Search results for: Tiantian Feng

Authors: Jhuang Jin-Jhong, Hsieh Wei-Fan

Abstract:

Climate change causes natural disasters persistently. Therefore, nowadays environmental planning objective tends to the issues of respecting nature and coexisting with nature. As a result, the natural environment analysis, e.g., the analysis of topography, soil, hydrology, climate, vegetation, is highly emphasized. On the other hand, Feng Shui has been a criterion of site selection for residence in Eastern since the ancient times and has had farther influence on site selection for castles and even for temples and tombs. The primary criterion of site selection is judging the quality of Long: mountain range, Sha: nearby mountains, Shui: hydrology, Xue: foundation, Xiang: aspect, which are similar to the environmental variables of mountain range, topography, hydrology and aspect. For the reason, a lot researchers attempt to probe into the connection between the criterion of Feng Shui and environmental planning factors. Most researches only discussed with the composition and theory of space of Feng Shui, but there is no research which explained Feng Shui through the environmental field. Consequently, this study reviewed the theory of Feng Shui through the environmental planning viewpoint and assembled essential composition factors of Feng Shui. The results of this study point. From literature review and comparison of theoretical meanings, we find that the ideal principles for planning the Feng Shui environment can also be used for environmental planning. Therefore, this article uses 12 ideal environmental features used in Feng Shui to contrast the natural aspects of the environment and make comparisons with previous research and classifies the environmental factors into climate, topography, hydrology, vegetation, and soil.

Keywords: the composition of Feng Shui, environmental planning, site selection, main components of the Feng Shui environment

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Authors: Tesfaye Tebeka Simur, Tian-Yu Peng, Yi-Feng Wang, Xiu-Wei Wu, Feng-Lian Zhang

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A boryl radical-promoted dehydroxylative alkylation of 3-hydroxy-oxindole derivatives is achieved. The reaction starts from addition of 4-dimethylaminopyridine (DMAP)-boryl radical to the amide carbonyl oxygen atom, which induces a spin-center shift process to promote the C−O bond cleavage. The elimination of a hydroxide anion from a free hydroxy group is also accomplished. Capture of the generated carbon radical with alkenes furnishes a variety of C-3 alkylated oxindoles. This method features a simple operation and broad substrate scope.

Keywords: boryl radical, C-O, C-F, C=C, C=N bond activation, spin center shift

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Authors: Tiantian Feng

Abstract:

There is a dearth of research on the literary circle as a teaching strategy in English as a Foreign Language (EFL) classes in Chinese colleges and universities and even fewer empirical studies on its impacts. In this one-quarter, design-based project, the researcher aims to increase students’ engagement, cooperation, and, on top of that, reading comprehension performance by utilizing a researcher-developed, adapted reading circle model in an EFL reading course at a Chinese college. The model also integrated team-based learning and portfolio assessment, with an emphasis on the specialization of individual responsibilities, contributions, and outcomes in reading projects, with the goal of addressing current issues in EFL classes at Chinese colleges, such as passive learning, test orientation, ineffective and uncooperative teamwork, and lack of dynamics. In this quasi-experimental research, two groups of students enrolled in the course were invited to participate in four in-class team projects, with the intervention class following the adapted literature circle model and team members rotating as Leader, Coordinator, Brain trust, and Reporter. The researcher/instructor used a sequential explanatory mixed-methods approach to quantitatively analyze the final grades for the pre-and post-tests, as well as individual scores for team projects and will code students' artifacts in the next step, with the results to be reported in a subsequent paper(s). Initial analysis showed that both groups saw an increase in final grades, but the intervention group enjoyed a more significant boost, suggesting that the adapted reading circle model is effective in improving students’ reading comprehension performance. This research not only closes the empirical research gap of literature circles in college EFL classes in China but also adds to the pool of effective ways to optimize reading comprehension performance and class performance in college EFL classes.

