• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.2
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• pp.131-139
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• 2024

In Korea, mackerel is the most preferred red fish commodity and has been increasingly consumed in chillstored fresh state rather than in frozen or salted fish. Modified atmosphere packaging (MAP) technology as a replacement of air with low O₂ and high CO₂ concentration gas was applied in this study to preserve its freshness. Four MAP conditions of CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) were compared in quality preservation effect with air package used as Control. Three hundred grams mackerel fillets packaged in gas barrier tray were stored for duration of 10 days at 5℃. Quality was assessed in total aerobic bacterial count, pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid-reactive substances (TBARS), peroxide value (POV), texture, and surface color. High CO₂ concentration MAPs (CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), and CO₂(60):O₂(0): N₂(40)) inhibited total aerobic bacteria growth in the fish fillets. MAPs of high CO₂ concentration with O₂ containment (CO₂(60):O₂(30):N₂(10) and CO₂(60):O₂(5):N₂(35)) showed a low TVB-N content through the storage. The treatments containing O₂ above 20% (Control and CO₂(60):O₂(30):N₂(10)) showed more accelerated increases in TBARS and POV than other treatments. The visual appearance was better for fillets in the packages of CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) than for those of other treatments. The MAPs of CO₂(60):O₂(5):N₂(35) and CO₂(60):O₂(0):N₂(40) are expected to be effective in keeping the freshness of mackerel fillets.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.393-412
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• 2024

In selecting a disposal site for high-level radioactive waste, the hydrogeological research of the site is very important, and the hydraulic conductivity and the storage coefficient are key parameters. In this study, the hydraulic conductivity obtained by two different types of field hydraulic test equipment and methods was compared and analyzed for the deep granite rockmass in the Wonju area to understand the hydraulic characteristics of the deep granite rockmass. One was to perform the lugeon test, constant pressure injection test, and slug test at a maximum depth of 602.0 m by using the auto pressure/flow injection system, and the calculated hydraulic conductivity ranged from 1.26E-9 to 4.16E-8 m/s. In the overall depth, the maximum and minimum differences of the hydraulic conductivity were found to be about 33 times, and in the same test section, the difference by test method or analysis method was 1.13 to 8.25 times. In the other, the hydraulic conductivity calculated by performing a constant pressure injection test and a pulse test at a maximum depth of 705.1 m using the deep borehole hydraulic testing system was found to be 1.60E-10 to 2.05E-8 m/s, and the maximum and minimum differences were found to be about 130 times. In the constant pressure injection test, the difference depending on the analysis method was found to be 1.02 to 2.8 times. The hydraulic conductivity calculated by the two test equipment and methods generally showed similar ranges as E-9 and E-8 m/s, and no clear trend was observed according to depth. It was found that the granite rockmass in the Wonju area where the field hydraulic test was conducted showed low or very low rockmass permeability, and although there are differences in the range of hydraulic conductivity and the depth of application that can be measured depending on the applied test equipment and test method, it is generally believed that reliable results were presented.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.214-223
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• 2013

BACKGROUND: This study focused on the development of an analytical method about dichlorprop (DCPP; 2-(2,4-dichlorophenoxy)propionic acid) which is a plant growth regulator, a synthetic auxin for agricultural commodities. DCPP prevents falling of fruits during their growth periods. However, the overdose of DCPP caused the unwanted maturing time and reduce the safe storage period. If we take fruits with exceeding maximum residue limits, it could be harmful. Therefore, this study presented the analytical method of DCPP in agricultural commodities for the nation-wide pesticide residues monitoring program of the Ministry of Food and Drug Safety. METHODS AND RESULTS: We adopted the analytical method for DCPP in agricultural commodities by gas chromatograph in cooperated with Electron Capture Detector(ECD). Sample extraction and purification by ion-associated partition method were applied, then quantitation was done by GC/ECD with DB-17, a moderate polarity column under the temperature-rising condition with nitrogen as a carrier gas and split-less mode. Standard calibration curve presented linearity with the correlation coefficient ($r^2$) > 0.9998, analysed from 0.1 to 2.0 mg/L concentration. Limit of quantitation in agricultural commodities represents 0.05 mg/kg, and average recoveries ranged from 78.8 to 102.2%. The repeatability of measurements expressed as coefficient of variation (CV %) was less than 9.5% in 0.05, 0.10, and 0.50 mg/kg. CONCLUSION(S): Our newly improved analytical method for DCPP residues in agricultural commodities was applicable to the nation-wide pesticide residues monitoring program with the acceptable level of sensitivity, repeatability and reproducibility.

