• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.596-602
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• 2020

Blending process of adhesive production has a cooling process to cool down the temperature of the solution which was heated up to 76 ℃ with a mineral insulated (MI) cable by 30 ℃ at room temperature. Using a MI cable in the adhesive production process makes the production inefficient because it takes about 10 h for the cooling process. If a jacketed vessel is used instead of the MI cable, it would shorten the cooling downtime without any additional cooling system by using cold water. However, there are various types of jacketed vessels, and thus the most suitable type should be found before set up. In this study, we designed the optimized jacketed vessel for the adhesive production process by calculating the cooling downtime, which impacts production efficiency, as a function of the jacket types using computational fluid dynamics. As a result, the cooling performance of the plain jacket was 32.7% superior to that of the half-pipe coil jacket with the same height. In addition, the plain jacket with 60% spiral baffle reduced the cooling downtime and operating time by 80.4% and 25.1%, respectively.

• The Korean Journal of Food & Health Convergence
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• v.5 no.1
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• pp.1-11
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• 2019

Smoking has become one of the public health harzard affecting the world. In the UK, smoking is responsible for around one in five deaths. The illnesses caused by smoking extend beyond the well-reported links with cancer, heart disease and respiratory illnesses. Hence the research to determine the awareness of the predisposing factor to smoking among adults in sokoto metropolis. A cross-sectional form of descriptive survey research design was used for this study. This is because descriptive studies are used when the characteristics of a population are either unknown or partially known (Hennekens & Buring, 2007), and it was used by Ganley and Rosario (2013) in a related research this justified the use of similar design in a study of similar nature.Two hundred and seventy returned questionnaire was collected, analyzed using descriptive statistic of frequency count, normative percentage and grand mean; as well as inferential statistics of chi-square (${\chi}^2$). The level of significant was fixed at 0.05. Appropriate degrees of freedom were worked out. There was statistical significant influence or relationship with marital status on the predisposing factors of smoking chi-square of 19716.516 greater than the critical value 43.77297at df 30 p<0.05. There were statistical significance chi-square =27468.348 which is greater than the critical value 43.77297 at df= 30. These show that there is a relationship on gender awareness of predisposing factors to smoking rejecting the null hypotheses. The respondents across different lever/year higher institution shows that the awareness of predisposing factors of smoking there were a statistical significance difference chi-square =7168.429 (df=88) greater than critical value 102.342 rejecting the null hypotheses. There is consistent evidence that links exposure to depictions of smoking in movies and initiation of smoking in young people. Over the years television shows and films have effectively built up associations between smoking and glamour, sex and risk-taking. Social learning theory describes how we learn by example from others. We are strongly influenced by our parents, and other people we look up to, such as peers, actors and pop stars. This can lead us to emulate their behaviour and try smoking.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.77-83
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• 2023

Energy consumption is increased by rapid industrialization. As a result, climate change is accelerating due to the increase in CO₂ concentration in the atmosphere. Therefore, a shift in the energy paradigm is required. Hydrogen is in the spotlight as a part of that. Currently 95% of hydrogen is fossil fuel-based reforming hydrogen which is accompanied by CO₂ emissions. This is called gray hydrogen, if the CO₂ is captured and emission of CO₂ is reduced, it can be converted into blue hydrogen. There are 3 technologies to capture CO₂: absorption, adsorption and membrane technology. In order to select CO₂ capture technology, the analysis of the exhaust gas should be carried out. The concentration of CO₂ in the flue gas from the hydrogen production process is higher than 20%if water is removed as well as the emission scale is classified as small and medium. So, the application of the membrane technology is more advantageous than the absorption. In addition, if LNG cold energy can be used for low temperature CO₂ capture system, the CO₂/N₂ selectivity of the membrane is higher than room temperature CO₂ capture and enabling an efficient CO₂ capture process. In this study, we will analyze the flue gas from hydrogen production process and discuss suitable CO₂ capture technology for it.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.172-178
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• 2004