Keywords: literature circle, EFL teaching, college english reading, reading comprehension

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Authors: Jung-Feng Lin, Wei-Tang Chen, Chung-King Hsu, Chun-Pin Lin, Feng-Huei Lin

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One of the objectives of operative dentistry is to maintain pulp health in compromised teeth. Mostly used methods for this purpose are direct pulp capping and pulpotomy, which consist of placement of biocompatible materials and bio-inductors on the exposed pulp tissue to preserve its health and stimulate repair by mineralized tissue formation. In this study, we developed a material (calcium phosphate cement (CPC)/gypsum composite) as the dental pulp capping material for shortening setting time and improving handling properties. We further discussed the influence of five different ratio of gypsum to CPC on HAP conversion, microstructure, setting time, weight loss, pH value, temperature difference, viscosity, mechanical properties, porosity, and biocompatibility.

Keywords: calcium phosphate cement, calcium sulphate hemihydrate, pulp capping, fast setting time

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Authors: Kaixuan Feng, Ruixiang Lin, Yuyan Hu, Yuheng Feng, Dezhen Chen, Tongcheng Cao

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In this study, we propose a reaction system for the low-temperature reduction of NO by H₂ on carbon-based materials decorated with 5%wt. Ni. This cost-effective catalyst system efficiently utilizes pyrolysis carbon-based materials and waste hydrogen. Additionally, it yields environmentally friendly products without requiring extra heat sources in practical SCR devices. Density functional theory elucidates the mechanism of NO heterogeneous reduction by H₂ on Ni-decorated char surfaces. Two distinct reaction paths were identified, one involving the intermediate product N₂O and the other not. These pathways exhibit different rate-determination steps and activation energies. Kinetic analysis indicates that the N₂O byproduct pathway has a lower activation energy. Experimental results corroborate the theoretical findings. Thus, this research enhances our mechanistic understanding of the NO-H₂ reaction over char and offers insights for optimizing catalyst design in low-temperature NO reduction.

Keywords: char-based catalysis, NO reduction, DFT study, heterogeneous reaction, low-temperature H₂-reduction

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Authors: Jintang Zhou, Zhengjun Yao, Tiantian Yao

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Li₀.₃₅Zn₀.₃Fe₂.₃₅O₄(LZFO) grafted with polyaniline (PANI) fibers was synthesized by in situ polymerization. FTIR, XRD, SEM, and vector network analyzer were used to investigate chemical composition, micro-morphology, electromagnetic properties and microwave absorbing properties of the composite. The results show that PANI fibers were grafted on the surfaces of LZFO particles. The reflection loss exceeds 10 dB in the frequency range from 2.5 to 5 GHz and from 15 to 17GHz, and the maximum reflection loss reaches -33 dB at 15.9GHz. The enhanced microwave absorption properties of LZFO/PANI-fiber composites are mainly ascribed to the combined effect of both dielectric loss and magnetic loss and the improved impedance matching.

Keywords: Li₀.₃₅Zn₀.₃Fe₂.₃₅O₄, polyaniline, electromagnetic properties, microwave absorbing properties

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Authors: Tiantian Ma

Abstract:

The district of Doumen, Zhuhai has a sophisticated seabass value chain. However, unlike typical Global Value Chain (GVC) industries, the seabass value chain in Doumen is highly domestic both in terms of production and consumption. Still, since the highly-industrialized and capital-intensive industry involves many off-farm segments in both upstream and downstream, this paper will be utilizing the method of value chain analysis. To be specific, the paper will concentrate on two research goals: 1) the value chain mapping of the seabass industry, such as identifying actors in the hatchery, fish feed, fishponds, processing, logistics, and distribution, 2) the SWOT analysis of the seabass industry in Doumen, including incompetence of the waste disposal, the strategy of marketing, and the supportive role of the government, etc. In general, the seabass industry in Doumen is a sophisticated but not yet comprehensive value chain. It has achieved a lot in industrializing aqua-food products and fostering development, but there are still improvements that could be carried out, such as upholding environmental sustainability and promoting the brand better.

Keywords: agricultural value chain, fish farming, regional development, SWOT analysis, value chain mapping

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Authors: Tiantian Gu, Dezhi Li, Mian Zhang, Ying Jiang

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Considering the characteristics of residents’ participation in the governance of old community renewal (OCR), a theoretical model of the determinant of residents’ intention to participate in the governance of OCR has been built based on the theory of planned behavior. Seven old communities in Nanjing have been chosen as cases to conduct empirical analysis. The result indicates that participation attitude, subjective norm and perceived behavioral control have significant positive effects on residents’ intention to participate in the governance of the OCR. Recognition of the community, cognition of the OCR and perceived behavioral control have indirect positive effects on residents’ intention to participate in the OCR. In addition, the education level and the length of residence have positive effects on their participation intention, while the gender, age, and monthly income have little effect on it. The research result provides suggestions for the improvement of residents’ participation in the OCR.

