• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.67-73
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• 2020

In this study, the self-healing performance of mortar beams containing self-healing materials was evaluated through experiments. Normal mortar beams and self-healing mortar beams were used In the experiments. The self-healing performance was evaluated by comparing the mortar compressive strength, member strength, and self-healing effects of cracks. The experimental results showed that the compressive strength of mortar containing self-healing material was smaller than that of normal mortar, but the ratio of 118 days compressive strength to 28 days compressive strength was the same. The member strength tended to increase with increasing curing period. In normal mortar specimens, the member strength did not recover even if the curing period increased, but the strength of the self-healing mortar specimens tended to recover as reaction products were produced. The crack width tended to decrease after the healing periods in both specimens, but the reaction product was observed only in the self-healing mortar specimens.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.253-258
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• 2001

A macroeconomic minimodel was simulatedto suggest the public for sustainable us of Nakdong River Basin. The minimodel for the simulation shows the interrelationships between natural environment and economic activity. Topsoil, water, economic assets, and money stock are plotted for 300 years, beginning with 1996 in each simulation. The computer simulation runs suggest that the Nakdong River Basin system in the near future may strongly be influenced by the favorable availability of outside resources, while the economic assets and money stock may be declined by indigenous environmental stock depletion. The simulation run made under the constant decrease in systems purchased inputs with investment ratio of developed country and for sustainable use. The results of simulation shows the recover of natural environment and decrease of economic activity under these condition. Therefore, the economic structure of Nakdong River Basin should be transformed from the present industrial structure to the social-economic structure based on an ecological-recycling concept which depend on renewable resources rather than industrial structural which depend on outside resources.

• Journal of Chest Surgery
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• v.24 no.6
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• pp.555-559
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• 1991

Post-pneumonectomy empyema thoracis is an uncommon, but very serious problem. Early diagnosis & adequate drainage followed by thoracoplasty and or myoplasty are very important principles for the management of the empyema thoracis & will enable patient to recover from the toxic effects. During the period of January, 1985 to December, 1990, 13 patients with post-pneumonectomy empyema thoracis were treated in the department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine. There were 10 males % 3 females ranging from 31 years to 79 years of age. The occurrence ratio of left to right side was 8: 5. The underlying pathologic lesions of empyema thoracis were pulmonary tuberculosis[7], lung ca. [2] pneumothorax[2], lung abscess[1] pneumonia[1]. We treatment procedure for post-pneumonectomy empyema thoracis were open window thoracostomy in 10 cases, Clagett procedures in 2 cases, one thoracoplasty, and two cases of Clagett procedures followed by open window thoracostomy in one cases.

• Clinical and Experimental Pediatrics
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• v.53 no.11
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• pp.936-941
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• 2010

The systematic approach to pharmacologic treatment is typically to begin with the safest, simplest, and most conservative measures. It has been realized that the more rapidly inflammation is under control, the less likely it is that there will be permanent sequelae. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the mainstay of initial treatment for inflammation. In addition, the slow-acting antirheumatic drugs (SAARDs) and disease-modifying antirheumatic drugs (DMARDs) have efficacy of anti-inflammatory action in children with chronic arthritis. New therapeutic modalities for inflammation, such as etanercept and infliximab, promise even further improvements in the risk/benefit ratio of treatment. It is not typically possible at the onset of the disease to predict which children will recover and which will go on to have unremitting disease with lingering disability or enter adulthood with serious functional impairment. Therefore, the initial therapeutic approach must be vigorous in all children.

