Search results for: Scott X. Chang

Authors: Chia-Chi Chang

Abstract:

Most battery-driven wireless sensor devices will enter in sleep mode as soon as possible to extend the overall lifetime of a sensor network. It is necessary to turn off unnecessary radio and peripheral functions, especially the radio unit always consumes more energy than other components during wireless communication. The microcontroller is the most important part of the wireless sensor device. It is responsible for the manipulation of sensing data and communication protocols. The microcontroller always has different sleep modes, each with a different level of energy usage. The deeper the sleep, the lower the energy consumption. Most wireless sensor devices can only enter the sleep mode: the external low-frequency oscillator is still running to wake up the sleeping microcontroller when the sleep timer expires. In this paper, our sensor device can enter the extended sleep mode: none of the oscillator is running and the wireless sensor device has the nanoampere consumption and self-awaking ability. Finally, these wireless sensor devices were deployed in a smart home security network.

Keywords: wireless sensor network, battery-driven, sleep mode, home security

Procedia PDF Downloads 281

Authors: Woei-Shyan Lee, Shuo-Ling Chang

Abstract:

The nanoindentation behaviour and phase transformation of annealed single-crystal silicon wafers are examined. The silicon specimens are annealed at temperatures of 250, 350 and 450ºC, respectively, for 15 minutes and are then indented to maximum loads of 30, 50 and 70 mN. The phase changes induced in the indented specimens are observed using transmission electron microscopy (TEM) and micro-Raman scattering spectroscopy (RSS). For all annealing temperatures, an elbow feature is observed in the unloading curve following indentation to a maximum load of 30 mN. Under higher loads of 50 mN and 70 mN, respectively, the elbow feature is replaced by a pop-out event. The elbow feature reveals a complete amorphous phase transformation within the indented zone, whereas the pop-out event indicates the formation of Si XII and Si III phases. The experimental results show that the formation of these crystalline silicon phases increases with an increasing annealing temperature and indentation load. The hardness and Young’s modulus both decrease as the annealing temperature and indentation load are increased.

Keywords: nanoindentation, silicon, phase transformation, amorphous, annealing

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Authors: Myung Ho Lee, Hee Seung Lim, Young Jae Maeng, Chang Hoon Lee

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This study presents an automatic sequential extraction device for Pu and Am isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin and TRU resin. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO₃, the sample was allowed to evaporate to dryness after filtering the leaching solution with 0.45 micron filter. The Pu isotopes were separated in HNO₃ medium with anion exchange resin. For leaching solution passed through the anion exchange column, the Am isotopes were sequentially separated with TRU resin. Automatic sequential extraction device built-in software information of separation for Pu and Am isotopes was developed. The purified Pu and Am isotopes were measured by alpha spectrometer, respectively, after the micro-precipitation of neodymium. The data of Pu and Am isotopes in radioactive waste with an automatic sequential extraction device developed in this study were validated with the ICP-MS system.

Keywords: automatic sequential extraction device, Pu isotopes, Am isotopes, alpha spectrometer, radioactive waste samples, ICP-MS system

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Authors: Shuen-Tai Wang, Hsi-Ya Chang

Abstract:

Cloud computing is becoming more and more matured over the last few years and consequently the demands for better cloud services is increasing rapidly. One of the research topics to improve cloud services is the desktop computing in virtualized environment. This paper aims at the development of an adaptive virtual desktop service in cloud computing platform based on our previous research on the virtualization technology. We implement cloud virtual desktop and application software streaming technology that make it possible for providing Virtual Desktop as a Service (VDaaS). Given the development of remote desktop virtualization, it allows shifting the user’s desktop from the traditional PC environment to the cloud-enabled environment, which is stored on a remote virtual machine rather than locally. This proposed effort has the potential to positively provide an efficient, resilience and elastic environment for online cloud service. Users no longer need to burden the platform maintenances and drastically reduces the overall cost of hardware and software licenses. Moreover, this flexible remote desktop service represents the next significant step to the mobile workplace, and it lets users access their desktop environments from virtually anywhere.

