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The Computer-Aided Simulation Study on the Gasification Characteristics of the Roto Coal in the Partitioned Fluidized-Bed Gasifier (상용모사기를 이용한 로토석탄의 분할유동층 가스화기 가스화 특성 모사)

  • Park, Young Cheol;Moon, Jong-Ho;Lee, Seung-Yong;Lee, Dong-Ho;Jin, Gyoung Tae
    • Korean Chemical Engineering Research
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    • v.50 no.3
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    • pp.511-515
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    • 2012
  • In this study, we used a commercial simulator to investigate the gasification characteristics of Roto coal in the partitioned fluidized-bed gasifier, which consists of 4 parts such as coal pyrolysis, char gasification, tar/oil gasification and char combustion. The heating medium was exchanged between the combustion part and the gasification part in order to supply the energy needed for pyrolysis and gasification. The correlation model from experimental data in relation to the reaction temperatures, the reaction gases and the coal feed rates was derived for the coal pyrolysis. The equilibrium model was used for the gasification and the combustion model for the char combustion. In order to compare the reaction behavior of the partitioned fluidized-bed gasifier, the single-bed gasifier was also simulated. The cold gas efficiency of both partitioned fluidized-bed gasifier and single-bed gasifier was almost the same. The $H_2$ and $CH_4$ contents of the syngas in the partitioned fluidized-bed gasifier slightly increased and the CO and $CO_2$ contents slightly decreased, compared with the singlebed gasifier. In order to verify the model, ten cases of the single-bed gasification experiment have been simulated. The contents of CO, $CO_2$, $CH_4$ in the syngas from the simulation corresponded with the experimental data while those of $H_2$ was slightly higher than experimental data, but the tendency of $H_2$ content in the syngas was similar to the experiments. In the coal conversion, the simulation results were higher than the experiments since equilibrium model was used for the gasification so that the residence time and contact time in the model is different from the experiments.

Histomorphometry and Stability Analysis of Loaded Implants with two Different Surface Conditions in Beagle Dogs (하중을 가한 두 가지 표면의 임플란트에 관한 조직형태학적 분석 및 안정성 분석 (비글견을 이용한 연구))

  • Kim, Sang-Mi;Kim, Dae-Gon;Cho, Lee-Ra;Park, Chan-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.4
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    • pp.337-349
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    • 2008
  • Despite an improved bone reactions of Mg-incorporated implants in the animals, little yet has been carried out by the experimental investigations in functional loading conditions. This study investigated the clinical and histologic parameters of osseointegrated Mg-incorporated implants in delayed loading conditions. A total of 36 solid screw implants (diameter 3.75 mm, length 10mm) were placed in the mandibles of 6 beagle dogs. Test groups included 18 Mg-incorporated implants. Turned titanium Implants served as control. Gold crowns were inserted 3 months. Radiographic assessments and stabilitytests were performed at the time of fixture installation, $2^{nd}$ stage surgery, 1 and 3 months after loading. Histological observations and morphometrical measurements were also performed. Of 36 implants, 32 displayed no discernible mobility, corresponding to successful clinical function. There was no statistically significant difference between test implants and controls in marginal bone levels (p=0.413) and RFA values. The mean BIC % in the Mg-implants was $54.4{\pm}20.2%$. The mean BIC % in the turned implant was $48.9{\pm}8.0%$. These differences between the Mg-implant and control implant were not statistically significant (P=0.264). In the limitation of this study, bone-to-implant contact (BIC) and bone area of Mg-incorporated oxidized implant were similar to machine-turned implant. The stability analysis showed no significantly different ISQ values and marginal bone loss between two groups. Considering time-dependent bone responses of Mg-implant, it seems that Mg-implants enhanced bone responses in early loading conditions and osseointegrated similarly to cp Ti implants in delayed loading conditions. However, further investigations are necessary to obtain long-term bone response of the Mg-implant in human.

