• Korean journal of applied entomology
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• v.61 no.2
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• pp.357-368
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• 2022

We investigated the developmental characteristics of super mealworm (Coleoptera: Tenebrionidae) at four different temperatures (25℃, 27℃, 30℃, and 33℃). The rearing conditions were 9L/15D, 65% RH, and 1,330 to 1,800 lux with wheat bran. The length of developmental period of 1 to 18 instars at each temperature showed that 30℃ was the shortest at 120.0±5.8 days, compared to that at 27℃ (132.6±10.7 days), 33℃ (136.5±9.2 days), and 25℃ (156.7±7.5 days). The larval developmental period was statistically significantly longer at 25℃, 27℃, and 30℃ compared to the length at 33℃. However, the death rate of larvae at 33℃ was 2.7-3.3 times higher than the rate at other temperatures. Body weight was heaviest at 30℃ followed by 27℃, 33℃, and 25℃. The patterns of head capsule, body capsule, and body length were similar to that of body weight. Regression analyses of developmental period, larval body weight, and length according to temperature revealed 29-30℃ as the most suitable temperature. The prepupa rate was 43.1% in 17 instars, 30.3% in 18 instars, 15.4% in 16 instars, 7.1% in 19 instars, 2.2% in 15 instars, and 1.9% in 20 instars, accounting for 88.8% in 16-18 instars. Prepupal period was longer at lower temperatures. For the average prepupal period of 15-18 instars, prepupa time was 18.8±1.9 days at 27℃, 18.8±2.3 days at 30℃, 23.0±2.4 days at 33℃, and 23.1±2.9 days at 25℃. The average pupal period of females and males was 11.1±2.2 and 11.6±2.4 days, respectively. The data indicate that the most suitable rearing temperature of super mealworm was 30℃.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.721-734
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• 2022

This study analyzed the spatio-temporal variation characteristics of major environmental factors such as primary productivity (PP), chlorophyll a, nutrients, sinking particle matters, and organic contamination and biochemical composition of surface sediment on a monthly basis for approximately 2 years around shellfish mariculture in Jaran Bay, Korea. In addition, PP in Jaran Bay was compared with that in other coastal areas and related policy plans were proposed. The average PP of the study area was high in summer and autumn with 6.43~115.43 mgC m^-2 hr^-1 range. This was lower than that in Gamak Bay and Masan Bay, whereas higher than that in Garorim Bay and the West Sea. The PP in coastal waters, where many aquaculture farms were distributed, significantly fluctuated. The different size compositions of phytoplanktons constituting chlorophyll a slightly varied by month, and little restriction existed on the productivity of phytoplanktons owing to the depletion of nutrients. Typically, the Redfield ratio was less than 16, indicating that nitrogen was the limiting factor for the growth of phytoplanktons. The biochemical composition of particulate organic matters in the water column showed the highest carbohydrates, but lipids and protein contents were high in surface sediments. The concentration of TOC and AVS of the surface sediments was high at inside of bay, and sometimes, exceeded the environmental criteria of fishing grounds. The organic C:N ratio of sediments ranged from 8.1 to 10.4 on average. PP had the highest correlation with chlorophyll a, nitrogen and protein of particle organic materials. Recently, chlorophyll a, DIN, and DIP of water column trends tended to decrease, however, the contamination of sediments increased. Considering the annual PP of 125.9 gC m^-2 yr^-1 and mariculture area (oyster) of 4.97 km², the annual carbon production from phytoplanktons was estimated to be about 625 tons, and the annual total wet weight of shellfish (oyster) was estimated to be about 6,250 tons.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.85-103
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• 2023

The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.3
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• pp.360-372
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• 2023

