• Science of Emotion and Sensibility
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• v.18 no.4
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• pp.25-34
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• 2015

TThis study explored the requirement of fabric sensor that can measure the motion of the joint effectively by measuring and analyzing the variation in electric resistance of a sensor in accordance with bending and stretching motion of the arm by the implementation of a motion sensor utilizing conductive fabric. For this purpose, on both sides of two kinds of knitted fabric, namely 'L' fabric and 'W' fabric Single Wall Carbon Nano-Tube(SWCNT) was coated, fabric sensor was developed by finishing them in a variety of ways, and the sensor was attached to the arm band. The fabric sensor consisted of total 48 cases, namely background fabric for coating, the method of sensor attachment, the number of layer of sensors, the length of sensor, and the width of sensor. The performance of fabric motion sensors in terms of a dummy arm, that is, a Con-Trex MJ with 48 arm bands around it was evaluated. For each arm band, a total of 48, fastened around the dummy arm, it was adjusted to repeat the bending and stretching at the frequency : 0.5Hz, ROM : $20^{\circ}{\sim}120^{\circ}$, the voltage was recorded for each case after conducting three sets of repeat measurement for a total of 48 cases. As a result of the experiment, and as a consequences of the evaluation and analysis of the voltage based on the uniformity of the base line of the peak-to-peak voltage(Vp-p), the uniformity of Vp-p within the same set, and the uniformity of the Vp-p among three sets, the fabric sensors that have been configured in SWCNT coated 'L' fabric / welding / two layers / $50{\times}5mm$, $50{\times}10mm$, $100{\times}10mm$, and SWCNT coated 'W' fabric / welding / two layers / $50{\times}10mm$ exhibited the most uniform and stable signal value within 5% of the total variation rate. Through all these results of the experiment, it was confirmed that SWCNT coated fabric was suitable for a sensor that can measure the human limb operation when it was implemented as a fabric sensor in a variety of forms, and the optimal sensor types were identified.

• Elastomers and Composites
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• v.10 no.2
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• pp.136-156
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• 1975

고무는 불량열전도체(不良熱傳導體)이며 두께가 두꺼우면 내부(內部)가 적정온도수준(適正溫度水準)에 이르기 전까지 가황시간(加黃時間)이 길어진다. 가황온도(加黃溫度)가 상승(上昇)할수록 가황물(加黃物)의 물성(物性)은 열화(劣化)되는 경향(傾向이) 있다. 천연(天然)고무든지 합성(合成)고무든지 간(間)에 과가황(過加黃)에 대(對)한 저항성(抵抗性)이 나쁘므로 특(特)히 고온가황(高溫加黃)에 대(對)해 민감(敏感)하다. 이것은 고온(高溫)에서 단시간(短時間) 가황(加黃)일수록 가속(加速)된다. 평탄가황배합물(平坦加黃配合物)의 경우에서 보더라도 내부(內部)가 적절(適切)히 가황(加黃)되기도 전(前)에 외부(外部)는 과가황(過加黃)이 되는 수가 있다. 근래(近來) 발간(發刊)된 문헌(文獻)에서도 이러한 내용(內容)이 잘 설명(說明)이 되어 있는데 다른 각도(角度)에서 고찰(考察)해 볼것 같으면 정체시간(停滯時間)이 비교적(比較的) 길지 않는 한(限) 가황시간(加黃時間)은 정체시간(停滯時間)과 sheet 가황시간(加黃時間)과의 합(合)이라고 말할 수 있겠다. 예(例)를 들어 설명(說明)하자면 $130^{\circ}C(266^{\circ}F)$에서 정체시간(停滯時間)이 10분(分)이고 sheet 가황시간(加黃時間)이 20분(分)인 제품(製品)은 이 온도(溫度)에서 30분간(分間) 가황(加黃)해야 된다는 것이다. 온도계수(溫度係數)를 2라고 가정(假定)할 경우 $140^{\circ}C(284^{\circ}F)$에서의 가황시간(加黃時間)은 $30\times\frac{1}{2}=15$분(分)이 아니라 $20\times\frac{1}{2}+10=20$분(分)이 된다. 크기가 큰 제품(製品)은 보통(普通) 다음에 있는 여러 방법(方法)들 가운데 한 가지 또는 여러가지를 조합(組合)하여 가황(加黃)시킨다. a) 크기가 작은 것에 대한 것 보다 낮은 온도(溫度)에서 가황(加黃)한다. b) 침투가황-제품(浸透加黃-製品)을 가압하(加壓下)에 두고서 외부가황(外部加黃)은 단속(斷續)시키고 열(熱)이 중심(中心)으로 침투(浸透)하게 한다. c) 단계가황(段階加黃)-처음에는 저온(低溫)에서 시작(始作)하여 일정간격(一定間隔)을 두고 점차(漸次) 온도(溫度)를 상승(上昇)시켜 최종적(最終的)으로 가황온도(加黃溫度)까지 올린다. d) 가능(可能)하다면 metal base나 금형(金型)에서 고무를 증기가황(蒸氣加黃)시킬 경우에 있어서 속이 빈 축(軸)을 사용하여 내부(內部)로 부터 가열(加熱)하면 가황시간(加黃時間)이 단축(短縮)된다. e) 냉각중(冷却中)의 후가황(後加黃)-이것은 가열장치(加熱裝置)에서 끄집어낸 후 제품(製品)의 외부(外部)를 냉각(冷却)시키는 방법(方法)이다. 가열(加熱)된 제품(製品)이 쌓여 있거나 적절(適切)하게 냉각(冷却)되지 않을 때 가황(加黃)이 추가적(追加的)으로 되거나 과가황(過加黃)이 될 우려가 있는 제조공정(製造工程)에서는 흔히들 이 방법(方法)을 무시(無視)하고 있다. 여기서 강조(强調)해 두어야 할 것은 항상 제품(製品)의 외부(外部)를 완전(完全)히 가황(加黃)시킬 필요(必要)는 없다는 것이다. 다공성(多孔性)이나 기포생성(氣泡生成)을 조장(助長)하는 불량가황상태(不良加黃狀態)와 표면(表面)에서의 과가황상태간(過加黃狀態間)의 균형(均衡)을 취(取)해 줘야 하는데 물론(勿論) 이때는 가황시간(加黃時間)을 단축(短縮)시켜야 한다는 경제적(經濟的)인 측면(側面)도 아울러 고려(考慮)해야 한다. 이것은 고무기술자(技術者)가 당면(當面)해야할 과제(課題)에 속(屬)하며 바람직 한것은 본장(本章)의 내용(內容)이 여러 상황하(狀況下)에서 당면(當面)한 문제(問題)에 대(對)해 어떻게 대처(對處)해 야 할지를 모르는 여러 기술자(技術者)들에게 도움이 되었으면 하는 것이다.

