• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.778-782
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• 2007

This study investigated the dechlorination mechanisms of TCE by Fe(II) associated with cement. Batch slurry experiments were peformed to investigate the behaviors of selected ions; Fe(II), Fe(III), $Ca^{2+}$, $SO_4^{2-}$ in cement/Fe(II) system. The kinetic experiments of TCE in cement/Fe(II) systems showed that injected Fe(II) was mostly sorbed on cement within 0.5 day and 90% of injected 200 mM sulfate was sorbed on cement within 0.5 day when $[TCE]_0$ = 0.25 mM and $[Fe(II)]_0$ = 200 mM. The kinetic experiments of TCE in hematite/CaO/Fe((II) systems were conducted for simulation of cement/Fe(II) system. Calcium oxide that is one of the major components in cement hydration reactions or has a reactivity in limited conditions. Hematite assumed the ferric iron oxide component of cement. The reactivities observed in hematite/CaO/Fe(II) system were comparable to those reported for cement/Fe(II) systems containing similar molar amounts of Fe(II). The behavior of Fe(II) and $SO_4^{2-}$ sorbed on solid phase at an early stage of reaction in hematite/CaO/Fe(II) system was similar to that of cement/Fe(II) system. Ferric ion was released from hematite at an early period of reaction at low pH. The experimental evidence of kinetic test using hematite/CaO/Fe(II) system implies that the reactive reductant is a mixed-valent Fe(II)-Fe(III) mineral, which may be similar to green rust. Fe(II) sorbed on cement can be converted to new mineral phase having a reactivity such as Fe(II)-Fe(III) (hydr)oxides in cement/Fe(II) systems.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.1
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• pp.39-52
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• 2007

Quantitative analysis on release behavior of the $^{85}Kr\;and\;^{14}C$ fission gases from the spent fuel material during the voloxidation and OREOX process has been performed. This thermal treatment step in a remote fabrication process to fabricate the dry-processed fuel from spent fuel has been used to obtain a fine powder The fractional release percent of fission gases from spent fuel materials with burn-up ranges from 27,000 MWd/tU to 65,000 MWd/tU have been evaluated by comparing the measured data with these initial inventories calculated by ORIGEN code. The release characteristics of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation process at $500^{\circ}C$ seem to be closely linked to the degree of conversion efficiency of $UO_2\;to\;U_3O_8$ powder, and it is thus interpreted that the release from grain-boundary would be dominated during this step. The high release fraction of the fission gas from an oxidized powder during the OREOX process would be due to increase both in the gas diffusion at a temperature of $500^{\circ}C$ in a reduction step and in U atom mobility by the reduction. Therefore, it is believed that the fission gases release inventories in the OREOX step come from the inter-grain and inter-grain on $UO_2$ matrix. It is shown that the release fraction of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation step would be increased as fuel burn-up increases, ranging from 6 to 12%, and a residual fission gas would completely be removed during the OREOX step. It seems that more effective treatment conditions for a removal of volatile fission gas are of powder formation by the oxidation in advance than the reduction of spent fuel at the higher temperature.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.277-286
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• 1994

The pot experiment using $^{15}N$ isotope dilution technique was carried out to calculate the balance of nitrogen of surface applied urea in the rice-soil system. The $^{15}N$ concentration was determined by stable isotope ratio mass spcetrometer (model: VG ISO-GAS MM622). In the pots with $^{15}N$ labeled urea application at the rates of 15 and 30 kg N/10a, the percentage of nitrogen derived from fertilizer (NDFF) in rice was higher at the rate of 30 kg N/10a (average 89%) than at the rate of 15 kg N/10a (average 64%). However, the recovery as percentage of fertilizer N by rice was higher at the rate of 15 kg N/10a (65.5%) than at the rate of 30 kg N/10a (54.2%). The percentage of the fertilizer N remained in extractable inorganic N form at the rates of 15 and 30 kg N/10a were $13.5%\;(NH_4-N\;5.53%,\;NO_3-N\;7.99%)$ and $16.5%\;(NH_4-N\;7.49%,\;NO_3-N\;8.98%)$ in unplanted soil, and $2.0%\;(NH_4-N\;0.63%,\;NO_3-N\;1.32%)$ and$2.3%\;(NH_4-N\;0.87%,\;NO_3-N\;1.40%)$ in soil planted to rice, respectively. The dominant form of inorganic-N in soil after harvest was $NO_3-N$ form rather than $NH_4-N$ form regardless of urea application rate or rice cultivation. The percentage of the fertilizer N remained in organic N form at the rates of 15 and 30 kg N/10a were 65.0 and 41.8% in unplanted soil, and 23.7 and 26.9% in soil planted to rice, respectively. In conclusion, the efficiency of surface-applied urea was greater at the rate 15 kg N/10a than at the rate of 30 kg N/10a.