The aim of this study was to identify the current state of pediatric dentists, evaluate the adequacy of pediatric dentist supply and demand, and find out the perception of all pediatric dentists on the current state of pediatric dentists and policy establishment. An Online survey was conducted among pediatric dentists. The questionnaire was subdivided into 'general characteristics', 'number of dental treatments and working days per year', 'proportion of covered services', 'perceptions of supply and demand of pediatric dentists'. Through the Korean Academy of Pediatric Dentistry, the Health Insurance Review and Assessment Services, the National Health Insurance Service (NHIS), and the Korean Statistical Information Service, the current state of pediatric dentists, the number of claims for covered services, and the decrease in births per year were investigated. Dental clinics claiming to be pediatric dentistry reached half of all medical institutions, but only 3.78% of pediatric dentists actually worked. 61.36% of all pediatric dentists were concentrated in the metropolitan area, showing a national imbalance. Although the population of children and adolescents have continuously decreased over the past 20 years, the number of NHIS-covered services has shown a continuous increase. Over the past 10 years, the optimal supply of pediatric dentists has been maintained at around 4,000. According to the analysis, 92.15% of pediatric dentists thought that it was necessary to prepare policies and support measures at the government level. This study is expected to be used as basic data for establishing a demand estimation method for pediatric dentistry specialists in the future.

• Clean Technology
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• v.16 no.3
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• pp.198-205
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• 2010

Two sets of thermal reaction experiment for chlorinated hydrocarbons were performed using an isothermal tubular-flow reactor in order to investigate thermal decomposition, including product distribution of chlorinated hydrocarbons. The effects of $H_2$ or Ar as the reaction atmosphere on the thermal decomposition and product distribution for dichloromethane($CH_2Cl_2$) was examined. The experimental results showed that higher conversion of $CH_2Cl_2$ was obtained under $H_2$ atmosphere than under Ar atmosphere. This phenomenon indicates that reactive-gas $H_2$ reaction atmosphere was found to accelerate $CH_2Cl_2$ decomposition. The $H_2$ plays a key role in acceleration of $CH_2Cl_2$ decomposition and formation of dechlorinated light hydrocarbons, while reducing PAH and soot formation through hydrodechlorination process. It was also observed that $CH_3Cl,\;CH_4,\;C_2H_6,\;C_2H_4$ and HCl in $CH_2Cl_2/H_2$ reaction system were the major products with some minor products including chloroethylenes. The $CH_2Cl_2$/Ar reaction system gives poor carbon material balance above reaction temperature of $750^{\circ}C$. Chloroethylenes and soot were found to be the major products and small amounts of $CH_3Cl$ and $C_2H_2$ were formed above $750^{\circ}C$ in $CH_2Cl_2$/Ar. The thermal decomposition reactions of chloroform($CHCl_3$) with argon reaction atmosphere in the absence or the presence of $CH_4$ were carried out using the same tubular flow reactor. The slower $CH_3Cl$ decay occurred when $CH_4$ was added to $CH_3Cl$/Ar reaction system. This is because :$CCl_2$ diradicals that had been produced from $CHCl_3$ unimolecular dissociation reacted with $CH_4$. It appears that the added $CH_4$ worked as the :$CCl_2$ scavenger in the $CHCl_3$ decomposition process. The product distributions for $CHCl_3$ pyrolysis under argon bath gas were distinctly different for the two cases: one with $CH_4$ and the other without $CH_4$. The important pyrolytic reaction pathways to describe the important features of reagent decay and intermediate product distributions, based upon thermochemistry and kinetic principles, were proposed in this study.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.33-39
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• 2017