• Korean Journal of Poultry Science
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• v.12 no.1
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• pp.7-16
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• 1985

Present experiment was undertaken to compare the effects of two dietary fats whose free fatty acid content was quite different on performances and on meat quality of broilers. Yellow grease or animal fat (trade name) containing 15 or 38.6% free fatty acid, respectively, was added to the broiler starter and finisher diets at levels of 3.0 and 5,0%, respectively. A total of 108, day old, male Maniker(Chunho) broiler chicks was alloted to 3 dietary treatments with 3 replications per treatment and 12 chicks per replication Though control diet was not supplemented with fat, the three dietary groups were made isocaloric and isonitrogenous. All the chicks were ad libitum fed the test diets for 8 weeks. Feed intake and body weight were measured every other week. Shank color was measured at the end of feeding trial by Roche Color Fan. To evaluate meat quality, 7 chicks of mean body weight were selected from each treatment group after the trial. Measurements were made for abdominal fat content, organoleptic scores for thigh and breast, and for contents of total lipids, free fatty acids, iodine values and peroxide values of the breasts. During the period from 0 to 4 weeks of age, the broilers fed the diets added with fats performed the same as those fed the control diet. However, the body weight gam (25%), feed intake (10.8%) and feed efficiency (11.3%) of chicks fed the fat-supplemented diets, during the finisher period (5-8 weeks), appeared significantly improved compared to those of control group (p＜0.05). During overall period of 8 weeks, body weight gain, feed intake, and feed efficiency of chicks fed the diets added with fats were, on the average, 16.2. 8.8 and 6.8%, respectively, better than, those of control Monwhile the performance between the chicks fed diets added with the two different fat sources appeared to be of the same tendency. Though the shank pigmentation was not statistically different among the treatments, the chicks fed the fat-supple ented diets tended to have slightly less pigments than the control. Organoleptic scores of thigh or breast of chicks fed the animal fat diet were of the same range as those of the other two groups. The contents of total lipids, free fatty acids, iodine values and peroxide values of breasts from broilers fed the various diets appeared to be in the same ranges among the treatments. The values for control, yellow grease and animal fat groups were 7.77, 6.66 and 6.32% for total lipids, 9.23, 9.7 and 9.31mg oleic acid/g fat for free fatty acids, 65.36, 63.89 and 59.25g/ 100g fat for iodine values, and 9.62, 10.46 and 8.79 meq/kg fat for peroxide values, respect vely. Changes of free fatty acids contents of breast during a storage for 10 da s at 4$^{\circ}C$ were also not different among the dietary groups. From the observations n. this experiment, it seems possible to conclude that the animal fat containing 38.6% free fatty acid can be used as efficiently as yellow grease in broiler diets without any adverse effects on meat quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.123-136
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• 1982

We investigated the changes in protein and free amino acid compositions of the muscles, and amino acid composition of the muscle proteins during postmortem storage of dorsal white and lateral dark muscles of Yellowtail, Seriola quinqueradita, which were kept at $2^{\circ}C$. We present an extensive discussion on the relationship between the changes of freshness and those of protein compositions in the white and the dark muscle of the red-fleshed fish by analyzing polyacrylamide gel electrophoretograms of $NaDodSO_4-solubilized$ sarcoplasmic and myofibrillar proteins extracted from the both muscles. By assessing K-value, total volatile basic nitrogen and pH value as a criterion of freshness, we found that the dark muscle undergoes a more rapid decrease in its freshness compared to that of the white muscle. The contents of the sarcoplasmic and the myofibrillar protein were decreased with postmortem aging of the muscles while those of the residual intracellular protein were increased, and these changes were somewhat faster in the dark muscle than in the white muscle. From the analysis of the electrophoretograms and their densitograms, we found that the sarcoplasmic proteins of the white and the dark muscle were respectively composed of 16 and 12 components. The sarcoplasmic protein of the white muscle lapsed for 10 days showed an increase of 18,000 and 41,000 dalton components, and a