• Title/Summary/Keyword: Prevention of deterioration

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Development of System and Measured Results for Measuring Insulation Resistance of High-Power Cables in Operation (활선 고전력 케이블의 절연저항을 측정하기 위한 시스템 설계 및 측정결과)

  • Um, Kee-Hong;Kim, Bo-Kyeong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.4
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    • pp.165-170
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    • 2016
  • The XLPE(or CV) cables installed to deliver high electric power from generator at the power station have operating for the last 40 years in Korea. In 6-8 years from the time of initial operation, the cables in operation start a deteriorating process, depending on the installation and usage conditions. Some cables, even before 6-8 years from the installation, can cause accidents due to the faulty construction or other inadequate environments. In order to prevent cable accident in advance, the regular auditing of power cables are required. For a systematic realization of surveillance and prevention of accidents, we have invented a measuring device. In this paper, we present the device installed at Korean Western Power Co. Ltd., in order to detect the deterioration status of insulation resistances of dielectrics in the cables. We present that the measured results by the device we developed show the deteriorating processes in the cables in operation.

Thermodynamic Modelling of Blast Furnace Slag Blended Cement Composites (고로슬래그가 치환된 시멘트복합체의 열역학적 모델링)

  • Yang, Young-Tak;Cha, Soo-Won
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.4
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    • pp.488-495
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    • 2017
  • In this study, we conducted the kinetic hydration modeling of OPC and the final product according to the substitution ratio of GGBS by using the geochemical code, GEMS, in order to calculate the thermodynamic equilibrium. The thermodynamic data was used by GEMS's 3rd party database, Cemdata18, and the cement hydration model, the Parrot & Killoh model was applied to simulate the hydration process. In OPC modeling, ion concentration of pore solution and hydration products by mass and volume were observed according to time. In the GGBS modeling, as the substitution rate increases, the amount of C-S-H, which contributes the long-term strength, increases, but the amount of Portlandite decreases, which leads to carbonation and steel corrosion. Therefore, it is necessary to establish prevention of some deterioration.

THE EFFECT OF INTRACANAL BASE ON PREVENTION OF APICAL LEAKAGE OF BLEACHING AGENTS (무수치 표백술에서 근관내 Base가 표백약제의 누출 방지에 미치는 영향)

  • Choi, Seung-Ho;Ro, Byeng-Duck;Park, Sung-Ho;Lee, Seung-Jong
    • Restorative Dentistry and Endodontics
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    • v.24 no.3
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    • pp.453-464
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    • 1999
  • The non-vital bleaching technique has been used widely as a very effective treatment method on discolored non-vital teeth. But periodontal tissue deterioration and cervical external root resorption have been reported because of the high toxicity of hydrogen peroxide in bleaching agents. So in previous studies, placement of base over the root canal obturation prior to bleaching has been suggested in order to prevent microleakage of bleaching agents, however, the effectiveness of base is still controversial. The purpose of this study was to evaluate the effects of base and root canal sealer on prevention of leakage of bleaching agents in non-vital bleaching. Fifty-two extracted sound teeth with single root were used. For root canal obturation, Tubuli seal$^{(R)}$(Kerr Co., USA) was used in 39 teeth and in others, AH-26$^{(R)}$(De Trey Dentsply, Inc., Switzerland) was used as a root canal sealer. 26 teeth among the teeth obturated with Tubuli seal$^{(R)}$ were divided into two groups, and Dentin cement$^{(R)}$(GC corp., Japan) and JRM$^{(R)}$(De Trey Dentsply, Inc. Germany) were used in each group as a intracanal base. In all teeth, non-vital bleaching using bleaching agent mixed with methylene blue dye was performed and all specimens were stored in $37^{\circ}C$ water bath for 72 hours. After sectioning longitudinally, the depth of dye leakage was measured with digital vernier calipers under the stereobinocular microscope using ${\times}40$ magnification. It can be concluded as follows: 1. The microleakage of bleaching agent was observed ill all groups regardless of type of the base and the sealer. 2. The microleakage in the groups using AH-26$^{(R)}$ as a sealer was significantly reduced (p<0.05). 3. In the groups with intracanal base, micro leakage was observed through almost the whole depth of the base and there was no significant difference between Dentin cement$^{(R)}$ and IRM$^{(R)}$ group(p>0.05). In conclusion, all the basing materials and the sealers in this study did not prevent the microleakage of bleaching agent. Therefore further studies and attempts to seal off the pulp chamber will be necessary.

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Performance Criteria to Assess the Remodeling Feasibility of Office Buildings (업무용 건축물 리모델링 사업성 평가 성능기준)

  • Yang, Keek-Young;Yoon, Yer-Wan;Jeong, Dong-Whan
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.2
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    • pp.142-151
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    • 2012
  • Despite the changes to demands and perceptions according to building deterioration, most of the previous studies on remodeling have focused on apartment buildings, which are residential buildings. Few studies have been conducted on buildings for general commercial use, or office buildings. Accordingly, this study set out to prepare a set of performance criteria to assess the remodeling feasibility of office buildings. For that purpose, 23 assessment items were devised, their importance was tested, 13 were extracted, and a set of scoring criteria for each item was prepared. Case analysis was conducted to check the reliability of the assessment items and scoring criteria. Through this analysis, it was found that the criteria were reliable.