Purpose: Surgical risks associated with the resection of osteochondroma around the proximal tibia and fibula, as well as the proximal humerus have been well established; however, the clinical presentation and optimal surgical approach for osteochondroma around the lesser trochanter have not been fully addressed. Materials and Methods: Thirteen patients with osteochondroma around the lesser trochanter underwent resection. We described the chief complaint, duration of symptom, location of the tumor, mass protrusion pattern on axial computed tomography image, tumor volume, surgical approach, iliopsoas tendon integrity after resection, and complication according to the each surgical approach. Results: Pain on walking or exercise was the chief complaint in 7 patients, and numbness and radiating pain in 6 patients. The average duration of symptom was 19 months (2-72 months). The surgical approach for 5 tumors that protruded postero-laterally was postero-lateral (n=3), anterior (n=1), and medial (n=1). All 4 patients with antero-medially protruding tumor underwent the anterior approach. Two patients with both antero-medially and postero-laterally protruding tumor received the medial and anterior approach, respectively. Two patients who underwent medial approach for postero-laterally protruded tumor showed extensive cortical defect after resection. One patient who received the anterior approach to resect a large postero-laterally protruded tumor developed complete sciatic nerve palsy, which was recovered 6 months after re-exploration. Conclusion: For large osteochondromas with posterior protrusion, we should not underestimate the probability of sciatic nerve compression. When regarding the optimal surgical approach, the medial one is best suitable for small tumors, while the anterior approach is good for antero-medial or femur neck tumor. For postero-laterally protruded large tumors, posterior approach may minimize the risk of sciatic nerve palsy.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.339-350
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• 2024

Purpose: This study analyzes accessibility of 10 hydrogen charging stations in Seoul and identifies areas that were difficult to access. The purpose is to re-analyze accessibility by adding a new location in terms of equity and safety of location placement, and then draw implications by comparing the improvement effects. Method: By applying the location-allocation model and the service area model based on network analysis of the ArcGIS program, areas with weak access were identified. The location selection method applied the 'Minimize Facilities' method in consideration of the need for rapid arrival to insufficient hydrogen charging stations. The limit distance for arrival within a specific time was analyzed by applying the average vehicle traffic speed(23.1km/h, Seoul Open Data Square) in 2022 to three categories: 3,850m(10minutes), 5,775m(15minutes), 7,700m(20minutes). In order to minimize conflicts over the installation of hydrogen charging stations, special standards of the Ministry of Trade, Industry and Energy applied to derive candidate sites for additional installation of hydrogen charging stations among existing gas stations and LPG/CNG charging stations. Result: As a result of the analysis, it was confirmed that accessibility was significantly improved by installing 5 new hydrogen charging stations at relatively safe gas stations and LPG/CNG charging stations in areas where access to the existing 10 hydrogen charging stations is weak within 20 minutes. Nevertheless, it was found that there are still areas where access remains difficult. Conclusion: The location allocation model is used to identify areas where access to hydrogen charging stations is difficult and prioritize installation, decision-making to select locations for hydrogen charging stations based on scientific evidence can be supported.

• Research in Plant Disease
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• v.30 no.2
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• pp.139-147
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• 2024

Erwinia amylovora is a gram-negative plant pathogen that causes fire blight in apple and pear trees, resulting in significant damage worldwide. In this study, we monitored the emergence of fire blight from 2019 to 2023 to determine the emergence patterns and the factors affecting the outbreak of the disease. As a result of the 5-year survey on the emergence of fire blight, a total of 2,029 cases have emerged, mostly in apple trees of 1,378 cases (67.9%) followed by 645 cases (31.8%) in pear trees, and from quince, hawthorn, and mountain ash trees. Fire blight appeared in specific areas of Gyeonggi, Chungnam, Gangwon, and Chungbuk provinces in 2019, but spread to Andong and Yesan in 2021, Muju and Bonghwa in 2023. In 2020 and 2021, there were 744 and 618 cases of fire blight outbreaks, respectively, compared to other years (188-245 cases/year). Notably, 914 of these cases were observed in apple trees from May to July, with 667 cases reported in Chungju and Jecheon. The incidence of fire blight was positively correlated with the daily maximum temperatures and rainy days in January and February, as well as the rainy days in May and June. The average age of the diseased pear trees was 25 years, higher than the 10-year average age of the apple trees. This study provides fundamental information to understand the status and factors affecting the fire blight emergence in Korea. Prevention measures should be established through continuous analysis of the status of fire blight.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.170-179
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• 1999

