• Analytical Science and Technology
• /
• v.11 no.1
• /
• pp.62-72
• /
• 1998

This study was performed to characterize the trace organic pollutants in the industrial wastewater and to establish the database of the trace organic pollutants. The four manufacturing industries, which are refined petroleum, industrial chemicals, rubber & plastics and fabricated metals, were surveyed. The wastewater and discharging water of these 30 factories are analyzed to characterize the trace organic pollutants. In industrial chemicals, the kinds of products and organic pollutants are very various. Therefore to select the characteristic organic pollutants in this categories are also very difficult. In industrial chemicals, the gas chromatograpic peak patterns of wastewater are represented the various type according to their products, therefore the typical patterns of the characteristic organic pollutants could not be obtained because the kinds of manufactured goods and organic pollutants are very various. In refined petroleum, the effluent is discharged in the distillatory process of atmosphere pressure and contained the saturated hydrocarbons, phenol compounds, benzene compounds and naphtalene compounds. The saturated hydrocarbons peaks from $C_{15}$ to $C_{35}$ are represented the typical oil patterns by the uniform intervals therefore the peak can be easily distinguished. In rubber & plastics, the wastewater is discharged in the washing process which contains the additives. The problem of wastewater is not serious because the manufacturing process is not produced the effluent or the produced cooling water is recycled in that process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.195-202
• /
• 2019

This study was undertaken to investigate whether the local Woori black pigs could replace Duroc as the terminal sire in order to reduce foreign currency outgoings. This study compared the physicochemical properties of pork loins in two cultivars of three-way crossbred pigs: Landrace ${\times}$ Yorkshire ${\times}$ Duroc (LYD) and Landrace ${\times}$ Yorkshire ${\times}$ Woori black pig (LYW). A total of 119 pigs (59 LYD and 60 LYW) aged 180 days were used in the experiment. After 24 hours of cooling, pork loins were assessed for their physicochemical traits, meat color, fatty acid and sensory evaluation. The moisture content and water holding capacity showed no significant difference between the two cultivars. Fat content and cooking loss were significantly higher in LYW than in LYD (p<0.05), whereas shear force and pH were significantly lower in LYW than LYD (p<0.05). Redness ($a^*$), yellowness ($b^*$), and stearic acid (C18: 0) content were also significantly higher in LYW than in LYD (p<0.05). Sensory evaluation revealed significantly higher meat color and flavor in LYW than LYD (p<0.05). Taken together, these results indicate that certain physicochemical qualities are improved in the LYW cultivar, as compared to LYD. Therefore, Woori black pig (W) has the potential to be substituted for Duroc, a breeding pig used currently.

• Journal of Food Hygiene and Safety
• /
• v.36 no.5
• /
• pp.400-406
• /
• 2021

The purpose of this study was to evaluate the microbial contamination level of Korean traditional rice cakes (Garaetteok, Injeolmi, Gyeongdan), as well as manufacturing environment of small-sized businesses in Korea. The contamination levels of total aerobic bacteria, coliforms, and Bacillus cereus in raw materials were 3.76-4.48, 2.21-4.14, and 1.02-1.15 log CFU/g respectively. On the other hand, Escherichia coli was not found. It has been found that the contamination level of total aerobic bacteria, coliforms, and B. cereus in the raw material decreased after the washing process, but it increased again during the soaking and grinding process. However, after the steaming stage, the contamination level increased again during the molding and cooling process, suggesting the need to take cautions in managing cooling water and molded rice cakes in the process. These results suggest that the safe management of cooling water and taking cautions in the drying process after steaming of rice cakes are necessary for controlling cross-contamination. No E. coli was detected during the manufacturing process involving all tested rice cakes. The microbial contamination level of manufacturing environment such as rice grinder and rice cake forming machine was high. Therefore, in terms of food safety strategy, it is necessary to consider introducing systematic cleansing and disinfection procedure to processing equipment and environment for the sake of reducing microbiological risks.

• Journal of Intelligence and Information Systems
• /
• v.27 no.2
• /
• pp.33-54
• /
• 2021

