• Title/Summary/Keyword: Prevention of deterioration

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A Study for the Corrosion Property of Sprinkler Pipe and the Solution (스프링클러 배관의 부식 특성과 대책에 관한 연구)

  • Kim, Dong-Sung;Cho, Won-Cheol;Kim, Byung-Seon;Lee, Tae-Shik
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.461-464
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    • 2008
  • This study is for the corrosion property of sprinkler pipe and the prevention solution. The main causes of corrosion are the deterioration of pipe and wrong installation of pipe. This study includes the property of stainless pipe that is widely used as sprinkler pipe and other kinds of pipe, the theory of corrosion procedure and the result of test that is performed to ascertain the advance degree of corrosion about "A" factory complex using pipe samples that were collected at designated point of each factory complex.

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Acute kidney injury and continuous renal replacement therapy in children; what pediatricians need to know

  • Cho, Myung Hyun;Kang, Hee Gyung
    • Clinical and Experimental Pediatrics
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    • v.61 no.11
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    • pp.339-347
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    • 2018
  • Acute kidney injury (AKI) is characterized by abrupt deterioration of renal function, and its diagnosis relies on creatinine measurements and urine output. AKI is associated with higher morbidity and mortality, and is a risk factor for development of chronic kidney disease. There is no proven medication for AKI. Therefore, prevention and early detection are important. Physicians should be aware of the risk factors for AKI and should monitor renal function in high-risk patients. Management of AKI includes optimization of volume status and renal perfusion, avoidance of nephrotoxic agents, and sufficient nutritional support. Continuous renal replacement therapy is widely available for critically ill children, and this review provides basic information regarding this therapy. Long-term follow-up of patients with AKI for renal function, blood pressure, and proteinuria is recommended.

Traumatic Cardiac Perforation (외상성 심장파열의 외과적 고찰)

  • 성시찬
    • Journal of Chest Surgery
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    • v.12 no.4
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    • pp.365-370
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    • 1979
  • The first Mitral Commissurotomy was performed for tight mitral stenosis on March 1957. The patient was at that time 22-year-old male, student. The longest follow 9p for 22 years and 8 months has been obtained. During the follow up period, late deterioration due to restenosis developed 4 years after initial good result and reoperation was succeeded by transventricular Mitral Valvotomy with Tubb`s ilator on April 1964. The possible cause of restenosis was attributed to recurrent rheumatic activity. After more than 13 years long-good life following 2nd operation, Endocarditis such as episode of high fever & chill intermittently followed by mild fever and night sweat, I t. tibial artery embolization and rupture of aortic cusp. At present, patient complained of no subjective symptom, enjoying ordinary life {NYHA II]. Blood pressure has been 110/50-60 mmHg, trivial diastolic murmur at apex and moderate degree of mechanical murmur on diastole at Erb`s rea. Neither signs of RVH for mitral stenosis nor sign of LVH. ST-T change for aortic regurgitation appeared yet during last 2 yrs. The patient`s are for prevention of Rheumatic activity and development of endocarditis is important for obtaining the better long-term result.

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Evaluation on High-Temperature Mechanical Properties of 150MPa Concrete Mixed with PP and NY Fiber (PP, NY섬유를 혼입한 150MPa 콘크리트의 고온역학적 특성)

  • Baek, Jae-Uk;Kim, Gyu-Yong;Yoon, Min-Ho;Hwang, Eui-Chul;Son, Min-Jae;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.5-6
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    • 2017
  • Ultra high-strength concrete can prevent spalling by mixed ratio of PP and NY fiber. However, there is a lack of research on the deterioration of strength due to changes in mechanical properties after spalling prevention. In this study, the effect of high temperature on the mechanical properties of 150MPa concrete mixed with PP and NY fiber was evaluated. As a result, mixing PP and NY fiber is judge to be little effect on the mechanical properties of the 150MPa concrete at high temperature.

