• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.866-871
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• 2006

The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1061-1067
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• 2005

Purpose : We studied a clinical analysis of pediatric patients who visited the emergency medical center of Yeungnam University Hospital to compare the characteristics of pediatric emergency patients after year 2000 with the previous studies. Methods : We reviewed 7,034 children under the age of 15 years who visited the emergency medical center of Yeungnam University Hospital during the 2 year period from January 2001 to December 2002, and then we performed a clinical and statistical analysis. We analyzed the pediatric patients according to gender, age, season, day of the week, time of the visit, the disease classification and the final disposition of the patients. Results : Among the patients who visited the emergency room, 15.6% of the total emergency patients were under the age of 15. The male to female ratio was 1.6 : 1. Among the 7,034 pediatric patients, the most common age group was between 1 year and under 3 years of age(26.9%). The peak seasonal incidence was early summer and spring, especially during June(11.2%) and May(10.6 %). The peak incidence day of the week was Sunday(24.8%) and the peak time when the emergency pediatric patients visited the emergency room was between 20 and 24 o'clock(28.8%). The distribution of diseases, according to ICD-10 system, were injury and poisoning(30.4%), diseases of the respiratory system(22.8%), and diseases of the digestive system(14.6%). 30% of total pediatric patients were admitted to the hospital. Conclusion : After year 2000, as compared with the previous studies, the proportions of emergency pediatric patients has decreased. The distribution of diseases was not much different from the previous studies and the proportions of non-urgent diseases, such as acute nasopharyngitis or acute gastroenteritis, were still high. These result have come about due to the declining birth rate and changes of the medical system in Korea.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1132-1138
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• 2005

Purpose : The mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. They are caused by a deficiency of the enzymes involved in the degradation of glycosaminoglycans. Early recognition is important because recombinant enzyme replacement therapy is now available for MPS. We studied the clinical characteristics of 80 MPS children with the object of determining the epidemiological, clinical and radiological features in Korean MPS children. Methods : Diagnosis of MPS was confirmed by skin fibroblast enzyme analysis in 80 patients between February 1995 and December 2004. Charts were retrospectively reviewed for clinical and radiological findings, as well as for intelligence and speech evaluations. Results : Hunter syndrome (MPS type II) was the most prevalent type, appearing in 51/80 cases (64 %), followed by Sanfilippo syndrome (MPS III-18%), Hurler syndrome (MPS I-15%), and Morquio syndrome (MPS IV-4%). The average age at diagnosis was 5.5 years (range 1 to 20), and the male-to-female ratio was 4.7 : 1. Typical radiographic changes were observed in 45/54 cases (83%). Mitral regurgitation was the most common cardiac defect. Moderate to profound mental retardation and hearing loss were present in 14/35 cases (56%) and 33/38 cases (82%), respectively. Four MPS II patients had bone marrow transplantation, with mixed outcomes. Five MPS I patients are currently on enzyme replacement therapy. Conclusion : Our study showed a high proportion of MPS II cases (64%), which may represent population variability. By studying the clinical features of these patients, we hope to alert pediatricians of the warning signs of MPS.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.466-472
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• 2002

Purpose : The diagnosis of Meckel's diverticulum is difficult and delayed because it presents with various clinical symptoms. We evaluated clinical, imaging and pathologic findings of Meckel's diverticulum to facilitate detection of Meckel's diverticulum in children. Methods : Review of clinical, imaging, surgical and pathological findings in 10 children aged 7 days to 14 years with Meckel's diverticulum during an 8-year period, 1993-2001, at Ewha Womans University Hospital was undertaken. Results : The male to female ratio was 2.3 : 1. The chief complaint was painless lower gastrointestinal( GI) bleeding; others were abdominal pain, abdominal distention and vomiting, in order of frequency. The diagonsis before surgery were Meckel's diverticulum in 5 patients, non-reducible intussusception in 3 patients and intestinal obstruction in 2 patients. The diverticulum was located between 35 cm to 70 cm proximal to the ileocecal valve. The length of the diverticulum ranged from 4 cm to 12 cm and 80% of it was within 5 cm. A Meckel scan($^{99m}Tc-pertechnetate$ scintigraphy) after cimetidine administration was done in 6 cases. All 5 cases that presented with lower GI bleeding had ectopic gastric mucosa confirmed on pathology. Out of 5 cases of ectopic gastric mucosa, only 4 cases were positive on the Meckel's scan. Conclusion : In cases of unexplained GI bleeding, obstruction, or inflammation diagnostic workup should be carried out to rule out Meckel's diverticulum. Laparoscopy, high resolution ultrasonography and computed tomography of the abdomen may be indicated in the assessment of pediatric patient with lower GI bleeding, especially in patients with suspected bleeding from Meckel's diverticulum showing negative Meckel's scan.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1224-1229
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• 2003

