• 한국재료학회지
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• 제32권3호
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• pp.146-152
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• 2022

One disadvantage of deep cycle flooded lead-acid batteries is increasing water loss caused by use of (+) Pb-Sb / (-) Pb-Sb alloy grid. Water loss is generated by the emission of hydrogen gas from the (-) electrode during battery charging. In this paper, we maintain cycle life aspect through the development of hybrid flooded lead-acid batteries to which a (+) Pb-Sb / (-) Pb-Ca grid is applied and deal with the improvement of water loss. The amount of water loss compared to that of the (-) Pb-Sb grid decreased when Ca was added to the (-) Pb grid. For the (-) Pb-Ca grid, it was confirmed that the time to reach 0.0 V, at which water decomposition occurs, was increased compared to that of the (-) Pb-Sb grid at the NPV (Negative Potential Voltage). In the cycle life test conducted with the BCI (Battery Council International) standard, compared to the (+) Pb-Ca grid, the (+) Pb-Sb grid increased the life cycle of the batteries and the (+) Pb-Ca grid showed an early end of life due to PbO corrosion layer generation, as determined through SEM / EDS and Tear Down analysis. In conclusion, by addition of Sb to (+) Pb grid and Ca to (-) Pb grid, we developed a hybrid flooded lead-acid battery that meets user requirements to improve water loss characteristics and preserve cycle life characteristics.

• 콘크리트학회논문집
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• 제19권1호
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• pp.27-37
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• 2007

이 연구의 목적은 초기재령 콘크리트가 동해를 입을 경우가 예상될 때, 동해저항성을 확보하는데 필요한 최소 양생 시간의 예측법을 제안하는 것이다. 먼저, 실험을 통하여 동해시점이 지연될수록, w/c가 낮을수록, 그리고 1종 시멘트보다 3종 시멘트를 사용한 콘크리트가 동해에 의한 압축강도 감소율이 낮으며 동해는 얼음결정의 형성과 성장을 통해 발생됨을 확인하였다. 초기재령 콘크리트가 동해를 입었을 경우, 콘크리트 내에 존재하는 모세공극의 자유수가 얼음으로 상변화를 일으키면서 압축강도의 감소를 유발하므로 동해저항성은 모세공극의 포화도에 따라 결정된다. 따라서, 모세공극의 임계포화도 개념을 근거로 초기동해의 방지를 위한 최소양생시간의 예측법을 제안하였다.

• Journal of Chest Surgery
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• 제57권4호
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• pp.329-338
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• 2024

Background: Video-assisted thoracoscopic surgery (VATS) is recognized as a safe and effective treatment modality for early-stage lung cancer and anterior mediastinal masses. Recently, novel articulating instruments have been developed and introduced to endoscopic surgery. Here, we share our early experiences with VATS major pulmonary resection and thymectomy performed using ArtiSential articulating instruments. Methods: At the Seoul Metropolitan Government-Seoul National University Boramae Medical Center, 500 patients underwent VATS pulmonary resection between July 2020 and April 2023, while 43 patients underwent VATS thymectomy between January 2020 and April 2023. After exclusion, 224 patients were enrolled for VATS major pulmonary resection, and 38 were enrolled for VATS thymectomy. ArtiSential forceps were utilized in 35 of the 224 patients undergoing pulmonary resection and in 12 of the 38 individuals undergoing thymectomy. Early clinical outcomes were retrospectively analyzed. Results: No significant differences were observed in sex, age, surgical approach, operation time, histological diagnosis, or additional procedures between the patients who underwent surgery using novel articulating instruments and the group treated with conventional endoscopic instruments for both VATS major pulmonary resection and thymectomy. However, the use of the novel articulating endoscopic forceps was associated with a significantly larger number of dissected lymph nodes (p=0.028) and lower estimated blood loss (p=0.009) in VATS major pulmonary resection. Conclusion: Major pulmonary resection and thymectomy via VATS using ArtiSential forceps were found to be safe and effective, with early clinical outcomes comparable to established methods. Further research into long-term clinical outcomes and cost-effectiveness is warranted.