Purpose: To evaluate whether or not sodium restriction had its own beneficial effect and increased the efficiency of the anti-hypertensive drugs on the progression of renal failure. Methods: We studied using the excision remnant kidney model. Treatment groups were as follows: 5/6 nephrectomy and a 0.49% (normal-high) sodium diet (NN); 5/6 nephrectomy and a 0.25% (normal-low) sodium diet (LN); 5/6 nephrectomy, a 0.49% sodium diet and enalapril (NNE); 5/6 nephrectomy, a 0.49% sodium diet and nicardipine (NNN); 5/6 nephrectomy, a 0.25% sodium diet and enalapril (LNE); 5/6 nephrectomy, a 0.25% sodium diet and nicardipine (LNN). Both diets were isocaloric and had the same content of protein, phosphorus and calcium. Proteinuria, remnant kidney weight, mesangial expansion scores, and glomerular volume were assessed. Results: Blood pressure tended to be lower in LN compared to NN (P<0.05). NN developed progressive hypertension. LNE, LU, NNE, and NNN reduced blood pressure. LNE, LNN, NNE, NNN, and LN had significantly less proteinuria than NN at 16 weeks (P<0.05). At 24 weeks, LN developed proteinuria (82 mg/day), which were lessened in LNE (54 mg/day) and not lessened in LNN (76 mg/day). Mesangial expansion scores were significantly less in LN rats compared to those in NN rats. Glomerular volumes at 24 weeks in LN rats were significantly less compared to those at 16 weeks in NN rats. Mesangial expansion scores and glomerular volumes at 4, weeks, 12 weeks, and 24 weeks were not different among LN, LNE, and LNN groups. Conclusion: Dietary salt restriction lessens renal damage, at least in part, by inhibiting compensatory renal growth and reducing blood pressure. Enalapril was particularly successful in reducing proteinuria and glomerular injury when combined with dietary salt restriction.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.258-266
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• 2005

Licorice Extract and Erythritol, food additives used in korea, are widely used in foods as sweetener. Its application for use in food is regulated by the standard and specification for food additives but official analytical method far determination of these sweetener in food has not been established. Accordingly, we has been carried out to set up analytical method of the glycyrrhizic acid in several foods by the way of thin layer chromatography and high performance liquid chromatography glycyrrhizic acid is qualitative anaylsis technique consists of clean-up with a sep-pak $C_{18}$ cartridge, separation of the sweeteners by Silica gel 60 F254 TLC plate using 1-butanol:4Nammonia solution:ethanol (50:20:10) as mobile solvent. Also, the quantitative analysis for glycyrrhizic acid, was performed using Capcell prk $C_{18}$ column at wavelength 254nm and DW:Acetonitrile (62:38 (pH2.5)) as mobile phase. and we has been carried out to set up analytical method of the erythritol in several foods by the way of high performance liquid chromatography. erythritol is qualitative anaylsis technique consists of clean-up with a DW and hexane. The quantitative analysis for erythritol, was performed using Asahipak NH2P-50 column, Rl and DW:Acetonitrile (25:75) as mobile phase. The glycyrrhizic acid results determined as glycyrrhizic acid in 105 items were as follows; N.D$\∼$48.7ppm for 18 items in soy sauce, N.D$\∼$5.3ppm for 12 items in sauce, N.D$\∼$988.93ppm for 15 items in health food, N.D$\∼$180.7ppm for 26 items in beverages, N.D$\∼$2.6ppm for 8 items in alcoholic beverages repectively and ND for 63 items in the ethers. The erythritol results determined as erythritol in 52 items were as follows; N.D$\∼$155.6ppm for 13 items in gm, N.D$\∼$398.1ppm for 12 items in health foods repectively and ND for 45 items in the others.