• Title/Summary/Keyword: Cyclic Structure

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Evaluation of Characteristics of Re-liquefaction Resistance in Saturated Sand Deposits Using 1-g Shaking Table Test (1-g 진동대시험을 이용한 포화된 모래지반의 재액상화 강도 특성 평가)

  • Ha Ik-Soo;Kim Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.21 no.4
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    • pp.65-70
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    • 2005
  • Many case histories of re-liquefaction phenomena seem to support the idea that sand deposits, if they once have been liquefied, could be reliquefied again by a subsequent earthquake even though the earthquake is smaller than the previous one. The magnitude of the strains induced in the initial liquefaction has a significant influence on the resistance of the sample to re-liquefaction. The deposits undergoing liquefaction experience large shear strain during liquefaction. And this previous strain changes the microstructure into highly anisotropic structure such as columnlike structure and connected voids. This type of anisotropy is so unstable that it can reduce re-liquefaction resistance. It is blown that the extent of anisotropic structural change depends on the gradation characteristics of ground. The purpose of this study is to estimate the correlation between the gradation characteristics of the sand and the ratio of re-liquefaction resistance to liquefaction resistance. In this study, 1-g shaking table tests were carried out on five different kinds of sands. During the tests the values of excess pore pressure at various depths and surface settlements were measured. Re-liquefaction resistances were not affected by the initial void ratio and the effective confining pressures, and the deposits of all test sands which had once been liquefied were reliquefied in the cyclic loading number below 1 to 1.5. The ratio of re-liquefaction resistance to liquefaction resistance linearly decreased as $D_{10}/C_u$ increased, and was constant as about 0.2 above the value of $D_{10}/C_u$, 0.15 mm.

Determination of Electron Spin Relaxation Time of the Gadolinium-Chealted MRI Contrast Agents by Using an X-band EPR Technique (EPR을 통한 상자성 자기공명 조영제의 전자스핀 이완시간의 결정)

  • Sung-wook Hong;Yongmin Chang;Moon-jung Hwang;Il-su Rhee;Duk-Sik Kang
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.1
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    • pp.27-33
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    • 2000
  • Purpose: To determine the electronic spin relaxation times, $T_{le}$, of three commercially available Gd-chelated MR contrast agents, Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA, using Electron Paramagnetic Resonance(EPR) technique. Material and Methods: The paramagnetic MR contrast agents, Gd-DTFA(Magnevist) , Gd-DTFA-BMA(OMNISCAN) and Gd-DOTA(Dotarem), were used for this study, The EPR spectra of these contrast agents, which were prepared 2:1 methanol/water solution, were obtained at low temperatures, from $-160^{\circ}C~20^{\circ}C$. The glassy-state EPR spectra for these contrast agents were then fitted by the simulation spectra generated with different zero-field splitting (ZFS) parameters by a computer simulation program 'GEN', which generates the EPR powder spectrum using a given ZFS in $3{\times}3$ tensor. Finally, the spin relaxation times of the contrast agents were then determined from the $T_{2e}$, D, and E values of the best simulation spectra using the McLachlan's theory of average relaxation rate. Results: The electronic transverse spin relaxation times, $T_{2e}'s$, of Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA were 0.113ns, 0.147ns and 1.81ns respectively. The g-values were 1.9737, 1.9735 and 1.9830 and the electronic spin relaxation times, $T_{1e}'s$, were 18.70ns, 33.40ns and $1.66{\mu}s$, respectively. Conclusion: The results of these studies reconfirm that the paramagnetic MR contrast agents with larger ZFS parameters should have shorter $T_{1e}'s$. Among three contrast agents used for this study, Gd-DOTA chelated with cyclic ligand structure shows better electronic property then the others with linear structure. Thus, it is concluded that the exact determination of ZFS parameters is the important factor in evaluating relaxation enhancement effect of the agents and in developing new contrast agents.