gradual decrease of 23,000 and 23,500 dalton components, whereas the sarcoplasmic protein of the dark muscle lapsed for 9 days showed a decrease of 49,000 dalton component, an appearence of a newly formed component of 47,000 dalton, and a disappearance of 26,000 dalton component. The electrophoretograms of the myofibrillar proteins shelved that the white and the dark muscle were composed of 17 and 16 components, respectively. Depending on the lapsed time of postmortem under the controlled condition, the myofibrillar proteins of the white muscle showed an increase of 40,000 dalton component, a gradual decrease of 37,500 dalton component, an appearance of a newly forming component of 32,000 dalton and a disappearance of 26,000 dalton component. On the other hand, the myofibrillar proteins of the dark muscle showed an increase of 58,000 and 64,000 dalton bands, a disappearance of light chain-2 protein and an appearance of a newly forming protein of 32,000 dalton. These changes on the electrophoretic patterns in the dark muscle were more rapid than those in the white muscle. In almost all of the cases, we observed that the changes in the sarcoplasmic protein were faster than those in the myofibrillar protein. The analysis of amino acid of the both muscle proteins showed that the white muscle was rich in glutamic acid, aspartic acid, leucine, arginine, lysine, etc. but was poor in proline and tryptophan. No significant difference was found in the amino acid composition of protein of both the white and the dark muscles. The sample of white muscle lapsed for 10 days shows a remarkable decrease in glutamic and aspartic acids, while that of the dark muscle lapsed for 9 days shows an appreciable decrease in alanine, glycine and arginine. The free amino acid compositions of the white and the dark muscles are respectively characterized with $63\%$ of histidine and $67\%$ of taurine with respect to the total free amino acids of the yellowtail at-death, respectively. The white muscle lapsed for 10 days showed an increase of histidine, valine and taurine, and a slight decrease of alanine, leucine and glycine. The dark muscle lapsed for 9 days shelved an increase of taurine, phenylalanine and glycine, and a decrease of histidine, alanine and serine.

• Journal of Nutrition and Health
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• v.7 no.3
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• pp.1-13
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• 1974

The relative state of human iron storage may be ascertained more reliably through determination of the serum iron, iron binding capacity, transferrin saturation and absorption of radioactive iron in conjunction with studies of red cell morphology than from the study of red cell morphology alone. Recent investigations have shown that there is an increase in red cell protoporphyrin concentration in iron deficiency anemia. The significance of the red cell protoporphyrin has been discussed greatly during the years since its discovery. Two of the main factors which appear to influence the amaunt of protoporphyrin are increased erythropoiesis and factors interfering with the utilization of iron in the synthesis of hemoglobin, and iron deficiency. Recently Heller et al. have described a simplified method for blood protoporphyrin assay and this technique could be used assess nutritional iron status, wherein even minor insufficiencies are detectable as increased protoporphyrin concentrations. Based on the evaluation of the relationship between nutritional iron status and red cell protoporphyrin as an index suitable for the detection of the iron deficiency is described in this paper. RESULTS 1. Hemoglobin Concentrations and Anthropometric Measurements. The mean and standard deviations of the various anthropometric measurements of different age and sex groups are shown in table 1. There measurements have been compared with the Korean Standard. In the absence of local standards for arm circumference and skin-fold thickness over triceps, they have been compared with the standard from Jelliffe. Table 2,3, and 4 give anthropometric measurements and frequency (%) of anemia in children surveyed. The mean height of the children studid was 10 to 20 percent; below the Korean Standard. The distribution of height below 80 percent of the Standard was 21.2 percent, however, among anemic group this percentage was 27.7 percent. In general, the mean weight of the children was 10 to 15 percent below the Korean Standard. The percentage of children with weight less than 80 percent of the Standard was about 35 percent. But in the anemic group of the children, this percentage was 44 percent. The mean arm circumference was about 15 percent lower than the Jelliffe's standard. 