• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.243-252
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• 2018

In a satellite gravimetry mission similar to GRACE, the precision of inter-satellite ranging is one of the key factors affecting the quality of gravity field recovery. In this paper, the impact of ranging precision on the accuracy of recovered geopotential coefficients is analyzed. Simulated precise orbit determination (POD) data and inter-satellite range data of formation-flying satellites containing white noise were generated, and geopotential coefficients were recovered from these simulated data sets using the crude acceleration approach. The accuracy of the recovered coefficients was quantitatively compared between data sets encompassing different ranging precisions. From this analysis, a rough prediction of the accuracy of geopotential coefficients could be obtained from the hypothetical mission. For a given POD precision, a ranging measurement precision that matches the POD precision was determined. Since the purpose of adopting inter-satellite ranging in a gravimetry mission is to overcome the imprecision of determining orbits, ranging measurements should be more precise than POD. For that reason, it can be concluded that this critical ranging precision matching the POD precision can serve as the minimum precision requirement for an on-board ranging device. Although the result obtained herein is about a very particular case, this methodology can also be applied in cases where different parameters are used.

• Archives of Metallurgy and Materials
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• 제64권2호
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• pp.481-485
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• 2019

This study was attempted to study for recovery of Li as Li₂CO₃ from cathode active material, especially NCA (LiNiCoAlO₂), recovered from spent lithium ion batteries. This consists of two major processes, carbonation using CO₂ and water leaching. Carbonation using CO₂ was performed at 600℃, 700℃ and 800℃, and NCA (LiNiCoAlO₂) was phase-separated into Li₂CO₃, NiO and CoO. The water leaching process using the differences in solubility was performed to obtain the optimum conditions by using the washing time and the ratio of the sample to the distilled water as variables. As a result, NCA (LiNiCoAlO₂) was phase-separated into Li₂CO₃ and NiO, CoO at 700℃, and Li₂CO₃ in water was recovered through vacuum filtration after 1 hour at a 1:30 weight ratio of the powder and distilled water. Finally, Li₂CO₃ containing Li of more than 98 wt.% was recovered.

• Archives of Metallurgy and Materials
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• 제66권4호
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• pp.1001-1005
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• 2021

Liquid Metal Extraction process using molten Mg was carried out to obtain Nd-Mg alloys from Nd based permanent magnets at 900℃ for 24 h. with a magnet to magnesium mass ratio of 1:10. Nd was successfully extracted from magnet into Mg resulting in ~4 wt.% Nd-Mg alloy. Nd was recovered from the obtained Nd-Mg alloys based on the difference in their vapor pressures using vacuum distillation. Vacuum distillation experiments were carried out at 800℃ under vacuum of 2.67 Pa at various times for the recovery of high purity Nd. Nd having a purity of more than 99% was recovered at distillation time of 120 min and above. The phase transformations of the Nd-Mg alloy during the process, from Mg₁₂Nd to α-Nd, were confirmed as per the phase diagram at different distillation times. Pure Nd was recovered as a result of two step recycling process; Liquid Metal Extraction followed by Vacuum Distillation.

• 청정기술
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• 제26권3호
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• pp.177-185
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• 2020

본 연구에서는 석탄화력발전소에서 전량 폐기되고 있는 석탄재의 재활용 방안으로 석탄회의 80%를 차지하고 있는 비산재로 부터 유용성분을 회수하고 이를 산업재로 활용하기 위한 청정부유선별 공정을 개발하였다. 비산재로부터 미연탄소(unburned carbon, UC) 를 회수하기 위해 비이온성 포수제인 등유 대신에 친환경 식물성 오일인 대두유를 사용하여 등유로부터 악취 발생을 예방하였고 부유선별 후 잔류물로부터 CM (ceramic microsphere)과 CA (cleaned ash)를 분리하기 위해 황산용액을 사용하지 않고 hydro-cyclone를 사용함으로써 산성폐수를 발생시키지 않고 미립의 CM를 회수할 수 있었다. 등유를 포수제로 사용하여 UC를 분리할 때 보다 대두유를 포수제로 사용하였을 때, 대두유의 높은 점성으로 인한 UC의 흡착성 증가와 대두유에 포함된 리놀레산에 의해 부유성 향상으로 UC의 회수율이 85.8%로 높게 나타났다. 회수된 UC에 포함된 연소가능성분(combustible component, CC)은 모두 탄소성분으로 대두유를 사용하였을 때 탄소의 함량이 높게 나타났으며, 회수된 UC는 표면이 거칠면서 기공이 많아 분쇄가 쉬워 미립화로 산업용 소재로 활용할 수 있을 것이다. Hydro-cyclone을 이용한 입도선별 청정분리공정에 의해 회수된 CM과 CA는 구형 형상으로 입자들이 서로 뭉치지 않고 뚜렷하게 분리되었으며 입자의 평균직경(D₅₀)은 5 ㎛로 미세하여 공정변경에 의한 CM의 미립화를 구현할 수 있었다.