Keywords: cloud computing, virtualization, virtual desktop, VDaaS

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Authors: Pedro Cabrales, Scott Caroen, Tony R. Reid, Bryan Oronsky

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Introduction and Purpose RRx-001 is an NLRP3 inhibitor and Nrf2 agonist in Phase 3 trials for the treatment of cancer. The purpose of this study was to examine whether treatment with RRx-001, given itsanti-inflammatory and antioxidant properties, improvedexercise and skeletal muscle oxidative capacity in mice on the generalpremiss that better health outcomes correlatewith more activity. Material and Methods Male and female adult mice (n=6 per group) were subjected to an endurance exercise capacity (EEC)test until exhaustion on a motorized treadmill after 3 once weekly doses of either RRx-001 5 mg/kg, RRx-001 2 mg/kg, or vehicle. The EEC protocol consisted of a treadmill velocity of 30meters per min at an uphill inclination (slope of 10%) until the mice reached fatigue, which was defined as the inability of the mice to maintain the appropriate pace despitecontinuous hand stimulation for 1 min. The concentration of malondialdehyde (MDA), an indicator of lipid peroxidation, and creatine kinase (CK), an indicator of muscle damage, in the blood samples collected immediately after the acute exercise was determined with a commercial ELISA assay kit. ResultsThe exhaustive exercise times of the RRx-001 groups were significantly longer than that of the vehicle group (p<0.05) by weeks 2 and 3. In addition, MDA levels in the gastrocnemius, soleus, and extensor digitorum longus muscles were significantly lower than those of the vehicle group were (p<0.05), as were the serum CK levels(p<0.05). ConclusionsIn conclusion, this study found that RRx-001 has anti-fatigue properties, as evidenced by an increase in exercise capacity with RRx-001 treatment, and protects against strenuous exercise-induced muscle damage and lipid peroxidation. This data potentially supports the use of RRx-001 in the clinic to improve exercise performance and reduce physical fatigue.

Keywords: RRx-001, anti-fatigue, muscle protection, increased exercise tolerance, lipid peroxidation

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Authors: Seok Woo Chang

Abstract:

Aim: The objective of this study was to compare and evaluate the hydration products of commercial and experimental calcium silicate cement. Materials and Methods: The commercial calcium silicate cement (ProRoot MTA, Dentsply) and experimental calcium silicate cement (n=10) were mixed with distilled water (water/powder ratio = 20 w/w) and stirred at room temperature for 10 hours. These mixtures were dispersed on wafer and dried for 12 hours at room temperature. Thereafter, the dried specimens were examined with Scanning Electron Microscope (SEM). Electron Dispersive Spectrometry (EDS) was also carried out. Results: The commercial calcium silicate cement (ProRoot MTA) and experimental calcium silicate cement both showed precipitation of rod-like and globule-like crystals. Based on EDS analysis, these precipitates were supposed to be calcium hydroxide or calcium silicate hydrates. The degree of formation of these precipitates was higher in commercial MTA. Conclusions: Based on the results, both commercial and experimental calcium silicate cement had ability to produce calcium hydroxide or calcium silicate hydrate precipitates.

Keywords: calcium silicate cement, ProRoot MTA, precipitation, calcium hydroxide, calcium silicate hydrate

Procedia PDF Downloads 236

Authors: Lin Chang

Abstract:

Birmingham, England was a town in the late-eighteenth century and became the nation’s second largest city in the late nineteenth century. The city expanded rapidly in terms of its population and size. Three generations of artists from a local family, the Lines, made a large number of drawings and paintings depicting the growth and changes of their city. At first sight, the meaning of the pictures seems straight-forward: providing records of what were torn down and newly-built. However, except for being read as maps, the pictures reveal a struggle in vision as to whether unsightly manufactories and their smoking chimneys should be visualized and how far the borders of the town should have been positioned and understood as they continued to grow and encroached upon its immediate countryside. This art-historic paper examines some topographic views by the Lines family and explores how they, through unusual depiction of rural and urban scenery, manage to give form to the borderlands between the country and the city. This paper argues that while the idea of the country and the city seems to be common sense, the two realms actually pose difficulty for visual representation as to where exactly their borders are and the idea itself has dichotomized the way people consider landscape imageries to be.