Purpose : Bacterial meningitis is a serious disease, especially in the neonatal period, and it carries a significant degree of mortality and morbidity. Group B streptococcus(GBS) is a common cause of neonatal bacterial meningitis. The purpose of this study was to evaluate the clinical manifestations, treatment results and complications of GBS meningitis. Methods : We analyzed 29 cases retrospectively who had been admitted to the pediatric ward or NICU in Asan Medical Center from May 1990 to January 2002. They had proven GBS in culture or latex agglutination test in CSF. Results : The male to female ratio was 1 : 1.9. There were two cases of early onset type and 27 cases of late onset type. All cases had normal birth weight with full term at delivery. The perinatal predisposing factors were premature rupture of membrane(two cases), and maternal colonization(two cases). The most common presenting symptoms were fever and irritability. Associated diseases were GBS sepsis(21 cases). There was relatively high sensitivity to penicillin derivatives. There were abnormal brain CT or MRI findings in 16 cases(64%), such as infarction, encephalomalatic change, effusion, hydrocephalus, hemorrhage and abscess. The intensive care unit admission rate and the incidence of DIC were higher in the group with complications. Two cases were discharged against advice. Conclusion : We recommend early detection and active treatment in Group B streptococcal meningitis to improve the prognosis.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.217-223
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• 2003

Purpose : Every year, there is a remarkable increase in the prevalence of children with excess body fat. The aim of this study is to find a useful screening method in assessing adolescent, obesity and to specify the predictable risk factors that are related to adult cardiovascular disease according to BMI and obesity index. Methods : From July to November in 2001, a total of 2,814(male : female=2,011 : 803) mid to high school students who were in the obesity range according to obesity index(>20%) were evaluated according to height, weight, body mass index(BMI), obesity index, and serum lipid levels. Results : Among the obese students over 20% by obesity index, 86.6% were over the range of 95 percentile by BMI. Among students defined as obese by BMI, 21.0% of males and 21.4% of females students had hypercholesterolemia; by obesity index, the ratio was 20.7% male and 19.0% female. The frequency of hypertriglyceremia in male students was 15.0% in group I(overweight group, 85P97p); in female students 11.8%, 20.7% and 28.2% respectively. Conclusion : In this study, using BMI alone to test the serum lipid level in adolescent obesity had a limit of 10.0-17.0% omission. Therefore using obesity index as a screening method to find the adult cardiovascular disease would rather reduce the omission rate. The risk factor of cardiovascular disease according to BMI was the increasing level of triglyceride in both male and female students. We think that using the obesity index has more rationale rather than BMI in assessing lipid profiles.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.5-14
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• 2020

The study was initiated to reduce production cost and environmental pollution with the evaluation of nutrient requirement of 'Nero' black chokeberry (Aronia melanocarpa) and optimum amount of oil cake application. 100% of a recommended amount (RA) of oil cake was designated as a 100-RA, with 0-RA, 25-RA, 50-RA, and 75-RA for 0%, 25%, 50%, and 75% RA, respectively. The oil cake was scattered around the black chokeberry at every year for two years from 2018 to 2019, with investigation conducted for the second year. Soil mineral nutrient concentrations were not significantly different among the treatments. Dry weight (DW) of root and leaves was low for 0-RA-treated black chokeberry, with no significant difference observed for the all treatments for the DW of stems. 75-RA increased the fruit DW of 615 g and yield efficiency of 45.3%. Top:root ratio was the highest of 4.7 for 75-RA. Increased amount of oil cake application expanded the tree volume. Tree volume had a strong positive relationship with the root DW (r²=0.977). Mineral nutrient uptake in the root was the highest on the 25-RA-treated black chokeberry, except for Fe uptake. Mineral nutrient uptake in the leaves were similar to all the black chokeberries, except for T-N and Fe uptake. 75-RA increased mineral nutrient uptake in the fruit, except for Cu, in particular, 7.45 g in fruit N, which was the highest level compared to those of the other organs. T-N and P uptake were evenly distributed in the leaves, stems, and fruit, with high K uptake for leaves and fruit. 75-RA maximized to 17.2 g of the total nutrient uptake in a black chokeberry, with 4.9 g for the 0-RA. All mineral nutrient uptake were overall higher on the black chokeberry treated with 50-RA, 75-RA, and 100-RA compared to those of 0-RA and 25-RA.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.309-314
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• 2009