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Exacerbation Prevention and Management of Bronchiectasis

  • Joon Young Choi
    • Tuberculosis and Respiratory Diseases
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    • v.86 no.3
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    • pp.183-195
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    • 2023
  • Bronchiectasis, which is characterized by irreversibly damaged and dilated bronchi, causes significant symptoms, poor quality of life, and increased economic burden and mortality rates. Despite its increasing prevalence and clinical significance, bronchiectasis was previously regarded as an orphan disease, and ideal treatment of this disease has been poorly understood. The European Respiratory Society and British Thoracic Society have recently published guidelines to assist physicians in the clinical field. Guidelines and reports suggest comprehensive management that includes both non-pharmacological and pharmacological treatment. Physiotherapy and pulmonary rehabilitation are two of the most important non-pharmacologic therapies in bronchiectasis patients; long-term inhaled antibiotics and macrolide therapy have gained significant evidence in reducing exacerbation risk in frequent exacerbators. In this review, we summarize recent updates on bronchiectasis treatment to prevent exacerbation and manage clinical deterioration.

The Proposal of Efficient Hit Prevention Technique according to the Frequency Hopping Pattern in Orthogonal Multi-Carrier FH/CDMA System (직교 멀티캐리어 FH/CDMA 시스템에서 주파수 도약 패턴에 따른 효율적인 충돌 방지 기법 제안)

  • 이문승
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.2
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    • pp.141-150
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    • 2002
  • In this paper, we composed orthogonal multi carrier FH/CDMA system using frequency hopping sequence. Considering hit possibilities by delayed other user's signals we searched the optimal number of user access carrier slots not to influence on performance deterioration with the variation of number of carrier slots according to the number of user access carrier slots. A]io, we evaluated the BER performance improvement due to TCM and Concatenated coding technique by computer simulation.

Prevention of Fungal Contamination during Cheese Ripening - Current Situation and Future Prospects (치즈 숙성 중의 곰팡이 오염 방제 - 현황과 전망)

  • Jung, Hoo Kil;Choi, Ha Nuel;Oh, Hyun Hee;Huh, Chang Ki;Yang, Hee Sun;Oh, Jeon Hui;Park, Jong Hyuk;Choi, Hee Young;Kim, Kyoung Hee;Lee, Seung Gu
    • Journal of Dairy Science and Biotechnology
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    • v.30 no.2
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    • pp.75-81
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    • 2012
  • Molds cause severe cheese deterioration, even though some white and blue molds are used for the manufacture of Camembert and Blue cheese, respectively. The species of Geotrichum, Moniliella, Aspergillus, Penicillium, Mucor, Fusarium, Phoma, and Cladosporium are the main fungi that affect contamination during cheese ripening. Once deteriorated by fungal spoilage, cheese becomes toxic and inedible. Fungal deterioration of cheese decreases the nutritional value, flavor profiles, physicochemical and organoleptic properties, and increases toxicity and infectious disease. Fungal contamination during cheese ripening is highly damaging to cheese production in Korean farmstead milk processing companies. Therefore, these companies hesitate to develop natural and ripened cheese varieties. This article discusses the recent and ongoing developments in the removal techniques of fungal contamination during cheese ripening. There are 2 categories of antifungal agents: chemical and natural. Major chemical agents are preservatives (propionic acid, sodium propionate, and calcium propionate) and ethanol. Among the natural agents, grapefruit seed extract, phytoncide, essential oils, and garlic have been investigated as natural antifungal agents. Additionally, some studies have shown that antibiotics such as natamycin and Delvocid$^{(R)}$, have antifungal activities for cheese contaminated with fungi. Microbial resources such as probiotic lactic acid bacteria, Propionibacterium, lactic acid bacteria from Kimchi, and bacteriocin are well known as antifungal agents. In addition, ozonization treatment has been reported to inhibit the growth activity of cheese-contaminating fungi.

