• 펄프종이기술
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• 제33권2호
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• pp.58-67
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• 2001

MOW (Mixed Office Waste) mainly consisted of photocopied paper is being recycled to produce tissue or fine paper products. Toner particles that are fused and set on paper surface in photocopying process turns into large and plate-shaped particles after repulping which prevents them to be removed effectively in flotation deinking. The immediate purpose of this study is to find the effective deinking technology that increases the recycling potential of photocopied papers for manufacturing tissue and fine paper products. In this study the effects of pulping temperature and the type of hydrophobic groups of nonionic surfactants on the deinking efficiency of photocopied paper has been investigated. Particle size distribution of the toner particles after pulping and flotation, brightness, yield and ash removal were investigated. The size of toner particles after pulping increased as the pulping temperature was increased. When pulping at the low temperature finer toner particles were generated, however, greater amount of toner particles was found to attach to the fiber. When the pulping temperature was greater than Tg of the toner, the amount of coarse hairy particles increased. When nonionic surfactants with a double bond in hydrophobic groups were used, toner removal efficiency, brightness and ash removal were increased. As the addition level of surfactant was increased, yield decreased rather sharply without improving brightness.

• 펄프종이기술
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• 제40권4호
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• pp.51-58
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• 2008

This paper presents the effect of acid treatment on the removal of metals and the brightness of pulp. The bleached kraft pulps, metal-absorbed pulps and recycled pulps((ONP, OCC, MOW, and SC) were treated with the acidic solutions. Among metals in the bleached kraft pulps, Cu, Ca and Mg were removed easily by the acid washing, whereas Fe, Al and Si were not removed. The acid washing also removed distinctly metals from the metal-absorbed pulps. The metals absorbed in pulps reduced the brightness (%, ISO). Especially, Fe was the most detrimental metal. However, the brightness which was decreased by metals was restored to the status quo by the acid washing. The level of metals in recycled pulps was gradually reduced after the first flotation and acid treatment. Hence, the degree of metal removal by the acid washing was mainly dependent upon the kinds of waste pulps and metal ions.

• 대한의용생체공학회:의공학회지
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• 제22권4호
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• pp.349-358
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• 2001

A novel electro-mechanical implantable ventricular assist system is developed as a bridge to transplantation or recovery for patients with end-stage heart failure. The developed system is composed of an implanted blood pump, an external monitoring system which stores data, and a wearable system including a portable external driver and a portable power supply system. The blood pump is designed to be implanted into the left upper abdominal space and provides blood flow from the left ventricular apex to the aorta. The pulsatile blood flow is generated by a double cylindrical cam. There was mo excessive heat emission from the blood pump into the temperature-controlled chamber in the heat test and no stagnated flow within the blood sac by the observation in the flow visualization test. Animal experiments were performed using sheep and calves. The maximum assist flow rate reached 7.85L/min in the animal experiment. The evaluation results showed that the developed system was feasible for the implantable ventricular assist system. The long-term in vitro durability test and mid-term in vivo experiments are in progress and mow the modified next model is under development.

• 펄프종이기술
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• 제39권1호
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• pp.30-37
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• 2007

The seed paper was used in farm field recently for a sound young plant. The most of seed paper are made of synthetic non-woven sheet. Therefore, it is very difficult to bio-degrade in soil and is very hard to have some special function, for example keeping herbicide and/or insecticide activity because of its lack of chemical acceptability. The purpose of this research is manufacture of seedling paper which have a function of herbicide activity from waste paper. The fiber properties from waste paper were remarkably improved by fine removal with washing and/or flotation process. The paper-making ability for seed paper was enhanced with enzyme treatment of secondary fibers. The paper for seedling must have a good bio-degradation ability in soils. The absorption amount of chemical like as dithiopyr was increased remarkably in enzyme treated base paper. The embossing treatment of base paper was very effective for seed attachment and chemicals retention. And also, the developed seed paper showed a good penetration property of young root through embossed paper.

