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A Study on the Performance of Recycled Cells for application to Residential BESS (주택용 BESS에 적용하기 위한 재활용 셀의 성능에 관한 연구)

  • Phil-Jung Kim;Seong-Soo Yang
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.14-19
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    • 2024
  • To determine the performance of recycled cells for application to residential BESS, cells used over the past 5 years were selected. The basic specifications of the cell used in the test are nominal voltage of 3.7[V], nominal capacity of 2,200[mAh], charging voltage of 4.05[V], continuous discharge current of 1[C](2,200[mA]), continuous charging current of 0.5[C](1,100[mA]). For new cells, the internal resistance was 21.3±1[mΩ], but for recycled cells, the average internal resistance was 25.38[mΩ], an increase of about 19.1[%]. The charge·discharge capacity was approximately 18.9~19.3[%] lower than that of a new cell. Because internal resistance and charge·discharge capacity are closely related to cell aging, cells to be applied to BESS need to use products with an initial internal resistance of 1.5 times or less and a charge·discharge capacity performance of 70[%] or more.

A Study on Flow Characteristics around Foot to Investigate Principle of Underwater Exercise for Rheumatoid Arthritis Patients (류마티스 관절염 환자의 수중운동 원리 규명을 위한 발 주위 유동 특성 연구)

  • Choi, Ji-Hyun;Park, Sung-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.403-410
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    • 2021
  • There are positive effects, such as pain reduction, when rheumatism patients exercise in water, but the cause of the pain reduction is unclear, and research on this is inadequate. This study examined the flow of the surface of the foot and the principles of pain relief. Unsteady simulations were conducted to analyze the flow, which was performed by repeatedly setting the movement of the foot raising and descending three times. Pressure fluctuations and frequencies were analyzed by designating pressure points at the painful location. The results showed that a positive and negative pressure of approximately ±500Pa was applied overall. A pressure of approximately ±2000Pa was applied when the direction of movement was changed. A frequency of approximately 35 to 80Hz was generated in the area where rheumatoid arthritis pain frequently occurs. The effects of reducing pain could be predicted when continuous pressure fluctuations and frequencies are applied repeatedly to the painful location, blood circulation promotion. The results could be used as basic data to understand the principles of aquatic exercise and support the development of underwater exercise programs and developing related medical equipment.

Younger Dryas Type Climatic Oscillation in the East Sea

  • Kim, Gil-Young;Kim, Dae-Choul;Shin, Im-Chul
    • Journal of the korean society of oceanography
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    • v.34 no.1
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    • pp.43-48
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    • 1999
  • The latest-Quaternary paleoceanographic history of the Ulleung Basin, the East Sea (the Sea of Japan) is reconstructed on the base of planktonic foraminifera, oxygen and carbon isotopes, and accelerator mass spectrometer radiocarbon (AMS-$^{14}$C) data from two cores. Sinistral populations of Neogloboquadrina pachyderma are dominant during the last glacial period while dextral forms of Neogloboquadrina pachydeyma are abundant in the Holocene. An abrupt increase in ${\delta}^{18}$O values in both cores that began about 11 ka B.P may indicate the Younger Dryas cooling episode. A low-salinity event, marked by light ${\delta}^{18}$O values (0-1 %), is observed before the Younger Dryas event. As previous works suggested, the low-salinity event is probably due to the freshening of surface water caused by fresh water input from Huang Ho river and/or the excess of precipitation over evaporation. The lowest salinity water in the Ulleung Basin was probably continued from approximately 18 ka B.P. to 15 ka B.P. The ${\delta}^{18}$O values have gradually decreased since the Younger Dryas as a result of the continuous inflow of the warm Tsushima Current into the East Sea.

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The variation of elapsed time on fatigue and quality of single rescuer cardiopulmonary resuscitation (시간 경과에 따른 1인 심폐소생술의 질과 피로도의 변화)

  • Jang, Mun-Sun;Tak, Yang-Ju
    • The Korean Journal of Emergency Medical Services
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    • v.17 no.1
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    • pp.9-19
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    • 2013
  • Purpose : The purpose of this study was to investigate the variation of elapsed time in the cardiopulmonary resuscitation (CPR) quality and the fatigue in continuous CPR by single rescuer. This study will provide basic data about the time for the alternation of the CPR providers. Methods : The volunteer students having healthcare provider certification were recruited from the department of emergency medical service. The students performed 30:2 CPR for 20 minutes, and the data were recorded and analyzed. Metrics were based on the 2010 American Heart Association (AHA) Guidelines, and the CPR continued without any feedback. Results : Among the indicators of CPR, the accuracy and the depth of chest compressions decreased after about 5.3 minutes, and the rate increased approximately after 6.8 minutes. Changes in clinical indicators appeared, and fatigue increased after about 3 minutes. According to the increase in fatigue level, the changes in the CPR indicators and clinical indicators showed up, and these results proved to be statistically significant. However, there were no associations among the time, fatigue, and gender. Conclusion : Even though the times of changes in the indicators appeared differently, the times of changes in fatigue and CPR quality were able to be confirmed.