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Wireless structural health monitoring of bridges: present and future

  • Hoult, Neil A.;Fidler, Paul R.A.;Hill, Peter G.;Middleton, Campbell R.
    • Smart Structures and Systems
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    • v.6 no.3
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    • pp.277-290
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    • 2010
  • Internationally the load carrying capacity of bridges is decreasing due to material deterioration while at the same time increasing live loads mean that they are often exposed to stresses for which they were not designed. However there are limited resources available to ensure that these bridges are fit for purpose, meaning that new approaches to bridge maintenance are required that optimize both their service lives as well as maintenance costs. Wireless sensor networks (WSNs) provide a tool that could support such an optimized maintenance program. In many situations WSNs have advantages over conventional wired monitoring systems in terms of installation time and cost. In order to evaluate the potential of these systems two WSNs were installed starting in July 2007 on the Humber Bridge and on a nearby approach bridge. As part of a corrosion prevention strategy, a relative humidity and temperature monitoring system was installed in the north anchorage chambers of the main suspension bridge where the main cables of the bridge are anchored into the foundation. This system allows the Bridgemaster to check whether the maximum relative humidity threshold, above which corrosion of the steel wires might occur, is not crossed. A second WSN which monitors aspects of deterioration on a reinforced concrete bridge located on the approach to the main suspension bridge was also installed. Though both systems have provided useful data to the owners, there are still challenges that must be overcome in terms of monitoring corrosion of steel, measuring live loading and data management before WSNs can become an effective tool for bridge managers.

A New Design of Power Folding Controller for Deterioration Detection (열화방지형 파워폴딩 제어기 설계에 관한 연구)

  • Kim, Ji-Hyeon;Lee, Dong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.3
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    • pp.51-58
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    • 2008
  • This paper is a study of a prevention of power folding controller's thermal degradation. Power folding technology has been applied for many fields such as side rear vision mirror of vehicles, windshield wiper, antenna, power window. These controllers have been comprised with traditional DC moors, Switching electronic devices, and relays. But this methods have a limitation to overcome such problems of product reliability, endurance, noise margins. Therefore on this paper, to detect the movement of motor, sensing motor brush noise on a load sensing part has been used and controlling a precise RC timing control minimizes the thermal deterioration of motor. And using MOS FETs as a electronic switching device increases life-time and liability of control circuit. After testing such circuit and control method, repetition of operating time, cut-off time, wide operation voltage, power noise margin ware increased over eleven-fold.

Research on Durability Assessment of Asbestos Stabilizer for Asbestos-containing Ceiling Materials (석면 함유 천장재에 대한 석면 안정화제 내구성 평가 연구)

  • Ha, Joo-Yeon;Shin, Hyun-Gyoo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.1
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    • pp.18-27
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    • 2020
  • Objectives: For testing asbestos stabilizer products which are used for the maintenance and management of asbestos-containing materials, durability assessment should accompany the evaluation of basic properties and performance. Therefore, in this study we designed a testing method and constructed a database of durability performance, thereby providing basic data for reliability studies of asbestos stabilizer. Methods: Since the ceiling materials targeted in this study are interior materials, test conditions of 95% relative humidity and 60℃ temperature were designed in consideration of the effect of high relative humidity in summer and seasonal indoor temperatures. Plate-shaped specimens treated with asbestos stabilizers were maintained in a thermo-hygrostat for 5, 10, and 20 days, and then the asbestos scattering prevention rate was measured by air erosion testing. Results: The scattering concentration tended to increase with time under the single humidity condition, and exceeded the indoor air quality standard of 0.01 f/cc, during the 20 days of maintenance. On the other hand, there was little change according to the temperature condition. In the case of a complex condition with temperature and humidity, the results were similar to the humidity test, but the scattering concentration increased more sharply at 20 days. Conclusions: The main deterioration factor that affects the durability of asbestos stabilizer is humidity, and the deterioration is caused by a mechanism in which the stabilizer coated on the surface is re-dissolved by moisture and evaporates or the coating layer is peeled off, which is accelerated by high temperatures.