Spent SCR Catalyst Leach Liquor Processed for Valuable Metals Extraction by Solvent Extraction Technique (SCR 폐촉매 침출액으로부터 용매추출법에 의한 유가금속의 추출)

  • Sola, Ana Belen Cueva;Jeon, Jong-Hyuk;Lee, Jin-Young;Parhi, Pankaj Kumar;Jyothi, Rajesh Kumar
    • Resources Recycling
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    • v.29 no.2
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    • pp.55-61
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    • 2020
  • Selective catalytic reduction (SCR) has been a promising technology to reduce the air pollution caused by nitrogen oxides (NOx) in several industries. The consumption of SCR catalysts increases every year as technology evolves, however those have a limited lifespan and usually end up in landfills after they deactivate. Currently, the most widely used catalyst for and stationary applications is V2O5-WO3/TiO2 which can contain around 50% wt V2O5 and 7-10% wt of WO3. The vast uses for both vanadium and tungsten and the worldwide interest in recycling methods that allow for the extraction of metals from secondary sources represent the major motivation for this research. The extraction time, pH dependency, extraction concentration studies were carried out using Aliquat 336 in exxol D80 as the extractant. It was determined that to optimize the extraction of both metals 30min of contact time with an organic phase containing 0.5mol/L of Aliquat 336 are needed at a slightly acidic pH (~5.0). In addition, counter McCabe-Thiele studies allowed us to determine that one stage is necessary for the removal of 99% of vanadium while 2 stages are necessary for the extraction of tungsten and counter current simulations proved that the theoretical approach was correct.

Chronic pain control in patients with rheumatoid arthritis (만성통증 환자의 통증 조절)

  • Eun, Young
    • Journal of muscle and joint health
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    • v.2 no.1
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    • pp.17-40
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    • 1995
  • Rheumatoid arthritis is the one of the chronic diseases, one of its major symptoms is a chronic pain. Despite developing medical treatment and surgical techniques, it is suggested that to control the pain is the goal of the treatment. But pain is an inner experience and even those closest to the patient cannot truly observe its progress or share in its suffering. The National Academy of Sciences Institute of Medicine's report on Pain and Disability concluded that there is no objective measure of pain-(exactly) no pain thermometer-nor can there ever be one, because the experience of pain is inseparable from personal perception and social influence such as culture. To explore chronic pain experience is to understand the process and property of the patient's perception of pain through the response to pain, the coping with pain, and the adaptation to pain. Therefore a qualitative study was conducted in order to gain an understanding of pain experience of patients with RA in korea. I used naturalistic inquiry as a research methodology, which had 5 axioms, the first is that realities are multiple, constructed, and holistic, the second is that knower and known are interactive, inseparable, the third is only time and context bound working hypotheses(idiographic statements) are possible, the forth is all entities are in a state of mutual simultaneous shaping, so that it is impossible to distinguish causes from effects and the last is that inquiry is value-bound. Purposive sampling was conducted as a sampling. 20 subjects who experienced pain over 10 years, lived in middle-sized city and big city in Korea, and 17 women and 3 men. The subject's age was from 32 to 62 (average 48.8), all were married, living with their spouse and children, except two-one divorced and the other widow before they became ill. I collected data using In depth structured interview. I had interviews two or three times with each subject, and the interviews were conducted at each subject's home. Each interview lasted about two hours an average. A recording was taken with the consent of the subject. I used inductive data analysis-such as unitizing and categorizing. unitizing is a process of coding, whereby raw data are systematically transformed and aggregated into units. Categorizing is a process wherby previously unitized data are organized into categories that provide descriptive or inferential information about the context or setting from which the units were derived. This process is used constant comparative method. The pain controlling process is composed of behavior of pain control. The behaviors of pain control are rearranging of ADL, hiddening role conflict, balancing treatment, and changing social relation. Rearranging of ADL includes diet management, sleep management, and the adjustment of daily life activities. The subjects try to rearrange their daily activities by modified style of motions, rearranging time span & range of activities, using auxillary facilities, and getting help in order to keep on the pace of daily life. Hiddening role conflict means to reduce conflicts between sick role and their role as a family member. In this process, the subjects use two modes, one is to control the pain complaints, and the other is to internalize the value which is to stay home is good for caring her children and being a good mother. To control pain complaints is done by 'enduring', 'understanding' the other family members, or making them undersood in order to reduce pain. Balancing treatment is composed of two aspects. One is to keep the pain within the endurable level, the other is to keep in touch with medical personnel in order to get the information of treatment and emotional support. Changing social relation is made by information seeking and sharing, formation of mutual support relation, and finally simplification of social relationships. The subjects simplify their social relationships by refraining from relations with someone who makes them physically and psychologically strained. In particular the subjects are apt to avoid contact with in-laws, and the change of relation to in-laws results in lessening the family boundary. In the course of this process, they confront the crisis of family confict result in family dissolution. This crisis is related to the threat of self-existence. Findings from this study contribute to understanding the chronic pain experience. To advance this study, we should compare this result with other cases in different cultural contexts. I think to interpret these results, korean cultural background should be considered. Especially the different family concept, more broader family members and kinship network, and the traditional medical knowledge influences patients' behavior.