Keywords: old community renewal, residents’ participation in governance, intention, theory of planned behavior

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Authors: Hannah Jennica P. Ello, Regina Via G. Garcia

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Films are famous expressions of art in the country. As an expression of art, it serves as a medium in which a culture is reflected. This paper studied how films reflected the Filipino culture. In this study, social semiotics was used to analyze the semiotic resources identified in the film. The films studied were 'Feng Shui', 'Sukob', and 'The Healing', which were three of the highest grossing horror films of Chito S. Roño. The objectives of the paper were (1) to identify the semiotic resources in the film, (2) to extract their meanings, and (3) to determine how these resources were perceived in the Filipino culture. The semiotic resources identified in each film are organized into three categories: color, practices and supernatural occurrences. Each semiotic resource is analyzed through the four dimensions of social semiotics, genre, style, modality, and discourse. For color, some of the semiotic resources identified are red, white and blue; for practices, Hagiolatry, and Mariolatry, faith healing and the belief in superstitions; and for supernatural occurrences, haunting ghosts, doppelganger attacks and returning from the dead were identified. The practices that are prominent in the films are Hagiolatry and Mariolatry, belief in feng shui and belief in faith healers and albularyos. The belief of these practices shows that Filipinos have a dual faith; belief in religion and a belief in superstitions. In short, Filipinos highly practice folk Catholicism and because of this, a mixture of different cultures can be seen, as having molded the Filipino culture to what it is today.

Keywords: culture, film, semiotics, social semiotics

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Authors: Helena Park

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For the last three decades, Seoul has experienced an exponential increase in population and concomitant rapid urbanization. With such development, Korea adopted a predominantly Western style of architecture but still based the structures on Korea’s traditionalism and Confucian precepts of pung su (feng shui). While Korean urban planning is focusing on balancing out the modernism and traditionalism in its city architecture, particularly in and landmark sites like The Seoul N Tower and Gyeongbok Palace, the accessibility and convenience concerns of minorities in social groups like the disabled are habitually disregarded. With the implementations of ramps and elevators, the welfare of all citizens seemed to improve. According to the dictates of traditional Korean culture, it was crucial for those construed as “disabled” or “underprivileged” to feel natural in the city of Seoul, which is planned and built with the background aesthetic theory of being harmonized with nature. It was interesting and also alarming to see the extent to which Korean landmarks were lacking facilities for the disabled throughout the city. Standards set by the Ministry of Health and Welfare and the Seoul Metropolitan City insist that buildings accommodate the needs of the disabled as well as the non-disabled equally, but it was hard to find buildings in Seoul - old or new - that fulfilled all the requirements. If fulfilled, some of the facilities were hard to find or not well maintained. There is thus a serious concern for planning reform in connection with Seoul’s 2030 Urban Plan. This paper argues that alternative planning could better integrate Korea’s traditionalist architecture and concepts of pung su rather than insist on the necessity of Western-style modernism as the sole modality for achieving accessibility for the disabled in Korea.

Keywords: accessibility, architecture of Seoul , Pung Su (Feng Shui), traditionalism, modernism in Seoul

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Authors: Mengxin Feng, Feng Xu, Zhiyong Lai

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As a typical representative of the countryside, traditional Chinese villages are rich in cultural landscape resources and historical information, but they are still in continuous decline. The problems of people's weak protection awareness and low cultural recognition are still serious, and the protection of cultural heritage is imminent. At the same time, with the rapid development of rural tourism, its cultural value has been explored and paid attention to again. From the perspective of tourists, this study aimed to explore people's perception and identity of cultural landscape resources under the current cultural tourism development background. We selected eleven typical landscape elements of Lingshui Village, a traditional village in Beijing, as research objects and conducted a questionnaire survey with two scales of perception and identity to explore the characteristics of people's perception and identification of landscape elements. We found that there was a strong positive correlation between the perception and identity of each element and that geographical location influenced visitors' overall perception. The perception dimensions scored the highest in location, and the lowest in history and culture, and the identity dimensions scored the highest in meaning and lowest in emotion. We analyzed the impact of visitors' backgrounds on people's perception and identity characteristics and found that age and education were two important factors. The elderly had a higher degree of perceived identity, as the familiarity effect increased their attention. Highly educated tourists had more stringent criteria for perception and identification. The above findings suggest strategies for conserving and optimizing landscape elements in the traditional village to improve the acceptance and recognition of cultural information in traditional villages, which will inject new vitality into the development of traditional villages.

