• 한국압력기기공학회 논문집
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• 제7권2호
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• pp.7-13
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• 2011

Turbine journal bearings are designed to support the weight of the rotors on a hydrodynamic oil film and to provide dynamic stability to the rotor system. The life time of journal bearings is infinite theoretically because the journal bearings are separated from the shaft journal by oil film. But poor design, assembly, operation and maintenance can cause problems to the journal bearings. The FMEA(Failure Mode and Effects Analysis) results of the journal bearings show that frequent maintenance of the journal bearings can cause failures and reduction of the bearing life. Therefore, the maintenance periods and history of the journal bearings with the bearing FMEA results are reviewed in order to establish the optimized maintenance period of the journal bearing for the nuclear power plants. Consequently it is necessary to maintain a best condition of lubrication system, reject time-based maintenance and perform the condition-based maintenance of journal bearings in order to maintain optimum condition of the journal bearing.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.116-123
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• 1999

A case of the axle gear box which was one of tile power transmission components of high speed train was supported by the bearings installed in axle and the reaction arm connected in bogie frame. Structural analyses of this case were executed for investigation the application of aluminum for weight reduction. The evaluations of the material strength, the thermal strength and deformation, and the stability of natural vibration were carried out according to computer simulation. It was found out that the steel case was safe from the structural failure. For the aluminum case, there was no worry about the vibration resonance and the static failure, but some efforts to reduce tile deformation of the bearing mounting part.

• Korean Journal of Acupuncture
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• 제30권4호
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• pp.298-304
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• 2013

목적 : Carrageenan(CA)으로 유발시킨 슬관절염 동물 모델에서 족삼리와 대릉을 배오한 전침의 효과를 알아보기 위해 실험을 수행하였다. 두 개 이상의 경혈에 동시에 자침함으로써 상승작용을 일으키는 연구는 많이 보고되었으나, 본 연구에서는 배합한 경혈(족삼리와 대릉)에 의한 전침 진통 작용의 감쇄 효과가 발생할 수 있는지에 대해 알아보고자 하였다. 방법 : CA을 흰쥐의 슬관절강 내에 주입하여 염증성 통증을 유발시켰다. 실험동물을 임의로 4군으로 배정하였다; PC7 군: 양쪽 상지 대릉 전침 군, ST36 군: 양쪽 하지 족삼리 전침 군, ST36+PC7 군: 양쪽 상지 대릉과 양쪽 하지 족삼리 전침 군, CON: 무처치군. 통증 정도를 측정하기 위해서 weight bearing force의 변화를 측정하였고, 척수의 후각에 유도된 COX-2 발현을 측정하기 위해 면역조직화학법과 western blot 분석을 실시하였다. 결과 : ST36+PC7군은 ST36군과 비교하여, 행동실험에서는 weight bearing force가 유의하게 감소하였고, 면역조직화학법과 western blot 분석에서는 COX-2 발현이 상대적으로 유의하게 증가하였다. 결론 : 이상의 실험결과를 통하여 족삼리와 대릉을 배오한 전침 자극은 슬관절염 모델에서 족삼리 전침의 진통 효과를 감소시킴을 알 수 있었다.

• 대한기계학회논문집
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• 제10권3호
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• pp.298-304
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• 1986

본 연구에서는 첨가할 고분자로서 윤활유에 일반적으로 점도지수 향상제로 사용되는 PIB(polyisobutylene)를 사용하여, 되도록 실제 베어링에 가까운 조건에서 Toms효과에 대해 알아 본다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.384-387
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• 2006

Recently, the method of the apartment building design has been changed from wall type structures to moment structures. With like this reason, dry walls we used plentifully. Especially, the gypsum board was used from previously plentifully however the weak point of it is difficult to maintain because it weak strength. For the improvement of gypsum board, light weight concrete panel using cement board is used recently. As this study is the research of the series t on the development of non-bearing light weight concrete panel using bottom ash, the purpose of this study is to obtain basic data for application in the field. The results are that the structure 1 satisfies domestic standard concerned with sound insulation between households at the laboratory and field test.

• Geomechanics and Engineering
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• 제31권4호
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• pp.385-393
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• 2022

Previous studies postulated insignificant capillary rise (h_c) effect above the water table (H_w) for unsaturated soils. In addition, these studies utilised dry unit weight above H_w. This paper, therefore, addresses the effect of these postulations on strength where the influence of h_c using a modified upper bound approach, Discontinuity Layout Optimization (UNSAT-DLO) for a simulated soil was predicted. Two different parametric studies to model passive earth pressure and bearing capacity problems are carried out to provide an insight into the effect of capillary rise on strength. Significant increase in strength, owing to unsaturated conditions, was obtained where the maximum increase was when suction slightly less or greater than the air entry suction. On the other hand, the results showed a negative effect of h_c. For example, up to 8.24% decrease in passive thrust (P_p) was obtained at H_w=0 m when h_c rose 1 m from 0 m. To put this into perspective, this was equivalent to a decrease of about 2° in 𝜙 at H_w=0 m and h_c =0 m in order to obtain the same result at h_c =1 m. For the bearing capacity problem, the effect was seen to be higher, up to 18.4% decrease in N_𝛾 was obtained when h_c rose from 0 m to 2.5 m at H_w =0 m. In addition, the results revealed a negative influence of assigning dry unit weight above H_w or h_c.. However, considerable increase in strength was obtained when unsaturated unit weight above h_c was assigned.