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Efficiency Analysis of Spiral Structured Twist Screen (식품분말 진동선별기 개선을 위한 구조물 효율 분석)

  • Park, In-soon;Na, En-soo;Jang, Dong-soon;Paek, Young-soo
    • Food Engineering Progress
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    • v.14 no.2
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    • pp.85-91
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    • 2010
  • In the food process, twist screen is widely used to divide particles on the basis of size. As screen equipped in the twist screen perfoms an important part in the particle size distribution mechanism, the contact area of screen and particles, retention time of particles on the screen, mesh and string thickness of screen and the flow pattern of particles on the screen are major points of the separation efficiency. To improve the separation efficiency, increase the retention time and control the flow pattern of particles, screen frame dam and spiral blockage are installed on the sieve of twist screen ${\emptyset}$ 1200 and ${\emptyset}$ 1500. Twist screen ${\emptyset}$ 1500 with frame dam treated similar separation capacity, 37% higher separation ratio and less non-separated particles of product output 1 than general twist screen. Twist screens with frame dam and spiral blockage showed less treatment capacity, three times higher division ratio and entire separation than general twist screen.

District 9 : Science Fiction as Social Critique (<디스트릭트 9> 사회비평으로서의 공상과학)

  • Cho, Peggy C.
    • Cross-Cultural Studies
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    • v.42
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    • pp.505-524
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    • 2016
  • This study examines the ways District 9, a film released in 2009, reworks the sci-fi genre to explore the human encounter with "other" alien populations. Like Avatar, released in the same year, District 9 addresses the tropes of conflict over land and human-alien hybridity and introduces non-humans and aliens, not as invaders, but as objects of human oppression and cruelty. Unlike many other science fiction films where the encounter between humans and non-humans occurs in an unidentifiable future time and location, District 9 crosses genre barriers to engage with urban realism, producing a social critique of contemporary urban population problems. The arrival of aliens in District 9 occurs as part of the recorded human past and the film's action is carried out in the present time in the specifically identified city of Johannesburg. A distinctly anti-Hollywood film that locates the action at the street level, District 9 plays out human anxieties about contact with others by referencing the divisions and conflicts historically attached to South Africa's sprawling metropolis and its current problems of urban poverty and illegal immigrants. Focusing on how this particular urban setting frames the film, the study investigates the ways Blomkamp's sci-fi film about extra-terrestrials presents a curious postcolonial mix of aliens and immigrants surviving in abject conditions in an urban slum and forces a realistic examination of the contemporary social problems faced by South Africa's largest city and by extension other major global cities. The paper also examines the film's representation of the human-alien hybrid and its potential as a force to resist human exploitation of the other. It also claims that though the setting is highly local, District 9 speaks to a wider global audience by making obvious the exploitative practices of profit-seeking multinationals. A sci-fi film that is keen on making a social commentary on urban population conflicts, District 9 resonates with the wider sense of insecurity and fear of others that form the horizon of the uncertain and potentially violent contemporary human world.