• 한국간담췌외과학회지
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• 제28권1호
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• pp.48-52
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• 2024

Backgrounds/Aims: Splenectomy is the most frequently performed procedure as definitive management or as part of shunt surgery or devascularization in portal hypertension. Splenectomy is technically challenging because of the frequent coexistence of multiple collateral varices, splenomegaly, poor liver function, and thrombocytopenia. Early arterial ligation and late mobilization (EALDEM) is the traditional method for splenectomy in portal hypertension. Early spleen mobilization offers good control of the hilum. We aim to compare the effect of the early mobilization and delayed arterial ligation (EMDAL) technique with that of the conventional splenectomy technique in patients with portal hypertension. Methods: During the study period from September 2011 to September 2022, 173 patients underwent surgical intervention for portal hypertension at our institution. Among these patients, 114 underwent the conventional method of splenectomy (early arterial ligation and late splenic mobilization) while 59 underwent splenectomy with the EMDAL technique. Demographics were compared between the two groups. Intraoperative and postoperative outcomes were analyzed using the Mann-Whitney test in each group. A minimum follow-up of 12 months was performed in each group. Results: Demographics and type of surgical procedure were comparable in the two surgical method groups. Median blood loss was higher in the conventional group than in the EMDAL method. The median duration of surgery was comparable in the two surgical procedures. Clavien-Dindo grade III/IV complications were reported more frequently in the conventional group. Conclusions: The splenic hilum can be controlled well and bleeding can be minimised with early mobilization and delayed arterial ligation.

• 재활복지공학회논문지
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• 제11권1호
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• pp.9-14
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• 2017

학령 전기 아동은 옹알이 단계부터 8세까지 모국어의 음운 체계를 습득하고 정상적으로 산출한다. 이 시기 청력손실은 외부 소리 자극을 수용하는데 어려움이 따른다. 청각적 수용의 문제는 언어 습득 및 발달을 지체시키고, 의사소통 장애를 일으킬 수 있다. 이외에도 학습, 사회성, 정서 발달 등에도 영향을 준다. 청력 손실은 조기 선별과 진단 및 중재가 중요하다. 그러나 그 정도가 낮거나 특정 음역에 국한된 경우 발견이 어려울 수 있고, 발견하더라도 재활 중재로 연결되기 어려운 경우가 많다. 이 연구는 학령 전기 아동에서 나타난 경도 및 중등고도 대칭성 고음급추형 감각신경성 난청의 사례를 청각학적 평가 결과 해석과 함께 의사소통 관련 문제를 분석하고, 청각 언어병리학적 재활 방향 등을 고찰하고자 한다.

• Nutrition Research and Practice
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• 제8권5호
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• pp.571-579
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• 2014

BACKGROUND/OBJECTIVES: The objectives were to investigate the effect of a 12-wk intervention with behavioral modification on clinical characteristics and dietary intakes of young and otherwise healthy obese and to identify factors for successful weight loss. The goal was to lose 0.5 kg per week by reducing 300-500 kcal/day and by increasing physical activities. SUBJECTS AND METHODS: Forty four obese subjects (BMI > 25) and 19 normal weight subjects (BMI 18.5-23) finished the 12-week intervention. Obese subjects participated in 5 group educations and 6 individual counseling sessions. Normal weight subjects attended 6 individual counseling sessions for evaluations of dietary intake and exercise pattern. Anthropometric and clinical characteristics and 3-day dietary records were evaluated at baseline and week12. RESULTS: Weight and serum triglyceride and free fatty acid concentrations in obese group decreased significantly with intervention. Intakes of energy, fat, and cholesterol decreased significantly in the obese. Active participation, realistic weight loss goal setting, and weight gain after high school graduation not during childhood were identified as key factors for successful weight loss. CONCLUSIONS: The 12-week intervention with behavioral modification resulted in reduced energy and fat intakes and led to significant weight loss and improvements of clinical characteristics in the obese. The finding that those who became obese during childhood lost less weight indicates the importance of 'early' intervention.