• 한국잡초학회지
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• 제7권1호
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• pp.52-57
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• 1987

To know the effects of weeding periods (weeding from 12 days, 28 days and 42 days after seeding to harvest, and weeding from seeding to 14 days, 28 days and 42 days after seeding) and growing conditions such as transparent polyethylene film mulch (P.E. mulch) and bare soil on growth and yield of peanuts, "Yeongho-Tangkong" was planted on May 10, 1984. Under P.E. mulch, the number of weeds was higher, but the weed dry weight was lower than in bare soil by the middle of July. Sixty days after seedings, the length of main stems in weedy check plots was longer, but shoot dry weight was lower compared to weed free plot. In the correlation coefficients between weed dry weight and the shoot dry weight of peanut on July 14, the growth retardation of peanuts due to weeds was showed earlier under P.E. mulch than in bare soil. Shoot dry weight, shelling ratio, number of seeds per pod, 100 pod weight, and seed yield were higher under P.E, mulch compared to bare soil. But weed dry weight, length of branches, number of pod bearing branches, number of pods per square meters, and pod yield were similar between P.E. mulch and bare soil. Shoot dry weight of peanuts, length of branches, number of pod bearing branches, number of pods per square meters, pod yield, 100 pod weight, 100 seed weight, and seed yield in weed free plots from 28 days after seeding to harvest (28 DAS-Harvest) were higher compared to weed free plots from 42 DAS-Harvest. However, in the weed free plot from seeding to 42 days after seeding seed yield was lower than that of the continuous weeding plot due to lower number of pod bearing branches and number of pods per square meters. When weed was not controlled at the later growth stages of peanuts, reduction in seed yield due to weeds was greater in bare soil than that under P.E. mulch.

• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.81-86
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• 1996

This study was performed to evaluate the reduction in bending properties of radiata pine sapwood associated with incipient brown-rot decay. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested destructively. Brown-rot decay by T. palustris and G. trabeum caused serious reduction in bending properties at very early stages of decay, with about 30 percent decrease in bending strength observed for only 1~2 percent weight loss. In general, the reduction in bending properties caused by T. palustris was somewhat greater than that by G. trabeum. Work to maximum load was reduced most severely and rapidly from the onset of decay, while modulus of elasticity showed a much more moderate rate of reduction. Modulus of rupture was affected by decay to a greater extent than was modulus of elasticity. Since a relatively strong correlation between weight loss and bending strength was observed, the residual strength of decayed wood can be predicted by weight loss due to decay. The results of this study indicate that very early stages of brown-rot decay reduce the bending strength significantly. Thus, it is recommended that all load-bearing members in wooden structures, especially those that are periodically wetted, should be inspected regularly to prevent a sudden failure even though there are no definite signs of decay.

• 한국임상수의학회지
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• 제16권1호
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• pp.230-234
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• 1999

Canine medial patellar luxation can cause hindlimb lameness in toy breeds and surgical operation needs when the lameness does not improve or worsen. In this study, the 2 dogs that showed postoperative non-weight bearing lameness were treated with electroacupuncture (EA) and the effects of postoperative EA were examined. Xue Hai (Sea of Blood), Du Bi (calf's nose, 2 acupoint), Zu San Li (leg 3 miles) acupoints were used in acupuncture. Xue Hai acupoint was connected to positive pole and Zu San Li was negative for 20 min with 2~5 volt, 5~30 Hz in EA. In case 1, EA were performed eight times for 26 days after 29th postoperative day and walking was improved from 6th EA. In case 2, EA were conducted five times for 17 day after 26th postoperative day and walking was improved from 4th EA. It may be possible to improve walking by EA treatment in the dogs that show post-operative non-weight bearing lameness, but the relationship between the effects of EA and the injury of stifle joint should be inspected.

• 한국임상수의학회지
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• 제21권4호
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• pp.406-408
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• 2004

A nine-month-old male Jindo with non weight-bearing on the right forelimb in flexed position, pain and edema of the elbow, and resist elbow extension was brought to the Veterinary Teaching Hospital, Chungbuk National University. Elbow radiographs showed loss of humeroradial joint space and lateral displacement of the radius and ulna. Closed reduction was reported the best therapy in most cases of luxation of the elbow but conservative reduction was impossible. Open reduction of the luxated elbow was performed and ruptured collateral ligaments were identified. Displaced elbow was required bloody surgical operation and gentle reduction to restore elbow joint. Internal reduction of choice for elbow luxation with rupture of collateral ligament in the dog was a double locking-loop suture pattern. To ensure secure grasping of parallel bundles of ligament fibers to transverse bites of each suture were placed superficial to the longitudinal bites. All ligaments were repaired with 3-metric (size 2 USP) monofilament polypropylene suture. No complications have been noted during a five-month follow up.