Keywords: Birmingham, suburb, urban fringes, landscape

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Authors: Ludmilla Wikkeling-Scott, Amira Karim

Abstract:

Background: In a rapidly developing environment, concerns for pollution and depletion of natural resources are challenges facing global communities. A major source of waste on university campuses is the use of plastic bottles, while cost of production and processing is high. Consumer demand stimulates popularity of plastic bottle production, but researchers agree this is not a sustainable solution. This pilot study assesses plastic water bottle used and attitude towards alternatives among Emirati college students. Methods: This study was conducted in December 2016, using an anonymous self-administered survey of 17 questions. The survey included personal characteristics, plastic water bottle used, attitude towards alternative replacement and sustainability. For statistical analysis, STATA 14C was used to determine significance of association. Results: A total of 500 Emirati students (94.6% female) completed the survey. Of the students, 82.6% preferred bottled water over tap water, and 44.6% reported disposable bottled water use in their household, 42.6% purchased disposable bottled water more than twice a week, and 44.2% purchased bottled water at least once, while on campus. Students were willing to consider switching to alternative water bottle use if it was more convenient (22.54%), cost less (55.13%) or improved the taste (22.54%), while only 7.85% students would not consider any alternatives. There was a significant difference in attitude towards alternatives to water bottle use by area of study (p < 0.005). Conclusion: The UAE strives to be at the forefront of sustainable development and protecting biodiversity. However, a major challenge is the increasing amount of waste, exacerbated by the increasing consumer demand for convenience as seen in this billion-dollar industry. Plastic bottles, for all purposes, pose a serious threat to the environment and sustainable campus initiatives can help reduce the ecological footprint, improve awareness of safe alternatives and benefits to the environment.

Keywords: ecological foot print, emirati students, plastic bottle consumption, sustainable campus

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Authors: Sari F. Alkhatib, Chang Je Park, Gyuhong Roh

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The iterative scheme which is used to treat buildup factors for stratified shields is being investigated here using the layer-splitting technique. A simple suggested formalism for the scheme based on the Kalos’ formula is introduced, based on which the implementation of the testing technique is carried out. The second layer in a double-layer shield was split into two equivalent layers and the scheme (with the suggested formalism) was implemented on the new “three-layer” shield configuration. The results of such manipulation on water-lead and water-iron shields combinations are presented here for 1 MeV photons. It was found that splitting the second layer introduces some deviation on the overall buildup factor value. This expected deviation appeared to be higher in the case of low Z layer followed by high Z. However, the overall performance of the iterative scheme showed a great consistency and strong coherence even with the introduced changes. The introduced layer-splitting testing technique shows the capability to be implemented in test the iterative scheme with a wide range of formalisms.

Keywords: buildup factor, iterative scheme, stratified shields, layer-splitting tecnique

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Authors: Yu-Lin Shen, Ming-Kuen Chang

Abstract:

In addition to a considerable amount of machinery and equipment, intricacies of the transmission pipeline exist in Petrochemical plants. Long term corrosion may lead to pipeline thinning and rupture, causing serious safety concerns. With the advances in non-destructive testing technology, more rapid and long-range ultrasonic detection techniques are often used for pipeline inspection, EMAT without coupling to detect, it is a non-contact ultrasonic, suitable for detecting elevated temperature or roughened e surface of line. In this study, we prepared artificial defects in pipeline for Electromagnetic Acoustic Transducer testing (EMAT) to survey the relationship between the defect location, sizing and the EMAT signal. It was found that the signal amplitude of EMAT exhibited greater signal attenuation with larger defect depth and length. In addition, with bigger flat hole diameter, greater amplitude attenuation was obtained. In summary, signal amplitude attenuation of EMAT was affected by the defect depth, defect length and the hole diameter and size.

