• Journal of Chest Surgery
• /
• v.30 no.4
• /
• pp.383-389
• /
• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.3
• /
• pp.222-231
• /
• 2005

Most of the tailings have been left without any management in abandoned metalliferous mines and have become the main source of heavy metal contamination of agricultural soils and crops in the these areas. To compare of environmental assessment of heavy metals in tailings derived from various 25-metalliferous mines in Korea, 3 different analysis methods such as water soluble, 0.1 M-HCl extractable, and total acid digestion method (aqua regia) were used. The chemical composition of water soluble in mine tailing were in the order ${SO_4}^{2-}>Ca^{2+}>Mn^{2+},\;Na^+,\;Al^{3+}>Mg^{2+},\;Fe^{3+}>Cl^-$. Specially, pH, EC, ${SO_4}^{2-},\;and\;Ca^{2+}$ concentrations in tailing varied considerably among the different mines. The average total concentrations of Cd, Cu, Pb, Zn, and As in tailing were 31.8, 708, 4,961, 2,275 and 3,235 mg/kg, respectively. Specially, the contents of Cd, Zn and As were higher than those of countermeasure values for soil contamination (Cd : 4, Zn : 700 and As : 15 mg/kg in soil) by Soil Environmental Conservation Act in Korea. The rates of water soluble heavy metals to total contents in tailings were in the order Cd > Zn > Cu > Pb > As. The rates of 0.1M-HCl extractable Cd, Cu, Pb, Zn, and As (1M-HCl) to total content were 17.4, 10.2, 6.5, 6.8 and 11.4% respectively. The enrichment factor of heavy metals in tailings were in the order As > Pb > Cd > Cu > Zn. The pollution index in tailing Au-Ag mine tailing were higher than those of other mine tailing. As a results of enrichment factor and pollution index for heavy metal contaminations in mine tailing of metalliferous mines, the main contaminants are mine waste materials including tailings.

• Clean Technology
• /
• v.27 no.4
• /
• pp.350-358
• /
• 2021

The results of this study shows that the combustor temperature ranged from 848.27 to 1,026.80 ℃, averaging about 976.61 ℃, and the NOx concentration increased as the temperature increased. The urea usage ranged from 291.00 to 693.00 kg d^-1, averaging about 542.34 kg d^-1, and the NOx concentration decreased as the urea usage increased. Residence time was about 3.38 to 9.17 s, averaging about 5.22 s, about 2.61 times larger than the 2 s of the design details. This is 1,086 kg h^-1, averaging about 55.71%, compared to the 1,950 kg h^-1 SRF input permission standard. The combustion chamber area is constant, but the residence time is shown to increase with the decrease of exhaust gas. The O₂/CO ratio was 847.05 to 14,877.34, averaging about 3,111.30, and the NOx concentration slightly increased as the O₂/CO ratio increased. As the combustor temperature and O₂/CO ratio increased, the combustion reaction with nitrogen in the air increased and the NOx concentration slightly increased. As the urea usage and residence time increased, the NOx concentration decreased slightly with an increase in reactivity with NOx. The NOx concentration at the stack ranged from 7.88 to 34.02 ppm with an average of 19.92 ppm, and was discharged within the 60 ppm emission limit value. The NOhx emission factor was 1.058 to 1.795 kg ton^-1, averaging about 1.450 kg ton^-1. This value was about 24.87% of the maximum emission factor of 5.830 kg ton^-1 of other solid fuels. Other synthetic resins and industrial wastes were 79.80% and 43.65% compared to 1.817 kg ton^-1 and 3.322 kg ton^-1, respectively. This value was similar to 1.400 kg ton^-1 of RDF in the NIER notice (2005-9), 10.98% compared to the maximum SRF of 13.210 kg ton^-1. Therefore, the NOx emission factor had a large deviation.

• The Korean Journal of Malacology
• /
• v.28 no.3
• /
• pp.233-244
• /
• 2012

Goseong bay, located in southeast sea of Korea with an area of 2,100 ha, is a semi-enclosed bay well-known for oyster farming cultured in an extended range of 148 ha. The objective of this study is to provide the fundamental data in order to manage the effective sea area. A total 26 of surface sediment were collected from Goseong bay to evaluate their sedimentary environment and heavy metals. The loss on Ignition (LOI), C/N ratio, acid volatile sulfide (AVS) and heavy metals were analyzed. loss on ignition (LOI) of surface sediment range from 1.00% to 3.03% (average 2.00%). The carbonate content ranges from 0.52% to 4.29% (average 2.37%). C/N ratio of organic matter showed that most part of organic matter comes from neighboring continent. Acid volatile sulfide (AVS) value of surface sediment from 0.02 mg/g to 1.43 mg/g (average 0.24 mg/g). A ten element of surface sediments (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, Zn) were calculated by enrichment factor (Ef) and the results show that some areas are highly polluted with respect Cu and Hg. The correlation matrix displays the existence of remarkable levels of correlation with both positive and negative values among different variable pairs. LOI and AVS showed both positive values. LOI and AVS values falls under 2% and 1%. Therefore, Goseong bay showed good in quality of sediment.

