• The Korean Journal of Malacology
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• v.27 no.2
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• pp.107-114
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• 2011

The manila clam (Ruditapes philippinarum) is mainly distributed in the coastal area which consist of mud, sand and gravel, but they rarely live on the upper and down reaches of river. For a long time the manila clam has been inhabited in Taehwa river which has been exploited as a traditional earning resources and has become as a major object by neighborhood fishermen. This study was undertaken to evaluate stock assessment and to build management implications with the ecological parameters in Taehwa river from June 2009 to June 2010. The maximum age of manila clam was determined to 6 years old from observing ring radius of shell, the length and weight relationship was TW = $0.0002SL^{3.063}$ ($R^2$ = 0.925). K and $L_{\infty}$ were respectively estimated 46.64 mm and 0.341/year by von Bertalanffy growth. The instantaneous total mortality was estimated to be 1.171/year and the age at first capture was 1.37 years by the Pauly's method using shell length composition. The current total biomass of manila clam was calculated 1,483 mt over study area $1.46\;km^2$ by swept area method. ABC (Acceptable Biological Catch) estimates of manila clam showed 512 mt with using $F_{0.1}$. It's desirable to determine the optimum harvesting time as after main spawning season, as well as it's required to manage fisheries resources considering capture age and biomass through adjusting a first age at capture.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.102-109
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• 2019

Purpose: The purpose of this study was to evaluate the accuracy of three types of intraoral scanners and the accuracy of the single abutment and bridge abutment model. Materials and methods: In this study, a single abutment, and a bridge abutment with missing first molar was fabricated and set as the reference model. The reference model was scanned with an industrial three-dimensional scanner and set as reference scan data. The reference model was scanned five times using the three intraoral scanners (CS3600, CS3500, and EZIS PO). This was set as the evaluation scan data. In the three-dimensional analysis (Geomagic control X), the divided abutment region was selected and analyzed to verify the scan accuracy of the abutment. Statistical analysis was performed using SPSS software (${\alpha}=.05$). The accuracy of intraoral scanners was compared using the Kruskal-Wallis test and post-test was performed using the Pairwise test. The accuracy difference between the single abutment model and the bridge abutment model was analyzed by the Mann-Whitney U test. Results: The accuracy according to the intraoral scanner was significantly different (P < .05). The trueness of the single abutment model and the bridge abutment model showed a statistically significant difference and showed better trueness in the single abutment (P < .05). There was no significant difference in the precision (P = .616). Conclusion: As a result of comparing the accuracy of single and bridge abutments, the error of abutment scan increased with increasing scan area, and the accuracy of bridge abutment model was clinically acceptable in three types of intraoral scanners.

• Journal of agriculture & life science
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• v.53 no.1
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• pp.117-126
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• 2019

This paper presents an experiment to examine the possibility of treating carcass while making compost with a horizontal cylinder composting equipment. The findings were as follows: as for heavy metal content, zinc content was above the allowed level in some measuring sections of the general operation and the entire measuring sections of the carcass operation, whose copper content was higher than the general operation. The wood chip operation was lower than the allowed level in all the heavy metals and similar or the same as the carcass operation in copper, cadmium and arsenic. Its nickel content was 29.5~63.8%, which was relatively higher than 9.3~18.0% and 15.8~18.0% of the general and carcass operation, respectively. Its chrome content was 14.2~31.9%, which was relatively higher than that of the general and carcass operation. The integrated operation was lower than the allowed level in all the heavy metals. Its copper and zinc content was 34.9~54.5% and 53.1~75.9%, which was similar to 48.9~52.6% and 64.6~85.9%, respectively, in the wood chip operation. Its chrome and nickel content was stabilized while their content was rather high in the wood chip operation. The average and final moisture content of the carcass operation was 60.7% and 49.6%, respectively. Its average moisture content was a little bit higher than the recommended level of 55.0%, but its final moisture content was lower than the recommended level. The average and final moisture content of the integrated operation was 29.2% and 18.6%, respectively, which was the lowest level among the four operation modes. The overall moisture content of the operation modes was under the recommended level of 55.0% with some variance among the modes. The C/N ratio was the lowest in the carcass operation and the highest in the general operation. The average C/N ratio of the operation modes was in the range of 13.7~20.3 with the total average of 18.3, and the modes kept it under the proper level of 30.0.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.35-51
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• 2009

Three different Cordyceps militaris(Paecilomyces tenuipes and Cordyceps militaris from grain or pupae) were analysed for their chemical composition, fatty acids composition and the concentration of amino acids, cordycepin and heavy metal to obtain basic information on them as feed supplements for livestock. The crude protein content of C. militaris from grain and pupae was 76.16 and 75.45%, respectively, being higher than that of P. tenuipes(57.21%). The concentration of linoleic acid was much higher but that of linolenic acid was much lower for C. militaris from grain than for the others. The cordycepin content was significantly higher for C. militaris from grain than for that from pupae (1.64% vs 0.68% on a DM basis). But cordycepin was not detected in P. tenuipes. Heavy metal contents(Cr, Pb, Cd, Hg) for all C. militaris were below the allowance levels recommended by Ministry of Agriculture and Forestry in Republic of Korea.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.172-180
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• 2023