Pulmonary hypertension due to obstructive sleep apnea in a child with Rubinstein-Taybi syndrome

  • Choi, Hyung Soon;Yu, Jeong Jin;Kim, Young-Hwue;Ko, Jae-Kon;Park, In-Sook
    • Clinical and Experimental Pediatrics
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    • v.55 no.6
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    • pp.212-214
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    • 2012
  • Rubinstein-Taybi syndrome (RTS) is characterized by peculiar facies, mental retardation, broad thumbs, and great toes. Approximately one-third of the affected individuals have a variety of congenital heart diseases. They can also have upper airway obstruction during sleep, due to hypotonia and the anatomy of the oropharynx and airway, which make these patients susceptible to obstructive sleep apnea (OSA). In our case, pulmonary hypertension was caused, successively, by congenital heart defects (a large patent ductus arteriosus and arch hypoplasia) and obstructive sleep apnea during early infancy. The congenital heart defects were surgically corrected, but persistent pulmonary hypertension was identified 2 months after the operation. This pulmonary hypertension was due to OSA, and it was relieved by nasal continuous positive airway pressure. This case is the first report of pulmonary hypertension from OSA in a young infant with RTS.

Analysis of the Foreign Worker Patients in Plastic Surgery (외국인 근로자 환자의 성형외과 영역에 대한 분석)

  • Baek, In-Soo;Roh, Sang-Hoon;Hong, In-Pyo;Park, Chul-Gyoo
    • Archives of Plastic Surgery
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    • v.37 no.5
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    • pp.561-564
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    • 2010
  • Purpose: According to the data presented by ministry of justice, a number of foreign workers in Korea is approximately 700 thousands and among them 22 thousands are illegal workers. We would like to provide the basic information the foreign workers by analyzing clinical contents. Methods: 1456 patients who visited the hospital were reviewed by nationality, medical department, gender and age. 62 patients have visited plastic surgery department and they were additionally reviewed by diagnosis, chief complant and operation. Results: Mongolians were 388 cases (26.7%), followed by Chineses with 452 cases (31.1%). General surgery had 264 visits (18.1%) followed by internal medicine with 388 visits (26.6%). In gender grouping, 781 patients were males and 675 patients were females. Hand, face and extremity injuries were common in plastic surgery field but many foreign worker patients also wanted to take aesthetic surgery such as scar revision, blepharoplasty and augmentation rhinoplasty. Conclusion: It has been twenty years since foreign workers have come to the Korean society. In the past foreign workers were mostly neglected. However with the vast improvement in labor and welfare related services, demands for plastic surgery, especially aesthetic surgery are increasing among foreign workers. Therefore plastic surgeons' continuous interest in foreign workers is required.

Propofol as an Adjuvant in the Treatment of Cancer-Related Pain -A case report- (암성 통증 관리에 사용된 부가적 진통제로서의 Propofol -증례 보고-)

  • Han, Tae-Hyung;Hwang, Won-Gyoon
    • The Korean Journal of Pain
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    • v.10 no.1
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    • pp.117-120
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    • 1997
  • Cancer is a devastating disease, and the treatment of related pain is an extremely challenging task. Providing adequate analgesia while avoiding unnecessary drug effects often requires a polypharmacologic approach in cancer pain management. A 36-year old woman with breast cancer metastatic to the axial skeleton and bilateral hip joints was admitted to hemato-oncology service with complaints of intractable abdominal and hip pain. Despite rapidly increasing doses of intravenous morphine up to 350 mg per day; transdermal fentanyl; midazolam; ketorolac; lorazepam; dexamethasone, the patient continued to describe her pain as 10 of 10, refusing all surgical/diagnostic interventions not directly related to pain control. She did, however, consent to lumbar epidural catheter placement. The patient was sedated with titrating doses of propofol to assist with positioning. Even though the procedure was not successful due to significant thoracolumbar scoliosis, the patient admitted feeling better than she has in months during attempted placement. After continuous infusion of propofol was initiated at subhypnotic dose, the patient's analgesic demand was drastically reduced and described her pain as "1 to 3" of "10". Approximately 96 hours after the propofol infusion was started, the patient expired comfortably. There had been no change in her medical regimen during fecal 48 hours. In the case described, propofol was extremely advantageous as an adjuvant in the management of cancer related pain.