• Archives of design research
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• v.18 no.2 s.60
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• pp.243-254
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• 2005

Great Britain and the United States and Finland are having an interest in long policy subject about child design education through early design education. And they approaches and practices it systematically. The research about the design learning program instance of advanced nation of primary school's design education for various objective is necessary for use with the fundamental reference data for an elementary design education. And so, This research presented the program instance investigation and analysis result of British primary school's design education. U.K is teaching an primary design education from two subjects of Art & Design and Design and Technology which is a legal subject with national curriculum. The analysis result of design relation unit learning program of two subjects is: Design relation unit learning programs of 'Design and Technology' subject's 20 unit which except 4 food relation unit is largely scientific engineering contents that include utility function contents in part. The reason is as behavior styles based on Design process solve problems scientifically & rationally. Design relation 6 units in subject of Art & Design which except the units which relates with the pure fine arts and architecture in 19 units is aesthetic-symbolic and utility-functional contents largely. And so, the result was analyzed about relation of scientific-engineering content of 'Arts & Design' subject is insufficient comparing with 'Design and Technology' subject Specially, I think that the design relation's unit learning program instances of 'Design and Technology' subject of the British primary school which have been presented by this research paper is a possibility becoming one reference model for a program development. And so I expects that this research could be applied in the program development for the primary design education of primary teacher & education agency.

• Archives of design research
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• v.18 no.2 s.60
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• pp.155-164
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• 2005

Home-service robots need to have sufficient spatial information about the surroundings for interacting with human intelligently and performing services efficiently. It is very important to investigate the efficient interaction style that supports map building task through human-robot collaboration. We first analyzed map building task with a cleaning robot and drew 4 design factors and tentative solutions, including map building procedure (task-preferred procedure/space- preferred procedure), LCD display installation (robot/robot+remote control), navigation method (push type/pull type), feedback modality(GUI/GUI+TTS). The design factors and tentative solutions were defined as independent variables and levels. This research investigated how those variables affect to the human task performance and behavior in map building tast. 8 kinds of experiment prototypes were built and usability test among 16 house wives was conducted for acquiring empirical data. As the experiment result, in terms of map building procedure, space-preferred procedure indicated better task performance than task-proffered procedure as we expected. For the LCD display installation factor, remote control with LCD display indicated higher task performance and subjective satisfaction. In robot navigation method, it was very difficult to find a significant difference between push type and pull type which contrary to our expectation. In fact, push type indicated higher subjective satisfaction. Also in feedback modality, we have acquired negative feedback an additional TTS operation guidance. It seems that robot's autonomy before achieving spatial information is rudiment condition which means users are just interacting with a mobile appliance. Thus they prefer remote-control-based interaction style in robot map building process as they used in traditional appliance control.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.151-159
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• 1994

This study was conducted to investigate the $NO_3-N$ concentration, the relationship between $NO_3-N$ and other ions, and patterns of ions in ground water used as drinking water in Cheju Island. Samples were collected from 19 wells in the northwest region, near the district of poultry complex, and 9 wells in the northeast region. In the northwest region, $NO_3-N$ concentrations in D-14 and D-202 wells near the pig farming facilities were 10.95 and 13.1 mg/L, respectively, exceeding the standard concentration of drinking water. The concentration in D-65, D-35, and D-120 wells were slightly lower than the standard concentration. However, $NO_3-N$ concentrations in the wells in the northeast region were lower than 3mg/L. In wells in the northwest region, $NO_3-N$ concentrations were negatively correlated with pH and positively correlated with $Ca^{++}$, $Mg^{++}$, $Na^+$ $Cl^-$, $SO_4^{--}$, and $Cl^-/HCO_3^-$. However, in the northeast region, they were not related with pH and the ions. The chemical compositions in D-65, D-35, and D-41 wells showed higher concentrations of $Ca^{++}$, $Mg^{++}$, $Na^+$, $Cl^-$, $NO_3-N$ and $SO_4^{--}$ than the unpolluted D-42 well. These results suggest that ground water near the pig farming complex was polluted by pig farming waste in the northwest region.

