• E2M - 전기 전자와 첨단 소재
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• 제10권6호
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• pp.519-527
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• 1997

The micro crack was occurred where the stress concentrated by the thermal stress which was induced during the cooling period after molding process or by the various reliability tests. In order to estimate the possibility of development from inside micro crack to outside fracture, the fracture toughness of EMC should be measured under the various applicable condition. But study was conducted very rarely for the above area. In order to provide a was to decide the fracture resistance of EMC (Epoxy Molding Compound) of plastic package which is produced by using transfer molding method, measuring fracture is studied. The specimens were made with various EMC material. The diverse combination of test conditions, such as different temperature, temperature /humidity conditions, different filler shapes, and post cure treatment, were tried to examine the effects of environmental condition on the fracture toughness. This study proposed a way which could improve the reliability of LOC(Lead On Chip) type package by comparing the measured $J_{IC}$ of EMC and the calculated J-integral value from FEM(Finite Element Method). The measured $K_{IC}$ value of EMC above glass transition temperature dropped sharply as the temperature increased. The $K_{IC}$ was observed to be higher before the post cure treatment than after the post cure treatment. The change of $J_{IC}$ was significant by time change. J-integral was calculated to have maximum value the angle of the direction of fracture at the lead tip was 0 degree in SOJ package and -30 degree in TSOP package. The results FEM simulation were well agreed with the results of measurement within 5% tolerance. The package crack was proved to be affected more by the structure than by the composing material of package. The structure and the composing material are the variables to reduce the package crack.ack.

• 한국물환경학회지
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• 제27권1호
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• pp.54-60
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• 2011

To evaluate the feasibility of electrodialysis for copper removal from industrial wastewater, the effect of operating parameters on the removal of copper was experimentally estimated. The limiting current density (LCD) linearly increased with the copper concentration and the flow rate. The time when the copper concentration of diluate reaches to 3 mg/L was linearly proportional to initial concentration of diluate, and the concentration of concentrate did not affect the removal rate. Increase in the flow rate gave a positive effect on the removal rate and became insignificant at flow rates greater than 2.4 L/min. The removal rate increased with the applied voltage. From the operation of the electrodialysis module used in this research, the flow rate of 2.4 L/min and the voltage corresponding to the 80~90% of LCD were found be the optimum operating condition for the copper removal from highly concentrated copper solutions.

• 열처리공학회지
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• 제22권1호
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• pp.16-22
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• 2009

The rolling process is an efficient and economical approach for the manufacturing of plate metals. In the rolling process, the temperature variation is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. Also the exit plate thickness is mainly affected by the rolling conditions such as mill modulus, plate thickness and plate width. Hence the thickness variation in top-end is also dependent on these factors. Therefore this study has concentrated on determining the correct amounts of thickness variation due to top-end temperature drop and process parameters.

• 한국물환경학회지
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• 제31권3호
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• pp.253-261
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• 2015

The purpose of this study is the efficient biological treatment of highly concentrated nitrate nitrogen by calcium ion control present within the pickling wastewater. In laboratory scale's experiments research was performed using a sequencing batch reactor and the evaluation of denitrification reaction in accordance with the injection condition of calcium ions, the surface properties of microorganisms, and the evaluation of sludge precipitability were performed. Results of the study showed that the denitrification reaction was delayed when injecting more than 600 mg/L of the calcium ion within the denitrification process. In addition, we observed the absorption form of calcium ions absorbed on the surface of microorganisms following an increase in the calcium ion dose. It was found that as the calcium ion dose increased the sludge precipitability also increased continuously and it is judged that a smooth denitrification induction is possible when treating the nitrate nitrogen by the calcium ion control of pickling waste water and the shortening of precipitation time enables a liquid operation to increase the reaction time.

