• Title/Summary/Keyword: core stability

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Effects of anatase-rutile phase transition and grain growth with WO3 on thermal stability for TiO2 SCR catalyst (WO3 첨가에 의한 TiO2계 SCR 촉매의 상전이 및 입자성장이 고온안정성에 미치는 영향)

  • Yoon, Sang-Hyeon;Kim, Jang-Hoon;Shin, Byeong-Kil;Park, Sam-Sik;Shin, Dong-Woo;Lee, Hee-Soo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.21 no.4
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    • pp.181-186
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    • 2011
  • Thermal stability of the $TiO_2$ SCR catalyst with W03 loading was investigated in terms of structural and morphological analyses. The $TiO_2$ catalysts with 10 w% $WO_3$ content and without $WO_3$ were prepared. which were heat-treated at $800^{\circ}C$ for 5 h. It was found that the catalytic acidity was decreased by thermal degradation in the $WO_3-TiO_2$ specimen that relatively less than the $TiO_2$ specimen from FT-IR analysis. The phase transition of the $TiO_2$ catalyst from anatase to rutile was increased by heal-treatment, and the percentage of the rutile phase was 28.4 % in the $WO_3-TiO_2$ and 22.9 % in the $TiO_2$. A shell region of $WO_3$ distinguished from a $TiO_2$ particle was also observed in the grain boundary region, and the $WO_3$ led to the suppression of grain growth. It could be confirmed that the suppression of grain growth can contribute to the improvement of catalytic properties for thermal stability more than the increase of anatase-rutile phase transformation which cause the reduction of the catalytic activity in the $TiO_2$ SCR catalyst by the presence of $WO_3$.

Development of Gate Non-stop system using RFID(900MHz) Technology (RFID(900MHz) 기술을 이용한 GATE 무정차 시스템 개발)

  • Choi, Gi-Jin;Kim, Young-Mi;Choi, Jae-Sin;Lee, Chang
    • 한국ITS학회:학술대회논문집
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    • 2008.11a
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    • pp.570-574
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    • 2008
  • The 'gate non-stop system utilizing RFID (900MHz)', which is the core of this research, is the system which connects RFID to recognize the vehicle information without stopping when a vehicle (trailer) passes a gate to carry in or out containers in a terminal and automatically provides the container information provided by the terminal for the RFLDU device installed in the vehicle.In order to design and implement this, the RFID technical section uses a UHF band (900MHz) RFID tag and a reader and implements a RFID middleware and an application program for smooth data collection and execution (operation). In addition, the system stability was verified through experiments and operations of the system implemented in this research at real harbors/quays, and based on the verified result, the maximization of vehicle (trailer) and terminal productivity and the reduction of distribution cost are expected.

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Wave propagation simulation and its wavelet package analysis for debonding detection of circular CFST members

  • Xu, Bin;Chen, Hongbing;Xia, Song
    • Smart Structures and Systems
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    • v.19 no.2
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    • pp.181-194
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    • 2017
  • In order to investigate the interface debonding defects detection mechanism between steel tube and concrete core of concrete-filled steel tubes (CFSTs), multi-physical fields coupling finite element models constituted of a surface mounted Piezoceramic Lead Zirconate Titanate (PZT) actuator, an embedded PZT sensor and a circular cross section of CFST column are established. The stress wave initiation and propagation induced by the PZT actuator under sinusoidal and sweep frequency excitations are simulated with a two dimensional (2D) plain strain analysis and the difference of stress wave fields close to the interface debonding defect and within the cross section of the CFST members without and with debonding defects are compared in time domain. The linearity and stability of the embedded PZT response under sinusoidal signals with different frequencies and amplitudes are validated. The relationship between the amplitudes of stress wave and the measurement distances in a healthy CFST cross section is also studied. Meanwhile, the responses of PZT sensor under both sinusoidal and sweep frequency excitations are compared and the influence of debonding defect depth and length on the output voltage is also illustrated. The results show the output voltage signal amplitude and head wave arriving time are affected significantly by debonding defects. Moreover, the measurement of PZT sensor is sensitive to the initiation of interface debonding defects. Furthermore, wavelet packet analysis on the voltage signal under sweep frequency excitations is carried out and a normalized wavelet packet energy index (NWPEI) is defined to identify the interfacial debonding. The value of NWPEI attenuates with the increase in the dimension of debonding defects. The results help understand the debonding defects detection mechanism for circular CFST members with PZT technique.