• Archives of design research
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• v.19 no.5 s.67
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• pp.203-212
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• 2006

With interests and participation in the costumeplay that mimics characters appeared on carton or animation in recent days, the costumeplay becomes one of cultural phenomena. Using a qualitative research method, this study identified costumeplayers' costume consumption pattern and explored its meanings from the perspective of consumption culture. Indeed, this study intended to help for understanding costumeplayer group as a consumer, and to provide basic knowledge about new market analysis related to fashion design and marketing. The results from the analyzing participant observation and in-depth interviews data are as follows: first, costumeplayers usually begin costumeplay by friends' invitations or by themselves and then continue on participating. Through the costumeplay, participants have benefits such as fun, departure from the daily life, and social interaction. Second, participants acquire costumes through purchase, rent, producing or combination of daily wear, but both purchase and rent account high. Third, the meanings of consumption culture in costumeplay include consumption behavior repeating possession and disposal. Also, costumeplayers concerns efficiency when purchasing or renting the costumes, and internet is a place where information search, comparison, and actual purchasing are occurred. Based on the results, fashion design and marketing implication, limitation of this study and further research ideas were suggested.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.237-251
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• 2020

This study examined structural analysis of supports in tunnel and displacement and underground stress of tunnel by measurement, in order to evaluate the performance of high-strength lattice girders developed as a substitute for H-profiles. According to the three-dimensional nonlinear structural analysis results of the tunnel support, the load and displacement relationship between the H-profiles and the high-strength lattice girders showed almost the same behavior, and the maximum load of the high-strength lattice girders were 1.0 to 1.2 times greater than the H-profiles. By the results of the three-dimensional tunnel cross-section analysis of the supports, the axial force was occurred largely in the lower left and right sides of the tunnel, and showed a similar trend to the field test values. In the results of the measurement of the roof settlement and rod extension, the final displacement of the steel arch rib (H-profile) and high-strength lattice girder section in tunnel was converged to a constant value without significant difference within the first management standard of 23.5 mm. According to the results of underground displacement measurement, the final change amount of the two support sections showed a slight displacement change, but converged to a constant value within the first management standard of 10 mm. By the results of measurement of shotcrete stress and steel arch rib stress, the final change amount of the two support sections showed a slight stress change, but converged to a constant value within the first management standard of 81.1 kg/㎠ and 54.2 tonf.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.253-259
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• 2004

in this study, we developed a Monte Carlo imaging simulation code written by the visual C$\^$++/ programing language for design optimization of a digital X-ray imaging system. As a digital X-ray imaging system, we considered a Gd$_2$O$_2$S(Tb) scintillator and a photosensor array, and included a 2D parallel grid to simulate general test renditions. The interactions between X-ray beams and the system structure, the behavior of lights generated in the scintillator, and their collection in the photosensor array were simulated by using the Monte Carlo method. The scintillator thickness and the photosensor array pitch were assumed to 66$\mu\textrm{m}$ and 48$\mu\textrm{m}$, respertively, and the pixel format was set to 256 x 256. Using the code, we obtained X-ray images under various simulation conditions, and evaluated their image qualities through the calculations of SNR (signal-to-noise ratio), MTF (modulation transfer function), NPS (noise power spectrum), DQE (detective quantum efficiency). The image simulation code developed in this study can be applied effectively for a variety of digital X-ray imaging systems for their design optimization on various design parameters.

• The Korean Journal of Pharmacology
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• v.17 no.2
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• pp.47-62
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• 1981