• Korean Journal of Psychosomatic Medicine
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• v.4 no.1
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• pp.120-123
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• 1996

Regarding menopause as a turning point in woman's lift, the author reviewed the psychosocial aspects of menopause. Seeing menstruation as the symbolic meaning of female sexuality, psychoanalysts argue that menopause, the loss of symbolic meaning of female sexuality, may bring a mourning reaction to woman. It is reported that the high ratio of depression does not have a serious relationship with the menopause syndrome, and that depression cannot be viewed as a different symptoms. It is also proved that most women successfully recover themselves from temporary menopause symptom. Research data shows that some women have a negative thought on the meaning of menopause. Others, however, have a positive concept on the meaning of menopause because of the feeling of release and freedom. In sum, the author suggests that psychosocial consideration is very important as much as bilogical consideration in considering the meaning of menopausal syndrome.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.664-667
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• 2001

Segregation of binary particle systems in a horizontally gyrated bed has been experimentally studied to recover the heavy metals from municipal waste incineration (MWI) ash. Differences in density and size had less effect on segregation. Effective segregation took place under the centrifugal effect of 1 or less for any particle size ratio. Zn, Cu and Pb were concentrated in the upper side of bed by the horizontal vibration. However, there was less change in concentration for other metals such as Mg, Al and Fe etc. The separation system with the horizontal gyrating separator proved to be an effective method for the pretreatment of recovering Zn, Cu and Pb from incineration residues.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.448-452
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• 2001

An Experimental study was carried out to develop a simple method of processing copper waste sludge which is produced by PBC manufacturing. The procedure is based on leaching of wet sludge in 2N H$_2$SO$_4$, and the solid / liquid ratio is controlled approximately at 1/10. The recovery of copper is 85.4%, and pH of the leachate is 3.20. Adding ammonia solution into leachate forms ammine, and hydroxide compounds derived from other impurities in leachate at pH 10. The hydroxide compound can be treated by ferrite process, and the product is a stable oxide compound. Then the ammine solution is heated to evaporate ammonia, and the copper hydroxide is formed. Heating at 8$0^{\circ}C$by aeration, copper hydroxide is transformed into copper oxide with a purity of 98.4%. This process can recover most copper from sludge and the residue can be stabilized by the formation of a stable oxide compound which is not hazardous to environment.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2417-2419
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• 1999

Among educational environment, lighting's role is getting more important since it improves the visual tasks, capability of work, and it help to build both balanced mind and body. Also, since students spend most of their time inside rather than outside, students need appropriate illuminance everyday. If optimum illuminance, the color rendering properties and controlled distribution of lighting is given, people can decrease the fatigue of eyes, recover their health, and also, people can maximize their efficiency of work. In this paper, their is a comparison between the real illuminance and illuminance distribution due to the uniformity ratio of 2 or 3 dimensions by simulation.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.478-481
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• 1997

Hadamard Transform Spectrometer (HTS) is an instrument which measures the spectrum of a source with high signal to noise ratio using multiplexing advantage. While the conventional HTS has the 1-dimensional characteristics because it measures only the spectrum, the system presented in this paper is 2-dimensional so that it can measure the spectrum of each position. We introduce here 2-dimensional Hadamard transform spectrometer and analyze it. The $T^{-1}$ method which recover the spectrum and compensate the transmissive nonideality of the stationary electro-optical mask(EOM) are applied to the system. By computer simulations we show we can get better estimates from the proposed system than that from the conventional HTS.

• Journal of Korean Society on Water Environment
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• v.31 no.4
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• pp.387-391
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• 2015

This study was performed to evaluate the effect of pH (8-12) and molar ratio of magnesium and phosphate ($[Mg^{2+}]/[PO_4{^{3-}}]$) (0.6-1.4) on struvite crystallization of anaerobic digester supernatant using seawater as magnesium source. pH range of 9-10 is favorable for ammonium and phosphate recoveries. The recovery efficiency of ammonium was highest at $[Mg^{2+}]/[PO_4{^{3-}}]$ of 1.0 and pH 10. On the other hand, high phosphate recovery efficiency (> 99%) was achieved at ($[Mg^{2+}]/[PO_4{^{3-}}]$) of 1.4 and pH 10. The results demonstrated that seawater can be considered as low-cost magnesium source to recover phosphorus from anaerobic digester supernatant.