The Biomechanical Analysis of a One-Legged Jump in Traditional Korean Dance According to Breathing Method (호흡 방법에 따른 한국무용 외발뛰기 동작의 운동역학적 분석)

  • An, Ju-Yeun;Yi, Kyung-Ock
    • Korean Journal of Applied Biomechanics
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    • v.25 no.2
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    • pp.199-206
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    • 2015
  • Objective : The purpose of this study was to conduct a biomechanical analysis of a one-legged jump in a traditional Korean dance (Wae Bal Ddwigi) according to breathing method. Method : Participants for this study were 10 dancers with experience for at least 10 years in traditional Korean dance. Independent variables for this test were two different types of breathing methods. Dependent variables were ground reaction force and lower extremity kinematic variables. The jumping movement was divided into three separate stages, take off, flight, and landing. The subjects were asked a questionnaire regarding the degree of impact force and stability of landing posture after the experiment. The Kistler Force Plate (9281B, Switzerland) was used to measure ground reaction force. A digital camera was used to look into angles of each joint of the lower part of body. SPSS was used for statistical analysis via the dependent t-test(p<.05). Results : There were significant differences in jumping according to breathing method. The inhalation & exhalation method yielded significantly longer flight times combined with greater ground reaction force. The breath-holding method required more core flexion during landing, increasing movement at the hips and shoulders. Conclusion : Consequently, there was more flexion at the knee to compensate for this movement. As a result, landing time was significantly higher for breath-holding.

DNA fingerprinting analysis for soybean (Glycine max) varieties in Korea using a core set of microsatellite marker (핵심 Microsatellite 마커를 이용한 한국 콩 품종에 대한 Fingerprinting 분석)

  • Kwon, Yong-Sham
    • Journal of Plant Biotechnology
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    • v.43 no.4
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    • pp.457-465
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    • 2016
  • Microsatellites are one of the most suitable markers for identification of variety, as they have the capability to discriminate between narrow genetic variations. The polymorphism level between 120 microsatellite primer pairs and 148 soybean varieties was investigated through the fluorescence based automatic detection system. A set of 16 primer pairs showed highly reproducible polymorphism in these varieties. A total of 204 alleles were detected using the 16 microsatellite markers. The number of alleles per locus ranged from 6 to 28, with an average of 12.75 alleles per locus. The average polymorphism information content (PIC) was 0.86, ranging from 0.75 to 0.95. The unweighted pair group method using the arithmetic averages (UPGMA) cluster analysis for 148 varieties were divided into five distinctive groups, reflecting the varietal types and pedigree information. All the varieties were perfectly discriminated by marker genotypes. These markers may be useful to complement a morphological assessment of candidate varieties in the DUS (distinctness, uniformity and stability) test, intervening of seed disputes relating to variety authentication, and testing of genetic purity in soybean varieties.

A Study of Material Removal Characteristics by Friction Monitoring System of Sapphire Wafer in Single Side DMP (사파이어 웨이퍼 DMP에서 마찰력 모니터링을 통한 재료 제거 특성에 관한 연구)

  • Jo, Wonseok;Lee, Sangjik;Kim, Hyoungjae;Lee, Taekyung;Lee, Seongbeom
    • Tribology and Lubricants
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    • v.32 no.2
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    • pp.56-60
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    • 2016
  • Sapphire has a high hardness and strength and chemical stability as a superior material. It is used mainly as a material for a semiconductor as well as LED. Recently, the cover glass industry used by a sapphire is getting a lot of attention. The sapphire substrate is manufactured through ingot sawing, lapping, diamond mechanical polishing (DMP) and chemical mechanical polishing (CMP) process. DMP is an important process to ensure the surface quality of several nm for CMP process as well as to determine the final form accuracy of the substrate. In DMP process, the material removal is achieved by using the mechanical energy of the relative motion to each other in the state that the diamond slurry is disposed between the sapphire substrate and the polishing platen. The polishing platen is one of the most important factors that determine the material removal characteristics in DMP. Especially, it is known that the geometric characteristics of the polishing platen affects the material removal amount and its distribution. This paper investigated the material removal characteristics and the effects of the polishing platen groove in sapphire DMP. The experiments were preliminarily carried out to evaluate the sapphire material removal characteristics according to process parameters such as pressure, relative velocity and so on. In the experiment, the monitoring apparatus was applied to analyze process phenomena in accordance with the processing conditions. From the experimental results, the correlation was analyzed among process parameters, polishing phenomena and the material removal characteristics. The material removal equation based on phenomenological factors could be derived. And the experiment was followed to investigate the effects of platen groove on material removal characteristics.

A PNF Intervention Strategy with ICF Tool Applied for Improvement of Dressing in a Patient with Rotator Cuff Syndrome : A Case Report (회전근개 파열 환자의 옷입고 벗기 향상을 위해 ICF Tool을 적용한 PNF 중재전략 : 증례보고)

  • Kim, Jin-Cheol;Lee, Jeong-A
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.3
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    • pp.49-60
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    • 2018
  • PURPOSE: This study was conducted to investigate the intervention effect obtained by applying an ICF tool to improve the dressing in a patient with rotator cuff syndrome to schematize the problems and approaching with PNF to solve the problems. METHODS: The subject of this study was a 44-year-old patient who underwent surgery after complete right rotator cuff tear. To treat his symptoms, the processes of clinical practice were implemented in the order of examination, assessment, diagnosis, prognosis, intervention, and outcome. During examination, patient information was collected using the ICF core set. In the assessment, the problems were schematized, and an ICF assessment sheet was used to identify the interaction of the problems. The diagnosis was made by clearly describing the causal relationship derived from the assessment in ICF terms. To solve the problems, the intervention was given in the order of indirect, direct, and task based on the philosophy of PNF. To evaluate the outcome, the differences before and after the intervention were compared. Additionally, the comparison for the ICF qualifier is presented with the ICF evaluation display. RESULTS: The results of the study showed clinical advantages in shoulder strength, eccentric control, range of motion, scapular stability, and shoulder pain. Overall, our patient with rotator cuff syndrome showed improvement in dressing and undressing activity in response to the PNF strategy. CONCLUSION: Application of the PNF intervention strategy after complete rotator cuff tear would have a positive effect on patient upper extremity function.