The Effect of 6 Month Alphacalcidol Treatment or Nutrition Education on the Nutrient Intakes, Bone Mineral Density and Bone Markers in Continuous Ambulatory Peritoneal Dialysis Patients (6개월간의 Alphacalcidol의 투여와 영양교육의 실시가 지속성복막투석 환자의 영양소 섭취, 골밀도 및 골대사 지표에 미치는 영향)

  • Son, Sook-Mee;Park, Jin-Kyung
    • Korean Journal of Community Nutrition
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    • v.11 no.6
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    • pp.793-807
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    • 2006
  • This study was performed to estimate the effect of alphacalcidol supplementation or nutrition education on the nutrient intakes, bone mineral density and bone markers in continuous ambulatory peritoneal dialysis (CAPD) patients. The 90 CAPD subjects were randomly assigned to 3 groups (alphacalcidol group: AG, nutrition education group: NG, and control group: CG). Alphacalcidol supplementation($0.5{\mu}g/day$) was carried out for 8 months. Nutrition counseling was performed according to the patient s individual question for the first 6 months and scheduled nutrition education with individual counseling was carried out for the last 2 months. In baseline data. there were no significant differences in age, sex, family number, education years and monthly income except the NG showed significantly less duration of CAPD (p< 0.05) compared to other two groups. After intervention all three groups showed tendency of lower intakes. NG revealed less decrease in protein, especially in animal protein calcium from Ca-P binder, dietary calcium, dietary iron and niacin. NG showed significantly more increase in dry weight (p<0.05) and AG in waist circumference (p<0.001) after intervention. The groups did not show significant differences in the changes of biochemical indices related to bone metabolism. NG revealed more increase in trochanter BMD(p < 0.05) compared to other two groups. It seems that nutrition education is more effective in preventing deterioration or improving the bone and general nutrition status.

Dual-Task Training Effect on Cognitive and Body Function, β-amyloid Levels in Alzheimer's Dementia Patients: A Randomized Controlled Trial

  • Nam, Seung-Min;Kim, Seong-gil
    • The Journal of Korean Physical Therapy
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    • v.33 no.3
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    • pp.136-141
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    • 2021
  • Purpose: Dementia is a disease in which cognitive function declines, leading to deterioration of body functions and activities of daily living. The purpose of this study is to explore the effects of dual-task training, including cognitive tasks, on cognitive and body function and β-amyloid levels in Alzheimer's dementia patients. Methods: 34 inpatients diagnosed with Alzheimer's dementia at a nursing hospital located in South Korea. The patients were randomly divided into a dual-task group (n=16) and a single-task group (n=18). Each group was trained for 30 minutes three times a week for eight weeks. The MMSE-K was used to measure the patients' cognitive function. To assess the patients' static balance ability, their LOS was measured using BioRescue. while dynamic balance was measured using the BBS. The 10MWT were conducted to evaluate the patients' walking ability. Blood analysis was performed to measure levels of β-amyloid. Results: Both groups exhibited statistically significant improvements in gait function after the training (p<0.05). The dual-task group exhibited statistically significant differences in cognitive function, static and dynamic balance function, and β-amyloid levels after training (p<0.05). A significant difference was observed between the two groups (p<0.05). Conclusion: Dual-task training were found to be effective in improving cognitive and bodily functioning and reducing β-amyloid levels in Alzheimer's dementia patients. Thus, this may be suggested as an effective exercise method for the treatment and early prevention of Alzheimer's dementia.

A Study on Improvement of Soldier Mental Health Care Using Wearable Devices (웨어러블 기기를 이용한 군 장병 정신건강 관리 향상 방안)

  • In-Chan Kim;Sang-Keun Cho;Jun-Hak Sim;Jong-Hoon Kim;Sang-Hyuk Park
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.801-805
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    • 2023
  • In Korea, the population is continuously decreasing due to the decrease in fertility rates. Military troops are continuously decreasing, but soldiers' suicide, mental health care and medicine prescriptions, and inadequate decisions are increasing. In other words, the mental health of the intestines is getting worse. The mental health of the soldiers is a personal problem, but it can also have a big impact on the troops. This is because accidents such as suicide, divorce, and military leave lead to the restriction of the combat power and the deterioration of fraud. Currently, domestic and foreign academics are studying mental health care plans using wearable devices. The Korean military can also use this to objectively measure the mental health of soldiers and use the accumulated big data to predict and measure various situations. In this study, this study suggests mental health care measures for military soldiers using wearable devices, and further research will be conducted smoothly to improve the mental health of our soldiers.