• 한국수정란이식학회지
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• 제26권3호
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• pp.159-164
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• 2011

This study was performed in order to determine optimum flushing solution using the direct embryo collection (DEC). Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. On the 3$^{rd}$ day administration of FSH, 25 mg $PGF_2{\alpha}$ was administered and CIDR was withdrawn. After FSH injections were complete, donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 ${\mu}g$ GnRH at time of 1$^{st}$ insemination and embryos were recovered 8 days after the 1$^{st}$ insemination. Embryo collection from superovulated donors were performed to flushing by DEC and conventional method. As a results, the average number of recovered embryos were significantly higher as 19.1${\pm}$1.40 with DEC method than 12.0${\pm}$0.44 with conventional embryo collection method, respectively (p<0.05). Also, The average number of transferable embryos were significantly higher (p<0.05) as 15.8${\pm}$1.72 with DEC method than 6.9${\pm}$0.35 from conventional embryo recovery procedures. Meanwhile, number of recovered embryos and number of recovered transferable embryos following the number of flushing times until 6${dr}$ flushing were significantly higher as 8.6${\pm}$0.53 and 8.6${\pm}$0.53 from 2$^{nd}$ flushing time than other groups (p<0.05). No. of Ear. B stage embryos were significantly higher as 3.9${\pm}$0.90 and 3.9${\pm}$0.90 with 2$^{nd}$ flushing time in total collected embryos and transferable embryos (p<0.05). Com M stage embryos were significantly higher as 3.7${\pm}$1.00 in 2$^{nd}$ flushing time and as 2.2${\pm}$0.76 in 3$^{rd}$ flushing time for recovered embryos (p<0.05). In transferable embryos, Com. M stage embryos were significantly higher (p<0.05) as 3.7${\pm}$1.00 in 2$^{nd}$ flushing time and as 2.2${\pm}$0.76 in 34$^{dr}$ flushing time, also. No. of degradation embryos was significantly higher as 2.2${\pm}$0.72 in 5${rd}$ flushing time, On the other hand, degradation embryos was not observed in transferable embryos (p<0.05). In conclusion, these results suggest that DEC method should effective methods for production of in vivo embryos using less flushing solution following perform until 4$^{rd}$ flushing time than conventional embryo collecting method. Also, it might be effectively collection of transferable embryos following more less procedure times compared to conventional embryo recovery methods.

• 대한약침학회지
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• 제12권4호
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• pp.89-96
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• 2009

목적:이 연구의 목적은 유산균발효애엽 물추출물이 에탄올 등으로 약화된 마우스 대식세포의 NO 생성에 미치는 영향을 조사하는 것이다. 방법:애엽을 유산균으로 발효시켜 시료(AFL)를 만들고 만들어진 시료를 10, 50, 100, 200, 400 ug/mL의 농도로 에탄올, 갈릭산, 아세트아미노펜, 아세트알데히드, 니코틴과 함께 24시간동안 마우스 대식세포에 처리한 후 세포배양액을 채취, NO 생성정도를 측정하여 비교하였다. 결과:1. AFL은 400 ug/mL의 농도에서 갈릭산에 의한 마우스 대식세포의 NO생성억제를 유의하게 회복시켰다. 2. AFL은 200, 400 ug/mL의 농도에서 에탄올에 의한 마우스 대식세포의 NO생성억제를 유의하게 회복시켰다. 3. AFL은 400 ug/mL의 농도에서 니코틴에 의한 마우스 대식세포의 NO생성억제를 유의하게 회복시켰다. 4. AFL은 200, 400 ug/mL의 농도에서 아세트아미노펜에 의한 마우스 대식세포의 NO생성억제를 유의하게 회복시켰다. 5. AFL은 200, 400 ug/mL의 농도에서 아세트알데히드에 의한 마우스 대식세포의 NO생성억제를 유의하게 회복시켰다. 결론:유산균발효애엽추출물(AFL)은 에탄올, 갈릭산, 니코틴, 아세트알데히드, 아세트아미노펜 등에 의해 약화된 대식세포의 NO생성을 회복시킴으로서 다양한 독성물질에 의하여 약화되는 식세포의 항병능력을 회복시키는 면역강화물질로 개발될 수 있을 것이다.