With the fourth industrial revolution and the arrival of the New Normal era due to Corona, the importance of Non-contact technologies such as artificial intelligence and big data research has been increasing. Convergent research is being conducted in earnest to keep up with these research trends, but not many studies have been conducted in the area of nuclear research using artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. This study was conducted to confirm the applicability of data science analysis techniques to the field of nuclear research. Furthermore, the study of identifying trends in nuclear spent fuel recognition is critical in terms of being able to determine directions to nuclear industry policies and respond in advance to changes in industrial policies. For those reasons, this study conducted a media trend analysis of pyroprocessing, a spent nuclear fuel treatment technology. We objectively analyze changes in media perception of spent nuclear fuel dry treatment techniques by applying text mining analysis techniques. Text data specializing in Naver's web news articles, including the keywords "Pyroprocessing" and "Sodium Cooled Reactor," were collected through Python code to identify changes in perception over time. The analysis period was set from 2007 to 2020, when the first article was published, and detailed and multi-layered analysis of text data was carried out through analysis methods such as word cloud writing based on frequency analysis, TF-IDF and degree centrality calculation. Analysis of the frequency of the keyword showed that there was a change in media perception of spent nuclear fuel dry treatment technology in the mid-2010s, which was influenced by the Gyeongju earthquake in 2016 and the implementation of the new government's energy conversion policy in 2017. Therefore, trend analysis was conducted based on the corresponding time period, and word frequency analysis, TF-IDF, degree centrality values, and semantic network graphs were derived. Studies show that before the 2010s, media perception of spent nuclear fuel dry treatment technology was diplomatic and positive. However, over time, the frequency of keywords such as "safety", "reexamination", "disposal", and "disassembly" has increased, indicating that the sustainability of spent nuclear fuel dry treatment technology is being seriously considered. It was confirmed that social awareness also changed as spent nuclear fuel dry treatment technology, which was recognized as a political and diplomatic technology, became ambiguous due to changes in domestic policy. This means that domestic policy changes such as nuclear power policy have a greater impact on media perceptions than issues of "spent nuclear fuel processing technology" itself. This seems to be because nuclear policy is a socially more discussed and public-friendly topic than spent nuclear fuel. Therefore, in order to improve social awareness of spent nuclear fuel processing technology, it would be necessary to provide sufficient information about this, and linking it to nuclear policy issues would also be a good idea. In addition, the study highlighted the importance of social science research in nuclear power. It is necessary to apply the social sciences sector widely to the nuclear engineering sector, and considering national policy changes, we could confirm that the nuclear industry would be sustainable. However, this study has limitations that it has applied big data analysis methods only to detailed research areas such as "Pyroprocessing," a spent nuclear fuel dry processing technology. Furthermore, there was no clear basis for the cause of the change in social perception, and only news articles were analyzed to determine social perception. Considering future comments, it is expected that more reliable results will be produced and efficiently used in the field of nuclear policy research if a media trend analysis study on nuclear power is conducted. Recently, the development of uncontact-related technologies such as artificial intelligence and big data research is accelerating in the wake of the recent arrival of the New Normal era caused by corona. Convergence research is being conducted in earnest in various research fields to follow these research trends, but not many studies have been conducted in the nuclear field with artificial intelligence and big data-related technologies such as natural language processing and text mining analysis. The academic significance of this study is that it was possible to confirm the applicability of data science analysis technology in the field of nuclear research. Furthermore, due to the impact of current government energy policies such as nuclear power plant reductions, re-evaluation of spent fuel treatment technology research is undertaken, and key keyword analysis in the field can contribute to future research orientation. It is important to consider the views of others outside, not just the safety technology and engineering integrity of nuclear power, and further reconsider whether it is appropriate to discuss nuclear engineering technology internally. In addition, if multidisciplinary research on nuclear power is carried out, reasonable alternatives can be prepared to maintain the nuclear industry.

• Korean Journal of Animal Reproduction
• /
• v.27 no.3
• /
• pp.215-223
• /
• 2003

This study was to investigate the effects of fertilization time and culture medium of pig oocytes matured in-vitro by liquid boar sperm. The sperm rich fraction (30∼60 ml) was slowly cooled to room temperature (20∼23$^{\circ}C$) by 2 h after collection. Semen was transferred into 15 ml tubes, centrifuged at room temperature for 10 min 800 ${\times}$ g, and the supernatant solution was poured off. The concentrated sperm was resuspended with 5 ml of the LEN diluent to provide 1.0${\times}$10$^{9}$ sperm/ml at room temperature. The resuspended semen was cooled in a refrigerator to 4$^{\circ}C$. The medium used for oocyte maturation was TCM-199 supplemented with 26.19 mM sodium bicarbonate, 0.9 mM sodium pyruvate, 10 $\mu\textrm{g}$/ml insulin, 2 $\mu\textrm{g}$/ml vitamin B$_{12}$ , 25 mM HEPES, 10 $\mu\textrm{g}$/ml bovine apotransferrin, 150 $\mu$M cysteamine, 10 IU/ml PMSG, 10 IU/ml hCG, 10 ng/ml EGF, 0.4% BSA, 75 $\mu\textrm{g}$/ml sodium penicillin G, 50 $\mu\textrm{g}$/ml streptomycin sulfate and 10% pFF. After about 22 h of culture, oocytes were cultured without cysteamine and hormones for 22 h at 38.5$^{\circ}C$, 5% $CO_2$ in air. Oocytes were inseminated with liquid boar sperm stored at 4$^{\circ}C$ for 2 days after collection. Oocytes were coincubated for 1, 3, 6 and 9 h in 500 ${mu}ell$ mTBM fertilization media with 1.0${\times}$10$^{6}$ sperm/ml concentration, respectively. Thereafter, oocytes were transferred into 500 ${mu}ell$ NCSU-23, HEPES buffered NCSU-23, PZM-3 and PZM-4 culture media, respectively, for further culture of 6, 48 and 144 h. The rates of sperm penetration and male pronuclear formation were higher in the fertilization times for 6 and 9 h than in those for 1 and 3 h. The rates of cleaved oocytes were higher in the fertilization times for 6 and 9 h (85.0 and 84.6%) than in those for 1 and 3 h (61.1 and 76.8%). The percentage of blastocyst formation from the cleaved oocytes was highest in the fertilization time for 6 h (33.6%) than in that for 1, 3 and 9 h (11.4, 23.0 and 29.6%). Mean cell numbers per blastocyst were 32.9, 27.6, 26.3 and 24.4 in the fertilization times for 6, 9, 3 and 1 h, respectively. The rate of blastocyst from the cleaved oocytes and the number of cells per blastocyst were higher in HEPES buffered NCSU-23 culture medium than in NCSU-23, PZM-3 and PZM-4 culture media. In conclusion, we found out that liquid boar sperm stored at 4$^{\circ}C$ could be used for in-vitro fertilization of pig oocytes matured in-vitro. Also, we recommend the coincubation time of 6 h in 500 ${mu}ell$ TBM fertilization medium with 1${\times}$10$^{6}$ sperm/ml concentration and the HEPES buffered NCSU-23 culture medium for in-vitro fertilization of pig oocytes matured in-vitro.