d-amphetamine이 사람에서 paranoid schizophrenia와 아주 유사한 model psychosis를 일으키며 또한 사람과 실험동물에서 실제 정신분열증에서 뚜렷이 관찰되는 behavioral perservation을 일으킬 수 있음이 관찰되었다. 이에 많은 학자들은 이러한 양상의 행동변화가 정신분열증의 원인 추구에 중요한 의미를 주는 뇌변화를 반영할지도 모른다는 생각에 많은 연구를 거듭하여 왔다. 지금까지는 주로 catecholamine기전에 대하여 집중적 연구가 수행되어져 왔으나 최근에는 d-amphetamine의 약리기전의 일부는 5-HT기전이 차지하고 있으며, 여러 행동변화에는 catecholaimin 보다 5-HT 가 더 중요하게 관계하고 있다는 주장이 나오고 있다. 또한 d-amphetamine은 시험관내에서 MAO 특히 신경전달물질 분해요소인 A type를 가역적으로 억제할 수 있음이 보고되어 많은 흥미를 끌어왔으나 생체내에서의 억제여부는 직접적으로 확인이 되고 있지 않다. 그러나 최근에 Braestrup(1977)과 El Hait(1978)등은 간접적인 방법으로 생체내에서도 억제시킬 수 있음을 보고하고 있다. 이에 저자는 d-amphetamine에 의해 야기되는 행동변화와 그 밑바탕을 이루는 생화학적 기전에 5-HT가 차지하는 역할을 알아보기 위해서 다음의 실험을 시행하였다. 첫째, d-amphetamine의 급성, 만성 투여가 5-HT의 5-HIAA 로의 turnover와 MAO활성도에 어떤 영향을 미치며, 더 나아가서 이 양자사이에 어느 정도 상관관계가 있는지를 알아보기 위해서 d-amphetamine을 투여한 후 시간 경과에 따라서 뇌내 5-HT, 5-HIAA, 5-HT turnover rate와 MAO 활성도를 측정하였다. 둘째, d-amphetamine, 5-HT 합성을 증가시키는 약물과 합성을 억제시키는 약물을 투여하고, 위의 생화학적 실험과 행동관찰을 병합 실시하여 비교분석하였다. 그 결과는 다음과 같다. 1) d-amphetamine (6 mg/kg)을 급성투여시, 뇌내 5-HT함량이 투여 1시간 후에 최고로(대조치의 123%, p<0.001) 증가되다가 이후 감소하며, 5-HIAA 함량은 처음 15분부터 감소하기 시작하다가 30분에 최저로 떨어지며(대조치의 78%, p<0.005) 이후 증가하여 24시간째는 약간 대조치 이상으로 회복되었다. 미토콘드리아 MAO활성도는 1시간째에 최저로 떨어지다가(대조치의 89%, p<0.05)이후 회복하기 시작하여 24시간째에 약간 대조치 이상으로 회복되었다. 5-HT의 turnover rate는 MAO활성도 변화와 거의 같은 변화를 보였다. 2) 만성투여시 (하루 2번, 14일간 투여)는 5-HT 함량, 5-HIAA 함량, MAO 활성도 및 5-HT turnover rate 모두가 중등도로 감소되었다. (각각 대조치의 87%, 69%, 80%, 79%). 3) MAO 활성도와 5-HT turnover rate 사이에는 높은 상관관계가 있었다. (r=0.866, p<0.001, N=94). 4) MAO 활성도의 역동학 실험에서는 대조치에 비해 투여군에서 Km 값은 의미가 있는 증가가 있었으나 $V_{max}$값은 큰 변동이 없었다. 5) d-amphetamine을 급성 투여할때는 sleeping과 lying components는 상당한 감소를 보인 반면, locomotor activity 는 1시간까지는 상당한 증가를 보였으며 용량이 적을수록 더 큰 증가가 있었다. 반면 stereotypy는 1시간까지 용량이 증가할수록 더 큰 증가가 나타나서 locomotor activity에서 stereotypy 의 증가로 이행을 나타내었다. 만성 투여시는 locomotor activity는 점차적인 감소를 보였으나 stereotypy는 점차적인 증가가 나타나서 14일쯤에는 평형에 도달하였다. 6) PCPA 단독 투여군(400 mg/kg, 3번)에 있어서는 5-HT와 5-HIAA 함량의 상당한 감소가 나타났으나 MAO 활성도와 행동에는 큰 변화를 나타내지 않았다. PCPA전 처치군에 있어서도 5-HT와 5-HIAA 함량은 마찬가지로 상당한 감소를 나타내었으나 gnawing, sniffing과 locomotor activity는 더 증가를, stereotyped head weaving, forepaw treading과 hindlimb abduction은 상당한 감소를 나타내었다. 7) L-tryptophan(100 mg/kg)단독 투여시는 5-HT 함량은 약간 증가를 나타내었으나 5-HIAA 함량은 상당한 증가를 보였다. MAO활성도나 행동은 큰 변화없었다. L-tryptophan 전처치군에 있어서는 5-HT 함량은 더 큰 증가를 보였으나, 5-HIaa 함량은 MAO 활성도는 별 변화없었으며 stereotypedlateral head waving, forepaw treading 과 hindlimb abduction은 증가를, locomotor activity, gnawing과 sniffing components는 감소를 나타내었다. 8) d-amphetamine 단독투여, 혹은 L-tryptophan 전처치, PCPA 전처치후 측정한 5-HT 함량과 stereotyped head weaving, forepaw treading, hinilimb abduction components 사이에는 높은 상관관계가 있었다(r=0.789, p<0.001). 반면 5-HT 함량과 locomotor activity, stereotyped gnawing과 sniffing components 사이에는 약한 음성의 상관관계가 있었다. (r=0.554, p <0.005). 이상의 결과로 미루어 볼때 5-HT의 5-HIAA 로의 turnover rate 는 주로 MAO 활성도에 의해서 조절되며 5-HT 기전이 d-amphetamine에 의해서 야기된 여러 행동변화 중 상당한 부분에서 중요한 역할을 하리라고 생각된다.