• Journal of Aquaculture
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• v.21 no.1
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• pp.26-33
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• 2008

This study investigated the synergistic effects of dietary supplementation of quartz porphyry(QP) and a laboratory developed feed stimulants, BAISM(BS) on growth performance and utilization as the additives for juvenile eel Anguilla japonica. Six isoenergetic experimental diets(18.2 kJ/g) were formulated to contain 50% crude protein, 15% lipid with or without dietary QP(Song-Gang stone, Davistone, Korea) and BS supplementation. QP and BS were provided at 0% in the control diet($Q_0B_0$) and at 0.7% QP+0% BS($Q_{0.7}B_0$), 0.7% QP+0.3% BS($Q_{0.7}B_{0.3}$), 0.7% QP+0.5% BS($Q_{0.7}B_{0.5}$), 0.7% QP+0.75% BS($Q_{0.7}B_{0.75}$) and 0.7% QP+1.0% BS($Q_{0.7}B_{1.0}$) in experimental diets on dry matter basis. After four weeks of adaptation, triplicate groups of 30 fish initially averaging $15{\pm}0.1g(mean{\pm}SD)$ were randomly distributed into each aquarium, and they were fed one of the experimental diets for 8 weeks. By the end of the feeding trial, weight gain(%), specific growth rate(%), feed efficiency(%) and protein efficiency ratio of fish fed diet $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$, were significantly higher(P<0.05) than those of fish fed the other diets. But, $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$ were no significant differences(P<0.05). In challenge test, fish were infected by intraperitoneal injection of 0.1 mL bacterial suspension with Edwardsiella tarda per fish after the feeding trial. As a result, fish fed QP and BS supplemented diets have a significantly higher cumulative survival rate than those of fish fed control diet(P<0.05). In conclusion, these results indicated that the optimum dietary supplementation level of QP and BS could be approximately 0.7% quartz porphyry+0.5% BAISM($Q_{0.7}B_{0.5}$) of diet based on WG, FER, SGR, PER, cumulative survival rate in juvenile eel A. japonica.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.187-196
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• 1989