61.2 percent of the children had values of arm circumference below 80 percent of the standard. Children with low hemoglobin levels, this percentage was 80 percent. The mean skinfold thickness over the triceps of the children studied was about 25 Percent lower than the Jelliffe's standard and 61.2 percent of the children had the value less than 80 percent of the standard. Among anemic children, this percentage was 70.8%. As may be seen from table 5, the mean hemoglobin concentration of the total group was 11.3g/100ml. Hemoglobin concentration was less than 11.0g/100ml. in 65(36.5%) of the 178 children. The degree of anemia in most of these children was mild with a hemoglobin level of less than 8.0g/100ml. found in only one child. In general, the prevalence of anemia was high in female children than male and decreased its frequency with increasing age. Relatively close relationship was observed between hemoglobin level and anthrophometric measurements especially high between arm circumference and skinfold thickness and hemoglobin but very low in height and low in weight and hemoglobin level, estimated by chi-square value. II. Serum iron, Transferrin saturation (1) Serum iron, and transferrin saturation Serum iron, transferrin saturation and red cell protoporphyrin concentrations were estimated in sub-sample of 84 children from 1 to 6 years and 24 older children between 7 and 13 years of age. The findings are presented in table 6. The mean serum iron concentration of the total group was 59ug/100ml. However, the level incrased with age from 36.6ug/100ml. (1-3years) to 80.8ug/100ml. (7-13 years). 60 percent of these children had a serum iron level less than 50ug/10ml. in the 1-3 years age group and 31.4 percent for 4-6 years group. These contrast with the finding of 12.5 percent anemic children in the 7-13 years age group. The mean transferrin saturation for the total group was 18.1 percent and frequency of anemia by transferrin saturation was observed same pattern as serum iron concentration. (2) Red cell protoporphyrin concentrations. (a) Red cell protoporphrin levels of children: Red cell protoporphyrin and other biochemical data are shown in table 4. The mean concentration in red cell of all children was fround 46.3ug/100ml. RBC. and differences with age groups were observed; in the age group 1-3 years, the mean concentration was $59.5{\pm}32.14$ ug/100ml. RBC; 4-6 years $44.1{\pm}22.57$ ug/100ml. RBC. and 7-13 years, $39.0{\pm}13.56$ ug/100ml. RBC. (b) Normal protoporphyrin values in adults: It was observed that in 10 normal adult males studied here the level of protoporphyrin in red cell ranged from 18 to 54 ug/100ml. RBC. and the mean concentration was $47.5{\sim}14.47$ ug/100ml. RBC. Other biochemical determination made on the same subjects are presented in table 8. (c) Red tell protoporphyrin concentration of occupational blood donors: The results of analyses for red cell protoporphyrin as well as serum iron, transferrin saturation and hemoglobin in the 76 blood donors are presented in table 7 and 8. In this experiment, donors were selected at random, however, most of them bled repeatedly because of poor economic situation, I doubt. Table 9 shows the distribution of red cell protoporphyrin concentration and hemoglobin concentration of occupational donors. The mean hemoglobin value for the total was 11.9 g/100 ml. When iron deficiency anemia is defined as a transferrin saturation below 15%, prevalence of anemia was 47.4 percent and the mean serum iron was 27.1ug/100ml. and red cell protoporphyrin, 168.3ug/100ml. RBC. However, mean serum iron and protoporphyrin concentration of above 15% transferrin saturation were 11.6 ug/100 ml. and 58.8 ug/100 ml. RBC. respectively. The mean Protoporphyrin concentration of non-anemic (above 15% transferrin saturation) donors was slightly higher than the results of normal adult males.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.77-87
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• 1996

In order to compare the difference of the measurement of delta aminolevulinic acid(${\delta}$-ALA) in urine between HPLC method(HALA) and colorimetric method(CALA), and also to provide useful information for the new diagnostic criteria of ${\delta}$-ALA in urine in lead poisoning, if at all possible in the future, authors studied 234 male lead workers who were selected from 7 storage battery factories, 3 secondary smelting industries, and 2 litharge making industries. Study subjects were selected on the basis of blood Zinc protoporphyrin(ZPP) level from low to high concentration to cover wide range of lead exposure. Study variables for this study were ${\delta}$-ALA measured by two different methods, blood lead(PbB), and blood ZPP. The results were as follows: 1. There was very high correlation between ${\delta}$-ALA measured by two method(r = 0.989 : HALA = -0.8194 + 0.8110 ${\times}$ CALA), but the value of CALA was measured about 2mg/L greater than HALA. 2. While the correlations of ${\delta}$-ALA by two method with blood lead and blood ZPP were 0.46 and 0.37 respectively, they were increased to 0.63 and 0.57 if ${\delta}$-ALA values were log-transformed. 