedia PDF Downloads 136
688 An Expert System Designed to Be Used with MOEAs for Efficient Portfolio Selection

Authors: Kostas Metaxiotis, Kostas Liagkouras

Abstract:

This study presents an Expert System specially designed to be used with Multiobjective Evolutionary Algorithms (MOEAs) for the solution of the portfolio selection problem. The validation of the proposed hybrid System is done by using data sets from Hang Seng 31 in Hong Kong, DAX 100 in Germany and FTSE 100 in UK. The performance of the proposed system is assessed in comparison with the Non-dominated Sorting Genetic Algorithm II (NSGAII). The evaluation of the performance is based on different performance metrics that evaluate both the proximity of the solutions to the Pareto front and their dispersion on it. The results show that the proposed hybrid system is efficient for the solution of this kind of problems.

Keywords: expert systems, multi-objective optimization, evolutionary algorithms, portfolio selection

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687 Multiphase Coexistence for Aqueous System with Hydrophilic Agent

Authors: G. B. Hong

Abstract:

Liquid-Liquid Equilibrium (LLE) data are measured for the ternary mixtures of water + 1-butanol + butyl acetate and quaternary mixtures of water + 1-butanol + butyl acetate + glycerol at atmospheric pressure at 313.15 K. In addition, isothermal Vapor–Liquid–Liquid Equilibrium (VLLE) data are determined experimentally at 333.15 K. The region of heterogeneity is found to increase as the hydrophilic agent (glycerol) is introduced into the aqueous mixtures. The experimental data are correlated with the NRTL model. The predicted results from the solution model with the model parameters determined from the constituent binaries are also compared with the experimental values.

Keywords: LLE, VLLE, hydrophilic agent, NRTL

Procedia PDF Downloads 217