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parve were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, and then the metacercariae were isolated and in(ected to rats. The third (Scheme 3) was irradiation on the rat livers after infection with normal metacercariae. Irradiation doses varied from 5 to 100 Gy for Schemes 1 and 2, and 10 to 25 Gy for Scheme 3. The rats were sacrificed 2 to 6 weeks after infection. In Scheme 1, the metacercariae irradiated at 50 Gy failed to survive in the rats after 2 or 6 weeks. However, 1 to 44% of the metacercariae irradiated at 5∼30 Gy survived. The estimated LD50 of Scheme 1 was 16.5 Gy. The flukes irradiated in Scheme 2 survived better than those in Scheme 1. The average worm recovery rate in 50 Gy was 28%(7∼39% individually). Increasing the dose up to 100 Gy brought a remarkably low survival rate of an average 1%(0∼3% individually). The LD50 of Scheme 2 was 47.5 Gy. Worm recovery rates in the 10 Gy group of Scheme 3 were 21∼39%, and those in the 25 Gy group were 2% and 34%. Although the metacercariae were irradiated, all of the recovered worms were morphologically normal. Only the worms irradiated with 10 Gy or 25 Gy after 9 days from infection in Scheme 3 showed underdeveloped testes and seminal receptacle. The present results suggest that irradiation of the fish by 100 Gy could be adopted as a control measure for clonorchiasis.

• Clean Technology
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• v.29 no.4
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• pp.255-261
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• 2023

Power semiconductors are semiconductors used for power conversion, transformation, distribution, and control. Recently, the global demand for high-voltage power semiconductors is increasing across various industrial fields, and optimization research on high-voltage IGBT components is urgently needed in these industries. For high-voltage IGBT development, setting the resistance value of the wafer and optimizing key unit processes are major variables in the electrical characteristics of the finished chip. Furthermore, the securing process and optimization of the technology to support high breakdown voltage is also important. Etching is a process of transferring the pattern of the mask circuit in the photolithography process to the wafer and removing unnecessary parts at the bottom of the photoresist film. Ion implantation is a process of injecting impurities along with thermal diffusion technology into the wafer substrate during the semiconductor manufacturing process. This process helps achieve a certain conductivity. In this study, dry etching and wet etching were controlled during field ring etching, which is an important process for forming a ring structure that supports the 3.3 kV breakdown voltage of IGBT, in order to analyze four conditions and form a stable body junction depth to secure the breakdown voltage. The field ring ion implantation process was optimized based on the TEG design by dividing it into four conditions. The wet etching 1-step method was advantageous in terms of process and work efficiency, and the ring pattern ion implantation conditions showed a doping concentration of 9.0E13 and an energy of 120 keV. The p-ion implantation conditions were optimized at a doping concentration of 6.5E13 and an energy of 80 keV, and the p+ ion implantation conditions were optimized at a doping concentration of 3.0E15 and an energy of 160 keV.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.97-107
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• 1999

Background: This study was designed to develop a Korean version of the heparin-coated vascular bypass shunt by using a physical dispersing technique. The safety and effectiveness of the thrombo-resistant shunt were tested in experimental animals. Material and Method: A bypass shunt model was constructed on the descending thoracic aorta of 21 adult mongrel dogs(17.5-25 kg). The animals were divided into groups of no-treatment(CONTROL group; n=3), no-treatment with systemic heparinization(HEPARIN group; n=6), Gott heparin shunt (GOTT group; n=6), or Korean heparin shunt(KIST group; n=6). Parameters observed were complete blood cell counts, coagulation profiles, kidney and liver function(BUN/Cr and AST/ ALT), and surface scanning electron microscope(SSEM) findings. Blood was sampled from the aortic blood distal to the shunt and was compared before the bypass and at 2 hours after the bypass. Result: There were no differences between the groups before the bypass. At bypass 2 hours, platelet level increased in the HEPARIN and GOTT groups(p<0.05), but there were no differences between the groups. Changes in other blood cell counts were insignificant between the groups. Activated clotting time, activated partial thromboplastin time, and thrombin time were prolonged in the HEPARIN group(p<0.05) and differences between the groups were significant(p<0.005). Prothrombin time increased in the GOTT group(p<0.05) without having any differences between the groups. Changes in fibrinogen level were insignificant between the groups. Antithrombin III levels were increased in the HEPARIN and KIST groups(p<0.05), and the inter-group differences were also significant(p<0.05). Protein C level decreased in the HEPARIN group(p<0.05) without having any differences between the groups. BUN levels increased in all groups, especially in the HEPARIN and KIST groups(p<0.05), but there were no differences between the groups. Changes of Cr, AST, and ALT levels were insignificant between the groups. SSEM findings revealed severe aggregation of platelets and other cellular elements in the CONTROL group, and the HEPARIN group showed more adherence of the cellular elements than the GOTT or KIST group. Conclusion: Above results show that the heparin-coated bypass shunts(either GOTT or KIST) can suppress thrombus formation on the surface without inducing bleeding tendencies, while systemic heparinization(HEPARIN) may not be able to block activation of the coagulation system on the surface in contact with foreign materials but increases the bleeding tendencies. We also conclude that the thrombo-resistant effects of the Korean version of heparin shunt(KIST) are similar to those of the commercialized heparin shunt(GOTT).