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Synthesis and Characterization of Thermally Cross-linkable Hole Transporting Material Based on Poly(p-phenylenevinylene) Derivative (열경화가 가능한 poly(p-phenylenevinylene)계 정공전달 물질의 합성 및 특성)

  • Choi, Jiyoung;Lee, Bong;Kim, Joo Hyun
    • Applied Chemistry for Engineering
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    • v.19 no.3
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    • pp.299-303
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    • 2008
  • A thermally cross-linkable polymer, poly[(2,5-dimethoxy-1,4-phenylenevinylene)-alt-(1,4-phenylenevinylene)] (Cross-PPV), was synthesized by the Heck coupling reaction. In order for the polymer to be cross-linkable, 20 mol% excess divinylbenzene was added. The chemical structure of Cross-PPV and thermally crosslinked Cross-PPV were confirmed by FT-IR spectroscopy. From the FT-IR, UV-Vis, and PL spectral data, thermally crosslinked Cross-PPV was insoluble in common organic solvents. The HOMO and LUMO energy level of thermally cross-linked Cross-PPV were estimated -5.11 and -2.56 eV, respectively, which were determined by the cyclic voltammetry and UV-Vis spectroscopy. From the energy level data, one can easily notice that thermally crosslinked Cross-PPV can be used for hole injection layer effectively. Bilayer structured device (ITO/crosslinked Cross-PPV/PM-PPV/Al) was fabricated using poly(1,4-phenylenevinylene-(4-dicyanomethylene-4H-pyran)-2,6-vinylene-1,4-phenylenevinylene-2,5-bis(dodecyloxy)-1,4-phenylenevinylene (PM-PPV) as the emitting layer, which have HOMO and LUMO energy levels of -5.44 eV and -3.48 eV, respectively. The bilayered device had much enhanced the maximum efficiency (0.024 cd/A) and luminescence ($45cd/m^2$) than those of a single layer device (ITO/PM-PPV/Al, 0.003 cd/A, $3cd/m^2$). The enhanced performance originated from that fact that cross-linked Cross-PPV facilitatse the hole injection to the emissive layer and the injected hole and electron from ITO and Al are recombined in emitting layer (PM-PPV) effectively.

Geology of Athabasca Oil Sands in Canada (캐나다 아사바스카 오일샌드 지질특성)

  • Kwon, Yi-Kwon
    • The Korean Journal of Petroleum Geology
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    • v.14 no.1
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    • pp.1-11
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    • 2008
  • As conventional oil and gas reservoirs become depleted, interests for oil sands has rapidly increased in the last decade. Oil sands are mixture of bitumen, water, and host sediments of sand and clay. Most oil sand is unconsolidated sand that is held together by bitumen. Bitumen has hydrocarbon in situ viscosity of >10,000 centipoises (cP) at reservoir condition and has API gravity between $8-14^{\circ}$. The largest oil sand deposits are in Alberta and Saskatchewan, Canada. The reverves are approximated at 1.7 trillion barrels of initial oil-in-place and 173 billion barrels of remaining established reserves. Alberta has a number of oil sands deposits which are grouped into three oil sand development areas - the Athabasca, Cold Lake, and Peace River, with the largest current bitumen production from Athabasca. Principal oil sands deposits consist of the McMurray Fm and Wabiskaw Mbr in Athabasca area, the Gething and Bluesky formations in Peace River area, and relatively thin multi-reservoir deposits of McMurray, Clearwater, and Grand Rapid formations in Cold Lake area. The reservoir sediments were deposited in the foreland basin (Western Canada Sedimentary Basin) formed by collision between the Pacific and North America plates and the subsequent thrusting movements in the Mesozoic. The deposits are underlain by basement rocks of Paleozoic carbonates with highly variable topography. The oil sands deposits were formed during the Early Cretaceous transgression which occurred along the Cretaceous Interior Seaway in North America. The oil-sands-hosting McMurray and Wabiskaw deposits in the Athabasca area consist of the lower fluvial and the upper estuarine-offshore sediments, reflecting the broad and overall transgression. The deposits are characterized by facies heterogeneity of channelized reservoir sands and non-reservoir muds. Main reservoir bodies of the McMurray Formation are fluvial and estuarine channel-point bar complexes which are interbedded with fine-grained deposits formed in floodplain, tidal flat, and estuarine bay. The Wabiskaw deposits (basal member of the Clearwater Formation) commonly comprise sheet-shaped offshore muds and sands, but occasionally show deep-incision into the McMurray deposits, forming channelized reservoir sand bodies of oil sands. In Canada, bitumen of oil sands deposits is produced by surface mining or in-situ thermal recovery processes. Bitumen sands recovered by surface mining are changed into synthetic crude oil through extraction and upgrading processes. On the other hand, bitumen produced by in-situ thermal recovery is transported to refinery only through bitumen blending process. The in-situ thermal recovery technology is represented by Steam-Assisted Gravity Drainage and Cyclic Steam Stimulation. These technologies are based on steam injection into bitumen sand reservoirs for increase in reservoir in-situ temperature and in bitumen mobility. In oil sands reservoirs, efficiency for steam propagation is controlled mainly by reservoir geology. Accordingly, understanding of geological factors and characteristics of oil sands reservoir deposits is prerequisite for well-designed development planning and effective bitumen production. As significant geological factors and characteristics in oil sands reservoir deposits, this study suggests (1) pay of bitumen sands and connectivity, (2) bitumen content and saturation, (3) geologic structure, (4) distribution of mud baffles and plugs, (5) thickness and lateral continuity of mud interbeds, (6) distribution of water-saturated sands, (7) distribution of gas-saturated sands, (8) direction of lateral accretion of point bar, (9) distribution of diagenetic layers and nodules, and (10) texture and fabric change within reservoir sand body.