• The Korean Journal of Pain
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• 제11권1호
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• pp.30-35
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• 1998

Background: Idiopathic sudden sensorineural hearing loss(ISSHL) has been generally defined as an abrupt loss of auditory acuity without precipitating factors. Since ISSHL was first described as a disease entity, numerous reports assessing a variety of treatment regimens have been published. But its etiology, pathogenesis, treatment, and prognosis are controversial at the present time. Stellate ganglion block(SGB) has been used for the treatment of ISSHL by vasodilatation and increased blood flow to the inner ear. Methods: We reviewed the records of 152 patients to investigate the efficacy of SGB for ISSHL. The control group was managed with medications such as hypaque, heparin, steroid, nicotinic acid, and vitamins. The SGB group was managed with SGB and the same medications. SGB was performed with 8 ml of 1.0% mepivacaine. The efficacy of treatment was evaluated by pure-tone average following therapy. The recovery of hearing was defined as Siegel's criteria I, II, or III. Results: The recovery rate of the SGB group was higher than that of the control group(61.5 vs. 42.9%, p<0.05). The recovery rate was higher in patients who were treated early, within 7 days from the onset of symptoms, especially in the SGB group(79.7%). And in the case that initial hearing loss was severe (>70dB), the SGB group had a higher recovery rate(64.2%) than the control group(42.5%). Conclusions: SGB is thought to be a useful therapy for ISSHL, especially in the patients who were treated soon after onset or whose initial hearing loss was severe.

• 수산해양기술연구
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• 제28권2호
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• pp.171-183
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• 1992

In this paper, the behaviour of cavitation erosion, influence of corrosion and corrosion control on slide bearing metals for internal combustion engine were investigated, and this experiment was done by the vibratory cavitation erosion tester. The main results obtained are as follows: 1. With decreasing the space between horn and specimen, the weight loss and its rate increased step by step. But the weight loss and its rate of 0.2mm space decreased conversely more than that of 0.4mm space at early stage. 2. The weight loss and its rate with change of pH were appeared to the order of pH2>pH12>pH7>pH4. And the weight loss and its rate at pH 4 decreased at best. 3. The weight loss and its rate by cavitation erosion for bearing metals were shown to the order of W.M7>W.M1>K.M4. 4. There appeared mainly small pit hole at pH2, and appeared the pit of netting thread type at pH12 by the results of the damaged surfaces at pH2 and pH12 environments that were sensitive to cavitation erosion. 5. With increasing the viscosity of lubricating oil, the weight loss rate by cavitation erosion became dull at the space below 0.5mm. 6. The protective efficiency of cavitation erosion-corrosion is superior inhibitor of chormate(25 ppm) to cathodic protection.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.235-243
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• 2013

Purpose: This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. Materials and Methods: One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. Results: There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, "With CCAP" and "Without CCAP", there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. Conclusion: This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

• Archives of Plastic Surgery
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• 제32권5호
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• pp.567-572
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• 2005

An electrical burn used to result in the damage of the skin and underlying deep soft tissue injury. Thus, in order to preserve devitalizing tissues and promote the structural survival free flaps with ample blood supply are frequently employed. However, early unpredictable vascular injury and progressive tissue necrosis may cause the free flaps full of hazards. We applied 50 free flaps upon 41 acute electrical burn cases between 1998 and 2004. Injured areas, timing of operation and causes of flap loss were studied. The victim's ages ranged from 13 to 60 years. (an average 37.8 years) Thirteen out of 50 free flaps were lost totally: three cases were due to arterial insufficiency and ten venous congestion. Total loss of flaps were observed in 5 of 12 cases in the postoperative 3 weeks, 6 of 20 cases between 3 and 6 weeks and 2 of 18 cases after 6 weeks. In three of 12 cases the free flap was lost partially in the postoperative 3 weeks, 4 of 20 cases between 3 and 6 weeks and 1 of 18 cases after 6 weeks. The result was statistically significant by a T-test (p<0.05). This study showed that timing of the operation is accountable for the loss of free flap. It is most important to conduct the free flap procedure on an electrical injury at the time when the recipient vessel is definitely discernible and intact so as to minimize the loss of flap and spare the structures.