Keywords: traditional village, tourist perception, landscape elements, perception and identity

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Authors: Lingzhi Li, Jiankun Zhang, Tiantian Gu

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Hazard management that can prevent fatal accidents and property losses is a fundamental process during the buildings’ construction stage. However, due to lack of safety supervision resources and operational pressures, the conduction of hazard management is poor and ineffective in China. In order to improve the quality of construction safety management, it is critical to explore the use of information technologies to ensure that the process of hazard management is efficient and effective. After exploring the existing problems of construction hazard management in China, this paper develops the griddization management model for construction hazard management. First, following the knowledge grid infrastructure, the griddization computing infrastructure for construction hazards management is designed which includes five layers: resource entity layer, information management layer, task management layer, knowledge transformation layer and application layer. This infrastructure will be as the technical support for realizing grid management. Second, this study divides the construction hazards into grids through city level, district level and construction site level according to grid principles. Last, a griddization management process including hazard identification, assessment and control is developed. Meanwhile, all stakeholders of construction safety management, such as owners, contractors, supervision organizations and government departments, should take the corresponding responsibilities in this process. Finally, a case study based on actual construction hazard identification, assessment and control is used to validate the effectiveness and efficiency of the proposed griddization management model. The advantage of this designed model is to realize information sharing and cooperative management between various safety management departments.

Keywords: construction hazard, griddization computing, grid management, process

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Authors: Haroon Jan Khan, Xian-Feng Xu, Syed Nasir Shah, Anooshay Niazi

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CNC machines are not only used on a large scale but also now become a prominent necessity among households and smaller businesses. Printed Circuit Boards manufactured by the chemical process are not only risky and unsafe but also expensive and time-consuming. A 3-axis precise CNC machine has been developed, which not only fabricates PCB but has also been used for multi-tasks just by changing the materials used and tools, making it versatile. The advanced CNC machine takes data from CAM software. The TB-6560 controller is used in the CNC machine to adjust variation in the X, Y, and Z axes. The advanced machine is efficient in automatic drilling, engraving, and cutting.

Keywords: CNC, G-code, CAD, CAM, Proteus, FLATCAM, Easel

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Authors: Tao Feng, Wei-Wei Zhang, Chang-Ming Ding

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Cross-site scripting (XSS) is one of the most popular WEB Attacking methods at present, and also one of the most risky web attacks. Because of the population of JavaScript, the scene of the cross site scripting attack is also gradually expanded. However, since the web application developers tend to only focus on functional testing and lack the awareness of the XSS, which has made the on-line web projects exist many XSS vulnerabilities. In this paper, different various techniques of XSS attack are analyzed, and a method automatically to detect it is proposed. It is easy to check the results of vulnerability detection when running it as a plug-in.

Keywords: XSS, no target attack platform, automatic detection，XSS detection

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Authors: Xing Lu, Yi-ming Wu, Yan-hong Zhu, Zhen-feng Chen, Hong Liang, Yan Peng

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[Eu(BMQ)2(NO3)3(CH3OH)(H2O)] (1),and [Er(BMQ)2(NO3)3(CH3OH)(H2O)] (2),were synthesized. Compounds 1 and 2 exhibit a certain extent cytotoxicity against Hep G2, Hela 229, MGC80-3 and BEL-7404 cell lines invitro, with IC50 values in the14.51±1.41μM to 52.49±4.01μM range. Compound 1 exhibited significantly enhanced cytotoxicity against MGC80-3 cell line, comparing with free 3-(1H-benzimidazol-2-yl)-6-methyl-2(1H)- quinolinone. The binding abilities of 1 to DNA were stronger than that of 2. Intercalation is the most probable binding mode for both the complexes.

Keywords: quinolinone, Eu(II) complex, Er(III) complex, cytotoxicity.