Keywords: EMAT, artificial defect, NDT, ultrasonic testing

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Authors: Kai-Yi Cho, Fa-Shian Chang, Lih-Tyng Hwang, Chih-Feng Liu, Jeng-Nan Lee, Shun-Min Wang, Jhu-Wei Ji

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This paper presents a ground robot which has the tracked transformative structures of the motion mechanism. The robot has a good ability to adapt to the terrain, due to the front end of the track can be deformed, it can more easily pass the more complex area, such as to climb stairs and ramp areas. Usually in the disaster area, where the terrain is generally broken and complicated, there will be many slopes, broken walls, rubble, and obstacles, then if you want the robot through this area, you need to have a good off-road performance for possible complex terrain, this robot with the transformative tracked mechanism has a strong adaptability, it can overcome the limitation of the terrains to be a good rescue robot. Also, the robot has a good flexibility in the shape of contact with the ground; that can adapt the varied terrain by the deformable track, thus able to pass the different terrains, that was verified through the experiments on a test-platform and a field test. The prototype of the robot system has been developed, and experiments are carried out to verify the validity of the proposed design.

Keywords: tracked robot, rescue robot, transformation mechanism, deformable track, hull design

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Authors: Ting Hsiang Chang, Cheng Zuo Tsai

Abstract:

In recent years, sports culture dominated in Taiwan, which spurred the rapid development of the sports industry. More innovative and high-tech sporting goods were developed to provide choices for consumers. Nowadays, Taiwan has gradually entered the aging society where people pay more attention to health promotion, delay of aging and other related issues among senior. However, it is an undeniable fact that moderate exercise is a great help to delay aging. Therefore, how senior select the appropriate sporting goods, including sports shoes, sportswear, sports equipment, and even the sports brands when engaged in various kinds of sports, are explored in this research. Therefore, this study sets the reference indicators by exploring the brands of sporting goods, that senior aged 50-70 choose in a fog peak district, the Taichung City, as the subjects of study by answering a questionnaire. Also, this study offers recommendations in terms of the design, marketing or selling of sporting goods for the senior, and how owners of sports brands or related sports industries should target them.

Keywords: senior, aging, sporting goods, sports brand

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Authors: Y. T. Ku, S. W. Chen, J. R. Wang, C. Shih, Y. F. Chang

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In order to respond the policy decision of non-nuclear homes, Tai Power Company (TPC) will provide the decommissioning project of Kuosheng Nuclear power plant (KSNPP) to meet the regulatory requirement in near future. In this study, the computational fluid dynamics (CFD) methodology has been employed to develop a flow prediction model for boiling water reactor (BWR) with upper pool under decommissioning stage. The model can be utilized to investigate the flow behavior as the vessel combined with upper pool and continuity cooling system. At normal operating condition, different parameters are obtained for the full fluid area, including velocity, mass flow, and mixing phenomenon in the reactor pressure vessel (RPV) and upper pool. Through the efforts of the study, an integrated simulation model will be developed for flow field analysis of decommissioning KSNPP under normal operating condition. It can be expected that a basis result for future analysis application of TPC can be provide from this study.

Keywords: CFD, BWR, decommissioning, upper pool

Procedia PDF Downloads 237

Authors: Jesmin Akter, Chang Hyuk Ahn, Ilho Kim, Fumitake Nishimura, Jaiyeop Lee

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This study aimed to compare two pre-treatment and two RNA extraction methods, namely PEG, and Nano bubble, Viral RNA Soil, and Mini Kit, in terms of their efficiency in detecting SARS-CoV-2 and PMMoV in influent and 1st sedimentation samples from a wastewater treatment plant. The extracted RNA samples were quantified and evaluated for purity, yield, and integrity. The results indicated that the nanobubble PEG method provided the highest yield of RNA, while the QIAamp Viral RNA Mini Kit produced the purest RNA samples. In terms of sensitivity and specificity, all these methods were able to detect SARS-CoV-2 and PMMoV in both influent and 1st sedimentation samples. However, the nanobubble PEG method showed slightly higher sensitivity compared to the other methods. These findings suggest that the choice of RNA extraction method should depend on the downstream application and the quality of the RNA required. The study also highlights the potential of wastewater-based epidemiology as an effective and non-invasive method for monitoring the spread of infectious diseases in a community.