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GENE EXPRESSION PATTERNS INDUCED BY $TAXOL^{(R)}$ AND CYCLOSPORIN A IN ORAL SQUAMOUS CELL CARCINOMA CELL LINE USING CDNA MICROARRAY (cDNA Microarray를 이용한 구강편평세포암종 세포주에서 $Taxol^{(R)}$과 Cyclosporin A로 유도된 유전자 발현양상)

  • Kim, Yong-Kwan;Lee, Jae-Hoon;Kim, Chul-Hwan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.3
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    • pp.202-212
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    • 2006
  • It is well-known that paclitaxel($Taxol^{(R)}$), which is extracted from the pacific and English yew, has been used as a chemotherapeutic agent for ovarian carcinoma and advanced breast carcinoma and Cyclosporin A, which is highly lipophilic cyclic peptide and isolated from a fungus, has been also used as an useful immunosuppressive drug after transplantation and is associated with cellular apoptosis. Since 1953, in which James Watson, Rosalind Franklin and Francis Crick discovered the double helical structure of DNA, a few kinds of techniques for identifying gene expression have been developed. In postgenomic period, many of researchers have used the DNA microarray which is high throughput screening technique to screen large numbers of gene expression simultaneously. In this study, we searched and screened the gene expression in the oral squamous cell carcinoma cell lines treated with $Taxol^{(R)}$, cyclosporin or cyclosporin combined with $Taxol^{(R)}$ using cDNA microarray. The results were as following; 1. It was useful that the appropriate concentration of Cyclosporin A and $Taxol^{(R)}$ used in oral squamous cell carcinoma cell line was under 1${\mu}g/ml$ and 3${\mu}g/ml$. 2. In the experimental group in which $Taxol^{(R)}$ and $Taxol^{(R)}$ + Cyclosporin A were used, the cell growth was extremely decreased. 3. In the group in which Cyclosporin A was used, the MTT assay was rarely decreased which means the activity of succinyl dehydrogenase is remained in mitochondria but in the group in which the mixture of Cyclosporin A and $Taxol^{(R)}$ were used, the MTT assay was extremely decreased. 4. In the each group in which Cyclosporin A(3 ${\mu}g/ml$) and $Taxol^{(R)}$(1 ${\mu}g/ml$) were used, the cell arrest was appeared in $G_2/M$ phase and in the group in which $Taxol^{(R)}$(3 ${\mu}g/ml$) was used, the cell arrest was appeared in both S phase and $G_2/M$ phase. 5. In the oral squamous cell carcinoma cell line treated with $Taxol^{(R)}$, several genes including ANGPTL4, RALBP1 and TXNRD1, associated with apoptosis, SUI1, MAC30, RRAGA and CTGF, related with cell growth, HUS1 and DUSP5, related with cell cycle and proliferation, ATF4 and CEBPG, associated with transcription factor, BTG1 and VEGF, associated with angiogenesis, FDPS, FCER1G, GPA33 and EPHA4 associated with signal transduction and receptor activity and AKR1C2 and UGTA10 related with carcinogenesis were detected in increased levels. The genes that showed increaced expression in the oral squamous cell carcinoma cell line treated with Cyclosporin A were CYR61, SERPINB2, SSR3 and UPA3A which are known as genes associated with cell growth, carcinogenesis, receptor activity and transcription factor. The genes expressed in the HN22 cell line treated with cyclosporin combined with $taxol^{(R)}$ were ALCAM and GTSE1 associated with cancer invasiveness and cell cycle regulation.