• Journal of Korean Academy of Nursing
• /
• v.24 no.4
• /
• pp.597-615
• /
• 1994

This study is designed to facilitate the creation of home environment conducive to the family taking care of chronic bed-ridden patients with more effective method. The need for this study has emerged against the background of marked changes in the structure of ailments and causes of death, resulting in the number and plights of chronic bed-ridden patients as well as of a rapid increase in demand for medical care and resulting premature discharge. Keeping these in mind, this study focused on home-wards where the majority of chronic bed-ridden patients are being cared for. Despite. their overriding importance, home-words are less than efficient in caring (or chronic bed-ridden patients. These circumstances require the designing of home-wards that can offer greater comfort to patients and at the same time make things easier for caregivers, on the basis of an overall analysis of patients' life and home - ward situation. According1y this study adopted a Participant Observation Method derived cultural anthropology, Toward this end, 3 patients were chosen as subjects of this study for intensive interviewing and participant observation. In the process of this field re-search efforts were made to collect emprical data, that is, to faithfully record the words of the subjects and their caregivers for analysis and interpretation. The findings of these analyses are as follows. Firstly, the chronic bed-ridden patients are mostly being taken care by close family members. Secondly, a room for the exclusive use of the patient, floor, kitchen, bathroom and multipurpose space were found to be necessary for proper caring of the patient. These spaces were respectively used with a view to 1) accomodating the patient as well as caregivers' activities, 2) keeping general and medical supplies and other appliances for patient's care and drying the patient's washing, 3) preparing and keeping the patient's foods and beverages, 4) keeping the supplies necessary for cleaning the patient's body and treating the patient's eliminations, 5) washing the patient's clothes, underwears and bedclothes. The patient's room in turn is subdivided into six portions in terms of uses : specifically the places for accomodating 1) the patient, 2) medical supplies, 3) medicines, 4) linens St clothes, 5) bedclothes and, 6) diapers. Thirdly, the activities of the caregiver are subdivided into seven key areas : hygiene, exercise, diet, elimination, therapeutic nursing, prevention of sore, and other activities. Each area is further classified into several different activities of caring. These activities we mainly carried out in the patient's room. Fourthly, the supplies for caring the chronic bed-ridden patient is divided into two large domains : medical and general supplies. Finally, three main problems areas were found in this study on the part of caregivers, that is, sore prevention, hygiene problem related frequent urination / defecation, the caregiver's physical, psych ological and emotional burden. In consideration of the aforesaid problem areas, a model home-ward was developed in this study. The newly-developed model has been found to have the following six advantages. Firstly, the time and effort required for maintaining the patient's hygiene are reduced, thus relievins the caregiver's physical and psychological bur-den. Secondly, the patient's hygiene can be maintained in satisfactory conditions, because the patient's eliminations are more easily removed. Thirdly, skin irritations caused by the patient's eliminations were remarkably reduced and so were the patient's sores due to moisture and bacteria. Fourthly, the home-ward have a tilt-table ef-fect thanks to the inclining room floor. This improves the patient's cardiovascular function as well as constantly changes pressed skin areas and thus prevents sores. Fifthly, improved shelf arrangements help make the best use of patient's supplies. Sixthly, the trouble of continuously changing clothes, underwears, diapers & bedclothes is remarkably reduced simply by covering the patient with cotton sheets when laid in bed. This is espected to cut down expenses by reducing the comsumptions of diapers and other disposable supplies.

• Journal of Chest Surgery
• /
• v.41 no.3
• /
• pp.320-328
• /
• 2008

Background: Numerous surgical devices for mitral repair have been used in the past with good results. In this study we describe a simple annuloplasty technique with using a new device ($Mitracon^{(R)}$). The aim of this study was to assess its efficacy and surgical results with using $Mitracon^{(R)}$. Material and Method: From May 2003 to October 2005, 46 patients (21 women and 25 men (mean age of $51.4{\pm}17.8$ years) with mitral regurgitation from various causes were treated with either the $Mitracon^{(R)}$ (the $Mitracon^{(R)}$ group) or the Capentier Edward rigid ring (the CE group). The median follow-up duration was 18.9 months. Result: The mean grade of mitral regurgitation before and immediately after surgery in the $Mitracon^{(R)}$ group and the CE group decreased from $3.2{\pm}0.8$ to $0.6{\pm}0.7$ and $3.4{\pm}0.7$ to $0.3{\pm}0.5$, respectively. There were no significant changes in the ejection fraction either between the two groups or before and immediately after surgery. No deaths were seen in either group. Early postoperative echocardiography of all 46 patients showed only trivial mitral regurgitation or none at all. Echocardiography at a median of 18.9 months also showed no progression in mitral regurgitation. The mean grade of mitral regurgitation in the $Mitracon^{(R)}$ group at this time point decreased from $3.2{\pm}0.8$ to $0.8{\pm}0.7$ (p<0.05). The CE group also showed a similar degree of decrease from $3.4{\pm}0.7$ to $0.3{\pm}0.6$ (p<0.05). The mitral valve area in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.3{\pm}0.9cm^2$. The mitral valve area in the CE group was $2.7{\pm}0.6cm^2$. The mean mitral pressure gradient in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.1{\pm}1.3$ mmHg. The mean pressure gradient in the CE group was $4.5{\pm}2.1$ mmHg, although any statistical significant difference for this between the groups was not reached. Conclusion: The present study showed the described technique to be safe and effective in the intermediate term. Because long term results are unavailable, a more extensive prospective randomized multicenter trial may be warranted to determine whether this procedure should be generally applied for repair of mitral valve disease.