Keywords: influent, PMMoV, SARS-CoV-2, wastewater based epidemiology

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Authors: Debit Datta, Jeffrey J. Coleman, Scott A. Enebak, Lori G. Eckhardt

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Loblolly pine (Pinus taeda) is a leading productive timber species in the southeastern USA. Over the past three years, an emerging threat is expressed by successive needle defoliation followed by stunted growth and tree mortality in loblolly pine plantations. Considering economic significance, it has now become a rising concern among landowners, forest managers, and forest health state cooperators. However, the symptoms of the disease were perplexed somewhat with root disease(s) and recurrently attributed to invasive Phytophthora species due to the similarity of disease nature and devastation. Therefore, the study investigated the potential causal agent of this disease and characterized the fungi associated with loblolly pine needle defoliation in the southeastern USA. Besides, 70 trees were selected at seven long-term monitoring plots at Chatom, Alabama, to monitor and record the annual disease incidence and severity. Based on colony morphology and ITS-rDNA sequence data, a total of 28 species of fungi representing 17 families have been recovered from diseased loblolly pine needles. The native brown-spot pathogen, Lecanosticta acicola, was the species most frequently recovered from unhealthy loblolly pine needles in combination with some other common needle cast and rust pathogen(s). Identification was confirmed using morphological similarity and amplification of translation elongation factor 1-alpha gene region of interest. Tagged trees were consistently found chlorotic and defoliated from 2019 to 2020. The current emergence of the brown-spot pathogen causing loblolly pine mortality necessitates the investigation of the role of changing climatic conditions, which might be associated with increased pathogen pressure to loblolly pines in the southeastern USA.

Keywords: brown-spot needle blight, loblolly pine, needle defoliation, plantation forestry

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Authors: Jennifer Nutton, Gayle Ployer, Ky Scott, Jenny Morgan

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Working in a circle within higher education creates a decolonial space of mutual respect, responsibility, and reciprocity that facilitates collaborative learning and deep connections among learners and instructors. This approach is beyond simply facilitating a group in a circle but opens the door to creating a sacred space connecting each member to the land, to the Indigenous peoples who have taken care of the lands since time immemorial, to one another, and to one’s own positionality. These deep connections not only center human knowledges and relationships but also acknowledges responsibilities to land. Working in a circle as a relational pedagogical praxis also disrupts institutional power dynamics by creating a space of collaborative learning and deep connections in the classroom. Inherent within circle work is to facilitate connections not just academically but emotionally, physically, culturally, and spiritually. Recent literature supports the use of online talking circles, finding that it can offer a more relational and experiential learning environment, which is often absent in the virtual world and has been made more evident and necessary since the pandemic. These deeper experiences of learning and connection, rooted in both knowledge and the land, can then be shared with openness and vulnerability with one another, facilitating growth and change. This process of beginning with the land is critical to ensure we have the grounding to obstruct the ongoing realities of colonialism. The authors, who identify as both Indigenous and non-Indigenous, as both educators and learners, reflect on their teaching and learning experiences in circle. They share a relational pedagogical praxis framework that has been successful in educating future social workers, environmental activists, and leaders in social and human services, health, legal and political fields.

Keywords: circle work, relational pedagogies, decolonization, distance education

Procedia PDF Downloads 53

Authors: Zhang Bian, Zhao Jijun

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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 20^th 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 20^th 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 138

Authors: Yu-Jen Chang, Yun Chen, Hei-Lam Wong

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The Economic Lot Scheduling Problem (ELSP) is a valuable mathematical model that can support decision-makers to make scheduling decisions. The basic period approach is effective for solving the ELSP. The assumption for applying the basic period approach is that a product must use its maximum production rate to be produced. However, a product can lower its production rate to reduce the average total cost when a facility has extra idle time. The past researches discussed how a product adjusts its production rate under the common cycle approach. To the best of our knowledge, no studies have addressed how a product lowers its production rate under the basic period approach. This research is the first paper to discuss this topic. The research develops a simple fixed rate approach that adjusts the production rate of a product under the basic period approach to solve the ELSP. Our numerical example shows our approach can find a better solution than the traditional basic period approach. Our mathematical model that applies the fixed rate approach under the basic period approach can serve as a reference for other related researches.