• 대한환경공학회지
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• 제31권10호
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• pp.855-864
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• 2009

본 연구에서는 질산화 반응이 활발히 진행되고 있는 기존 하수처리장 슬러지를 이용하여 3개월 이상 농축 배양한 후에 부착 및 부유성장 상태로 적응시킨 질화균을 이용하여 독성물질에 대한 영향을 조사하였다. 본 실험의 목적은 부유 및 부착성장 질화균을 이용하여 이들의 비표면적에 따른 독성물질의 영향을 상호비교하기 위한 것이다. 이를 위하여 부유 및 부착상태의 농축 질화균의 비표면적을 다르게 하여 각각에 대한 독성물질의 영향을 조사하였다. 연구 결과 부착성장 질화균 및 부유성장 질화균의 경우 비표면적이 클수록 독성에 대한 영향을 더 많이 받는 것으로 나타났다. 부착상태와 탈착상태의 질화균을 사용한 실험에서, 독성물질에 대한 영향은 탈착상태보다 부착상태에서 독성의 영향을 적게 받았으며, Nitrosomonas의 경우에는 1.12배, Nitrobacter의 경우에는 1.09배 독성의 영향을 적게 받았다. 부유성장 질화균을 사용한 경우에는 분쇄 전보다 분쇄 후에 독성의 영향을 더 크게 받았으며, Nitrosomonas의 경우에 1.46배, Nitrobacter의 경우에 1.35배 독성의 영향을 적게 받았다. 또한, 기질에 아질산염을 주입하지 않고 실험한 결과에서도 유사한 결과를 얻었다. 부착상태와 탈착상태의 질화균을 사용한 실험에서, 독성물질에 대한 영향은 탈착상태보다 부착상태에서 독성의 영향을 적게 받았으며, Nitrosomonas의 경우에는 1.83배, Nitrobacter의 경우에는 1.78배 독성의 영향을 적게 받았다. 부유성장 질화균을 사용한 경우에는 분쇄 전보다 분쇄 후에 독성의 영향을 더 크게 받았으며, Nitrosomonas의 경우에 1.27배, Nitrobacter의 경우에 1.32배 독성의 영향을 적게 받았다.

• 생물환경조절학회지
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• 제16권4호
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• pp.333-337
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• 2007

토양수분 조건 및 송풍처리가 참외 발효과 발생에 미치는 영향을 검토한 결과는 다음과 같다. 토양수분이 과다한 조건(-10kPa)에서 뿌리로부터 수분흡수는 많고 저온다습의 기상조건으로 증산이 억제될 때 흡수된 수분이 삼투압이 낮은 과실부위 특히 당 농도가 높은 태좌부로 이동하여 물찬 참외가 발생하는 것으로 생각된다. 참외 발효과는 신토좌, 엘리트 등 세력이 강한 대목에서 많이 발생하고 세력이 약한 홍토좌 대목에서는 적게 발생하고 자근묘에서는 발생하지 않았다. 과실부위 송풍처리로 신토좌, 엘리트, 홍토좌, 자근묘 등 대목의 종류와 관계없이 발효과가 발생하지 않았다. 과육 및 태좌부의 칼슘함량은 무처리구에 비하여 송풍처리구에서 유의하게 높았으며 acetaldehyde, ethanol, ethylacetate 등 발효산물의 함량도 적었다.

• Journal of Acupuncture Research
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• 제20권5호
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• pp.151-158
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• 2003

Objective: There have not been so many study about the quality of acupuncture needle tip. In order to ensure safe acupuncture treatment, the quality of needle tip is essential. Therefore we investigated the current condition of the tip of the acupuncture needles in Korea. Methods: We have selected the needles that made by 8 companies in Korea, and selected 50 pieces from 1000 pieces each company by randomized methods. and observed the tip of each needle using a scanning electron microscope at ${\times}800$ magnification. Results & Discussion: We found that needles had several defects such as scratch marks on the surface, metallic scuff, lumps and irregularities of the needle tips, stubbed or malformed tips, tips of point off-center, peeled off coated tips. There was much difference on the quality of needle among the manufacturer, and some needles seem to need to do- thorough quality control. It is necessary to intensify quality management and a concentrated control on manufacturing process of acupuncture needles.