• 지질공학
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• 제14권3호
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• pp.287-300
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• 2004

Visual Modflow를 이용하여 터널 굴착 시 터널 내 지하수 유입 량과 영항반경에 영향을 미치는 수리 인자들에 대한 민감도 분석을 수행하였다. 터널의 심도 및 수리전도도의 민감도가 가장 크게 나타났으며, 굴착 후 경과 시간에 따라 민감도의 순위가 달라지는 것으로 분석되었다. 비산출률의 경우 굴착 후 시간이 경과함에 따라 민감도가 지속적으로 증가하는 것으로 나타나 배수형 터널 설계 시 수리전도도와 함께 중요하게 고려되어야 할 변수인 것으로 밝혀졌다. 터널굴착 및 방수 처리 과정을 모사할 수 있는 부정류 모델링 기법을 제시하였으며, 실제 터널 설계 지역에 적용하여 굴착과정에서 발생하는 터널 내 지하수 유입량 주변 지역 지하수계의 변화를 예측하였다. 예측 모델의 결과는 모델 보정을 통하여 설정한 수리 전도도에 매우 민감하므로, 사후 모니터 링을 통한 모델 검증이 요구된다.

• 수산해양기술연구
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• 제23권1호
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• pp.30-38
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• 1987

좁은 틈새를 가진 원판밸브의 추력에 대한 이론적 해석 및 실험 결과로부터 다음과 같이 요약할 수 있다. 1. 원판 밸브의 틈새가 비교적 작은 경우(H/D sub(1)가 0.1 이하) 즉, 유량이 적을 때에는 점성류가 지배적이고 이론식으로부터 추력을 높게 예측할 수 있었다. 2. 압력의 영향에 대한 추력은 입구 압력이 낮을수록 이론결과와 실험결과가 잘 일치하고 높을수록 관성의 영향이 크게 나타나는 경향을 보였다. 3. 밸브 크기 변화에 대한 추력의 영향은 D sub(2)/D sub(1)=>4.6에서는 포물선적으로 감소하고 그 이하에서는 직선적으로 감소하였다.

• 대한치과기공학회지
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• 제20권1호
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• pp.61-89
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• 1998

Having taken as cause of dental technicians separation from their service a variety of individual idiosyncrasies, function-related factors, external environment factors, functional satisfaction, organizational commitment, and intention to remain, the present study conducted a mail questionnaire poll and interviews on those dental technicians who are mow in the service with private dental technical workshops and dental technical workshops in general hospitals and private dental clinics. The resultant findings from analysis of the repondent's general characteristics of cause of separation form service were revealed, as follows : 1) It was shown that the higher the academic career, the considerably higher cause of position commitment among causes of individual idio-syncrasies, reflecting a statistically significant result(P<0.05) 2) The less the number of working hours as viewed from the average number of working hours per day, the higher the positive emotion, reflecting a significant relation(P<0.01) 3) Causes from performing duties among function-related causes diclosed a statistically significant relation among marital status, career, monthly income, and positions(P<0.01) 4) Causes from wages showed a statistically significant relation in the average number of working hours per day(P<0.01), monthly income(P,0.05), and positions(P<0.05) 5) Causes from supervision exposed a significant relation in workplaces(P<0.01) 6) Causes from promotion represented a significant relation in positions(P<0.001) 7) Causes from opportunnities for taking a job as seen from external environment causes also disclosed a statistically significant relation in workplaces(P<0.05) 8) Reponsibility for family sustenace reflected a statistically significant relation in sex, age, marital status, career, monthly income, work fields, term of employment, positions, and experience of separation(P<0.001) 9) Functional satisfaction showed a statistically significant relation in marital status, career, monthly income, and the average number of hours a day(P<0.05) 10) Oraganizational commitment disclosed a statistically significant relation in work experience, monthly income, term of employment, positions(P<0.05) and the average number of working hours a day(P<0.001) 11) The intention to remain indicated a statistically significant relation in age, marital status, work experience, monthly income, positions(P<0.001) and term of employment. the average number of working hours a day(P<0.01), and in the performing work field(P<0.05)

• 한국환경과학회지
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• 제7권3호
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• pp.335-348
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• 1998