Keywords: economic lot, basic period, genetic algorithm, fixed rate

Procedia PDF Downloads 539

Authors: Dong-Hyun Ha, Young-Min Ko, Chang-Bin Ha, Hyoung-Kyu Song

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In Heterogeneous network (HetNet) can provide high quality of a service in a wireless communication system by composition of small cell networks. The composition of small cell networks improves cell coverage and capacity to the mobile users.Recently, various techniques using small cell networks have been researched in the wireless communication system. In this paper, the cooperative scheme obtaining high reliability is proposed in the small cell networks. The proposed scheme suggests a cooperative small cell system and the new signal transmission technique in the proposed system model. The new signal transmission technique applies a cyclic delay diversity (CDD) scheme based on the multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) system to obtain improved performance. The improved performance of the proposed scheme is confirmed by the simulation results.

Keywords: adaptive transmission, cooperative communication, diversity gain, OFDM

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Authors: Su-Hyun Cho, Chang-U Chae

Abstract:

Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in particular in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a results, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

Keywords: CO₂ emissions, CO₂ reduction, ready-mixed concrete, environmental impact assessment

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Authors: Chang Soo Chon, Cheol Woong Ko, Han Sung Kim

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The aim of this study is to develop an anterior lumbar interbody fusion (ALIF) PEEK cage suitable for Korean people. In this study, CT images were obtained from Korean male (173cm, 71kg) and 3D Korean lumbar models were reconstructed based on the CT images to investigate anatomical characteristics. Major design parameters of anterior lumbar interbody fusion (ALIF) PEEK Cage were selected using the morphological measurement information of the Korean Lumbar models. Through finite element analysis and mechanical tests, the developed ALIF PEEK Cage prototype was compared with the Fidji Cage (Zimmer.Inc, USA) and it was found that the ALIF prototype showed similar and/or superior mechanical performance compared to the FidJi Cage. Also, clinical validation for the ALIF PEEK Cage prototype was carried out to check predictable troubles in surgical operations. Finally, it is considered that the convenience and stability of the prototype was clinically verified.

Keywords: inter-body anterior fusion, ALIF cage, PEEK, Korean lumbar, CT image, animal test

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Authors: Yen-Ping Peng, Ku-Fan Chen, Ken-Lin Chang, Jian Sun

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In this study, palladium loaded titanium dioxide nanotube arrays (Pd/TNAs) was successfully synthesized by anodic oxidation etching method combined with microwave hydrothermal method, using tea or coffee as a green reductant. Pd/TNAs was employed as an electrode in a photoelectrochemcial (PEC) system to simultaneously remove azo-dye and to generate hydrogen in the anodic and cathodic chamber, respectively. The chemical and physical properties of as-synthesized Pd/TNAs were characterized by scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV-vis), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM image indicates the diameter and the length of Pd/TNAs were approximately 300 nm and 2.5 μm, respectively. XPS analyses indicate that 1.13% (atomic %) of Pd was loaded onto the surface of TNAs. UV-vis results show that the band gap of TNAs was reduced from 3.2 eV to 2.37 eV after Pd loading. In addition, the electrochemical performances of Pd/TNAs were investigated by photocurrent density test and electrochemical impedance spectroscopy (EIS). The photocurrent (4.0 mA/cm²) of Pd /TNAs was higher than that of the uncoated TNAs (1.4 mA/cm²) at a bias potential of 1 V (vs. Ag/AgCl), indicating that Pd/TNAs-C can effectively separate photogenerated electrons and holes. The mechanism of our PEC system was proposed and discussed in detail in this study.