• Childhood Kidney Diseases
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• 제17권2호
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• pp.29-34
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• 2013

Urine production is vital for the removal of certain waste products produced by metabolism in the body and for the maintenance of homeostasis in the body. The kidneys produce urine by the following three precisely regulated processes: filtration, reabsorption, and secretion. Urine is composed of water, certain electrolytes, and various waste products that are filtered out of the blood through the glomeruli. The physical features of urine are evaluated carefully to detect any abnormal findings that may indicate underlying diseases in the genitourinary system. A change in urine color may indicate an underlying pathological condition, although many of the causes of abnormal urine color are benign effects of medications and foods. A characteristic and specific odor may be the result of a metabolic disease rather than a concentrated specimen or a simple urinary tract infection. Although transient changes in urine output and nocturia are usually benign conditions, persistent abnormal findings require further workup, with a thorough medical history taking. This article presents many of the conditions that physicians may encounter and will help them in the diagnosis and in establishing a treatment plan.

• Structural Engineering and Mechanics
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• 제83권4호
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• pp.451-463
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• 2022

The present study deals with forced vibrations of an elastic circular plate supported along its circular edge by unilateral elastic springs. The plate is assumed to be subjected to a uniformly distributed and a concentrated load. Under the combination of these loads, equations of motion are explicitly derived for static and dynamic response analyses by assuming a series of the displacement functions of time and other unknown parameters which are to be determined by employing Lagrangian functional. The approximate solution is sought by applying the Lagrange equations of motions by using the potential energy of the external forces that includes the contributions of the edge forces and the external moments, i.e., those of the effects of the boundary condition to the analysis. For the numerical treatment of the problem in the time domain, the linear acceleration procedure is adopted. The tensionless character of the support is taken into account by using an iterative process and, the coordinate functions for the displacement field are selected to partially fulfill the boundary conditions so that an acceptable approximation can be achieved faster. Numerical results are presented in the figures focusing on the nonlinearity of the problem due to the plate lift-off from the unilateral springs at the edge support.

• 한국수정란이식학회지
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• 제1권1호
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• pp.35-49
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• 1986

Recipients are an integral part of embryo transfer and they are expensive to maintain as a good recipient. Recipient management is one of the most important components in a successful embryo transfer program. Management includes selection and subsequent care of the animals. A good recipient is basically on "open" cows or heffers whose reproductive tract is capable of receiving one or two embryos and incubating it to term. Potential recipients should be always be healthy and cycling normally ranging from 18 to 23 days. A thorough veterinary examination is recommended for candidate of recipients and cattle for questionable health should be eliminated from the recipient herd. Age and size of recipients are particularly important considerations when heifers are used, because of most embryos available for transfer are from large dams and sires. Body condition can influence a recipient's production, reproduction and health. Obese and underconditioned cattle should be avoided for use. Transfer of fresh embryos especially requires precise synchronization of donors and recipients. For estrus synchronization, PGF$_2$$\alpha$ is injected twice 10 to 12 days apart and short4erm progestagen treatment is applied to potential recipient cattle by coil into vagina (PRID) or ear implant (Synchro-Mate-B). The highest pregnancy results are achieved in recipients at exact synchrony with donors or 12 to 24 hr earlier than donors. Estrus detection is a major factor in breeding efficiency. High accuracy can be achieved by use of heat mount detection alds or by obserbing cattle for 30-minute peroids 3 times daily. Assay progesterone in milk can be used to discrIminate between pregnant and nonprenant recipients. Rectal palpation on day 35 to 70 after is an accurate and safe method of pregnancy diagnosis. Embryonic mortality in recipients may be associated with factors such as high environmental temperature and nutritional or lactational stress in early lactation period. Achievement of short calving interval requires concentrated management activity during the first 90 days following calving. Acceptable candidate for a recipient should be routinely vaccinated for infectious diseases. Proper nutritional programs according to NRC requirements and body condition scoring system for recipient cattles are vital to the ultimate success of an embryo transfer program.r program.