3. Simple linear regression of ${\delta}$-ALA measured by two method on ZPP were as follows: CALA = 2.0421 + 0.0341 ${\times}$ ZPP ($R^2=0.1385$ p = 0.0001) HALA = 0.8006 + 0.0280 ${\times}$ ZPP ($R^2=0.1389$ p = 0.0001) 4. Simple linear regression of ${\delta}$-ALA measured by two method on PbB were as follows: CALA = - 0.4134 + 0.1545 ${\times}$ PbB ($R^2=0.2085$ p = 0.0001) HALA = -1.2893 + 0.1287 PbB ($R^2=0.2154$ p = 0.0001), 5. Simple linear regression of log-transformed ${\delta}$-ALA by two method on ZPP and PbB were as follows: logHALA = 0.3078 + 0.0060 ZPP ($R^2=0.3329$ p = 0.0001) logCALA = 1.0189 + 0.0044 ZPP ($R^2=0.3290$ p = 0.0001) logHALA = -0.0221 + 0.0246 PbB ($R^2=0.4046$ p = 0.0001) logCALA = 0.7662 + 0.0184 PbB ($R^2=0.4108$ p = 0.0001) 6. The cumulative percent of colorimetric method to detect lead workers whose value of PbS and ZPP were over screening level such as $40{\mu}/dl$ and $100{\mu}/dl$ respectively was higher than HPLC method if cut-off level of ${\delta}$-ALA for screening of lead poisoning was 5 mg/L. But if cut-off level of ${\delta}$-ALA measured by HPLC was reduced to 3 mg/L which is compatible to 5 mg/L of ${\delta}$-ALA measured by colorimetric method, there were good agreement between two methods and showed dose-response relationship with other lead exposure indices such as PbB and ZPP.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.299-311
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• 1995

Platelets resemble monoaminergic neurons in several respects, i.e. the uptake of 5-HT and its inhibition, the subcellular storage and release of 5-HT, and the metabolism of aromatic amines brought about by monoamine oxidase. And the 5-HT content of rabbit platelets is well known to be about 40 times higher than that of human platelets. Therefore, this study was carried out to investigate the influences of amitriptyline (AMT) and sertraline (SRT) on the aggregation, contents of signaling second messengers, and protein phosphorylations of rabbit platelets in response to thrombin, 0.25 unit/ml, comparing with those of chlorpromazine (CPZ). Thrombin-induced aggregation was inhibited by SRT $(IC50:4.37{\times}10^{-5}\;M)$, CPZ $(IC50:5.76{\times}10^{-5}\;M)$, and AMT $(IC50:1.15{\times}10^{-4}\;M)$, respectively, and the aggregation by A23187 $(1.0\;{\mu}M)$ or PMA (320 nM) was also inhibited by SRT, CPZ, and AMT. AMT, SRT, and CPZ had little affects on basal contents of platelet $TXB_2$ and $PGE_2$, but all of them inhibited the thrombin-induced increase of $TXB_2$. Thrombin did not change the platelet contents of cAMP and cGMP. CPZ, AMT, and SRT produced the slight decrease of basal cAMP content, and their effects were not affected by thrombin-treatment. But SRT and AMT moderately increased the basal cGMP content, and the cGMP content of thrombin-stimulated platelets was gradually increased by the pretreatment with SRT, AMT, and CPZ. Particularly, the SRT-dependent increase of the cGMP content was notable. Platelet $Ins(1,4,5)P_3$ content was rapidly increased up to a plateau within 10 sec after thrombin-stimulation, AMT, SRT, and CPZ increased the basal $Ins(1,4,5)P_3$ content, and the thrombin-dependent increase was enhanced by pretreatment with CPZ and AMT, but was blunted by SRT. Platelet $[Ca^{2+}]_i$, was rapidly increased up to a peak level within 20 sec after thrombin-stimulation. The increase of $[Ca^{2+}]_i$ was sisnificantly inhibited by AMT, SRT, and CPZ. Thrombin- or PMA-induced phosphorylations of platelet $41{\sim}43\;kDa$ and 20 kDa proteins were significantly inhibited by AMT, SRT, and CPZ. These results suggest that the antiplatelet activities of AMT and CPZ may be considerably attributed to the inhibition of protein kinase C activity, and the activity of SRT may be associated with the inhibitory effect on the thrombin-induced increase of $Ins(1,4,5)P_3$ and the increasing effect on the cGMP content of ptatelets. Therefore, it seems to be evident that AMT and SRT may produce their antidepressant activity, at least, partly through the inhibition of protein kinase C activity or the increase of resting $Ins(1,4,5)P_3$, content and in case of SRT, to a lesser extent, via the increase of cGMP in the brain.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.1-26
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• 2009

