• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.116-124
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• 2015

The objective of this study is to evaluate the effects of the replacement levels of grinded fly-ash on the repaired mortar based on a polymer. The main parameters are the curing temperature and replacement levels of grinded fly-ash. The curing temperature and the replacement levels of grinded fly-ash are varied at $40^{\circ}C$, $20^{\circ}C$ and $5^{\circ}C$, and between 0% and 35% of the total binder by weight, respectively. The flow in fresh mortar and compressive strengths according to ages, the relationship of stress-strain, elastic modulus and modulus rupture in hardened mortar, as well as scanning the electron microscopy and the X-ray diffraction of mortar, were measured, respectively. The test results showed that the flow, elastic modulus and modulus rupture are great in mortar specimens with 20~30% of the replacement levels of grinded fly-ash. In addition, compressive strengths according to ages were affected by the replacement levels of grinded fly-ash and the curing temperature indicated that the strength development ratio of mortar with 20% of the replacement levels of grinded fly-ash was greater than others. In the prediction of the compressive strength specified by the ACI 209 code, the strength development at an early and late age can be generalized by the functions of the replacement levels of grinded fly-ash and the curing temperature. In the analysis of scanning the electron microscopy and the X-ray diffraction, the number and intensity of peaks increased and the form of CSH gels on the surface of the particle of grinded fly-ash was observed.

• Journal of Chest Surgery
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• v.40 no.12
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• pp.817-824
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• 2007

Background: There are two choices for heart valve replacement-the use of a tissue valve and the use of a mechanical valve. Using a tissue valve, additional surgery will be problematic due to valve degeneration. If the risk of additional surgery could be reduced, the tissue valve could be more widely used. Therefore, we analyzed the risk factors and mortality of patients undergoing repeated heart valve replacement and primary replacement. Material and Method: We analyzed 25 consecutive patients who underwent repeated heart valve replacement and 158 patients who underwent primary heart valve replacement among 239 patients that underwent heart vale replacement in out hospital from January 1995 to December 2004. Result: There were no differences in age, sex, and preoperative ejection fraction between the repeated valve replacement group of patients and the primary valve replacement group of patients. In the repeated valve replacement group, the previously used artificial valves were 3 mechanical valves and 23 tissue valves. One of these cases had simultaneous replacement of the tricuspid and aortic valve with tissue valves. The mean duration after a previous operation was 92 months for the use of a mechanical valve and 160 months for the use of a tissue valve. The mean cardiopulmonary bypass time and aortic cross clamp time were 152 minutes and 108 minutes, respectively, for the repeated valve replacement group of patients and 130 minutes and 89 minutes, respectively, for the primary valve replacement group of patients. These results were statistically significant. The use of an intra aortic balloon pump (IABP) was required for 2 cases (8%) in the repeated valve replacement group of patients and 6 cases (3.8%) in the primary valve replacement group of patients. An operative death occurred in one case (4%) in the repeated valve replacement group of patients and occurred in nine cases (5.1%) in the primary valve replacement group of patients. Among postoperative complications, the need for mechanical ventilation over 48 hours was different between the two groups. The mean follow up period after surgery was $6.5{\pm}3.2$ years. The 5-year survival of patients in the repeated valve replacement group was 74% and the 5-year survival of patients in the primary valve replacement group was 95%. Conclusion: The risk was slightly increased, but there was little difference in mortality between the repeated and primary heart valve replacement group of patients. Therefore, it is necessary to reconsider the issue of avoiding the use of a tissue valve due to the risk of additional surgery, and it is encouraged to use the tissue valve selectively, which has several advantages over the use of a mechanical valve. In the case of a repeated replacement, however, the mortality rate was high for a patient whose preoperative status was not poor. A proper as sessment of cardiac function and patient status is required after the primary valve replacement. Subsequently, a secondary replacement could then be considered.

• Journal of Species Research
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• v.2 no.1
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• pp.85-90
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• 2013

Based on 440 skulls recently collected from two areas of the wild ass population in Mongolia, the time course of tooth eruption and replacement was investigated. The dentition pattern allows identification of age up to five years. We also conclude that annual lines in the tooth cementum can be used to determine the age in years for wild asses older than five years after longitudinal tooth sections were made with a low-speed precision saw. The first upper incisor proved to be most suitable for age determination, although the starting time of cement deposition is different between the labial and lingual sides of the tooth. The accurate age of the wild ass can be determined from the number of annual lines and the time before the first formation of the cementum at the respective side of the tooth.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.241-244
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• 1991

An experiment was conducted to investigate the nutritional and economic effects of complete replacement of maize with sun-dried cassava (SDC) in the diet of broiler chickens raised from one day of age to seven weeks. The complete replacement of maize by SDC resulted in a 10 percent reduction (p<0.05) in final bodyweights (1.91 vs 1.72 kg); and a 5 percent reduction (p>0.05) in average feed intake (4.01 vs 3.81 kg). Feed efficiency was not affected (p > 0.05). Cost per kilogramme of feed was reduced by nearly 30 percent and cost per kilogramme of bodyweight gain lowered by about 26 percent by using SDC diet. Relative profit return after accounting for cost of feed and cost of day old chick was higher by 11 percent on the SDC diet. It was concluded that despite the reduction in final bodyweight, the attractive economic return obtained from using SDC, a locally produced ingredient, may be justified in place of maize which is imported.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.99-102
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• 1999