This study was carried out to determine the sprouting period of early and mid-season varieties, which includes 'Atlantic', 'Chubaek', and 'Superior', during the summer storage period in a semi-underground warehouse without cooling system. And also it was investigated the effect of chlorpropham [Propan-2-yl N-(3-chlorophenyl)carbamate, CIPC] treatment on the sprouting inhibition for the varieties. This study was conducted to figure out a sprout inhibitory effect when CIPC was applied to 1kg of the potato tubers at concentrations of 10 mg and 20 mg which are lower than the treatment concentrations of ca 30 mg prescribed by the positive list system (PLS). The internal temperature of the warehouse used in this experiment was lowered by 5℃ or more than the outside temperature. The difference between the lowest and highest temperature during the experiment throughout the day was 5℃. It showed the effect of reducing to 1/2 of the difference in outdoor temperature. As for the sprouting of potatoes, the extremely early variety 'Chubaek' sprouts appeared at the 6th week of storage of control and it was the fastest sprouting potato among the control groups of the varieties. Sprouting began to appear in the Superior at the 6th week of storage, while the 'Atlantic' sprouted at the 8th week of storage. The appearance of sprouts was suppressed in all treatment groups of 'Atlantic' and 'Superior' varieties in CIPC treatments. Sprouts were observed in all treatment groups of 'Chubaek' after the 7th week, but the elongations of the sprouts in tubers were completely inhibited until the 8th week of storage. 'Atlantic' and 'Superior' seemed to have a sprouting inhibitory effect even with a low CIPC concentration of 10 mg·kg^-1, with the exception of extremely early variety 'Chubaek' that breaks out of the dormancy quickly. Although weight loss occurred continuously during storage, it was minor loss of 0.7-1.6%. There was no consistent trend for changes of the loss in the varieties and CIPC treatments. Most common pathological disorder was the dry rot during the experiment, but only few were affected. The use of the tubers treated at 18℃ and 90% RH for 10 days and the rack of refrigeration system which lead to lack of convection seemed to have suppressed the spread of pathogens.

• Tuberculosis and Respiratory Diseases
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• v.42 no.6
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• pp.923-933
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• 1995

Background: Pleural abnormality is the the most common respiratory change caused by asbestos dust inhalation and also develop other asbestos related disease after cessation of asbestos exposure. So we conducted epidemiologic study to investigate if the pleural abnormality is associated with pulmonary function change and what factors are influenced on pulmonary function impairment. Methods: Two hundred and twenty two asbestos workers from 9 industries using asbestos in Korea were selected to measure the concentration of sectional asbestos fiber. Ouestionnaire, chest X-ray, PFT were also performed. All the data were analyzed by student t-test and chi-square test using SAS. Regressional analysis was performed to evaluate important factors, for example smoking, exposure concentration, period and the existence of pleural thickening, affecting to the change of pulmonary function. Results: 1) All nine industries except two, airborn asbestos fiber concentration was less than an average permissible concentration. PFT was performed on 222 workers and the percentage of male was 88.3%, their mean age was $41{\pm}9$ years old, and the duration of asbestos exposure was $10.6{\pm}7.8$ yrs. 2) The chest X-ray showed normal(89.19%), pulmonary Tb(inactive)(2.7%), pleral thickening (7.66%), suspected reticulonodular shadow(0.9%). 3) The mean values of height, smoking status, concentration of asbestos fiberwere not different between the subjects with pleural thickening and others, but age, cumulative pack-years, the duration of asbestos exposure were higher in subjects with pleural thickening. 4) All the PFT indices were lower in the subjects with pleural thickening than in the subjects without pleural thickening. 5) Simple regression analysis showed there was a significant correlation between $FEF_{75}$ which is sensitive in small airway obstruction and cumulative smoking pack-years, the duration of asbestos exposure and the concentration of asbestos fiber. 6) Multiple regression analysis showed all the pulmonary function indices were decreased as the increase of cumulative smoking pack-years and especially in the indices those are sensitive in small airway obstruction. Pleural thickening was associated with reduction in FVC, $FEV_1$, PEFR and $FEF_{25}$. Conclusion: The more concentration of asbestos fiber and the more duration of asbestos exposure, the greater reduction in $FEF_{50}$, $FEF_{75}$. Therefore PFT was important in the evaluation of early detection for small airway obstruction. Furthermore pleural thickening without asbesto-related parenchymal lung disease is associated with reduction in pulmonary function.