We conclude the following with air pollution data measured from city measurement net administered and managed in Gwangju for the last 7 years from January in 2001 to December in 2007. In addition, some major statistics governed by Gwangju city and data administered by Gwangju as national official statistics obtained by estimating the amount of national air pollutant emission from National Institute of Environmental Research were used. The results are as follows ; 1. The distribution by main managements of air emission factory is the following ; Gwangju City Hall(67.8%) > Gwangsan District Office(13.6%) > Buk District Office(9.8%) > Seo District Office(5.5%) > Nam District Office(3.0%) > Dong District Office(0.3%) and the distribution by districts of air emission factory ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%). That by types(Year 2004~2007 average) is also following ; Type 5(45.2%) > Type 4(40.7%) > Type 3(8.6%) > Type 2(3.2%) > Type 1(2.2%) and the most of them are small size of factory, Type 4 and 5. 2. The distribution by districts of the number of car registrations is the following ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%) and the distribution by use of car fuel in 2001 ; Gasoline(56.3%) > Diesel(30.3%) > LPG(13.4%) > etc.(0.2%). In 2007, there was no ranking change ; Gasoline(47.8%) > Diesel(35.6%) > LPG(16.2%) >etc.(0.4%). The number of gasoline cars increased slightly, but that of diesel and LPG cars increased remarkably. 3. The distribution by items of the amount of air pollutant emission in Gwangju is the following; CO(36.7%) > NOx(32.7%) > VOC(26.7%) > SOx(2.3%) > PM-10(1.5%). The amount of CO and NOx, which are generally generated from cars, is very large percentage among them. 4. The distribution by mean of air pollutant emission(SOx, NOx, CO, VOC, PM-10) of each county for 5 years(2001~2005) is the following ; Buk District(31.0%) > Gwangsan District(28.2%) > Seo District(20.4%) > Nam District(12.5%) > Dong District(7.9%). The amount of air pollutant emission in Buk District, which has the most population, car registrations, and air pollutant emission businesses, was the highest. On the other hand, that of air pollutant emission in Dong District, which has the least population, car registrations, and air pollutant emission businesses, was the least. 5. The average rates of SOx for 5 years(2001~2005) in Gwangju is the following ; Non industrial combustion(59.5%) > Combustion in manufacturing industry(20.4%) > Road transportation(11.4%) > Non-road transportation(3.8%) > Waste disposal(3.7%) > Production process(1.1%). And the distribution of average amount of SOx emission of each county is shown as Gwangsan District(33.3%) > Buk District(28.0%) > Seo District(19.3%) > Nam District(10.2%) > Dong District(9.1%). 6. The distribution of the amount of NOx emission in Gwangju is shown as Road transportation(59.1%) > Non-road transportation(18.9%) > Non industrial combustion(13.3%) > Combustion in manufacturing industry(6.9%) > Waste disposal(1.6%) > Production process(0.1%). And the distribution of the amount of NOx emission from each county is the following ; Buk District(30.7%) > Gwangsan District(28.8%) > Seo District(20.5%) > Nam District(12.2%) > Dong District(7.8%). 7. The distribution of the amount of carbon monoxide emission in Gwangju is shown as Road transportation(82.0%) > Non industrial combustion(10.6%) > Non-road transportation(5.4%) > Combustion in manufacturing industry(1.7%) > Waste disposal(0.3%). And the distribution of the amount of carbon monoxide emission from each county is the following ; Buk District(33.0%) > Seo District(22.3%) > Gwangsan District(21.3%) > Nam District(14.3%) > Dong District(9.1%). 8. The distribution of the amount of Volatile Organic Compound emission in Gwangju is shown as Solvent utilization(69.5%) > Road transportation(19.8%) > Energy storage & transport(4.4%) > Non-road transportation(2.8%) > Waste disposal(2.4%) > Non industrial combustion(0.5%) > Production process(0.4%) > Combustion in manufacturing industry(0.3%). And the distribution of the amount of Volatile Organic Compound emission from each county is the following ; Gwangsan District(36.8%) > Buk District(28.7%) > Seo District(17.8%) > Nam District(10.4%) > Dong District(6.3%). 9. The distribution of the amount of minute dust emission in Gwangju is shown as Road transportation(76.7%) > Non-road transportation(16.3%) > Non industrial combustion(6.1%) > Combustion in manufacturing industry(0.7%) > Waste disposal(0.2%) > Production process(0.1%). And the distribution of the amount of minute dust emission from each county is the following ; Buk District(32.8%) > Gwangsan District(26.0%) > Seo District(19.5%) > Nam District(13.2%) > Dong District(8.5%). 