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Authors: Feng-Ming Fan, Xiu-Hui Wen, Po-Feng Chen, Yi-Ching Tu

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Because of inborn natural conditions and man-made sabotage, the water resources insufficient phenomenon in Taiwan is a very important issue needed to face immediately. The regulations and law of water resources protection and recycling are gradually completed now but still lack of specific water recycling effectiveness checking method. The research focused on the industrial parks that already had been certificated with EIA to establish a professional checking system, carry through and forge ahead to contribute one’s bit in water resources sustainable usage. Taiwan Government Policies of Environmental Impact Assessment established in 1994, some development projects were requested to set certain water recycling ratio for water resources effective usage. The water covers and contains everything because all-inclusive companies enter and be stationed. For control the execution status of industrial park water and waste water recycling ratio about EIA commitment effectively, we invited experts and scholars in this filed to discuss with related organs to formulate the policy and audit plan. Besides, call a meeting to set public version water equilibrium diagrams and recycles parameter. We selected nine industrial parks that were requested set certain water recycling ratio in EIA examination stage and then according to the water usage quantity, we audited 340 factories in these industrial parks with spot and documents examination and got fruitful results – the average water usage of unit area per year of all these examined industrial parks is 31,000 tons/hectare/year, the value is just half of Taiwan industries average. It is obvious that the industrial parks with EIA commitment can decrease the water resources consumption effectively. Taiwan government policies of Environmental Impact Assessment took follow though tracking function into consideration at the beginning. The results of this research verify the importance of the implementing with water recycling to save water resources in EIA commitment. Inducing development units to follow EIA commitment to get the balance between environmental protection and economic development is one of the important EIA value.

Keywords: Taiwan government policies of environmental impact assessment, water recycling ratio of EIA commitment, water resources sustainable usage, water recycling

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Authors: Li Feng

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In IEEE 802.11 networks, it is well known that the traditional time-domain contention often leads to low channel utilization. The first frequency-domain contention scheme, the time to frequency (T2F), has recently been proposed to improve the channel utilization and has attracted a great deal of attention. In this paper, we survey the latest research progress on the weighed frequency-domain contention. We present the basic ideas, work principles of these related schemes and point out their differences. This paper is very useful for further study on frequency-domain contention.

Keywords: 802.11, wireless LANs, frequency-domain contention, T2F

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Authors: Xiaoli Zhang, Xiongfei Li, Yuncong Feng

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ROC curves, as a widely used evaluating tool in machine learning field, are the tradeoff of true positive rate and negative rate. However, they are blamed for ignoring some vital information in the evaluation process, such as the amount of information about the target that each instance carries, predicted score given by each classification model to each instance. Hence, in this paper, a new classification performance method is proposed by extending the Receiver Operator Characteristic (ROC) curves to 3D space, which is denoted as 3D ROC Histogram. In the histogram, the

Keywords: classification, performance evaluation, receiver operating characteristic histogram, hardness prediction

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Authors: Zhuo-Xin Lu, Yan Shi, Chang-Feng Yan, Ying Huang, Yuan Gan, Zhi-Da Wang

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With TiO2 nanotube arrays (TNTA) as template, a IrO2 nanopores membrane electrode assembly (MEA) was synthesized by a novel depositi-assemble-etch strategy. By analysing the morphology of IrO2/TNTA and cyclic voltammetry (CV) curve at different deposition cycles, we proposed a reasonable scheme for the process of IrO2 electrodeposition on TNTA. The current density of IrO2/TNTA at 1.5V vs RHE reaches 5.12mA/cm2 after 55 cycles deposition, which shows promising performance for its high OER activity after template removal.

Keywords: electrodeposition, IrO2 nanopores, MEA, OER

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Authors: Shu-Feng Chang

Abstract:

During the past years, gender issues have been discussed in many fields. It causes such differences not only in physical field but also in mental field. Gender differences also appear in our daily life, especially in the communication of spoken language. This statement was proved in the descriptions of color. However, the research about describing shape was fewer. The purpose of the study was to determine the description of the shape was different or alike due to gender. If it was different, this difference was dissimilar or as the same as the conclusion of color. Data were collected on the shape descriptions by 15 female and 15male participants in describing five pictures. As a result, it was really different for the descriptions of shape due to gender factor. The findings of shape descriptions were almost as the same as color naming with gender factor.