Potential of gas generation and/or natural gas hydrate formation, and evidences of their presence in near seafloor sediments of the southwestern Ulleung Basin, East Sea (동해 울릉분지 남서부 천부 퇴적층에서의 가스 생성 및 천연가스 하이드레이트 형성 잠재력과 이들의 부존 증거)

  • Ryu, Byong-Jae;Lee, Young-Joo;Kim, Ji-Hoon;Riedel, M.;Hyndman, R.D.;Kim, Il-Soo
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.50-53
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    • 2006
  • Regional geophysical surveys and geological cal studies on natural gas hydrate (NGH) in the East Sea were carried out by the Korea Institute of Geoscience and Mineral Resources (KIGAM) from 2000 to 2004. 16 piston cores, 2270 L-km of multi-channel reflection seismic (MCRS) data and 730 L-km of 3.5kHz Chirp data obtained from the southwestern part of the deep-water Ulleung Basin were analyzed in this study. In piston cores, cracks generally developed parallel to bedding suggest significant gas content. The core analyses showed high total organic carbon (TOC) content, sedimentation rate and heat flow of sediments. These are in favor of the general ion of substantial biogenic methane, which can form the NGH within the stability zone of the near seafloor sediments in the study area. The cores generally show also high residual hydrocarbon gas concentrations for the formation of natural gas hydrates The geophysical indicators of the presence of gas and/or NGH such as bottom simulating reflectors (BSRs), seismic blank Bones, pockmarks and gas seeping features were well defined on the MCRS and Chirp data.

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Physical and Mechanical Properties and Fire-endurance Characteristics of Recycled Particleboards

  • Suh, Jin-Suk;Han, Tae-Hyung;Park, Joo-Saeng;Park, Jong-Young
    • Journal of the Korea Furniture Society
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    • v.19 no.6
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    • pp.475-486
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    • 2008
  • In this study, fire-retardant chemicals were melt with mixed composition ratios of dibasic ammonium phosphate and each half of boric acid and borax in hot water, in which hammer-milled chips were immersed to increase swelling of waste particleboards. Also, fire-retardant treated particles from sawn lumber chip and recycled particleboard chip were composed in ratio of 70:30 in core layer to improve boards' properties. Retention ratio of fire-retardant chemicals for the particles for face layer was high due to high specific surface area, and that of sawn lumber chips was somewhat higher than that of recycled particleboard chips. The mixture of particles from sawn lumber chips and recycled PB of 70:30 in weight ratio exceeded bending strength of 100 $kgf/cm^2$. It seemed that the relatively greater portions of dibasic ammonium phosphate affected adversely to dimensional stability, however fire-retardants treatment resulted in distinct effect lowering formaldehyde emission such as $E_0$ type(0.5mg/$\ell$ or less) in KS F 3104. In fire-retardancy, the recycled boards with a mixed ratio of dibasic ammonium phosphate to boric acid borax(50:50 mixture) of 70% to 30% in weight satisfied fire-retardancy 3rd grade in KS F 2271, and also this composition from cone calorimeter test met same standard grade figuring total heat release of 4.6MJ/$m^2$.

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Effect of Emulsifiers on Characteristics of Microcapsule Containing Squid Liver Oil as a Core Material (유화제 종류에 따른 오징어 간유의 미세캡슐화 특성)

  • Hwang, Sung-Hee;Lee, Ki-Teak;Youn, Kwang-Sup
    • Korean Journal of Food Science and Technology
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    • v.39 no.1
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    • pp.29-32
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    • 2007
  • This study was carried out to investigate the effect of emulsifiers on the characteristics of microcapsule containing squid liver oil. The emulsion stability of glycerine monostearate (HLB 4) separated after 1 hr. Sucrose fatty acid esters (monostearate: di-, tri-, and tetrastearate=6:4; HLB 11), sucrose fatty acid esters (monostearate: di-, tri-, and tetrastearate=7:3; HLB 16) and glycerine monostearate (HLB 4) plus sucrose fatty acid esters (monostearate: di-, tri-, and tetrastearate= 7:3; HLB 16) separated after 1 hr 30 min. The microencapsulation efficiency prepared by HLB 16 was 35.0%. The polyunsaturated fatty acid composition was shown to be higher than 50% in all powders, and the ratio of the polyunsaturated fatty acid composition to the saturated fatty acid composition was found to be the same (2.07) for HLB 11 and HLB 16.