10. According to the major source of emission of each items, that of oxides of sulfur is Non industrial combustion, heating of residence, business and agriculture and stockbreeding. And that of NOx, carbon monoxide, minute dust is Road transportation, emission of cars and two-wheeled vehicles. Also, that of VOC is Solvent utilization emission facilities due to Solvent utilization. 11. The concentration of sulfurous acid gas has been 0.004ppm since 2001 and there has not been no concentration change year by year. It is considered that the use of sulfurous acid gas is now reaching to the stabilization stage. This is found by the facts that the use of fuel is steadily changing from solid or liquid fuel to low sulfur liquid fuel containing very little amount of sulfur element or gas, so that nearly no change in concentration has been shown regularly. 12. Concerning changes of the concentration of throughout time, the concentration of NO has been shown relatively higher than that of $NO_2$ between 6AM~1PM and the concentration of $NO_2$ higher during the other time. The concentration of NOx(NO, $NO_2$) has been relatively high during weekday evenings. This result shows that there is correlation between the concentration of NOx and car traffics as we can see the Road transportation which accounts for 59.1% among the amount of NOx emission. 13. 49.1~61.2% of PM-10 shows PM-2.5 concerning the relationship between PM-10 and PM-2.5 and PM-2.5 among dust accounts for 45.4%~44.5% of PM-10 during March and April which is the lowest rates. This proves that particles of yellow sand that are bigger than the size $2.5\;{\mu}m$ are sent more than those that are smaller from China. This result shows that particles smaller than $2.5\;{\mu}m$ among dust exist much during July~August and December~January and 76.7% of minute dust is proved to be road transportation in Gwangju.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.534-542
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• 2012

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) on fruit quality and incidence of physiological disorders for keeping freshness during marketing period in Asian pear (Pyrus pyrifolia Nakai) 'Wonhwang' and 'Whasan'. Fruits were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 12 hours at $25^{\circ}C$, at two or three stages of ripeness as determined by days after full bloom (DAFB). Fruits were harvested at 130 and 140 DAFB in early season cultivar 'Wonhwang' and 135, 145, and 150 DAFB in mid-season cultivar 'Whasan', respectively. Fruits were stored at $25^{\circ}C$ for 21 days and measured the flesh firmness, weight loss, soluble solids, acidity, ethylene, respiration and severity of physiological disorders at week interval. 1-MCP treatment to 'Wonhwang' pears harvested at 130 and 140 DAFB effectively delayed firmness loss during storage at $25^{\circ}C$. Untreated fruits of 'Wonhwang' pears harvested at 130 DAFB showed 32.3 and 10.1N of firmness after 14 and 21 days of shelf-life at $25^{\circ}C$, respectively, while those of the 1-MCP treated fruits showed 39.4 and 33.1N during same period. In the fruits harvested at 140 DAFB, the firmness of untreated fruit was lowered to 14.8 and 6.6N after 14 and 21 days, respectively, but those of 1-MCP treated fruit were 35.0 and 33.3N, respectively. Whereas, 1-MCP treatment delayed firmness loss only in the fruit harvested late (150 DAFB) in 'Whasan' pears. Higher soluble solids content and acidity during extended shelf-life were apparent in 1-MCP treated 'Wonhwang' pears, while those of 'Whasan' pears were little changed. 'Wonhwang' pears showed a relatively high ethylene production (maximum $0.58{\mu}l{\cdot}L^{-1}$) in the fruits harvested late than early harvested one. 'Whasan' pears showed little amount of ethylene production regardless of extended shelf-life. 1-MCP treatment to 'Wonhwang' pears decreased respiration rate following shelf-life, 42 and 50% reduction were observed at 14 days of shelf-life when compared with those of untreated ones harvested at 130 and 140 DAFB, respectively. No reduction of respiration rate by the treatment of 1-MCP was detected in 'Whasan' pears which showed considerably low respiration rate compared with 'Wonhwang' pears. Harvest time influenced the level of physiological disorders together with extension of shelf-life in both the cultivars. 1-MCP treatment completely blocked the incidence of internal browning of 'Wonhwang' pears harvested at 130 DAFB, and reduced the incidences of pithiness and core browning, while it promoted the flesh spot decay disorder regardless of harvest time. 1-MCP treatment was of little benefit for the prevention of physiological disorders in 'Whasan' pears compared with those of 'Wonhwang'.