Keywords: gender, naming, shape, sociolinguistics

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Authors: Feng-Hisang Lai

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CFD(Computational Fluid Dynamics) is conducted to numerically study the flow and heat transfer features of a two-pole, 6,080HP, 60Hz, 3,150V open drip-proof (ODP) motor. The stator and rotor cores in this high voltage induction motor are segmented with the use of spacers for cooling purposes, which leads to difficulties in meshing when the entire system is to be simulated. The system is divided into 4 parts, meshed separately and then combined using interfaces. The deviation between the CFD and experimental results in temperature and flow rate is less than 10%. The internal flow is further examined and a final design is proposed to reduce the winding temperature by 10 degrees.

Keywords: CFD, open drip proof, induction motor, cooling

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Authors: Wen-Jye Shyr, Chia-Ming Lin, Hung-Yun Feng

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The purpose of this study was to develop an energy management system for university campuses based on the Internet of Things (IoT) technique. The proposed IoT technique based on WebAccess is used via network browser Internet Explore and applies TCP/IP protocol. The case study of IoT for lighting energy usage management system was proposed. Structure of proposed IoT technique included perception layer, equipment layer, control layer, application layer and network layer.

Keywords: energy management, IoT technique, sensor, WebAccess

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Authors: Nurulasma Zainudin, Mashitah Mohd Yusoff, Kwok Feng Chong

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Functionalized reduced graphene oxide is essential importance for their end applications. Chemical functionalization of reduced graphene oxide with strange atoms is a leading strategy to modify the properties of the materials moreover maintains the inherent properties of reduced graphene oxide. A thionine functionalized reduce graphene oxide electrode was fabricated and was used to electrochemically determine nitrite. The electrochemical behaviour of thionine functionalized reduced graphene oxide towards oxidation of nitrite via cyclic voltammetry was studied and the proposed method exhibited enhanced electrocatalytic behaviour.

Keywords: nitrite, sensor, thionine, reduced graphene oxide

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Authors: Shengjun Zhang, Xu Cheng, Feng Shen

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The passive containment cooling system (PCCS) is widely used in the advanced nuclear reactor in case of the loss of coolant accident (LOCA) and the main steam line break accident (MSLB). The internal heat exchanger is one of the most important equipment in the PCCS and its heat transfer characteristic determines the performance of the system. In this investigation, a theoretical model is presented for predicting the heat and mass transfer which accompanies condensation. The conduction through the liquid condensate is considered and the interface temperature is defined by iteration. The parameter in the correlation to describe the suction effect should be further determined through experimental data.

Keywords: non-condensable gas, condensation, heat transfer coefficient, heat and mass transfer analogy

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Authors: Ruina Xu, Peixue Jiang, Feng Luo

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The novel concept of enhanced geothermal system with CO2 instead of water as working fluid (CO2-EGS) has attracted wide attention due to additional benefit of CO2 geological storage during the power generation process. In this research, numerical investigation on a doublet CO2-EGS system is performed, focusing on the influence of the injection/production well perforation location in the targeted geothermal reservoir. Three different reservoir inlet and outlet boundary conditions are used in simulations since the well constrains are different in reality. The results show that CO2-EGS system performance of power generation and power cost vary greatly among cases of different wells perforation locations, and the optimum options under different boundary conditions are also different.

Keywords: Enhanced Geothermal System, supercritical CO2, heat transfer, CO2-EGS

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Authors: Chong Hu, Tiantian Wang, Zhe Li, Ourui Huang, Yichen Pan