Designing Mobile Framework for Intelligent Personalized Marketing Service in Interactive Exhibition Space (인터랙티브 전시 환경에서 개인화 마케팅 서비스를 위한 모바일 프레임워크 설계)

  • Bae, Jong-Hwan;Sho, Su-Hwan;Choi, Lee-Kwon
    • Journal of Intelligence and Information Systems
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    • v.18 no.1
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    • pp.59-69
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    • 2012
  • As exhibition industry, which is a part of 17 new growth engines of the government, is related to other industries such as tourism, transportation and financial industries. So it has a significant ripple effect on other industries. Exhibition is a knowledge-intensive, eco-friendly and high value-added Industry. Over 13,000 exhibitions are held every year around the world which contributes to getting foreign currency. Exhibition industry is closely related with culture and tourism and could be utilized as local and national development strategies and improve national brand image as well. Many countries try various efforts to invigorate exhibition industry by arranging related laws and support system. In Korea, more than 200 exhibitions are being held every year, but only 2~3 exhibitions are hosted with over 400 exhibitors and except these exhibitions most exhibitions have few foreign exhibitors. The main reason of weakness of domestic trade show is that there are no agencies managing exhibitionrelated statistics and there is no specific and reliable evaluation. This might cause impossibility of providing buyer or seller with reliable data, poor growth of exhibitions in terms of quality and thus service quality of trade shows cannot be improved. Hosting a lot of visitors (Public/Buyer/Exhibitor) is very crucial to the development of domestic exhibition industry. In order to attract many visitors, service quality of exhibition and visitor's satisfaction should be enhanced. For this purpose, a variety of real-time customized services through digital media and the services for creating new customers and retaining existing customers should be provided. In addition, by providing visitors with personalized information services they could manage their time and space efficiently avoiding the complexity of exhibition space. Exhibition industry can have competitiveness and industrial foundation through building up exhibition-related statistics, creating new information and enhancing research ability. Therefore, this paper deals with customized service with visitor's smart-phone at the exhibition space and designing mobile framework which enables exhibition devices to interact with other devices. Mobile server framework is composed of three different systems; multi-server interaction, server, client, display device. By making knowledge pool of exhibition environment, the accumulated data for each visitor can be provided as personalized service. In addition, based on the reaction of visitors each of all information is utilized as customized information and so the cyclic chain structure is designed. Multiple interaction server is designed to have functions of event handling, interaction process between exhibition device and visitor's smart-phone and data management. Client is an application processed by visitor's smart-phone and could be driven on a variety of platforms. Client functions as interface representing customized service for individual visitors and event input and output for simultaneous participation. Exhibition device consists of display system to show visitors contents and information, interaction input-output system to receive event from visitors and input toward action and finally the control system to connect above two systems. The proposed mobile framework in this paper provides individual visitors with customized and active services using their information profile and advanced Knowledge. In addition, user participation service is suggested as well by using interaction connection system between server, client, and exhibition devices. Suggested mobile framework is a technology which could be applied to culture industry such as performance, show and exhibition. Thus, this builds up the foundation to improve visitor's participation in exhibition and bring about development of exhibition industry by raising visitor's interest.

Voltammetric Sensor Incorporated with Conductive Polymer, Tyrosinase, and Ionic Liquid Electrolyte for Bisphenol F (전도성고분자, 티로시나아제 효소 및 이온성 액체 전해질을 융합한 전압전류법 기반의 비스페놀F 검출 센서)

  • Sung Eun Ji;Sang Hyuk Lee;Hye Jin Lee
    • Applied Chemistry for Engineering
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    • v.34 no.3
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    • pp.258-263
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    • 2023
  • In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.