When soybean sprouts aye grown in the closed condition (where the ratio of $\textrm{O}_2$ and $\textrm{CO}_2$ is 7 ： 3), amount of $\textrm{CO}_2$ is increased and $\textrm{O}_2$ is decreased with the passage of time. At the same time, the amount of ethylene is automatically increased. By increasing the concentration of ethylene gas up to 0.5-1.0 ppm in the growth room, the length of sprouts was restricted to 6-7 cm and the thickness of sprouts was increased to 2.70$\pm$0.30 mm. The production of good quality sprouts which were fat and short was possible without application of any growth regulators such as indole-3-acetic acid known to have accumulation problem in humane body. To maintain the freshness during the transportation and prevent sprouts from rotting and bad smell at market, cold storage at 2-$5^{\circ}$ and airtightness which will restrict photosynthesis and respiration (higher than $10^{\circ}$) are needed. The freshness of sprouts is depended on the increase of $\textrm{CO}_2$ and the depletion of $\textrm{O}_2$ in the package. When the sprouts were stored below 1$0^{\circ}C$ (preferably below 8$^{\circ}C$), the concentration of $\textrm{CO}_2$ in the package remained below 30% for more than 60 hours, which was possible to keep sprouts in freshness without any offensive odor, But sprouts were maintained at $13^{\circ}$ for more than 25 hours, the concentration of $\textrm{CO}_2$ increased over 30% and produced an offensive odor. The little amount of $\textrm{O}_2$ gas was existing for 30 hours at $5^{\circ}$ but it was disappeared completely within 7 hours over $10^{\circ}$ and the sprouts became rot and produced severe offensive odor.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.371-376
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• 1996

Au films with a thickness around 1600 $\AA$ were deposited onto glass at room temperature by ion beam sputtering with a 5 cm cold-hollow ion gun at pressure $1\times 10^{-6}-1\times 10^{-5}$ Torr. Irradiation of the Au deposited samples was carried out at pressure of $7\times 10^{-6}$ Torr. For the sputter depositions, $Ar^+$ ion energy was 1 keV, and the current density at the substrate surface was 15 $\mu$A/$\textrm{cm}^2$. Effects of 1 keV $Ar^+$ ion dose($I_d$) between $1\times 10^{16}\; and\;2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$on properties such as crystallinity, surface roughness and adhesion, etc. of the films have been investigated. The Au films sputtered by $Ar^+$ ion beam had only (111) plane and the X-ray intensity of the films decreased with increase of $I_d$. The thickness of Au films reduced with Id. $R_{ms}$ surface roughness of the films increased from 16 $\AA$ at as-deposited to 1118 $\AA$ at ion dose= $2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$. Adhesion of Au film on sputtered at $I_d$= $2\times 10^{17}\;Ar^+\textrm{cm}^{-2}$ was 9 times greater than that of Au film with untreated, as determined by a scratch test.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.153-160
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• 2020

This study was conducted out to investigate the effect of harvest time of the day, precooling or not, and temperature of precooling and storage on the marketability in strawberries 'Maehyang' for export in May. Strawberry colored with 60±5% of the skin was harvested at 07:00 am or 15:00 pm, respectively. After harvesting, some strawberries were precooled to 0, 2, 4℃ for 3 hours in the cold store, respectively, and the others were kept at room temperature. And then, strawberries were stored at low temperature in the cold store set at 4, 8 or 10℃ storage temperatures. The weight loss rate, firmness, soluble solids content, color, incidence of gray mold of strawberries were measured at two days intervals during storage for 14 days. Both 07:00 am and 15:00 pm harvest, fruits as the storage periods lapses increased weight loss rate compared to the weight at harvest time of the day, and the difference in the weight loss rate of fruits depending on the treatment was greater at 15:00 pm harvest than at 07:00 am. Firmness tended to increase again after 8th day at 07:00 am or 15:00 pm harvest, respectively. In the afternoon harvest, 10℃ storage without precooling showed the lowest fruit firmness on the 2nd day after storage. The soluble solids content at 07:00 am or 15:00 pm harvest tended to be maintained at high value with precooled and stored at low temperature as storage days elapse. The color values were significantly higher at 'L' indicating brightness and lower at 'a', indicating redness at low storage temperature regardless of harvesting time of the day and whether it was precooling or not. The incidence of gray mold was higher at 15:00 pm harvest than at 07:00 am harvest, and it was significantly higher in the treatments stored at 10℃ after precooling similarly. In this study, strawberry 'Maehyang' for export harvested at 07:00 am and stored at 4℃ after precooling at 0℃ maintained the best shelf life, therefore, it is judged that desirable to harvest in the morning with low temperature and to precool and store at low temperature.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.25-30
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• 2019