• 동의신경정신과학회지
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• 제7권1호
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• pp.1-13
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• 1996

1. Out of 21 examples on a clinical base Alzheimer type dementia were 8 examples(38%), 11 vascular types(52%), 1 Alzheimer and vascular mixed type and rest 1 was secondary dementia type(NPH).2. Between the genders, there were 5 males and 3 females for Alzheimer types, 6 males and 5 females for the vascular types, 1 male for Alzheimer and vascular mixed type, and 1 female for secondary dementia type(NPH).3. For the degrees of Alzheimer type dementia there were 2 mild dementia, 4 moderate dementia, and 2 severe dementia. 4. Among the Alzheimer types 2 mild dementia were almost recovered back to normal in approximately 2 months, 2of 4 moderate dementia became significantly better in approximately 2 months and recovered to almost normal state in 3 to 5 months. The rest 2 have been under treatment for 3 months, but showed a little improvement. Out of 2 severe dementia examples, one showed a little improvement even if it has been under treatment over 2 years. The other example did not show any improvement, but dementia did not proceed any more.5. Among the 11 vascular examples, 7 recovered in 2 to 3 months, 1 in 5 months, 2 recovered in a year, and the treatment was stopped arbitrary for the last one.6 In the case of Alzheimer and vascular mixed type dementia, even the moderate dementia did not show any apparent result in 6 months.7. For NPHI (Normal Pressure Hydrocephalus), there was an improvement on dementia in 2 months after the treatment, but gait disturbance and urinary incontinence did not show any noticeable difference. As a conclusion, almost all the Alzheimer and vascular type patients recovered, but the treatment periods varied depending on the types of the dementia and the degree of seriousness, especially in the case of the severe Alzheimer patients, the treatment oniy suppression the progression of the dementia. The most important aspect from clinical point of view was even if almost all the patients were almost completely cired, they need to keep being cured for a long period of time. The method with respect to Four Constitutions is thought of the most desirable.

• 대한약리학회지
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• 제14권1_2호
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• pp.47-54
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• 1978

Recently, a major resection of the pancreas has been carried out not only to treat carcinoma of pancreas but also chronic pancreatitis. But limited and often contradictory reports have been made on the exocrine effects after partial surgical pancreatectomy in mammals. It was suggested that the growth of the residual tissue in pancreatectomized rat is very active, because pancreas has the great power of regeneration after partial pancreatectomy, while others observed that rat pancreas after partial surgical resection revealed a perplexing mixture of atrophy and regeneration of acinar tissue. On the other hand, another results showed that the amount of insulin required to control diabetes after partial resection of pancreas is much greater than that needed after total pancreatectomy. Because the anti-insulin system, such as glucagon secretion and hypophyseoadrenal function, is probably depressed after total pancreatectomy. Furthermore, minimal resection line which will not influence the normal function of pancreas is not agreeable, such 75%, 80% or 95% resection of the total pancreas in rat. So far, studies on the exocrine function other than endocrine function after partial pancreatectomy have been limited. Therefore, the main purpose of this study is to examine the changes of exocrine as well as endocrine function of pancreas at the different time interval after 60% or 80% pancreatectomy in rats. The results summerized as follow: 1) In both 60% and 80% resected groups, a slight decrease of the total body weight was observed at a day after partial pancreatectomy in rats, but the body weight was continued to increase for following 100 days. 2) The weight of residual pancreas was continuously increased during experiment in both 60% and 80% resected groups. But the content of tissue protein in residual pancreas was significantly decreased comparing with those of resected pancreas. 3) The flow rate of pancreatico-biliary juice was significantly decreased immediately after pancreatectomy in both resected groups. But it was recovered to control level after a day in 60% resected group, after 30 days in 80% resected group. 4) The output of amylase and lipase in resected groups were significantly decreased right after pancreatectomy comparing with control group. In the 60% resected group, the output of amylase was recovered during the following 100 days after pancreatectomy, while lipase output in 3 days. However, in the 80% resected group, the output of amylase and lipase were not recovered during 100 days after pancreatectomy. 5) In order to examine the endocrine function, blood sugar level were examined at all experimental periods after partial pancreatectomy. There was no difference between control and 60% resected group in the sugar level. But in the 80% resected group the level was significantly incresed immediately after pancreatectomy, and reached the highest level at 3 days. Then it was decreased to control level during the next 10 days after pancreatectomy. The above results showed that in 60% resected group little changes were observed on pancreatic function, but severe functional impairments were observed in 80% resected group. This results suggested that the endocrine function was recovered within a short period, although the exocrine function was not recovered for a long time after 80% pancreatectomy in rats.