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When the train is running in a high geothermal tunnel, changes in the temperature field will cause disturbances in the propagation and superposition of pressure waves in the tunnel, which in turn have an effect on the aerodynamic resistance of the train. The aim of this paper is to investigate the effect of the changes in the lengths of the high-temperature zone of the tunnel on the aerodynamic resistance of the train, clarifying the evolution mechanism of aerodynamic resistance of trains in tunnels with high ground temperatures. Firstly, moving model tests of trains passing through wall-heated tunnels were conducted to verify the reliability of the numerical method in this paper. Subsequently, based on the three-dimensional unsteady compressible RANS method and the standard k-ε two-equation turbulence model, the change laws of the average aerodynamic resistance under different high-temperature zone lengths were analyzed, and the influence of frictional resistance and pressure difference resistance on total resistance at different times was discussed. The results show that as the length of the high-temperature zone LH increases, the average aerodynamic resistance of a train running in a tunnel gradually decreases; when LH = 330 m, the aerodynamic resistance can be reduced by 5.7%. At the moment of maximum resistance, the total resistance, differential pressure resistance, and friction resistance all decrease gradually with the increase of LH and then remain basically unchanged. At the moment of the minimum value of resistance, with the increase of LH, the total resistance first increases and then slowly decreases; the differential pressure resistance first increases and then remains unchanged, while the friction resistance first remains unchanged and then gradually decreases, and the ratio of the differential pressure resistance to the total resistance gradually increases with the increase of LH. The results of this paper can provide guidance for scholars who need to investigate the mechanism of aerodynamic resistance change of trains in high geothermal environments, as well as provide a new way of thinking for resistance reduction in non-high geothermal tunnels.

Keywords: high-speed trains, aerodynamic resistance, high-ground temperature, tunnel

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Authors: Jing Qing-feng, Liu Danmei

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Based on the optimum detection, signal projection and Maximum A Posteriori (MAP) rule, Proakis has deduced the theoretical BER equation of Gray coded MPSK signals. Proakis analyzed the BER theoretical equations mainly based on the projection of signals, which is difficult to be understood. This article solve the same problem based on the signal space, which explains the vectors relations among the sending signals, received signals and noises. The more explicit and easy-deduced process is illustrated in this article based on the signal space, which can illustrated the relations among the signals and noises clearly. This kind of deduction has a univocal geometry meaning. It can explain the correlation between the production and calculation of BER in vector level.

Keywords: MPSK, MAP, signal space, BER

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Authors: Wei-Ru Chang, Jenn-Jiang Hwang, Zen-Ting Hsiao, Shu-Feng Lee

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Proton exchange membrane (PEM) fuel cells are widely used in electrical systems as an economical, low-polluting energy source. This study investigates the effects of PEMFC gas nitriding treatment on metal bipolar plates. The test material was SUS304 stainless steel. The study explored five different pretreatment processes, varying the corrosion resistance and electrical conductivity conditions. The most effective process was industrial acid washing, followed by heating to 500 °C. Under the condition, the corrosion current density was 8.695 μA, significantly lower than that of the untreated pretreatment sample flakes, which was measured as 38.351 μA.

Keywords: nitriding, bipolar, 304, corrosion, resistance, pretreatment

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Authors: Kai-Sheng Ji, Yi-Feng Lin

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The pervaporation process for solvent and water separation has attracted research attention due to its lower energy consumption compared with conventional distillation processes. The membranes used for the pervaporation approach should exhibit high flux and separation factors. In this study, the ZIF-7 crystal particles were successfully incorporated into chitosan (CS) membranes to form ZIF-7/CS mixed-matrix membranes. The as-prepared ZIF-7/CS mixed-matrix membranes were used to separate mixtures of water/ethanol at 25℃ in the pervaporation process. The mixed-matrix membranes with different ZIF-7 wt% incorporation showed better separation efficiency than the pristine CS membranes because of the smaller pore size of the mixed-matrix membranes. The separation factor and the flux of the ZIF-7/CS membranes clearly exceed the upper limit of the previously reported CS-based and mixed-matrix membranes.

Keywords: pervaporation, chitosan, ZIF-7, memberane separation

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Authors: Ming-Kwei Lee, Chih-Feng Yen

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The electrical characteristics of liquid phase deposited silicon oxynitride film on ammonium sulfide treated p-type (100) gallium arsenide substrate were investigated. Hydrofluosilicic acid, ammonia and boric acid aqueous solutions were used as precursors. The electrical characteristics of silicon oxynitride film are much improved on gallium arsenide substrate with ammonium sulfide treatment. With post-metallization annealing, hydrogen ions can further passivate defects in SiON/GaAs film and interface. The leakage currents can reach 7.1 × 10-8 and 1.8 × 10-7 at ± 2 V. The dielectric constant and effective oxide charges are 5.6 and -5.3 × 1010 C/cm2, respectively. The hysteresis offset of hysteresis loop is merely 0.09 V.

Keywords: liquid phase deposition, SiON, GaAs, PMA, (NH4)2S

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