This study investigated the quality changes in whole super sweet corn during thermal processing to extend its shelf-life. To minimize the reduction of unique texture of whole sweet corn after the sterilization, the alcohol sanitation applied and the cold point of a whole corn ear was determined using a computer simulation. The cold point was located between the corn kernel and the cob. The microorganisms on the surface of sweet corn were reduced by more than 1 log CFU/g after alcohol sanitation, then the whole corn was treated to satisfy the degree of sterilization ($F_{121.1}=4$). The quality of sterilized sweet corn was compared with the control that was treated with steaming. The quality changes of sterilized sweet corn during storage were monitored for 9 months at $25^{\circ}C$. The hardness was maintained within 30% of its initial value. The minimum of hardness was $464.50{\pm}103.35g$ and maximum of hardness was $514.50{\pm}81.83g$. The differences in the sugar content among the samples were found, but the sugar content of corn kernel remained within 30% of the control, ranging from $28.83{\pm}1.05$ to $34.36{\pm}0.42%$. The yellowness was higher than that of control by 5%. The maximum value of yellowness was $34.36{\pm}0.42$. The general bacteria and molds and yeasts in corn kernel stored at $25^{\circ}C$ were not detected after 9 months of storage at $25^{\circ}C$. Therefore, in this study, we have demonstrated that the thermal sterilized method extends the shelf-life of whole sweet corn with minimizing its quality changes over 6 months in room temperature.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.52-58
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• 2023

With the increasing awareness of the importance of carbon neutrality in response to global climate change, the utilization of hydrogen as a carbon-free fuel source is also growing. Hydrogen is commonly used in fuel cells (FC), but it can also be utilized in internal combustion engines (ICE) that are based on combustion. Particularly, ICEs that already have established infrastructure for production and supply can greatly contribute to the expansion of hydrogen energy utilization when it becomes difficult to rely solely on fuel cells or expand their infrastructure. However, a disadvantage of utilizing hydrogen through combustion is the potential generation of nitrogen oxides (NOx), which are harmful emissions formed when nitrogen in the air reacts with oxygen at high temperatures. In particular, for the EURO-7 exhaust regulation, which includes cold start operation, efforts to reduce exhaust emissions during the warm-up process are required. Therefore, in this study, the characteristics of nitrogen oxides and fuel consumption were investigated during the warm-up process of cooling water from room temperature to 88℃ using a 2-liter direct injection spark ignition (SI) engine fueled with hydrogen. One advantage of hydrogen, compared to conventional fuels like gasoline, natural gas, and liquefied petroleum gas (LPG), is its wide flammable range, which allows for sparser control of the excessive air ratio. In this study, the excessive air ratio was varied as 1.6/1.8/2.0 during the warm-up process, and the results were analyzed. The experimental results show that as the excessive air ratio becomes sparser during warm-up, the emission of nitrogen oxides per unit time decreases, and the thermal efficiency relatively increases. However, as the time required to reach the final temperature becomes longer, the cumulative emissions and fuel consumption may worsen.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.427-431
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• 2013