Keywords: Pd/TNAs, photoelectrochemical, azo-dye degradation, hydrogen generation

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Authors: M. Iqbal Mahmud, Haeng Muk Cho, Seo Hyun Sang, Wang Wen Hai, Chang Heon Yi, Man Ik Hwang, Dae Hoon Kang

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Solenoid operated electromagnetic control valve (ECV) playing an important role for car’s air conditioning control system. ECV is used in external variable displacement swash plate type compressor and controls the entire air conditioning system by means of a pulse width modulation (PWM) input signal supplying from an external source (controller). Complete form of ECV contains number of internal features like valve body, core, valve guide, plunger, guide pin, plunger spring, bellows etc. While designing the ECV; dimensions of different internal items must meet the standard requirements as it is quite challenging. In this research paper, especially the dimensioning of ECV body and its three pressure ports through which the air/refrigerant passes are considered. Here internal leakage test analysis of ECV body is being carried out from its discharge port (Pd) to crankcase port (Pc) when the guide valve is placed inside it. The experiments have made both in ordinary and digital system using different assumptions and thereafter compare the results.

Keywords: electromagnetic control valve (ECV), leakage, pressure port, valve body, valve guide

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Authors: Jhen-Ting Huang, Chia-Chia Chang, Hu-Cheng Weng, An-Ya Lo

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In this study, Co3O4-CNT-Graphene composite electrode was deposited by electrophoretic deposition (EPD) method, where micro polystyrene spheres (PSs) were added for co-deposition. Applied with heat treatment, a hierarchical porosity is left in the electrode which is beneficial for supercapacitor application. In terms of charge and discharge performance, we discussed the optimal CNT/Graphene ratio, macroporous ratio, and the effect of Co3O4 addition on electrode capacitance. For materials characterization, scanning electron microscope (SEM), X-ray diffraction, and BET were applied, while cyclic voltammetry (CV) and chronopotentiometry (CP) measurements, and Ragone plot were applied as in-situ analyses. Based on this, the effects of PS amount on the structure, porosity and their effect on capacitance of the electrodes were investigated. Finally, the full device performance was examined with charge-discharge and electron impedance spectrum (EIS) methods. The results show that the EPD coating with hierarchical porosity was successfully demonstrated in this study. As a result, the capacitance was greatly enhanced by 2.6 times with the hierarchical structure.

Keywords: supercapacitor, nanocarbon tub, graphene, metal oxide

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Authors: Y. R. Lai, J. C. Jehng, T. T. Chang

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Team is a popular job design in the management settings. Because people on a team need to work together to complete a lot of tasks, the interaction between team members strongly influences team effectiveness. The study examines the effect of social capital and empowering leadership on team cohesion. There are three facets of social capital: structural facet, relational facet, and cognitive facet. Empowering leadership includes enhancing the meaningfulness of work, fostering participation in decision making, expressing confidence in high performance, and providing autonomy from bureaucratic constraints. Data were collected from 181 team members of 47 teams in the real estate agency industry. The results show that the relational social capital, enhancing the meaningfulness of work, and providing autonomy from bureaucratic constraints are positively related to two dimensions of team cohesion: sense of belonging and feelings of moral. Additionally, expressing confidence in high performance is negatively related to sense of belonging.

Keywords: social capital, empowering leadership, team cohesion, team effectiveness

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Authors: Yu-Fu Chen, Zih-Jyun Dai, Chen-Te Chiu, Shiue-Chen Chiou, Yung-Wei Chen, Yu-Ming Lin, Kuan-Yu Chen, Hung-Wei Wu, Hsin-Ying Lee, Yan-Kuin Su, Shoou-Jinn Chang

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This paper presents a compact dual-band bandpass filter that involves using the quarter wavelength stepped impedance resonators (SIRs) for achieving simultaneously compact circuit size and good dual-band performance. The filter is designed at 2.4 / 3.5 GHz and constructed by two pairs of quarter wavelength SIRs and source-load lines. By properly tuning the impedance ratio, length ratio and radius of via hole of the SIRs, dual-passbands performance can be easily determined. To improve the passband selectivity, the use of source-load lines is to increase coupling energy between the resonators. The filter is showing simple configuration, effective design method and small circuit size. The measured results are in good agreement with the simulation results.