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The Influences of 5ea Breeze on Surface Ozone Concentration in Pusan Coastal Area, Korea (부산 연안역의 오존 농도에 미치는 해풍의 영향)

  • 김유근;이화운
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.265-275
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    • 1996
  • Air pollution characteristics and the influence of sea breeze on surface ozone concentration were studied using the data measured at 7 air quality continuous monitoring stations from June to September using 3 years (1990, 1993, 1994) in Pusan coastal area. Among the 246 sea breeze days for research Period, there were approximately 89 sea breeze days (36%) from lune to September, And there were 120 the episode days (68%) of ozone greater than or equal to 60 ppb in summer season. In 89 sea breeze days, the episode day was highly marked as 56 days (63%). So, we knew that the sea breeze greatly affects the occurence of ozone episode day. the ozone concentration under the condition of the sea breeze increase about 40% in the daytime. Frequencies distribution of $O_3$ concentration for sea breeze moved toward high concentration class. The characteristics of ozone concentration in relation to meteorological conditions of sea breeze is significant because we can discover major weather factors for eastablishing an air pollution- weather forecast system. For further. study about meterological approach method for photochemical air pollution, it is necessary to explain the characteristics of atmosphere below 1, 000 m, especially concerning the formation mechanism of inversion layers. And finally, we will study the relationships to synoptic weather conditions and vertical structure and diurnal variation of local wind systems including sea breeze, and the vertical movements of atmosphere in the city.

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A New CW CO2 Laser with Precise Output and Minimal Fluctuation by Adopting a High-frequency LCC Resonant Converter

  • Lee, Dong-Gil;Park, Seong-Wook;Yang, Yong-Su;Kim, Hee-Je;Xu, Guo-Cheng
    • Journal of Electrical Engineering and Technology
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    • v.6 no.6
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    • pp.842-848
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    • 2011
  • The current study proposes the design of a hybrid series-parallel resonant converter (SPRC) and a three-stage Cockcroft-Walton voltage multiplier for precisely adjusting the power generated by a continuous wave (CW) $CO_2$ laser. The design of a hybrid SPRC, called LCC resonant converter, is described, and the fundamental approximation of a high-voltage and high-frequency (HVHF) transformer with a resonant tank is discussed. The results of the current study show that the voltage drop and ripple of a three-stage Cockcroft-Walton voltage multiplier depend on frequency. The power generated by a CW $CO_2$ laser can be precisely adjusted by a variable-frequency controller using a DSP (TMS320F2812) microprocessor. The proposed LCC converter could be used to obtain a maximum laser output power of 23 W. Moreover, it could precisely adjust the laser output power within 4.3 to 23 W at an operating frequency range of 187.5 to 370 kHz. The maximum efficiency of the $CO_2$ laser system is approximately 16.5%, and the minimum ripple of output voltage is about 1.62%.

Yeast Single-Cell Protein Production Using Potato Processing Waste Water

  • Park, Eung-Yeal;Crawford, Don-L.;Korus, Roger-A.;Heimsch, Richard-D.
    • Journal of Microbiology and Biotechnology
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    • v.1 no.3
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    • pp.212-219
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    • 1991
  • Four species of yeast, Saccharomyces cerevisiae, Candida utilis, Saccharomycopsis flbuligera, and Schwanniomyces castellii were evaluated for their ability to bioconvert potato processing waste water into microbial protein and the resulting single-cell proteins were evaluated as protein sources for rainbow trout, using in vitro analyses. The studies indicated that Schwanniomyces castellii, which utilizes starch dircetly and converts it into cell mass efficiently, was suitable for the bioconversion. In the single-stage continuous bioconversion, the yield S. castellii cell mass, which contained approximately 37% protein, was 77%, at dilution rate 0.25 $h^{-1}$. Reduction of total carbohydrate was 81%. During batch fermentations, cell mass yield was about 72% and total carbohydrate reduction was 81%. Among the yeasts tested, S. castellii possessed the most fragile cell wall and had a favorable amino acid profile for salmonid fish; protein score of 86% (Met). In an in vitro pepsin digestibility test 80% digestibility (23~38% above control) was observed when cells were pre-heated in a steam bath for 30 min. Results presented should be regarded as being preliminary in nature because they were derived from single experiments.

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