Paprika fruits should be stored and distributed at above $7^{\circ}C$ to prevent chilling injury but the small amount of paprika that transports with other horticultural products in refrigerated container by ship usually stored less than $5^{\circ}C$ for other products. In this case, paprika fruits cannot help exposing chilling temperature, so that the paprika must be lost marketable value during a long period of transfer. This study was conducted to compare the alleviated effects of high $CO_2$ treatment (passive MAP), heat (hot water dipping), and UVc treatment on chilling injury of paprika fruits due to low temperature storage, and also to decide if these treatments can be used for transporting under $5^{\circ}C$. After each treatment the paprika were put in the low temperature storage ($4^{\circ}C$) for 20 days and afterwards change the in room temperature ($20^{\circ}C$) for 5 days. The fresh weight loss of all the treatments except the high $CO_2$ treatment showed around 7~12% after 25 days of storage and the ethylene concentration showed periodical increases and decreases as around 3 ${\mu}l/l$. The $CO_2$ concentration was rapidly increased 33% carbon dioxide in high $CO_2$ treatment during room temperature storage after cold storage for 20 days. The firmness which is key quality characteristics during storage and is decreasing caused by chilling injury was not significantly different among all treatments. However, the firmness of stored paprika was maintained highest in the treated with hot water dipping. Therefore, HWD and UVc treatment that showed 60% of electrolyte leakage in the $4^{\circ}C$ control (chilling injury control) and similar level with the $7^{\circ}C$ control (non-chilling injury control) would be effective to alleviate chilling injury in the stored paprika.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.150-155
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• 2011

The aim of this study was investigated long distance export condition of paprika from Korea to Canada, and evaluated the effect of non-perforated breathable films on the storability of paprika during MA storage in the simulated long distance export condition. The long distance export condition of paprika from Korea to Canada was $7{\pm}1^{\circ}C$ and RH 90% during shipping for 20 days, and then the temperature of that was increased to $13^{\circ}C$ for 3 hours during transferring from refrigerated container to storage room in Canada, and decreased $3{\sim}4^{\circ}C$ for 3 days before distributing to local markets. The temperature and relative humidity of local markets was $16^{\circ}C$ and 60%, respectively. The packing material treatments were non-packing, as control, perforated film (6 mm diameter hole, $18holes/m^2$), and 3 kind of laser treated non-perforated films (oxygen transmission rate was 5,000, 20,000 and 100,000 $cc/m^2{\cdot}day{\cdot}atm$). Under the simulated long distance export condition; $7^{\circ}C$ and RH 90% for 15 days and then $20^{\circ}C$ and RH 55% for 7 days, the fresh weight loss of paprika was less than 1% in 3 kind of laser treated non-perforated film treatments but was more than 4% in control and perforated film treatment that showed severe deterioration of visual quality after 20 days of storage. The atmosphere of paprika packages was changed 5% oxygen and 15% carbon dioxide in 5,000 $cc/m^2{\cdot}day{\cdot}atm$ treatment, and 16% oxygen and 4~5% carbon dioxide in 20,000 $cc/m^2{\cdot}day{\cdot}atm$ treatment during room temperature storage after cold storage for 15 days. A carbon dioxide concentration of these 2 treatments was exceeded the optimal MA and CA condition. There was no significant difference in ethylene concentration among 3 kind of laser treated non-perforated film treatments. A paprika packed with 100,000 $cc/m^2{\cdot}day{\cdot}atm$ non-perforated film showed the highest visual quality under the simulated long distance export condition. However, the firmness and soluble solids did not show any significant difference among 3 kind of laser treated non-perforated film treatments. Therefore, we may suggest that 100,000 $cc/m^2{\cdot}day{\cdot}atm$ laser treated non-perforated film was the proper film for MAP of paprika under long distance export condition that was $7{\pm}1^{\circ}C$ and RH 90% for 15 days, and then $20^{\circ}C$ and RH 55% for 7 days.