• Journal of the Korean Wood Science and Technology
• /
• v.2 no.2
• /
• pp.32-34
• /
• 1974

The important results which have been obtained in the investigation can be recapitulated as follows. 1. As demonstrated by the experimental results and analyses concerning their effects in the on-ground type mushroom house, the constructions in relation to the side wall and ceiling of the experimental house showed a sufficient heat insulation on effect to protect insides of the house from outside climatic conditions. 2. As the effect on the solar type experimental mushroom house which was constructed in a half basement has been shown by the experimental results and analyses, it has been proved to be effective for making use of solar heat. However there were found two problems to be improved for putting solar house to practical use in the farm mushroom growing: (1) the construction of the roof and ceiling should be the same as for the on ground type house, and (2) the solar heat generating system should be reconstructed properly. 3. Among several ventilation systems which have been studied in the experiments, the underground earthen pipe and ceiling ventilation, and vertical side wall and ceiling ventilation systems have been proved to be most effective for natural ventilation. 4. The experimental results have shown that ventilation systems such as the vertical side wall and underground ventilation systems are suitable to put to practical use as natural ventilation systems for farm mushroom house. These ventilation systems can remarkably improve the temperature of fresh air which is introduced into the house by heat transfers within the ventilation passages, so as to approach to the desired temperature of the house without any cooling or heating operation. For example, if it is assuming that X is the outside temperature and Y is the amount of temperature adjustment made by the influence of the ventilation system, the relationships that exist between X and Y can be expressed by the following regression lines. Underground iron pipe ventilation system. Y=0.9X-12.8 Underground earthen pipe ventilation system. Y=0.96X-15.11 Vertical side wall ventilation system. Y=0.94X-17.57 5. The experimental results have 8hown that the relationships existing between the admitted and expelled air and the $CO_2$ concentration can be described with experimental regression lines or an exponent equation as follows: 5.1 If it is assumed that X is an air speed cm/sec. and Y is an expelled air speed in cm/sec. in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the regression lines shown below: 5.2 If it IS assumed that X is an admitted volume of air in $m^3$/hr. and Y is an expelled volume of air in $m^3$/hr. in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the regression lines shown below. 5.3 If it is assumed that expelled air speed in emisec. and replacement air speed in cm/sec. at the bed surface in a natural ventilation system are shown as X and Y. respectively, since the Y is a function of the X. the relationships that exist between X and Y can be expressed by the following regression line: GE(100%)-CV (50%) ventilation system. Y=-0.54X+0.84 5.4 If it is assumed that the replacement air speed in cm/sec. at the bed surface is shown as X, and $CO_2$ concentration which is expressed by multiplying 1000 times the actual value of $CO_2$ % is shown as Y, in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the following regression line: GE(100%)-CV(50%) ventilation system. Y=114.53-6.42X 5.5 If it is assumed that the expelled volume of air is shown as X and the $CO_2$ concencration which is expressed by multiplying 1000 times the actual of $CO_2$% is shown as Y in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the following exponent equation: GE(100%)-CV(50%) ventilation system. Y=$127.18{\times}1.0093^{-x}$ 5.6 The experimental results have shown that the ratios of the cross sectional area of the GE and CV vent to the total cubic capacity of the house, required for providing an adequate amount of air in a natural ventilation system, can be estimated as follows: GE(admitting vent of the underground ventilation) 0.3-0.5% (controllable) CV(expelling vent of the ceiling ventilation) 0.8-1.0% (controllable) 6. Among several heating devices which were studied in the experiments, the hot-water boilor which wasmodified to be fitted both as hot-water boiler and as a pressureless steam-water was found most suitable for farm mushroom growing.