Keywords: dual-band, bandpass filter, stepped impedance resonators, SIR

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Authors: Xiaodong Xu, Dan Zhao, Xiujuan Chang, Chunming Li, Huiyun Zhou, Xin Li, Qiang Shi, Shifang Luan, Jinghua Yin

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Polypropylene (PP) is one of the most commonly used plastics because of its low density, outstanding mechanical properties, and low cost. However, its drawbacks such as low surface energy, poor dyeability, lack of chemical functionalities, and poor compatibility with polar polymers and inorganic materials, have restricted the application of PP. To expand its application in biomedical materials, functionalization is considered to be the most effective way. In this study, PP was functionalized with a chiral monomer, (S)-1-acryloylpyrrolidine-2-carboxylic acid ((S)-APCA), by free-radical grafting in the solid phase. The grafting degree of PP-g-APCA was determined by chemical titration method, and the chemical structure of functionalized PP was characterized by FTIR spectroscopy, which confirmed that the chiral monomer (S)-APCA was successfully grafted onto PP. Static water contact angle results suggested that the surface hydrophilicity of PP was significantly improved by solid phase grafting and assistance of surface water treatment. Protein adsorption and platelet adhesion results showed that hemocompatibility of PP was greatly improved by grafting the chiral monomer.

Keywords: functionalization, polypropylene, chiral monomer, hemocompatibility

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Authors: Shih-Jen Feng, Nai-Chia Chao, Meng-Chi Shih, Chien-Chi Chang

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Today, Taiwan agriculture operates under small business scale with economic insufficiency, due to aging population, unproductiveness, inadequate systematic management, insufficient agro-economic scale, and cultivation on agro-education. Moreover, because of farming special working method (physical tiring, shackled weather condition), environment (asymmetric distribution information), hours devoted (unbalance wealth), the willingness for younger generation to delicate into agriculture farming is rare. Although government had provided policies to harmonize the existing problem, significant result is unseen. Living lab (LL) is a methodology approach to sense, prototype and validate complex solutions in real life context. This paper contributes an innovative interaction methodology by probing under implementation of diverse LL sector merging big data analysis utilizing rural redevelopment and revitalization plan of Wufeng.

Keywords: living lab approach, historic rural redevelopment, innovation model, innovation approach

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Authors: Tsung-Yen Tsai, Naveen Bunekar, Ming Hsuan Chang, Wen-Kuang Wang, Satoshi Onda

Abstract:

The structure-property relationship and initiator effect on bulk polymerized poly(methyl methacrylate) (PMMA)–oragnomodified layered silicate nanocomposites was investigated. In this study, we used 2, 2'-azobis (4-methoxy-2,4-dimethyl valeronitrile and benzoyl peroxide initiators for bulk polymerization. The bulk polymerized nanocomposites’ morphology was investigated by X-ray diffraction and transmission electron microscopy. The type of initiator strongly influences the physiochemical properties of the polymer nanocomposite. The thermal degradation of PMMA in the presence of nanofiller was studied. 5 wt% weight loss temperature (T5d) increased as compared to pure PMMA. The peak degradation temperature increased for the nanocomposites. Differential scanning calorimetry and dynamic mechanical analysis were performed to investigate the glass transition temperature and the nature of the constrained region as the reinforcement mechanism respectively. Furthermore, the optical properties such as UV-Vis and Total Luminous Transmission of nanocomposites are examined.

Keywords: initiator, bulk polymerization, layered silicates, methyl methacrylate

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Authors: Dong-Ho Kim, Zheng-Xun Jin, Yong-Woon Cha, Su-Sang Lim, Sang-Won Han, Chang-Taek Hyun

Abstract:

As construction is a labor-intensive industry, it is important to identify and manage labor quantities for accurate progress management of the construction project. However, the progress management that focuses on construction cost calculated based on materials rather than labor quantities has led to a difference in the implementation of cost and progress of the actual construction. In addition, since it is not easy to predict accurate labor quantities in the estimation of labor quantity-based progress rate, there have been limited researches into the progress rate estimation based on labor quantity. Accordingly, this study proposed a process for labor quantity-based progress rate estimation using a standard of estimate to predict accurate progress rate of the construction project in Republic Korea. It is expected that the utilization of the proposed process will help to identify the progress rate closer to that of the actual site management and adjust the workforce in each construction type, thereby contributing to improving construction efficiency.

Keywords: labor based, labor cost, progress management, progress rate, progress payment

Procedia PDF Downloads 310