• 말소리와 음성과학
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• 제13권4호
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• pp.101-114
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• 2021

본 연구의 목적은 말더듬의 지속과 회복에 따른 하위유형의 기질 특성을 종단적으로 비교하고, 외현적 말더듬 중증도와 기질 특성의 관련성을 살피는 것이었다. 연구 참여자는 학령전 아동으로 41명의 말더듬 아동(CWS, children who stutter)과 30명의 말을 더듬지 않는 아동(CWNS, children who do not stutter)이었다. 아동들은 4년간 종단연구에 참여하였으며, 마지막 평가에 참여하였을 때 전체 CWS 중 27명은 말더듬이 회복된 아동으로, 14명은 말더듬이 지속된 아동으로 최종 진단되었다. 각 아동의 기질 특성은 유아기질척도-간편형을 사용하여 평가하였으며, 기질 평가는 첫 평가 이후 1년이 지난 시점과 첫 평가 이후 2년이 지난 시점에서 각각 이루어졌다. 기질 특성 비교를 위해 유아기질척도-간편형의 상위요인(외향성, 부정적 정서, 의도적 통제)과 15개의 하위영역 점수를 분석하였으며, 집단과 평가 시점에 따른 차이를 각각 비교하였다. 연구 결과, 말더듬이 지속된 아동 집단은 말더듬이 회복된 아동 집단과 CWNS보다 상위요인인 부정적 정서 점수가 평가 시점과 관계없이 유의하게 높은 것으로 나타났다. 또한, 말더듬이 지속된 아동 집단은 다른 아동 집단보다 부정적 정서를 구성하는 하위영역인 '공포'와 '분노/좌절' 점수가 유의하게 높았다. 말더듬이 지속된 아동 집단을 대상으로 평가 시점별로 외현적 말더듬 중증도와 기질의 상위요인 및 하위영역 점수 간 상관분석을 실시한 결과, 외현적 말더듬 중증도와 기질 특성은 유의한 상관을 보이지 않았다. 본 연구결과는 기질 특성이 말더듬의 지속 및 회복과 관련 있는 요인이라는 이론적 관점을 지지하며, 시간이 지남에 따라 기질이 말더듬으로 인한 반복적인 경험의 영향을 받을 수 있음을 시사한다.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.123-133
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• 1971

The author is the first man who tried to use an anesthetic on insect specially for silkworm in orde to evaluate the silkworm health and silk yielding ability and the obtained results are as followings. 1. The necessary ether vapor induction for narcosis on silkworms is varied by the glowth of the silkworm which the larger worm is, the longer induction is required. For instance, it was 2∼3 minutes for the worms of third day fifth instar silkworm in case use of ether anesthetic. 2. The longer anesthetic induction for silkworms, the longer recovery needs from anesthesia. In case five minutes ether vapor induction, silkworms recovered narcosis during in 5∼130 minutes which had varied very much by the health variation. 3. The ether induction caused silkworm to vomit digestive juice from a few per cent of the worms, but the chloroform induction showed majority of the worms to vomit the digestive juice out of mouth. So, the ether was found as better anesthetic for silkworms. 4. When ether induction last more than 20∼30 minutes, the recovered silkworms can eat mulberry, but when it gets more than three hours they can not eat mulberry. And when it last more than ten minutes, the silkworm may eat mulberry leaf, but they can not spinn cocoon properly. 5. In case five minutes ether induction for silkworms on third day fifth instar, the stronger variety is, the rallier recovered from narcosis. 6. The recovering duration from narcosis varies regarding with each worm health which shows Poisson′s distribution even in a same variety silkworm. 7. The female worms recover from narcosis earlier than male worms which means the female worm is stronger than male one. 8. The later recovered silkworm from narcosis spinned more rich cocoon silk and ended with smaller pupae weight. Such a tendency showed until at some recovery duration, then the silk yield droped down on the worms recovered in more longer duration. The author (Choe) had named such a relation curve as "Silk Yield Curve against Silkworm Health." 9. The silk yield or cocoon layer ratio had varied from 13 to 27% even in a same worm varity cocoon which showed serious variation and call attention carefulness for the duplication work of a variety silkworm eggs. 10. Not always the rich silk yielding worm is the best worm during the silkworm selection and it should be considered with the silkworm health evaluation. 11. At present situation, only specific breeding expert is allowed to join in the selection service because of need many years experience by use of visual observation, but the ether anesthesia method may help such an evaluation with more accuracy and easy way even for the people in fresh on the field. 12. The effect of the narcosis on the silkworm for the next generation or hybrid worm will be reported in next publication.