A Silk Road Hero: King Chashtana

  • ELMALI, MURAT
    • Acta Via Serica
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    • v.3 no.2
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    • pp.91-106
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    • 2018
  • During the Old Uighur period, many works were translated into Old Uighur under the influence of Buddhism. Among these works, literary works such as $Da{\acute{s}}akarmapath{\bar{a}}vad{\bar{a}}nam{\bar{a}}l{\bar{a}}$ hold an important place. These works were usually translated from Pali to Sanskrit, from Sanskrit to Sogdian, Tocharian and Chinese, and to Old Uighur from these languages. These works which were added to the Old Uighur repertoire by translation indicate that different peoples along the ancient Silk Road had deep linguistic interactions with one another. Aside from these works, other narratives that we have been so far unable to determine whether they were translations, adaptations or original works have also been discovered. The Tale of King Chashtana, which was found in the work titled $Da{\acute{s}}akarmapath{\bar{a}}vad{\bar{a}}nam{\bar{a}}l{\bar{a}}$, is one of the tales we have been unable to classify as a translation or an original work. This tale has never been discovered with this title or this content in the languages of any of the peoples that were exposed to Buddhism along the Silk Road. On the other hand, the person whom the protagonist of this tale was named after has a very important place in the history of India, one of the countries that the Silk Road goes through. Saka Mahakshatrapa Chashtana (or Cashtana), a contemporary of Nahapana, declared himself king in Gujarat. A short time later, Chashtana, having invaded Ujjain and Maharashtra, established a powerful Saka kingdom in the west of India. His descendants reigned in the region for a long time. Another important fact about Chashtana is that coinage minted in his name was used all along the Silk Road. Chashtana, who became a significant historical figure in north western India, inspired the name of the protagonist of a tale in Old Uighur. That it is probable that the tale of King Chashtana is an original Old Uighur tale and not found in any other languages of the Silk Road brings some questions to mind: Who is Chashtana, the hero of the story? Is he related to the Saka king Chashtana in any way? What sort of influence did Chashtana have on the Silk Road and its languages? If this tale which we have never encountered in any other language of the Silk Road is indeed an original tale, why did the Old Uighurs use the name of an important Saka ruler? Is Saka-Uighur contact in question, given tales of this kind? What can we say about the historical and cultural geography of the Silk Road, given the fact that coinage was minted in his name and used along the Silk Road? In this study, I will attempt to answer these questions and share the information we have gleaned about Chashtana the hero of the tale and the Saka king Chashtana. One of the main aim of this study is to reveal the relationship between the narrative hero Chashtana and the Saka king Chashtana according to this information. Another aim of this study is to understand the history of the Saka, the Uighur and the Silk Road and to reveal the relationship between these three important subjects of history. The importance of the Silk Road will be emphasized again with the understanding of these relations. In this way, new information about Chashtana, who is an important name in the history of the India and the Silk Road, will be put forward. The history of the Sakas will be viewed from a different perspective through the Old Uighur Buddhist story.

Manufacturing Techniques of a Backje Gilt-Bronze Cap from Bujang-ri Site in Seosan (서산 부장리 백제 금동관모의 제작기법 연구)

  • Chung, Kwang Yong;Lee, Su Hee;Kim, Gyongtaek
    • Korean Journal of Heritage: History & Science
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    • v.39
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    • pp.243-280
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    • 2006
  • At the Bujang-ri Site, Seosan, South Chungcheong Province, around 220 archaeological features, including semi-subterranean houses and pits of Bronze Age and semi-subterranean houses, pits, and burials of Baekje period had been identified and investigated. In Particular, mound burials No. 5 of 13 of Baekje mound burials yielding a gilt-bronze cap along with other valuable artifacts drew international scholarly attention. The gilt-bronze cap from the mound burial No. 5 is a significant archaeological data not only in the study of Baekje archaeology but also in the study of international affairs and exchange at that time. At the time of exposure, the gilt-bronze cap was already broken into a number of pieces and seriously damaged by corrosion, and hardening and urethane foam were necessary in the process of collecting its pieces. Ahead of main conservational treatments on cap, X-ray photograph and CT(computerizes tomography) were taken in order to examine interior structure of the cap and to decide appropriate treatments. In the five layers identified in the profile of cap, a textile layer was set between a metal and a layerof bark of paper birch for avoiding direct contact of the metal and the bark of paper birch. Analyses were executed for examining textile layer and a layer of fibroid material. According to microscopic analysis, while the textile layer consisted of the simplest plain fabric with one fold among three kinds of textile structures, the layer of fibroid material was mixed with two or three kinds of fibers. A comparative analysis with standard sample using FT-IR (Fourier Transform Infrared Spectroscopy) announced that both textiles and fabrics were hemp. Analysis of kind of the paper birch resulted in barks of paper birch with 15 fold. A metallographic microscope, SEM, and WDS were used for the analysis of microscopic structures of plated metal pieces. While amalgam plating was treated as a plating method, the thickness of the plated layer, a barometer of plating technique, was ranged from $1.72{\mu}m$ to $8.67{\mu}m$. The degree of purity of gold (Au) used in plating was 98% in average, and less than 1% of silver (Ag) was included.