Incidence of rice stripe disease, caused by Rice stripe tenuivirus (RSV), was surveyed during 2002 to 2004. The incidence area and ratio of diseased fields were decreased gradually during those period. Rate of diseased plants were 45.8%, 45.0% and 43.7% in the susceptible cultivars Chucheong, Saechucheong and Ilpum, respectively. However, the rate was 4.4% in resistant cultivar Hwaseong. In addition, breakdown rate was also significantly high in the susceptible cultivars in Chucheong, Saechucheong and Ilpum showing 33.6, 33.2 and 31.9%, respectively. In Hwaseong, the breakdown rate was 0.8%. Collection efficiency was compared between two insect vector collection methods. Insect-sucking machine method was much more efficient than sweeping net method in collecting small brown plant hopper (SBPH). According to the survey of the population density of the insect vector during 2002 to 2004, the national average population density was gradually decreased year by year, 3.6, 2.3, and 1.3%, respectively. This result was significantly related with the decrease of the incidence of rice stripe disease. Control efficiency of rice stripe disease by treating several seedling box and water surface with insecticides against SBPH resulted that imidacloprid GR, Fipronil FG, Clothianidin+Probenazole GR and Thiamethoxam GR showed over 80% of control efficiency at 28 days after treatment at the early stage in nursery.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.380-391
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• 1993

The experimental study was made to propose the treatment method of wastewater in the high-density fish culture system. The BOD to COD ratios of effluents were almost same to 0.65 in the eel-farm, but were various in the farm rearing together with tilapia etc. A BOD rate curve of the eel-farm effluent could be described mathematically by the equation, $BODu=14.1(1-10^{-0.222t})+30.9(1-10^{-0.035(t-8)})$. Nitrification in Biological Fluidized Bed(BFB) system to treat the fish-farm wastewater could be reduce ammonium level up to $65{\sim}79\%$ when ammonium loading rates were between 0.014 and 0.075g $NH_4/g$ BVS-day. Nitrification efficiency was decreased by organic matters in the wastewater when ammonium loading was low(0.014 g $NH_4/g$ BVS-day). T-N removal ratios were decreased to increase loading in denitrification process, because of low C/N ratio. Based on much higher biological mass concentrations, BFB system takes many advantages of a practical viewpoint, such as stability of treatment efficiency and reduction of necessary site area for the facility, as compared with conventional treatment systems.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.53-60
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• 2010

In the present study, experiments have been performed to investigate the possibility of removing Cochlodinium polykrikoides using the dredged sediment from a coastal fishery and then to derive the optimal conditions; the amount and particle size of dredged sediment besprinkled into water, the thermal treatment, the types and amounts of additives, and the depth profile of Cochlodinium polykrikoides. Results showed that the optimal amount of dredged sediment besprinkled into water was 6~10 g/L, and the removal efficiency of Cochlodinium polykrikoides after the reaction time for 60 min was 73~93%. Note that, in the real sea water, it is necessary to besprinkle 6~10 $kg/m^3$ of dry dredged sediment on a unit area (1 $m^2$). With decreasing particle size, Cochlodinium polykrikoides could be more efficiently removed. The removal efficiency was 93% with the dredged sediment smaller than 100 ${\mu}m$, whereas it was 51% with that of 100 ${\mu}m$ ${\mu}m$. Since most of dredged sediment (over 90%) was smaller than 100 ${\mu}m$, high efficiency could be obtained by besprinkling only the dredged sediment without pre-treatment. CaO was found to be an effective additive in promoting the removal efficiency (up to 99%). The optimal amount of additive was 5~10%, however, it was necessary to use as small amount of an additive as possible in order to avoid the sharp increase in pH. The removal efficiency increased with increasing depth profile of Cochlodinium polykrikoides. The removal efficiency was 83% at 5 cm depth, whereas it was 93% at 50 cm depth. In the sea water, red tide occurred within 3 m depth, and furthermore most Cochlodinium polykrikoides existed within 1 m depth. It was, therefore, expected that higher removal efficiency of Cochlodinium polykrikoides could be obtained when the dredged sediment was besprinkled into the sea water. The removal efficiency of Cochlodinium polykrikoides was up to 93% when the dredged sediment (<100 ${\mu}m$) was besprinkled into water at the ratio of 10 g/L. This result was comparable to that obtained with loess (90~97%). All the results in the present study indicated that the dredged sediment from a coastal fishery could be successfully used as a substitute of loess for removing the red tide alga.