The intensive meteorological observations including pibal balloon at Ungcheon, airsonde and 10m meteorological tower observations at Gulup-Do, where are located In the western coastal region, are taken to Investigate the characteristics of the upper and lower atmospheric structure and the local circulation pattern during the period of 17 to 22 September 1996. The diurnal variations of weather elements(i.e. air temperature, humidity, pressure, and Und speeds at Gulup-Do are analyzed and discussed with those at four inland meteorological stations. The vertical profiles of wind vector, ortho- gonality(Ω), and shear obtained from the pibal obsenrations are also presented to examine the change of wand structure according to the synoptic-scale pressure system's movement. The diurnal temperature changes at Gulup-Do are more sensitive than that of Inland meteorological stations In case of the mow of southwesterlies but are not dominant due to the ocean effect under the Influence of relatively cold northerlies. A well defined mixed layer Is developed from the 500m to the maximum 1700m with a significant capping Inversion layer on the top of it. It can be found from the vertical profiles of wind vector that the wind become generally strong at the interface heights between cloud lay- ers and non-cloud layers. The maximum Und shear Is appeared at the bel각t where the varlauon of wand direction Induced by the passage of synoptic-scale pressure system Is accompanied with the In- crease of Und speed. Based on the wind orthogonality, the change of wind direction with height is more complicated In cloudy day than In clear day. In case of a fair weather, the change of wand direction is showed to be at around 2km.

• 한국유기농업학회지
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• 제25권3호
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• pp.587-602
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• 2017

온난다습 한 기후대의 미국 남부지방에서 2008년에 유기인증을 받은 '엔터프라이즈' 사과나무(Malus${\times}$domestica Borkh.)를 대상으로 수체피해[왜콩풍뎅이(Popillia japonica Newman), 설치류, 고사율, 잡초밀도]에 대한 잎과 토양의 무기성분 및 수체생장과의 상관관계를 분석하였다. 과원은 유기질 멀칭 4종류와 비료 3종류를 복합으로 처리하였고, 멀칭은 초생, 종이, 우드칩, 식물성퇴비를 포함하였고, 비료는 무비료, 계분, 상업용 유기질비료를 매년 4월에 수체 주위에 시용하였다. 수체피해인 설치류와 잡초밀도는 무기성분이나 수체생장과는 별다른 상관관계가 관찰되지 않았다. 왜콩풍뎅이에 의한 잎 피해는 식물성퇴비 멀칭구에서 높았고(26.5%), 고사율은 초생멀칭구에서 가장 높았다. 주당 바이오매스 생산량은 우드칩과 식물성퇴비 멀칭구에서 약 3,700 g으로 나머지 처리보다 2배 이상 높게 나타났다. 상관관계분석을 통한 잎의 왜콩풍뎅이 피해율은 토양과 잎의 무기성분이 증가하면 심해지는 경향을 보였고, 영양생장 지표인 주간 단면적과 강한 정의 상관관계($r^2=0.585$)가 관찰되었다. 수체 고사율은 토양 내 무기성분보다는 수체의 무기성분 함량과 수체생장과 부의 상관관계가 관찰되었다. 이에 미국 남부지방 과원에서 시용된 우드칩은 유기물함량을 증가시키고 유목의 건전성을 확보하는 동시에 토양 내의 풍뎅이류 등의 해충과 설치류의 피해 정도를 최소화할 수 있는 지역 맞춤형 피복자재로 판단되었다.

• Journal of Chest Surgery
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• 제30권3호
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• pp.253-253
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• 1997

가토의 적출폐장보고시험의 모델을 이용하여 폐세척웅액과 폐장보존용액의 온도를 제 1군은 4℃로 제 2군은 10℃로 하여 6시간동안 적출폐장보존후에 재관류시켜 각각의 온도차이에 따른 폐기보존효과를 비교 실험하였으며 각 군은 10례씩으로 하였다. 폐정맥혈액산소분압, 폐포-동맥간 산소분압 차, 폐동 맥압 및 폐혈관저항은제 1군보다제 2군이 재관류동안에 성적이 우수하였으며 기도내압, 폐탄성도및 폐부종의 정도는 두 군간에 통계학적 유의성은 없었다. 결론적으로 가토의 적출폐기 보존온도에 따른 실험에서 10℃의 폐수*용액과 폐기보존온도가 4℃보다 재순환시 폐기능의 회복이 우수하였다.