In the study, the effect of the replacement content(20, 40, 60, 80%) and particle fineness and the chemical activator of the fly-ash on the flow and strength development of mortar was investigated. We found that the higher raito of the fly-ash replacement produced the lower the mortar strength and the higher fineness of the fly-ash yielded the higher strength. Also, we used Na2SO4 as activator of fly-ash to rise compressive strength mortar. The result as follows: the fly-ash mortar which stimulated by chemical activator, was higher strength development at early than the fly-ash mortar without chemical activator. But in the late age, the result indicated adversely.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.305-314
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• 1984

From May 1977 to April 1984, 204 cases of open heart surgery were performed under cardiopulmonary bypass. There were 99 male and 105 female patients ranging in age from 19 months to 58 years. 136 cases [66.7%] were congenital heart disease, and 68 cases [33.3%] were acquired heart disease, which were 66 valvular disease [97.1%], 1 IVC obstruction, and 1 myxoma. There were 136 congenital heart anomaly with 16 operative deaths [11.8%], consisting of 94 acyanotic cases with 7 death [7.4%] and 42 cases of cyanotic cases with 9 deaths [21.4%]. In 66 patients of acquired valvular disease, 52 valves were implanted; 47 mitral valve replacement with 4 death [8.5%] and 5 double valve replacement [MVR+AVR] with 1 death [20%]. Postoperative, warfarin sodium was medicated with checking prothrombin time. Finally, the operative mortality was 11.8% in congenital anomaly, and 11.8% in acquired heart disease, overall mortality rate was 8.5%.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.557-564
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• 1987

From September 1980 to July 1986, 135 cases of cardiac valve surgery were performed under the cardiopulmonary bypass. Out of 135 cases, single valve surgery was 114 cases including open mitral commissurotomy 17, mitral annuloplasty 2, mitral valve replacement 85, and aortic valve replacement 10 and double valve surgery was 21 cases. There were 68 males and 67 females ranging from 9 to 57 years of age. Early death within 30 days after operation was 17 cases [12.6%] and caused of death were ventricular arrhythmia 5, low cardiac output syndrome 4, excessive bleeding 3, pulmonary complication 2, and so on. Among 118 early survivors, 5 cases [5.1%] of late death were developed over a period of 2 to 72 months, and main cause of death was fatal bleeding complication associated with anticoagulation therapy. Symptomatically, 91.8% of patients were in NYHA functional class I or II at the end of the follow-up.

• Journal of Chest Surgery
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• v.44 no.4
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• pp.292-293
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• 2011

Surgical repair of the tetralogy of Fallot is one of the most successful operations in the treatment of congenital heart diseases. We report the case of a 65-year-old man who had an aortic valve replacement at the time of complete repair of the tetralogy of Fallot at the age of forty-three. He subsequently had progressive aortic root and ascending aorta dilation to 9 cm. The aortic root and ascending aorta replacement was done using a composite valve-graft and was performed along with other procedures. Thus, meticulous follow-up of aortic root and ascending aorta after corrective surgery for tetralogy of Fallot is recommended following initial curative surgery.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.26-27
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• 2016

This study analyzes the engineering characteristics of mortar according to admixture replacement ratios in cement mortar in a high-intensity ternary system, and changes in FA and BS combination ratios, in order to deduce the optimal combination ratio of FA and BS. Results showed that due to the characteristics of unhardened mortar, flow rate increased with the increase in admixture replacement and FA combination ratios, whereas air quantity decreased and setting time was delayed. Due to the characteristics of light mortar, compression strength decreased at early material ages as the overall combination ratio of FA increased. The FA : BS combination ratio was 2 : 3 on day 28 of material age, proving the best and potentially optimal combination ratio.

• Journal of Chest Surgery
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• v.24 no.10
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• pp.979-986
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• 1991

From October 1988 to November 1989, seven patients underwent valve replacement during the active phase of native valve endocarditis. There were 4 males and 3 females whose mean age was 41 years[range, 16 to 68 years]. Preoperative two-dimensional and Doppler echocardiography showed vegetations and severe valvular regurgitation in all patients. Blood cultures were positive in 4, and negative in 3 patients Organisms were alpha-hemolytic Streptococcus in 2, Staphylococcus epidermidis in 1, Erysipelothrix rhusiopathiae in 1 patient Valve tissue cultures were negative in all patients. Intravenous antibiotic therapy had been done for 3 to 18 days in 5 patients pre-operatively and was not done in 2 patients, Indications for operation were heart failure in h, and systemic emboli in 1 patient. The aortic valve was involved in 3, mitral in 1, and both aortic and mitral in 3 patients, One operative death[14.4%] occurred in patient with cardiogenic shock before operation. Late death occurred in one on 14 months after operation. The remaining 5 patients were followed up over a two year period in good condition. In conclusion, native valve endocarditis with severe heart failure must be considered for early operation.