Implication and Its Meaning Contact of Gwangje-jeong's Place Transmission (광제정(光霽亭) 장소 전승의 함의와 의미맥락)

  • Rho, Jae-Hyun;Lee, Suk-Woo;Lee Jung-Han;Jung, Kyung-Suk;Kim, Young-Suk
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.3
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    • pp.40-51
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    • 2011
  • The purpose of the study was to understand the symbol and locational meanings in building and relocating Gwangje-jeong(光霽亭) through the analysis and interpretation on the construction background, history, the location and its characteristics. Concerning physical environment, human activities, the symbol and meanings of the formal Gwangje-jeong site and the present location, the study was concluded about the site and its meaning of tradition as following. Gwangje, the name of the pavilion, represents the fidelity of Maedang(梅堂) Yangdon(楊墩) who refused as Seonbee(a man of virtue) to be tainted with the corrupt world, which was related with the situation at that time. It implies Maedang's feeling of realizing Noojeongjeyong(樓亭題詠) of Gwangje-jeong along with the high spirit of Gwangpoongjewol(光風霽月). According to the record about rebuilding Gwangje-jeong, Maedang was the very person who planted plum flowers at the pavilion and put up the tablet of its name, Gwangje. Even after his death, Gwangje-jeong was the symbol indicating Yangdon, given the triple high ground and the planting of plum flowers. Also, Sookho(宿虎) town at the entrance of Gwangje-jeong and Bokhoam(伏虎巖: a rock) at the right side of the pavilion signifies the location for praising Maedang Yangdon, and the Yangjipha's Oensi(五言詩: five words verse) engraved on the rock gives a good description about the place, Agyesa that worshiped Yangdon. As Agye-Sa(阿溪祠) where Yangdon was worshiped and praised had been abolished in the 5th year under the Kojong's reign(1868), the spirit praising Maedang had finally been used for the relocation of Gwangje-jeong. Despite the relocation of Gwangje-jeong, the old Gwangje-jeong site has remained at least for 359years at Hucheonli, and its surroundings have maintained the name 'Gwangje' as the front place name morpheme, for example, 'Gwangje-jeong,' 'Gwangje Town,' 'Gwangje Bridge' and 'Gwangje Creek,' for symbolizing the praising of Maedang. Gwangje-jeong, as the center place of solidarity among Namwon Yang's family clan, has been able to maintain its symbol and meanings in spite of relocation, mainly because of the fellowship among the descendants, family clan and alumni who respected virtuous achievements of ancestors and shared the agony of the time. In addition, the symbolism has been preserved since the spirit of Gwangpoonjewol of Yangdon and his high character were cherished along with the spirit of Bongseon(奉先) that inherited and kept virtuous achievements of ancestors.

A Study on the Effect of Improving Permeability by Injecting a Soil Remediation Agent in the In-situ Remediation Method Using Plasma Blasting, Pneumatic Fracturing, and Vacuum Suction Method (플라즈마 블라스팅, 공압파쇄, 진공추출이 활용된 지중 토양정화공법의 정화제 주입에 따른 투수성 개선 연구)

  • Geun-Chun Lee;Jae-Yong Song;Cha-Won Kang;Hyun-Shic Jang;Bo-An Jang;Yu-Chul Park
    • The Journal of Engineering Geology
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    • v.33 no.3
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    • pp.371-388
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    • 2023
  • A stratum with a complex composition and a distributed low-permeability soil layer is difficult to remediate quickly because the soil remediation does not proceed easily. For efficient purification, the permeability should be improved and the soil remediation agent (H2O2) should be injected into the contaminated section to make sufficient contact with the TPH (Total petroleum hydrocarbons). This study analyzed a method for crack formation and effective delivery of the soil remediation agent based on pneumatic fracturing, plasma blasting, and vacuum suction (the PPV method) and compared its improvement effect relative to chemical oxidation. A demonstration test confirmed the effective delivery of the soil remediation agent to a site contaminated with TPH. The injection amount and injection time were monitored to calculate the delivery characteristics and the range of influence, and electrical resistivity surveying qualitatively confirmed changes in the underground environment. Permeability tests also evaluated and compared the permeability changes for each method. The amount of soil remediation agent injected was increased by about 4.74 to 7.48 times in the experimental group (PPV method) compared with the control group (chemical oxidation); the PPV method allowed injection rates per unit time (L/min) about 5.00 to 7.54 times quicker than the control method. Electrical resistivity measurements assessed that in the PPV method, the diffusion of H2O22 and other fluids to the surface soil layer reduced the low resistivity change ratio: the horizontal change ratio between the injection well and the extraction well decreased the resistivity by about 1.12 to 2.38 times. Quantitative evaluation of hydraulic conductivity at the end of the test found that the control group had 21.1% of the original hydraulic conductivity and the experimental group retained 81.3% of the initial value, close to the initial permeability coefficient. Calculated radii of influence based on the survey results showed that the results of the PPV method were improved by 220% on average compared with those of the control group.