Introduction of Clean Techniques for Trace Metal Analysis in Seawater (해수 중의 미량금속 분석을 위한 청결기술의 소개)

  • Kim, Kyung-Tae;Kim, Eun-Soo;Ra, Kong-Tae;Moon, Deok-Soo;Kim, Hyeon-Ju
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.2
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    • pp.157-164
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    • 2009
  • The metals such as Al, Ag, Au, Cu, Cd, Co, Fe, Ni, Pb, Zn, etc are present at very low concentration in seawater and are classified as so-called trace metals. Whiles some of them are used in metabolism of living organism as a micronutrient, they may show toxic effects on organisms in case of a limited threshold concentration of them Plenty of studies on trace metals have been performed bemuse trace metals have a persistent influence and an adverse effect on marine environment and ecosystem. For long years, when the concentration of trace metals in natural waters such as seawater and fresh water are measured with high precision and accuracy, some systematic errors have been recognized to be present in measurements. Since 1975 in US and European countries, the measured concentration of trace metals in seawater have been found to be lower by factors of 10-1,000 than the previous data of trace metals measurements and the vertical profiles of the measurements have been shown to reflect well-known biological, physical and geochemical processes. These results are attributed to great advances in analytical instrumentation and methodology for trace metals measurements. Precautions against the contamination of samples are required to be taken in the process of sampling, storage, and analysis of samples. However, in Korea, erroneous data of trace metals with regard to ocean and marine environment related survey and investigations are reported The lock of exact understanding and information regarding precautions in sampling, storage and analysis of samples lead to the deterioration of data quality, especially in the analysis of trace metals. The major procedures to obtain the accurate data of trace metals in natural waters are introduced for applying to the study and assessment of marine environments.

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Use of Non-carbapenem Antibiotics in Patients with Urinary Tract Infection Caused by Extended-spectrum Beta-lactamase-producing Enterobacteriaceae (Extended-spectrum β-lactamase 를 생산하는 Enterobacteriaceae 요로감염에서 카바페넴 이외의 항생제 사용 가능성에 대한 고찰)

  • Seo, Yu Bin;Kim, Young Keun;Lee, Jacob;Song, Wonkeun
    • Korean Journal of Healthcare-Associated Infection Control and Prevention
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    • v.21 no.2
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    • pp.50-56
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    • 2016
  • Background: Alternatives to carbapenem are increasingly needed to decrease the usage of carbapenem. We evaluated the possibility of using non-carbapenem antibiotics against urinary tract infections (UTI) caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Methods: This retrospective study was performed at 2 university hospitals between October 2010 and December 2012. All diagnosed adult cases of ESBL-PE UTI were identified from the microbiological database. The subjects were divided into 3 groups based on the empirical antibiotic classes and susceptibility: carbapenem (C) group, susceptible non-carbapenem (SNC) group, and non-susceptible non-carbapenem (NSNC) group. Results: A total of 84 patients were eligible for analysis. For empirical therapy, 41, 23, and 20 patients were included in the NSNC, SNC, and C empirical groups, respectively. During the empirical therapy, 7 patients (17.1%) in the NSNC group, 18 patients (78.3%) in the SNC group, and 19 patients (78.3%) in the C group experienced clinical improvement. No significant difference was observed between the SNC and C empirical groups (P=0.192). Severe sepsis or shock was the predictor of empirical SNC treatment failure (P=0.048). There was a tendency to use carbapenem as a definite therapy in cases of NSNC. In contrast, empirical SNC was maintained as a definite therapy. Conclusion: SNC could be considered as an alternative to carbapenems for treating ESBL-PE UTI. This strategy might decrease the usage of carbapenem without clinical deterioration. However, it should be noted that SNC therapy may fail in the case of severe sepsis or shock.

A Study of Pain and Psychological Well-Being in Total Knee Replacement Patients (무릎 전치환술 환자의 통증과 심리적 안녕에 관한 연구)

  • Chae, Jung-Byung;Jung, Ju-Hyeon
    • PNF and Movement
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    • v.18 no.2
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    • pp.233-244
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    • 2020
  • Purpose: The study investigated pain and falls as psychological factors in Total Knee Replacement patients and examined the relationship between these factors. Methods: Ninety-six total knee replacement patients aged 69.31±7.01 (male: 21, female: 75) participated in the study. Post-surgery pain was assessed on a visual analog scale, and fall risk scores were evaluated on fall fear and fall efficacy scales. Other psychological factors assessed included national anxiety and trail anxiety, fear prevention, Beck depression score, and psychological health measures. The data were analyzed using SPSS version 22.0. Results: A statistically significant correlation was found between pain before surgery and FES fall fear score before surgery (p < 0.05). A statistically significant correlation was found between pain after surgery and PWBS fall fear score after surgery (p < 0.05). A statistically significant correlation was found between state anxiety and PWBS, Trail anxiety (p < 0.05). A statistically significant correlation was also found between trail anxiety and BDI, PWBS (p < 0.05). State anxiety and fear avoidance before surgery were found to affect trail anxiety, and pain before surgery and fall fear score before surgery were found to affect FES. In addition, PWBS was found to affect BDI. Conclusion: The study confirms that increased pain in Total Knee Replacement patients can be a risk factor for falls. In addition, fall fears increase fear avoidance and cause psychological deterioration. This suggests that efforts should be made to reduce pain and to manage psychological factors.